None of the medical testing currently allows you to get an absolutely reliable result. To confirm the final diagnosis, it is necessary to take into account the information of several laboratory tests. This applies even to complex studies of the patient’s biomaterial, such as serological methods, PCR, and others. From a psychological point of view, a false positive test for HIV is especially difficult. What can affect such a result? What should a patient who receives a similar printout of a blood test should do? All answers in our article.
Consequences of the error
False positive HIV testing and making mistakes can lead to many irreversible consequences. For example, the highly active antiretroviral treatment prescribed for this disease provokes the development of serious side effects and can cause disruption of the functioning of internal organs.
The moral aspect is no less difficult. A person can lose his family, friends, loved ones, even the desire to live.
Consider what you need to do when you receive a false-positive HIV test result.
Retest
A repeated blood test is the only way to avoid a mistake and put an end to the diagnosis. If the virus is detected during the second test, the patient has no choice but to come to terms with the harsh reality and immediately begin treatment.
The probability of error, according to statistics, is approximately 0.01%, but in reality this indicator is much higher.
Causes
False positive HIV tests are often observed in women during pregnancy. At a particular risk are ladies who have had several births. This phenomenon occurs due to a serious hormonal imbalance during the period of gestation.
The reasons for a false positive HIV test in men are:
- Allergic reactions of the cross type.
- Recently vaccinated.
- The presence of influenza or hepatitis virus in the body at the time of the study.
- Inflammation of small vessels in the body.
- Transplantation of internal organs.
- Increased bilirubin concentration in the blood.
- Oncological diseases.
- Various forms of sclerosis.
- Increased density or poor blood coagulation.
- Autoimmune liver pathology.
- Tuberculosis.
- Any infectious diseases.
In women, the period of menstrual bleeding should be added to this list.
Before undergoing the study, it is recommended to inform the specialist about the presence of pregnancy, operations performed and other manipulations that were present in the last few months.
Human factor
One of the reasons for a false-positive test for HIV can be a trivial human factor that no one has yet canceled. This is a laboratory technician’s elementary error directly during the study or in the documentation. There are even cases when the health care provider confused the tubes or incorrectly labeled them.
Any viral or infectious disease can lead to a false-positive HIV test. Sometimes a person does not suspect that other viruses (except HIV) are present in his body, for example, he has an incubation period of a disease. In this case, the test result may not be correct. There are also situations when a person was sick, for example, with flu, and was treated. He no longer has symptoms, but he has not yet recovered. If an HIV test is taken during this period, the result may be false positive. Conducting such laboratory tests is recommended only after a month and a half after recovery. This will help to be sure of an adequate diagnosis.
The reasons for a false-positive HIV test in women have their own nuances. In the weaker sex, the body is incredibly complex. The work of some of its systems can bring unwanted surprises.
Pregnancy
The factors for obtaining a false-positive HIV test during pregnancy in women (with the exception of ongoing hormonal changes) are divided into two main categories:
- The synthesis of female and male genetic biomaterials (the union of a sperm and an egg) during the nucleation of a new life in the body, which leads to the formation of foreign DNA. In response to such changes, the immune system begins to produce its own antibodies. When tested, this can lead to a false-positive HIV test in pregnant women.
- Stressful condition, which is often observed in women during the period of bearing a child. The likelihood of a false-positive HIV test during pregnancy increases with multiple psychological problems.
Women during this period undergo research several times throughout the nine months of fetal development. The timely detection of this infection helps to take a number of measures that are necessary in order to protect the future baby and prevent its infection during childbirth or breastfeeding.
The reasons for a false-positive HIV test in men and women are best known in advance so as not to panic later.
Basic rules for laboratory research
ELISA is considered the most accurate. Its error is up to 1%, but this study is carried out after 6-12 weeks from the date of the alleged infection. During the incubation period, the result will be negative (false-negative) or doubtful.
PCR can be done within 10-14 days after a possible infection, but the accuracy of this analysis is only 80-85%. Therefore, upon receipt of a positive response, additional studies are prescribed to the patient.
The list of basic rules for the analysis procedure in HIV-infected patients includes:
- If a person is infected with HIV, then he needs to take a general blood test once every three months. Such a measure allows the specialist to track the dynamics of the progression of the pathological process, to adjust and draw up therapeutic schemes.
- To obtain the most correct results when collecting venous blood, it is necessary to create the same conditions. For greater research accuracy, the procedure must be carried out in the same specialized medical laboratory.
