How to choose the right laboratory? What needs to be done to make the result as accurate as possible? What to do if there is a discrepancy between test results and clinical manifestations? Let's try to figure it out.
Laboratory analysis consists of the following steps:
- preanalytical— includes preparation for the analysis, the procedure for collecting material and its delivery to the laboratory;
- analytical— direct study of the material;
- post-analytical— analysis of the obtained data.
A defect at any of these stages can lead to an error.
Stage one.
Its participants are the patient himself, the doctor or nurse who collects the material, and the laboratory representative who delivers the material to the laboratory. Experts in clinical laboratory diagnostics have noted that from 53 to 75% of all errors occur precisely at the preanalytical stage.
Proper preparation for research the day before, provision of information about the physiological state, age, medication intake, physiotherapeutic procedures - these factors significantly influence the result.
Everyone knows that you need to take tests on an empty stomach. But not everyone knows that there are different requirements for different types of research.
It is recommended to donate blood from 8 to 11 am, on an empty stomach (at least 8 and no more than 14 hours after the last meal, drinking water as usual). Overeating the day before should be avoided. Biochemical, hormonal, immunological studies and indicators of the hemostasis system are carried out strictly on an empty stomach. Three to four hours after the last meal, samples can be taken for a general blood test, group and Rh factor, PCR diagnostics and determination of antibodies to infections.
Special requirements are set when taking blood to determine the lipid profile (cholesterol, HDL, LDL, triglycerides, lipoproteins). In this case, blood should be donated 12-14 hours after the last meal. The glucose tolerance test is performed in the morning on an empty stomach, no less than 12, but no more than 16 hours after the last meal.
You need to know that some blood tests must be taken before radiography, ultrasound, other instrumental research, massage and physiotherapy. These procedures can have a significant and often long-term (3-5 days) impact on test results.
Most laboratory tests have their own preparation characteristics and it is extremely important to perform them.
Stool analysis (coprogram).
The purpose of the study is to study the degree of absorption of food. In preparation for the analysis, a food regimen (Pevzner diet) with a dosed amount of proteins, fats and carbohydrates must be followed. The diet is based on the principle of maximum nutritional load for a healthy person. The stool of a healthy person, when following a diet, contains a large amount of undigested fiber and some muscle fibers. For people with pathologies of the digestive system, the gentle Schmidt diet is recommended. When following this diet under conditions of normal digestion, food residues are not detected in the feces. Your doctor will help you choose the right diet.
Before the study, you should stop taking medications that increase intestinal motility and affect the appearance of stool, color, and microscopic composition. These are laxatives, iron-containing preparations, suppositories, castor and vaseline oil.
Occult blood test.
Hidden blood is called blood in the stool, which indicates internal hidden bleeding. Normally, the reaction to occult blood gives a negative result. The reaction may be false positive if before the test you ate meat, fish, blood sausage, hemoglobin preparations, and green vegetables. To obtain reliable results, it is important to follow a 3-day diet that excludes the above foods.
Feces are collected in a special disposable container after natural bowel movements. Delivered to the laboratory within 1-2 hours at natural temperature or no later than 10-12 hours under storage conditions at a temperature of +3+5°C. Violation of delivery time leads to the action of fermentation and rotting processes, and this leads to incorrect results.
General urine analysis.
The analysis characterizes the functional state of the urinary system. For the study, morning urine is taken, which has accumulated in the bladder during the night. On the eve of the test, it is recommended not to eat vegetables and fruits that color the urine, and not to take diuretics or sena tincture. Before collecting urine, hygiene procedures are carried out.
Urine is collected in clean disposable containers. When urine remains in a room for a long time, cellular elements are destroyed, favorable conditions are created for the proliferation of microorganisms, salts precipitate, and the pH changes. Therefore, for a reliable result, it is important to conduct the analysis within 1.5-2 hours after receiving the material.
When the collection is carried out by the patient himself (urine, feces), it is important to observe all the features: use special containers, recommended time of day, etc.
How to prepare your child for blood sampling.
The issue of a high-quality procedure for collecting blood by a nurse in modern conditions (in the presence of special tubes) is of less importance. However, this issue remains relevant when collecting blood from children.
Taking blood from a child is more difficult for a number of reasons: the blood has increased viscosity due to its high cell content, the capillary network is still poorly developed, and the peripheral vessels have small lumen.
Properly preparing your child for blood collection will help make the procedure easier.
Food and drink. 5-10 minutes before taking blood, the child is given 10-15 g of food (bun or bread, breast milk or formula), as well as 25-60 ml of liquid (warm tea). The specified amount of food and liquid does not have a significant effect on blood circulation and its chemical composition, but helps to obtain blood in a volume sufficient for research.
Temperature. The child should be kept warm - only the blood collection site remains open. Before drawing blood from your finger, you can wash your hands in warm water.
Always relevant question: venous or capillary blood? The choice of taking capillary or venous blood depends on the age, weight, condition of the patient, and prescribed studies.
It is recommended to collect venous blood to determine hematological, biochemical, hormonal and immunological parameters. Closed vacuum systems are used for collection. This allows you to avoid many errors in the preanalytical stage and eliminate the need for repeated blood sampling.
Capillary blood is collected, when we are talking about a small volume (for clinical blood tests, glucose determination). It is easier to obtain blood from a capillary, and this is important for newborns, patients with very small or hard-to-reach veins, those prone to thrombosis, and obesity. But there are also disadvantages. These include a high probability of microclot formation and the presence of intercellular fluid, mechanical destruction of blood cells (hemolysis), and a short sample shelf life. All these factors contribute to the fact that quite often it is necessary to repeat blood sampling. And this means going through an unpleasant procedure for the child and parents again.
At the preanalytical stage, it is of great importance to minimize the influence of the human factor (nurse) on the selection of the correct test tube (with the right preservative) and the quality of sample labeling (so as not to mix up the test tubes). The latter can only be guaranteed by a barcoding system, which is used by most modern laboratories.
Another important point of the first stage— conditions for storing samples before shipment and delivery of samples to the laboratory. For some tests, delivery times are critical. There are tests that can only be taken in a laboratory.
No less important here is compliance with temperature, aseptic and antiseptic rules. The patient's sole influence on compliance with these conditions is when choosing a laboratory. A self-respecting laboratory takes these factors very seriously.
The second stage is analytical.
The result at this stage depends solely on the laboratory. How to choose a quality laboratory? It is necessary to find out the following points: does the laboratory have permitting documentation, does the laboratory undergo internal and external quality control, what equipment, reagents and consumables does it use in the laboratory process, the timing of the tests.
The third stage is post-analytical.
At this stage, the laboratory specialist carries out another stage of quality control. The laboratory doctor looks at the result obtained and compares it with controls and reference values. And if the data is in doubt (for example, all indicators are overestimated or all are underestimated), the result is rejected. There is a need to retake the material.
For the correct interpretation of the data obtained, information about the patient obtained at the preanalytical stage is important. So, for each age there are their own norms, and the same value can be the norm for a pregnant woman and a pathology for others.
A person can influence the quality of laboratory tests by following all the rules for taking tests. Ask your doctor questions: why this test is prescribed, what information you will receive as a result, how to properly prepare for the test. Share the necessary information about your health status, food intake, and medications.
REFERENCE
The clinical diagnostic laboratory INTO-SANA conducts general clinical, biochemical, immunoenzymatic, hormonal, bacteriological, as well as urgent (cito) studies around the clock. If there is a contradiction between the clinical manifestations and the result obtained, we conduct a repeat study free of charge.
The laboratory participates in the international quality control program PREVECAL.
Head of the clinical diagnostic laboratory Into-Sana Elena Nesenenko
Some people receive a false positive HIV test; the reasons for this result can vary. First of all, this may be due to the fact that the analysis was carried out at home. Errors can be made by medical personnel when the test is performed in a specialized clinic. In addition, many diseases and pathological changes in a person's health can cause the data obtained from the study to be incorrect.
Reasons for a false-positive HIV test during home testing
The developed methods that allow us to detect the presence or absence of the human immunodeficiency virus in the body give 100 percent results. However, in some cases, the data may be distorted, so they need to be double-checked. Nowadays, very often the examination is carried out at home, which gives a person the opportunity to keep the data anonymous. This study will remain confidential. However, it is precisely under such conditions that errors occur in the conduct of the study, which is why the test becomes of poor quality. To avoid such situations, it is better to conduct this study in a clinic and then get the results from the laboratory.
In this case, the risk that the data will be distorted is only 0.01%. In addition, home tests may give a completely different answer.
Cross-reactions can lead to similar consequences. Some diseases cause such reactions. For example, a person may have an allergic reaction. In this case, antigens of a certain type are produced that will be incomprehensible to the body. In this case, the immune system recognizes them as foreign. Such antigens may cause the data to be false positive.
In addition, during pregnancy, the hormonal levels in a woman’s body change, which causes false positive data. The same applies to the period of menstruation.
If the patient has normal type ribonucleoproteins, the test result will be changed. In addition, the positive type is caused by hepatitis and influenza viruses, so it is necessary to first treat these diseases, and only then donate blood for analysis. The same applies to vaccinations that were done recently. They will interfere with the progress of the blood test. It's better to donate blood later. Such reactions can be caused by vaccination against tetanus, influenza and hepatitis B. The same applies to the tuberculosis virus. It changes the research indicator in a positive direction. The herpes virus works in much the same way. Therefore, it is better to cure all diseases that are caused by a similar virus, wait for the rehabilitation period and only then donate blood for analysis.
If you have poor clotting ability, you should also not donate blood, since the indicator will be false positive. If the patient, on the contrary, has very thick blood, this will affect the result. If a person very often donates blood as a donor, then it is better to wait until the amount of blood in the body is restored. Otherwise, the analysis will give a false positive result. Various types of sclerosis and disturbances in the functioning of small blood vessels lead to an incorrect course of the study.
If there are problems with the respiratory system (infectious diseases), then the parameter may change. With fever, changes also appear that distort the study.
If the amount of antibodies in the blood increases or the level of bilirubin changes, then the reaction in the analysis may be positive, but this will be false data. In addition, sclerosis leads to the same results. Another disease that causes a positive indicator is cancer, therefore, with the presence of malignant tumors and other oncological diseases, it is quite difficult to determine HIV in the body.
When an organ transplant is performed, the test may give a false positive result, but this may not be true.
If a person develops autoimmune liver disease, the result will be distorted. Autoimmune diseases occur when the body's immune system begins to act against its own organs in the body, attacking them and blocking them from functioning. In general, if the regulatory processes of the immune system are disrupted, the result will be distorted, but positive. In addition, drinking alcohol can cause liver disease, which can lead to incorrect blood test results for HIV. Additionally, arthritis will act the same way.
Medical errors that cause test results to be incorrect
Quite often, situations occur when a person receives a positive result for HIV due to errors by the medical personnel themselves, although the study was carried out in a specialized institution.
A false result may be obtained due to incorrect blood sampling. Additionally, if the blood was not properly stored in the medical facility before the post-draw test was required, the data will be skewed. Such results can also be caused by transporting blood to the laboratory, which was not carried out according to the rules. Another reason that leads to a false positive result is the use of low-quality serum for analysis.
All these factors occur only because the medical personnel were negligent in their work. His incompetence may lead to distorted data.
Of course, not all medical centers make such mistakes; the risk of this is very small. However, it is better to check the data and do a repeat HIV test. At this stage of development of medical technologies, many clinics are equipped with special, latest equipment, which eliminates the risk of obtaining a false result.
How to avoid getting a false positive result when testing for HIV?
In order for the data obtained during the study to be as accurate as possible, it is necessary to adhere to certain rules. Before donating blood for analysis, you must warn your doctor that any disease may develop. In addition, it is necessary to mention all the drugs that are currently used.
The analysis should be carried out only 1.5-3 months after the suspicious contact was made.
It is better to use dietary food temporarily, stop smoking, and also not drink alcoholic beverages. In addition, you need to abstain from sexual activity 3 weeks before the tests.
krovetvorenie.ru
Does alcohol affect blood tests?
Laboratory testing of blood and urine is one of the main methods for diagnosing diseases. General clinical, biochemical and other tests allow us to determine the degree of metabolic disorders in the body, the presence of inflammatory and infectious diseases. Tests for hemoglobin, cholesterol, potassium, calcium, and magnesium are used in the diagnosis of cardiovascular diseases. Antibody tests play an important role in determining infectious, allergic, and oncological diseases. Alcohol affects the functioning of all organs. After its use, a change in the consistency and composition of the blood occurs.
One of the main conditions for taking tests and obtaining reliable results for hemoglobin, platelets, cholesterol and other indicators is abstaining from drinking alcohol. The patient must clarify in advance how much time should pass between drinking alcohol and the test procedure (1 or 3 days).
The influence of alcohol on test results
To establish diagnoses of various diseases and monitor the condition of patients after surgery, it is necessary to donate blood for the following studies:
In addition to these tests, urine testing is of great importance. For example, by the content of protein and leukocytes, the condition of the kidneys can be assessed; by the content of bilirubin, conclusions can be drawn about the functioning of the liver and pancreas. Detection of sugar content during urine examination indicates the presence of diabetes mellitus. If you drink alcohol before taking the test, your glucose level will inevitably increase. The load on the liver disrupts its normal functioning. In this case, a urine test may show the presence of protein.
How does alcohol affect a complete blood count?
Ethyl alcohol, which is part of alcoholic beverages, dissolves the fatty membrane of red blood cells and disrupts their structure. Red blood cells stick together, blood clotting increases, due to this it thickens, and the risk of blood clots increases. As a result of the effect of alcohol, the level of red blood cells decreases noticeably, and hemoglobin decreases. An increase in viscosity, a decrease in the level of hemoglobin and red blood cells may indicate the development of megaloblastic anemia (a fatal disease). A change in the red blood cell indicator also affects other indicators, can distort data on the composition of the blood and complicate the diagnosis of diseases and the prescription of treatment after examination. Since alcohol is a toxic substance, based on the results of a general blood and urine test carried out in a hangover, one can make an incorrect conclusion about poisoning if one does not know about the true cause of the violations.
The effect of alcohol on blood biochemical parameters
This study is most influenced by alcohol intake. First of all, the glucose content changes. Alcohol inhibits the process of glucose formation in the liver, so its level is significantly reduced. This can be dangerous for humans. Drinking alcohol is not recommended for people with diabetes. A healthy person will be incorrectly diagnosed with diabetes after a temporary decrease in glucose levels.
Under the influence of alcohol, the content of lactic acid increases. This usually happens with heart failure and other circulatory disorders, as well as with large blood loss. You may mistakenly assume the presence of internal bleeding.
Alcohol affects uric acid levels. This indicator can detect the accumulation of nitrogen, which happens with the development of gout, arthritis and other joint lesions.
Alcohol intake causes an increase in fat content, which may indicate the development of diseases in the body such as atherosclerosis, coronary heart disease, viral liver diseases, kidney failure, blockage of cerebral vessels, and thyroid diseases.
How does alcohol affect immunological analysis (ELISA) data?