- Blood donation is performed in the morning to detect antibodies produced by the body against HIV. This is due to the fact that at the beginning of the day in people the concentration of red blood cells increases.
Consultation on the implementation of the procedure for blood sampling, preparation and interpretation of research results can be obtained at a public or private clinic, as well as specialized centers for the fight against AIDS.
Rapid testing
Portable tests for detecting antibodies to HIV at home are a simple and quick way to find out about the presence of this infection in the body. To date, special kits are widely used for the study of blood, urine and saliva without contacting medical specialists.
The main drawback of rapid testing is the high probability of errors (compared with other diagnostic methods). People who do not have a medical education may misuse or decipher the results, which contributes to false positive diagnoses.
The frequency of such responses during rapid testing is approximately 1%. Obtained after the initial study, the result for making the correct diagnosis, as a rule, is not enough.
Such testing is carried out as follows: the biological material is placed in a special container containing the reagent. After that, to get an answer you need to wait 15-20 minutes.
Modern portable devices give out 3 options: negative, positive or doubtful result.
The last answer can be observed during the incubation period, when the growth and reproduction of the virus is just beginning, so the concentration of antibodies is relatively low. To make a diagnosis, you need to contact a specialized laboratory.
How to prepare for the analysis
Laboratory tests to detect antibodies to HIV are performed on an empty stomach. Between venous blood sampling and the last meal there should be a time interval of at least 8 hours.
When preparing for an HIV test, you must observe:
- Special drinking regimen. Only the use of still water is allowed. The use of tea, coffee, sugar, alcohol and other drinks is excluded.
- A special diet, which implies the rejection of fatty, fried and spicy foods a day before an HIV test.
- Stressful situations, physical fatigue, injuries and the use of antibacterial medications should be avoided.
If you adhere to the above rules, you can ensure maximum reliability of the results of laboratory tests.
HIV diagnosis in the laboratory
HIV tests performed in special laboratory conditions are considered the only basis for confirming the diagnosis. The procedure is performed openly or anonymously. Blood sampling in time takes only a few minutes.
This test must be given if there is any suspicion of infection (for example, during unprotected intercourse with an unfamiliar partner or after using non-sterile medical equipment).
Types of analyzes
If HIV is suspected, the following tests are carried out:
- ELISA (enzyme-linked immunosorbent assay), through which the presence of antibodies of the immune system is established. In fact, the analysis identifies suspicious and healthy cells.
- Immunoblotting - for the presence of antibodies, the serum is studied, which is obtained by the isolation of red blood cells and plasma from venous blood. This is a more effective and reliable method, but it does not give a 100% accurate result.
- PCR - a study that allows you to identify the DNA of viruses or its fragments. Its advantage is the detection of the virus in the early stages - even before the formation of antibodies. This analysis gives a large error if it is determined whether a person is infected or not. If the infection is confirmed, using PCR monitor the dynamics of changes during therapy.
Deciphering the results
The results of different diagnostic methods are slightly different, however, when identifying the three main groups of proteins, the doctor makes a positive diagnosis.
Deciphering the results:
- For people infected with HIV, the presence of lymphocytosis, a high number of lymphocytes, is characteristic. When decoding the HIV study, the deviation of this indicator from the norm can be observed in half. The norm is 25-40% of the total number of leukocytes or 1.2-3 × 109 / l in the absolute number. With AIDS, lymphopenia develops, which is caused by the death of T-lymphocytes.
- An important indicator for HIV is ESR. For patients with this pathology, a marked increase in this value is characteristic. The norm in men is 1-10 mm / h, in women - 2-15 mm / h.
- With HIV, a decrease in hemoglobin is noted, as a result of which the patient develops severe forms of anemia. The norm for women is 120-140 g / l, for men - 130-160 g / l.
- Another characteristic indicator for patients with immunodeficiency is a reduced platelet count, which can lead to bleeding. The norm is - 150-400 × 109 / l in adults.
Hepatitis False HIV Test
This disease is an inflammation of the liver in acute or chronic form. With this pathology, a somewhat more intense immune system is observed, which may explain the appearance of a false-positive HIV test result. If hepatitis is acute, then an erroneous result is almost guaranteed, because at this time a huge amount of different antibodies are present in the patient’s blood, which distort the result of laboratory analysis. In chronic hepatitis, the study is carried out during a stable period of remission, when there are no signs of acute inflammation in the blood.
We examined whether an HIV test could be false positive.