If you drink alcohol before the examination, the functioning of all organs changes. Alcohol affects the production of hormones, changing their ratio. Thanks to this, you can get false positive or false negative results when diagnosing serious diseases of the liver, kidneys, thyroid gland and other organs. Ethyl alcohol reduces the production of antibodies in the body. The ELISA method is based on diagnosing diseases and assessing the body's defenses based on the presence or absence of antibodies of a certain type. Distorted results after drinking alcohol and taking tests for markers can lead to incorrect conclusions and will not allow diagnosing serious diseases such as hepatitis (A,B,C,D), malignant tumors, gene abnormalities, and allergies.
When a person has to visit a doctor and take tests for red blood cells, hemoglobin, infectious or cancer markers, he should not drink alcoholic beverages at least 2 days before the examination. Alcohol distorts test results so much that specialists will not be able to recognize the true picture of serious (sometimes fatal) diseases. For taking blood and urine tests, the time is usually set in advance, so a person should ask the doctor about the rules for taking them, and also find out how long it takes to take various tests if you drink alcohol. If, however, on the eve of the tests the patient drank alcohol, then this must be reported. The timing of the examination will be changed.
Our regular reader shared an effective method that saved her husband from ALCOHOLISM. It seemed that nothing would help, there were several codings, treatment at a dispensary, nothing helped. An effective method recommended by Elena Malysheva helped. EFFECTIVE METHOD
It is impossible to cure alcoholism.
- Have you tried many methods, but nothing helps?
- Another coding turned out to be ineffective?
- Is alcoholism destroying your family?
- Tobacco smoking;
- Alcohol;
- Physical exercise;
- Stressful situations;
- Chronic depression;
- Food.
- Do not drink alcohol-containing drinks 2-3 days before donating blood from a vein;
- If you drank alcohol a day or two before the scheduled test date, it is better to postpone your visit to the doctor for several days.
- Discuss fears associated with analysis
- Find out how to reduce your risk of infection if you test negative
- Find out how to avoid infecting other people if the result is positive
- Think about personal issues, such as how the disease will affect your social, emotional, professional and financial aspects of life
- Find out what measures you need to take to stay healthy for as long as possible
- HIV is no longer a death sentence. Thanks to new drug therapy, many people with HIV can live a normal life without developing the disease.
- In many institutions, you can do the test anonymously, so that no one - not parents, close relatives, friends or teachers - will know about the test. Thanks to new methods, you won't even feel the needle insertion.
- Blood test or oral test. These days, you don't need to insert a needle to test for AIDS. In some institutions, it is enough to take blood from a finger. In other institutions, your saliva is enough.
- Fast or slow results. Some facilities will ask you to wait a few days to receive your results. In others, you can get results even after 20 minutes. With the express method, you can immediately find out if the result is negative. However, if the result is positive, you may have to wait a few days for a second test to confirm the first. In the institution where you will not receive test results immediately, but after a few days, the second test will already be performed when you come for the results.
- Anonymous or confidential analysis. It's not the same. results confidential analysis will be entered into the medical record. Your results may be reported to your health care providers and insurance company. If someone else is paying your insurance bill (for example, your parents), they may at least find out that you took an AIDS test. In contrast, the results anonymous analysis are known only to you. In many areas, anonymous (and free) testing is available through the city health department. Use the Yellow Pages or the Internet to find the health department in your area.
- Enzyme-linked immunosorbent assay (ELISA). This test is usually the first one used to detect HIV. If antibodies are present in the blood (the result is positive), the test is usually repeated to confirm the diagnosis. If the result is negative, additional tests are usually not needed. The chance of an erroneous result with this test is very low in the first few weeks after infection.
- Western blotting. This test is more difficult to perform than ELISA, but it is necessary to confirm the results of two positive ELISA tests.
- Polymerase chain reaction (PCR). This test detects either HIV RNA or HIV DNA in white blood cells infected with the virus. PCR testing is not performed as frequently as antibody testing because it requires technical skills and expensive equipment. It can be done days or weeks after exposure to the virus. The gene pool can be detected even if other tests are negative. This method may also be useful for detecting recent infection, determining the presence of HIV infection if antibody test results were unclear, and testing blood and organ testing for HIV before donation.
- Detection of HIV infection. Typically done for people with risk factors for HIV infection and people who have symptoms.
- Testing blood, blood products and organ donations to prevent HIV infection.
- HIV testing in pregnant women. The US Preventive Services Task Force recommends this test for all pregnant women. Pregnant women infected with HIV who are on treatment are less likely to infect their baby than women who are not on treatment.
- Detecting whether the child born to a woman who tests positive for HIV is infected. In this case, a PCR test is often done, since there is a possibility that the child received antibodies to HIV from the mother, but is not yet infected.
- How the analysis is performed, what the results mean and what additional research can be done.
- How an HIV diagnosis can affect your social, emotional, professional and financial life
- Benefits of early diagnosis and treatment.
- Use an elastic band to compress the upper arm to stop blood flow. This enlarges the veins below the band, making needle insertion easier.
- Wipe the needle insertion site with ethyl alcohol
- Connect a syringe to the needle to draw blood
- Apply a gauze compress or cotton swab over the needle when removing it.
- Apply pressure to the needle insertion site and then apply a bandage.
- You may develop a small hematoma at the injection site. You can reduce your risk of developing it by continuing to apply pressure to the injection site for several minutes after removing the needle.
- In rare cases, a vein may become inflamed after blood is drawn. This condition is called phlebitis and is usually treated with a warm compress applied several times a day.
- Continued bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood thinners may also contribute to bleeding. If you have clotting or bleeding problems or are taking blood thinners, tell your healthcare provider before having your blood drawn.
- Use of corticosteroids
- Carrying out analysis during the period of seroconversion
- Having an autoimmune disease, leukemia, or syphilis
- Drinking large amounts of alcohol
- After your first test, you should have your doctor contact you about the results. Be sure to tell your doctor where and how to find you. If he has not contacted you within 1 or 2 weeks after the test, call yourself and ask about the results.
- ELISA is a good test because, as a rule, it gives positive results if there is an HIV infection. But ELISA results can reveal the presence of HIV infection if there is none (false positive results). Thus, only one ELISA test cannot be performed to make a definite diagnosis of HIV infection. None of the results are considered HIV positive unless confirmed by positive Western blot, ELISA or PCR results.
- It is difficult to detect HIV infection in newborns. Before the age of 18 months, even an uninfected child can have antibodies from his or her HIV-positive mother. A PCR study can be performed to detect the presence of the gene pool (RNA or DNA) in the child.
- To be sure that there is no HIV infection, a person must have negative test results within 6 months of the suspected infection. Tests are usually carried out after 6 weeks, 3 months and 6 months to detect infection.
- Home blood test kits for HIV detection can be purchased without a prescription in pharmacies or by ordering by mail. The kits contain instructions and materials for collecting a blood sample, which is then sent to a laboratory for analysis. Results can be found by phone using an anonymous code. It is also possible to provide telephone consultation regarding the use of the kit. In addition, kits are available to quickly detect infection, and it is possible to get results within half an hour, as opposed to waiting for 1-2 weeks with a traditional test. Positive HIV rapid detection results must be confirmed by Western blot testing.
- An HIV screening test can also be done by examining urine or saliva. Oral tests detect antibodies to HIV. Urine tests for HIV are rarely performed.
- Oral test kits that detect HIV-1 and HIV-2 in saliva are approved by the US Food and Drug Administration. Test results are available on the same day. Positive results must be confirmed by Western blot analysis.
- Many states require health care providers, clinics, and hospitals to report confirmed HIV cases to the health department. Some states allow anonymous reporting (where the patient's name and identifying information are not provided). Other states require a confidential report (identifying information about patients is available only to authorized health officials). All states must report the number of AIDS cases without names or identifying information to the Centers for Disease Prevention and Control (CDC).
- If you test positive, tell your sexual partner. He may also want to get tested. To do this, seek help from your local health department.
- Once HIV infection is detected, other studies are carried out to determine the treatment method and its effectiveness. These tests include CD4 cell count and viral load.
- There are 2 types of HIV detected
- HIV-1 causes almost all cases of AIDS worldwide
- HIV-2 is found primarily in West Africa.
- Reverse transcriptase polymerase chain reaction (RT-PCR)
- Branched DNA hybridization (rDNA)
- Nucleic acid sequence based amplification (NASBA)
- Monitoring changes in the development of HIV infection
- Choosing a treatment method
- Monitoring the effectiveness of treatment
- If you are not on highly active antiretroviral therapy (HAART), your viral load should be measured every 3 to 4 months
- If you are undergoing this therapy then:
- Viral load is measured before treatment begins. This measurement is fundamental.
- Other measurements are taken 4 to 8 weeks after starting treatment to determine your response to the medications. At the beginning of treatment or when changing medications, a slight decrease in the viral load is expected.
- If your viral load has decreased as expected and your CD4 cell count remains stable, your viral load will be measured every 3 to 6 months. Your CD4 cell count reflects how well your immune system is working.
- Insert the needle into the vein. More than one needle may be needed.
- Remove the tape from the arm when sufficient blood has been obtained.
- In rare cases, a vein may become inflamed after blood is drawn. This condition is called phlebitis and is usually treated with a warm compress applied several times a day.
Your doctor can use your viral load and CD4 cell count measurements to decide whether to start antiretroviral therapy.
How to prepare
You do not need to do anything before conducting the test.
The healthcare professional who will draw the blood for testing will:
What can you feel
From the moment the needle is inserted, you may not feel anything, or you may feel a small prick or pinch when the needle pierces the skin. Some people experience sharp pain when the needle is inserted into a vein. But most people do not feel this (or only minor discomfort) after placing the needle in the vein. The degree of pain depends on the skill of the medical professional taking the blood, venous disease, or your sensitivity to pain.
Viral load testing reveals the concentration of human immunodeficiency virus (HIV) in the blood. The analysis result will be ready within 2 weeks.
The normal values listed below, called the normal range, are just a guideline. These ranges may vary depending on the laboratory and test method used (RT-PCR, rDNA, NASBA). Your laboratory may have a different range of values considered normal. The results report should include information about the values used in your laboratory. Your doctor will also evaluate the results based on your health and other factors. This means that a value outside the normal range listed in this article may be normal for you or your laboratory.
Viral load test results are expressed as the number of copies of HIV per milliliter of blood (copies/ml). Each virus is called a “copy” because HIV reproduces by making copies of itself (replication).
Final diagnosis. When does an HIV test give a false result?
The accuracy of an HIV test is affected by diet, hormones, and infections.
December 1 is World AIDS Day. On the eve of this date, the Russian Ministry of Health cited frightening statistics according to which the number of cases will increase by 2.5 times in just 15 years. HIV prevention is now one of the main directions of modern medicine, aimed at stopping the spread of the virus. And, first of all, you need to start with tests. AiF.ru found out where you can get tested for HIV and how to do it correctly so as not to get a false result.
There are two main types of tests for HIV/AIDS: enzyme immunoassay and PCR diagnostics. Both are informative and accurate.
Enzyme immunoassay is the most common today. It is based on the detection of antibodies to HIV in the patient’s blood serum. In most patients, they appear approximately 4-6 weeks after infection, in 10% - after 3-6 months, and in 5% - later. Therefore, ideally this test should be taken three times every 3 months.
PCR diagnostics are a polymerase chain reaction test that can test serum, antiviral RNA or DNA, and quantify CD-4 lymphocytes. At the same time, doctors often call PCR analysis the only possible early diagnosis of HIV infection, which is also carried out in children of the first year of life. The advantage of this research method is the fact that it can detect the virus in the incubation and early clinical periods, when there are no antibodies in the blood yet. This helps to start treatment earlier and reduce the negative impact of the disease.
You need to prepare for an HIV/AIDS test. Blood should be donated on an empty stomach, and the last meal should take place no later than 8 hours before. Naturally, it is recommended to maintain a unique diet, a few days before donating blood, giving up alcohol and “harmful” foods - fatty, fried, smoked foods, marinades and other refined foods.
It is worth considering that if you are unwell, even with any viral or infectious disease, it is better not to donate blood or come back for testing again 35-40 days after recovery. Otherwise, there is a risk of getting a false positive result.
The HIV/AIDS test goes through several stages of testing. Therefore, it takes 2-10 days to prepare.
The result can be positive, negative or doubtful. In the latter case, it is worth retaking the analysis a little later.
Doctors say that if the result is positive, it is impossible to immediately declare that a person has HIV or AIDS. Indeed, in some cases, indicators may be overestimated for other reasons. In this situation, you should retake the test again - everyone who has a “+” result goes through this procedure.
Where does the “false signal” come from? Due to certain diseases and conditions that may cause cross-reactions. For example, due to allergies, antigens that are incomprehensible to the body can be produced in the blood, which it recognizes as foreign.
Also, a similar reaction can occur due to a sharp change in blood composition - for example, due to a jump in cholesterol (with excessive consumption of fatty foods, fried foods, seeds), hormonal imbalance (in particular, during menstruation in women), infections (respiratory diseases, the presence of hepatitis and influenza viruses, recent vaccinations, tuberculosis), excessive blood thickness, arthritis, oncology. Fungi, viruses and bacteria can also contribute to the appearance of incorrect data. In addition, a false positive result can occur due to medical errors: violation of the rules for collecting and transporting blood, use of low-quality serum, and improper storage of the material.
If you wish, you can get tested for the immunodeficiency virus at any time. However, there are a number of situations when it is recommended to do this. Thus, it is worth donating blood when planning a pregnancy, before a planned operation, after questionable injections, unprotected sexual contact with a stranger, or in case of a sharp deterioration in health.
You can get checked at any clinic, private clinics and diagnostic centers, as well as specialized AIDS centers. Moreover, in public medical institutions this procedure will be completely free. Any citizen of the country can take tests at the AIDS center, regardless of where he lives.
There are two types of testing: confidential and anonymous. In the first case, the person tells the laboratory assistants his name. In the second case, he is assigned an identification number. All results are given exclusively to the patient, and even if the result is positive, the laboratory cannot report it anywhere - this will be regarded as a violation of medical confidentiality. In paid clinics, the principle of taking tests is no different, only in this case the service is provided for money. The cost is from 400 to 3,400 rubles, depending on the complexity and verification options.
Proper preparation for an HIV test is the key to obtaining a reliable result
All people are worried before an HIV test, even if there is no risk of infection. Since this disease is incurable and today is the “plague” of the century, everyone is afraid of getting infected.
Proper preparation for an HIV test can ensure an accurate result. All the details can be found out in the laboratory where the patient was going to donate biological material. For all studies related to infection with this virus, specialists take blood from a vein. To avoid false results, you must adhere to some rules and restrictions.
How to prepare for an HIV test?
The most reliable result can be obtained by donating blood in the morning. During the night, metabolic and cleansing processes take place in the organs, which “put the body in order” by the morning.
Blood counts return to normal only if there was no influence of extraneous factors. Before an HIV test, you should not do much of what has become a habit for most people.
What can affect the result:
Proper preparation for an HIV test will not give results if the patient is suffering from any viral infection. In this case, experts recommend waiting about a month. For example, influenza or ARVI distorts the result of immune status and viral load.
You can eat 8-12 hours before HIV tests - another reason why blood sampling is carried out in the morning. Skipping breakfast is much easier than skipping lunch and going through the whole day hungry. Immediately after submitting biological material, it is recommended to drink sweet tea and have a snack.
What can affect HIV testing in women is the menstrual cycle. During “critical days,” the result is distorted, especially if the study is carried out using the polymerase chain reaction method. This is due to a significant jump in hormone levels.
Experts know that the test system used to conduct the study also affects the HIV analysis. To get the most reliable results, it is advisable to donate blood in the same laboratory each time. This applies more to people who regularly come into contact with sick people and are forced to be checked frequently.
Test for HIV, AIDS - is it possible to eat before taking the test?
Blood is donated on an empty stomach, that is, you need to wait at least 8 hours between the last meal and the collection of biological fluid. Eating food 6 hours before the test will also not affect the result.
Is it possible to eat before an HIV test? The doctor should warn you when writing a referral according to the indications. If the test is performed anonymously, without first seeing a specialist, the nurse should ask about the previous day's food intake before drawing blood.
As for the drinking regime, you are allowed to drink only non-carbonated plain water. Sugar-containing drinks and any others are very rare, but can still affect the result.
Some doctors claim that you can eat absolutely all foods before taking an HIV test, but the facts speak for themselves. There were cases when, when eating fatty foods (fried chicken, jellied meat) the day before, the test gave a false positive result.
Does alcohol affect HIV testing?
Alcohol and HIV testing are two incompatible concepts. Since ethanol affects the biochemical parameters of the blood and hormonal levels, it is undesirable for everyone, especially infected people, to consume it in large quantities.
Alcohol is a solvent, so it destroys the walls of red blood cells, causing them to stick together, forming blood clots and thickening the blood. If alcohol damages the walls of red blood cells, it can also affect the amount of antibodies produced by the immune system to protect itself from the virus.
Since immediately after the pathogen enters the body there are already few antibodies in the blood, they may become even smaller, as a result of which it will be impossible to detect them.
In order to be properly examined and diagnose infection in a timely manner, you need to visit a doctor, get a referral and find out whether you can eat and drink before an HIV test, as well as other nuances. The more the patient is informed, the higher the likelihood of timely diagnosis and selection of effective treatment tactics (if a virus is detected).
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Blood test for AIDS and HIV
Getting tested for HIV is scary, but the disease is treatable and it's important to get tested if you suspect you've been infected. If the result is positive, early detection and monitoring of HIV progression will help the doctor determine whether the disease is progressing and when to begin treatment.
Feel free to get tested for AIDS
Why is an AIDS test important - what you need to know before taking it
“Ji, I have to take care of you, I never imagined that I would do this before. Not even for myself"
Justin rolled up the sleeve of his gray sports shirt and squeezed his hand as Becky watched. As their friendship grew, Justin opened up about a tumultuous past, including drug use and promiscuity. As their relationship turned romantic, Becky issued an ultimatum: No sex without an AIDS test.
They took the test together. And together they came for the results, worried, as the laboratory assistant handed them simple white envelopes. They opened them on a flight of stairs outside the clinic. When Justin saw the results - negative for both - he dropped to one knee and immediately proposed to Becky.
“He was very serious,” Becky says. “He felt that the gods were smiling at him. It was like cleansing from sins"
Two years later, they have yet to say their wedding vows at the altar, but they are living happily together in the mountains above Asheville. The test results are pinned up on a display in their home, a reminder of the day that accelerated their relationship.
“It really strengthened our friendship,” Becky says. “And it made me realize the emotional support we can give each other.”
"Justin" and "Becky" asked that their true names not be disclosed to protect their privacy.
According to the Centers for Disease Control and Prevention, one in three people infected with HIV in the United States does not know it. Many of them, without realizing it, infect loved ones with this disease.
If you are sexually active and have not had an HIV test, you need to know the following:
This article will help you prepare for the analysis. From it you will learn when and where you can get a test, what it is and what to expect when you receive the results.
When to test for AIDS
"In principle, anyone who has more than one sexual partner should get tested," says John Flaherty, MD, director of the HIV Treatment Center at Northwestern Memorial Hospital in Chicago. “If you have new partners year after year, you need to be tested for AIDS routinely, even if you use contraception.”
A large number of people come to Dr. Flaherty's hospital only when the HIV infection has progressed to full-blown AIDS, in other words, too late to receive treatment. If they had been tested and started treatment earlier, they could have lived into old age.
Some people think there's no point in getting tested because AIDS is an incurable disease that can kill you, says Chris Hubbard, an associate at the Whitman-Walker AIDS Clinic in Washington. They do not know that drug therapy makes life with AIDS manageable.
Other people fear they won't be able to provide treatment if they test positive, Hubbard says. But even the poorest patients can get treatment through health programs like Medicaid, he says.
Many young people do not get tested, so they feel absolutely healthy. But often, after several years, the HIV virus develops into the first signs of AIDS, says Amneris Luke, MD, director of the AIDS clinic at Core Memorial Hospital in Rochester, New York.
There is one important exception, says Luke. In about half the cases, he says, a person will develop an acute infection within days of contracting HIV. The tragedy is that doctors may confuse this infection with the flu or mononucleosis. People may not know about the real reason for years.
If you develop flu-like symptoms shortly after a risky sexual encounter, such as unprotected sex or a drug-related incident such as needle sharing, you should get an AIDS test, Luke says.
You also need to be aware of the “window period.” After infection with the human immunodeficiency virus, it can take up to 3 months for HIV antibodies to develop that can be detected by testing. If you have had an exposure, you may want to wait 3 months before getting tested (unless there are signs of a viral infection). In rare cases, it can take up to six months for antibodies to develop.
Where to get an AIDS test
You can get the test done at a variety of locations, including doctor's offices, clinics, hospitals, Planned Parenthood centers, and laboratory testing centers located in shopping malls. In some of them you will need to make an appointment in advance, in others - without an appointment.
Most of these facilities will ask you about your sexual and drug history, either in person or through a questionnaire. The testing procedure itself is the same in most institutions, but may differ in some important methods:
If you are really concerned about privacy, you can do the test at home. The US Food and Drug Administration has approved one test, called Home Access, sold in drug stores. The test kit instructs you to mail a blood sample to a Home Access laboratory. The US Food and Drug Administration is warning that "quick" home tests purchased online may not provide reliable results.
In an episode of the television series Sex and the City, Samantha received the results of her first AIDS test. As she waited at the clinic for the results, the doctor took her to a private room to discuss them. Of course, this was a signal that the results were positive; she became discouraged as she approached the door. But in reality the results were negative, and the doctor only wanted to explain the importance of safe sex.
When it comes time to notify you of the results, different institutions do it differently. Some will notify you by phone if the result is negative, but will ask you to come in if the result is positive. Other sites will ask you to return for your results anyway (Home Access kits include pre- and post-test telephone counseling).
It is not surprising that people who receive a positive test result are tense. Remember that institutions or clinics that specialize in AIDS testing can provide more detailed advice than, say, a general laboratory center or local doctor.
If the test results are positive, “I emphasize that it is possible to control the disease, treat it, and you can live a full, long life,” says Stacy Vlahakis, MD, of the Mayo Hospital AIDS Center in Rochester, Minnesota.
In fact, many patients can manage the disease with one-day, one-time therapy. But Vlahakis misses discussing treatment options, follow-up tests and social support for follow-up visits. "Usually they don't remember anything after the first visit," he adds.
If the results are negative, “I tell patients they are negative.” at this point in time" says Vlahakis. “That doesn't mean it can always be like this. Continue to use condoms with any partner or in any type of sexual relationship, and never share needles or blood products with another person."
That means taking precautions when visiting tattoo parlors, where there is the possibility of contracting diseases such as AIDS or hepatitis from dirty needles or equipment, Vlahakis says.
The human immunodeficiency virus (HIV) test detects HIV antibodies or genetic material (DNA or RNA) in blood or another type of sample. This is used to determine whether HIV infection is present (positive result). HIV attacks white blood cells called CD4 cells, which are part of the body's immune system that helps fight infections. HIV can progress to acquired immunodeficiency syndrome (AIDS).
After the initial infection, it will take from 2 weeks to 6 months before antibodies to HIV appear in the blood. This period between infection and the detection of antibodies in the blood is called seroconversion or the “window” period. During its course, a person infected with HIV can be a carrier of the disease, even if the test does not detect any antibodies in the blood.
Some tests can detect antibodies or genetic material (RNA) to HIV. These include:
Tests are usually performed 6 weeks, 3 months and 6 months after exposure to find out if a person is infected.
Why is the analysis performed?
Human immunodeficiency virus (HIV) testing is performed for:
The Centers for Disease Prevention and Control (CDC) recommends testing for HIV as part of your routine blood tests. You and your doctor can decide whether you need to do this.
This test is not done to detect AIDS. An AIDS diagnosis means that the HIV test results are positive and other problems exist.
There is no need to do anything in advance before analysis.
An HIV test cannot be done without your consent. Many doctors recommend pre- and post-test counseling to discuss:
Before the test, it is very important to tell your doctor how to contact you when the results are ready. If your doctor has not contacted you within 1-2 weeks after the test, call yourself to find out the results.
How is the analysis done?
The healthcare professional who draws the blood will:
From the moment the needle is inserted, you may not feel anything, or you may feel a small prick or pinch when the needle pierces the skin. Some people experience sharp pain when the needle is inserted into a vein. But most people do not feel this (or only minor discomfort) when a needle is inserted into a vein. The degree of pain depends on the skill of the medical professional taking the blood, venous disease, or your sensitivity to pain.
There are small risks of complications when taking blood from a vein.
The human immunodeficiency virus (HIV) test detects HIV antibodies or gene pool (DNA or RNA) in blood or another type of sample. This helps to detect the presence of HIV infection (HIV-positive result). ELISA test results are usually available in 2-4 days. The results of other studies, such as Western blotting or ELISA, will be ready in 1-2 weeks.
No HIV antibodies detected. Normal results are usually called negative.
If an antibody test is performed during seroconversion and the results are negative, a repeat test will be required. Many people develop antibodies to HIV within 6 months of infection. If a repeat test performed 6 months later is negative, the person is not infected.
PCR testing for genetic material does not detect HIV RNA or DNA.
Test results do not clearly indicate whether a person has HIV infection. This is usually called an indeterminate result. This can happen before HIV antibodies develop or when other antibodies interfere with the result. If this occurs, a PCR test may be performed to detect HIV RNA or DNA and identify the presence of infection.
A person who still has an indeterminate result after 6 months or longer is called “stable indeterminate” and is not considered infected with HIV.
HIV antibodies detected. Such results are called positive.
A positive ELISA test result is repeated using the same blood samples. If two or more ELISA results are positive, they must be confirmed by Western blot or ELISA tests.
As a result of the PCR study, genetic materials (RNA or DNA) of HIV were detected.
What influences the analysis
Reasons why the test cannot be performed or why the test may not be useful include:
Things to think about
Viral load measurement
A viral load test detects the concentration of human immunodeficiency virus (HIV) in the blood. The first time the viral load is measured is when HIV infection is diagnosed. This initial measurement serves as the baseline data and subsequent measurements will be compared to it. Because the viral load can change from day to day, the change over time is used to determine whether the infection is worsening. If your viral load continues to rise after several measurements, this means that the infection is progressing negatively. If the load decreases, this means that the infection is suppressed.
Viral load is measured using 3 different types of tests:
These tests measure the genetic material (RNA) of HIV in the blood. But they produce results differently, so it is important to use the same analysis over time.
Why is this being done?
Viral load measurement is performed for:
You and your healthcare provider may schedule different tests, but the most common schedule is as follows:
The site provides reference information for informational purposes only. Diagnosis and treatment of diseases must be carried out under the supervision of a specialist. All drugs have contraindications. Consultation with a specialist is required!
What are hormones?
Hormones– biologically active substances that have a complex systemic effect on the body. Thanks to hormones, all types of metabolism in the body are regulated: protein, carbohydrate, lipid and water-salt.Hormonal regulation ensures the constancy of the internal environment of the body and a rapid response to unfavorable external influences. Thus, due to rapid changes in hormonal levels, all the body’s forces are mobilized under stress factors. And this same system provides rest and restoration of expended energy.
Thanks to genetically programmed changes in hormonal levels, growth, development and maturation of the body occurs. A gradual decrease in the level of hormones in the blood leads to aging. The most complex changes in hormonal levels in a woman’s body provide the possibility of the birth of a new life, normal childbearing, childbirth and the process of lactation.
Most hormones are produced in specialized organs - endocrine glands. These glands received this name because they secrete their product inside - directly into the blood.
The endocrine glands are subject to the central complex of neuroendocrine regulation, the so-called hypothalamic-pituitary system, located in the brain.
Features of preparation for taking a hormonal analysis: one day before, it is necessary to exclude sexual contact and thermal procedures (sauna, bathhouse).
Human chorionic gonadotropin
Human chorionic gonadotropin is a specific pregnancy hormone, which is similar in action to gonadotropins (LH and FSH).
Progesterone
Progesterone is a hormone of the corpus luteum of the ovary, formed after the release of a mature egg from the follicle. This hormone is necessary for a normal pregnancy, so its concentration increases throughout gestation.
Outside of pregnancy, progesterone levels begin to increase immediately before ovulation, and reach a maximum in the middle of the luteal phase of the cycle (the interval between the release of the egg and the beginning of the next menstruation - days 14-28 of the cycle).
A hormonal blood test for progesterone is taken on the 22-23rd day of the cycle in the morning, on an empty stomach.
Estradiol
Estradiol is the most active female sex hormone, which is produced in the ovaries, placenta and adrenal cortex under the influence of gonadotropic hormones of the pituitary gland.
A hormonal test for estradiol is taken on the 6-7th day of the cycle in the morning, on an empty stomach.
Estriol
Estriol is a female sex hormone, which is called the main estrogen of pregnancy. When taking a hormonal test for estradiol, it should be taken into account that taking antibiotics and some other medications can significantly reduce the concentration of estriol in the blood.
Testosterone
Testosterone is the main male hormone that determines the development of secondary sexual characteristics, puberty and reproductive function.
In men, most of the testosterone is produced in the testicle, and less in the adrenal cortex. In women, testosterone is partially formed during the transformation process from other steroids, as well as in the cells of the inner lining of the follicle and the reticular layer of the adrenal glands.
Hormonal tests for amenorrhea
Amenorrhea is the absence of menstrual bleeding in women of reproductive age for 6 months or more. This is one of the most common sexual dysfunctions in women. There are primary and secondary amenorrhea. Primary amenorrhea is when a woman has never menstruated, secondary is when the monthly cycle was present and then stopped.
It should be noted that in both primary and secondary amenorrhea, first of all, it is necessary to do a pregnancy test (determine the level of hCG (chorionic gonadotropin) in the blood).
Primary amenorrhea
Primary amenorrhea can be caused by a number of reasons, such as congenital abnormalities (including chromosomal), infectious or immune damage to the ovaries, adrenal tumors, pathologies of the pituitary-hypothalamic system. Depending on the characteristics of hormonal imbalance, there are four groups of primary amenorrhea:
1.
Hypergonadotropic hypogonadism.
2.
Hypogonadotropic hypogonadism.
3.
Eugonadotropic hypogonadism.
4.
Hyperandrogenemia.
Hypergonadotropic hypogonadism (increased levels of pituitary stimulating hormones with decreased levels of ovarian hormones) indicates ovarian pathology, which may be the result of primary agenesis (underdevelopment) of the ovaries or Shereshevsky-Turner syndrome. This is a chromosomal pathology in which the set of chromosomes (karyotype) is missing one sex chromosome (karyotype X0).
With hypergonadotropic hypogonadism, there is an increase in the secretion of gonadotropins FSH (the level of follicle-stimulating hormone is especially increased in Shereshevsky-Turner syndrome) and LH (luteinizing hormone). A stimulation test with hCG (human chorionic gonadotropin) is negative.
To verify Shereshevsky-Turner syndrome, it is necessary to conduct a karyotype study. In addition, it is recommended to do hormonal tests that determine the level of testosterone (male sex hormone) and cortisol (adrenal cortex hormone) in the blood.
Hypogonadotropic hypogonadism (simultaneous decrease in the level of stimulating hormones of the pituitary gland and ovarian hormones) indicates damage to the hypothalamic-pituitary system. To determine the level of damage, a stimulation test with GnRH (gonadotropic-releasing hormone) is performed. If in response to stimulation the level of the hormone in the blood increases, then we can conclude that the cause of the pathology lies in the insufficient release of releasing factors by the cells of the hypothalamus. If the stimulation test is negative, then the cause of ovarian hypofunction is pathology of the pituitary gland.
Eugonadotropic hypogonadism (reduced level of ovarian hormones with normal concentration of gonadotropins in the blood). Occurs with anatomical defects, testicular feminization syndrome, polycystic ovary syndrome.
With anatomical defects leading to amenorrhea, the hormonal status is usually normal.
Thus, with the onset of placental insufficiency, the level of hCG and progesterone decreases, and with the development of chronic placental insufficiency, when fetal suffering is pronounced, the level of estrogen also decreases.
During a frozen pregnancy, there is a sharp decrease in the concentration of hCG and estrogen (100% below the average norm).
An increase in hCG levels is also a very important sign, which may indicate a multiple pregnancy or incorrect determination of gestational age. In addition, the level of hCG increases in pathological conditions such as early and late toxicosis of pregnancy, maternal diabetes, multiple fetal malformations, and Down syndrome.
Fetal malformations may also be indicated by a reduced level of estradiol, which is observed with anencephaly, intrauterine infection, fetal adrenal hypoplasia, and Down syndrome.
Hormonal blood tests for thyroid pathology
The thyroid gland is an internal secretion organ that produces iodine-containing hormones that regulate basal metabolism (maintaining the energy constancy of the internal environment). So, with an excess of thyroid hormones, all metabolic processes accelerate, which leads to their mismatch, and with a deficiency, metabolic processes slow down, which negatively affects the activity of organs and tissues. Since thyroid hormones are necessary for the normal functioning of all cells of the body without exception, diseases of the organ have systemic manifestations (central nervous activity suffers, vegetative-vascular reactions are disrupted, dystrophic processes occur in the myocardium, and the coordinated activity of the entire endocrine system of the body is disrupted).
Hormonal tests for suspected thyroid pathology
There are characteristic signs of hyperthyroidism:- a sharp decrease in body weight;
- exophthalmos (bulging eyes);
- goiter (severe enlargement of the gland).
- bradycardia;
- myxedema (mucoedema);
- endophthalmos (sunk eyes);
- hypothermia.
- amenorrhea;
- infertility;
- depression;
- cardiac arrhythmias;
- delayed mental and physical development in children.
Thyroid-stimulating hormone (TSH)
Thyroid-stimulating hormone is a hormone of the anterior pituitary gland that stimulates the secretion of thyroid hormones.The production of TSH is characterized by pronounced daily fluctuations with a maximum at 2-4 am, and a minimum at 17-18 hours. This rhythm gets lost during night vigils.
The concentration of TSH physiologically increases during pregnancy and with age (in the latter case - slightly).
The production of TSH is inhibited by thyroid hormones, therefore, when the level of fractions of its hormones increases, the concentration of TSH decreases, and when the gland is hypofunction, it increases.
Fractions of hormones synthesized by the thyroid gland
Fractions of the hormones of this gland are formed under the influence of TSH, and stimulate the basal metabolism and absorption of oxygen by the cells of the body.All fractions are subject to seasonal and diurnal rhythms. A physiological decrease in the level of thyroid hormones is observed after the age of 65 years, an increase during pregnancy, as well as with a rapid increase in body weight.
An increase in the level of thyroid hormone fractions may indicate its hyperfunction, or the presence of other diseases (hepatitis, nephrotic syndrome, HIV infection, increased estrogen levels).
In addition to hypothyroidism, a decrease in thyroid hormone levels is observed in the following cases:
- low protein diet or fasting;
- adrenal insufficiency;
- severe general exhaustion of the body;
- chronic liver diseases.
Total thyroxine (T4 total) is the main iodine-containing hormone of the thyroid gland (the gland produces 93% thyroxine and only 7% triiodothyronine).
The concentration of total T4 has pronounced daily fluctuations with a maximum occurring between 8 and 12 o'clock in the afternoon, and a minimum between 23 and 3 o'clock at night.
Free thyroxine
Free thyroxine (free T4) is the fraction of T4 not bound to proteins. In women, the concentration of free thyroxine is lower than in men and increases during pregnancy, reaching a maximum in the last trimester.
Triiodothyronine total
Total triiodothyronine (T3 total) is formed in the thyroid gland from T4, and has the same effect, but is 4-5 times more active than its predecessor. This hormone is characterized by seasonal fluctuations: its maximum level is found in the blood from September to February, the minimum in summer.
Free triiodothyronine
The concentration of free triiodothyronine (free T3) is the fraction of triiodothyronine in the blood that is not bound to proteins. The level of free T3 physiologically decreases in the last trimester of pregnancy.
Hormones of the adrenal cortex. Symptoms indicating cortical pathology
adrenal glands
Biological action of adrenal hormones
The adrenal cortex produces several dozen different hormones, which can be divided into three groups:1. Glucocorticoids.
2. Mineralocorticoids.
3. Adrenal androgens.
Glucocorticoids are the most important hormones of the adrenal cortex and, as the name implies, regulate glucose metabolism, having an effect opposite to insulin. They help increase blood glucose levels, causing its synthesis and reducing its uptake by peripheral tissues. So, with an increase in the concentration of glucocorticoids, so-called steroid diabetes develops.
In addition, glucocorticoids are involved in protecting the body from stress and shock and have a powerful anti-inflammatory and immunosuppressive effect.
Mineralocorticoids regulate water-salt metabolism, helping to maintain blood pressure and preserve water, sodium and chlorine in the body. With an increase in the concentration of mineralocorticoids in the body, hypertension and edema syndrome develop.
Adrenal androgens are secreted in small quantities, so their effect becomes noticeable only in the case of pathology (masculinization of women with tumors of the adrenal cortex, etc.).
All hormones of the adrenal cortex are secreted under the influence of the hormone of the anterior pituitary gland - ACTH (adrenocorticotropic hormone). In this case, feedback-type regulation occurs: with a decrease in the production of hormones from the adrenal cortex, the secretion of ACTH increases - and vice versa.
Clinical manifestations of hormonal imbalance requiring analysis
level of adrenal hormones in the blood
Hypoproduction of adrenal hormones is called Addison's disease
. This is a fairly rare disease that has the following symptoms: - increasing muscle weakness, constant feeling of fatigue;
- decreased blood pressure with increased heart rate;
- irritability, tendency to depression, anxiety;
- loss of appetite and weight, diarrhea, vomiting, abdominal pain;
- the formation of dark spots on exposed skin;
- craving for salty foods, constant thirst;
- excess urine when there are symptoms of dehydration.
Less commonly, Itsenko-Cushing syndrome develops with hyperplastic processes of the adrenal cortex, as well as with long-term treatment with glucocorticoid medications, and has very characteristic symptoms:
alcoholism, some neuropsychiatric diseases, sometimes during pregnancy. In such cases they talk about Pseudo-Cushing syndrome, or functional hypercortisolism.
We take hormonal tests if we suspect cortical pathology
adrenal glands
Adrenocotricotropic hormone (ACTH)
Adrenocotricotropic hormone (ACTH) is a hormone of the anterior pituitary gland that stimulates the production of hormones from the adrenal cortex.Increased levels occur with primary adrenal insufficiency, as well as with tumors that produce ACTH.
A decrease in the level of ACTH is observed with insufficiency of its production by the anterior lobe of the pituitary gland, as well as with hormone-producing tumors of the adrenal cortex (inhibition of synthesis according to the feedback principle).
Cortisol
The main glucocorticoid of the adrenal cortex, which is characterized by a pronounced circadian rhythm with a maximum in the morning (6-8), and a minimum in the evening (20-22). It should be remembered that during pregnancy there is a physiological increase in the concentration of cortisol levels in the blood.
Aldosterone
The main mineralocorticoid of the adrenal cortex. A hormonal test for aldosterone is mandatory for high blood pressure, and during the diagnosis of renal failure, as well as to monitor treatment in patients with heart failure.A physiological increase in aldosterone levels is observed during pregnancy, a salt-free diet, and increased water and physical activity.
Medicines: The influence of drugs on laboratory test results is varied and not always predictable.Meal: It is possible to have both a direct effect due to the absorption of food components, and an indirect effect - shifts in hormone levels in response to food intake, the influence of sample turbidity associated with an increased content of fat particles.
Physical and emotional overload: cause hormonal and biochemical changes.
Alcohol: has acute and chronic effects on many metabolic processes.
Smoking: changes the secretion of some biologically active substances.
Physiotherapy, instrumental examinations: may cause temporary changes in some laboratory parameters.
Phase of the menstrual cycle in women: is significant for a number of hormonal studies, before the study you should check with your doctor about the optimal days for taking a sample to determine the level of FSH, LH, prolactin, progesterone, estradiol, 17-OH-progesterone, androstenedione.
Time of day when blood is drawn: there are daily rhythms of human activity and, accordingly, daily fluctuations in many hormonal and biochemical parameters, expressed to a greater or lesser extent for different indicators; reference values - the boundaries of the “norm” - usually reflect statistical data obtained under standard conditions when blood is taken in the morning. 
General rules when preparing for research: It is advisable to follow these rules when conducting biochemical, hormonal, hematological tests, complex immunological tests; the results depend on the physiological state of the person.
- If possible, it is recommended to donate blood in the morning, between 8 and 11 o’clock, on an empty stomach (at least 8 hours and no more than 14 hours of fasting, drink water, as usual), and avoid food overload the day before.
- If you are taking any medications, you should consult with your doctor about the advisability of conducting a study while taking medications or the possibility of discontinuing the drug before the study; the duration of withdrawal is determined by the period of removal of the drug from the blood.
- Alcohol – avoid drinking alcohol on the eve of the test.
- Smoking – do not smoke for at least 1 hour before the test.
- Avoid physical and emotional stress on the eve of the test.
- After arriving at the laboratory, it is recommended to rest (preferably sit) for 10–20 minutes before taking blood samples.
- It is not advisable to donate blood for laboratory testing soon after physiotherapeutic procedures, instrumental examinations and other medical procedures. After some medical procedures (for example, a prostate biopsy before a PSA test), laboratory testing should be delayed for several days.
- When monitoring laboratory parameters over time, it is recommended to conduct repeated tests under the same conditions: in the same laboratory, donate blood at the same time of day, etc.
Time of day when taking blood samples for testing - recommendations
Note: “+” - recommended;
“+/-” - allowed with restrictions, the circadian rhythm should be taken into account when studying dynamics and the boundary values of the results relative to the reference limits;
“-” is undesirable.
PREPARATION FOR URINE STUDIES GENERAL RULES:
1. 10–12 hours before the test, it is not recommended to consume: alcohol, spicy and salty foods, as well as foods that change the color of urine (beets, carrots).2. If possible, avoid taking diuretics.
3. After cystoscopy, a urine test can be prescribed no earlier than 5–7 days later.
4. Women are not recommended to take a urine test during menstruation.
5. The patient collects urine independently (with the exception of children and seriously ill patients).
6. Before taking the test, perform a thorough toileting of the external genitalia:
- in women, use a cotton swab moistened with warm soapy water to clean the external genitalia (treating the labia by moving the swab in front and down); dried with a clean cloth, previously ironed with a hot iron.
- in men - the external opening of the urethra is toileted with warm water and soap, then washed with warm water and dried with a clean napkin, previously ironed with a hot iron.
General urine analysis
For general analysis, use the first morning portion of urine (the previous urination should be no later than 2 am).Toilet the external genitalia. For men, when urinating, completely pull back the skin fold and release the external opening of the urethra. For women, spread the labia. Pour the first few milliliters of urine into the toilet. Collect the entire portion of morning urine in a dry, clean container while urinating freely. Pour 40–50 milliliters of the total volume of urine into a special container and close the lid tightly. You cannot take urine from a vessel or potty. The collected urine should be immediately delivered to the laboratory. Urine can be stored in the refrigerator (at +2° +4° C), but not more than 1.5 hours.
24-hour urine collection
Collect urine for 24 hours with normal drinking regimen (1.5–2 liters per day):- at 6–8 o’clock in the morning, empty the bladder (pour out this portion of urine);
- within 24 hours, collect urine in a clean container with a capacity of at least 2 liters; during collection, the container with urine must be stored in a cool place (optimally in the refrigerator on the bottom shelf at t +4° +8°C), preventing it from freezing;
- collect the last portion of urine at exactly the same time the next day when collection began the day before;
- measure the amount of urine, pour 50–100 ml into a clean container. Be sure to write on the container the volume of urine collected per day (daily diuresis).
Urinalysis according to Nechiporenko
Collect urine in the morning (immediately after sleep) using the 3-glass sample method: start urinating in the toilet, collect the middle portion in a container for laboratory testing, and finish in the toilet.The second portion of urine should prevail in volume. Deliver a medium portion of urine to the laboratory. Report the time of urine collection to the registrar. It is allowed to store urine in the refrigerator (at t +2° +4°), but no more than 1.5 hours.
Urine analysis according to Zimnitsky
Collect urine for 24 hours at the usual drinking rate (1.5–2 liters per day), taking into account the amount of liquid drunk per day.At 6 o'clock in the morning, empty your bladder (pour out this portion of urine).
Every 3 hours during the day, collect urine in separate containers, which indicate the time of collection and the portion number.
Total 8 servings:
- 1 serving – from 6-00 to 9-00,
- 2 servings – from 9–00 to 12–00,
- 3 servings – from 12–00 to 15–00,
- 4 portions – from 15–00 to 18–00,
- 5 portion – from 18–00 to 21–00,
- 6 portion – from 21–00 to 24–00,
- 7 portion – from 24–00 to 3–00,
- 8th portion – from 3–00 to 6–00.
Deliver the entire collected amount of urine in 8 containers to the laboratory.
