What does a positive Wasserman reaction testify to and what to do with this result. What is the Wasserman reaction? What is blood for the Wasserman reaction

False-positive syphilis serological tests (PPR)- this positive reactions in people who have never been ill and do not have syphilis at the time of the examination. That is, there is no and never was a specific infection in the body, and serological tests give a positive result.

False-positive or non-specific results are positive results of serological tests for syphilis in people who do not suffer from syphilitic infection and have not had syphilis in the past.

Erroneous analysis for syphilis due to technical reasons

Decision makers may be due to technical errors and errors in the performance of research, as well as the quality of reagents. Despite the numerous advantages of diagnosticums for RPHA, ELISA and RIF and their modifications used for the diagnosis of syphilis, in some cases, unreliable test results are noted. This may be due to both the insufficient level of qualification and professional responsibility of the personnel (so-called non-biological or technical errors), and the characteristics of the tested samples (biological errors).

Errors of a non-biological nature can occur at any stage of research: pre-analytical, analytical, and post-analytical i.e. during the collection, transportation, storage of biomaterial, the use of chylous, germinated serum, repeated freezing and thawing of test samples, as well as the use of expired diagnostic kits, etc. In particular, non-compliance with the conditions and terms of storage of diagnostic kits is the reason for reducing the sensitivity of the reaction and obtaining false negative results.

False-positive results can be caused by contamination of sera from patients who are seronegative for treponema pallidum with traces of sera from seropositive individuals, which can occur during the preparation of sera.

There are many other technical errors that lead to unreliable (false negative and false positive), doubtful results of the study. In some laboratories, internal and external quality control of syphilis studies is not carried out, which leads to diagnostic errors and uncertainty of laboratory doctors in the results of the analysis.

The source of errors in setting up nonspecific tests can be the non-use of control sera, uneven concentration of the antigen in the experiment due to insufficient mixing before use, contamination of samples and dishes with microorganisms, violation of the terms and conditions of storage of reaction components, violation of the technique of taking blood.

In modern test systems, recombinant or synthetic peptides have been used as antigens. The former are more widespread. But with poor purification, Escherichia coli proteins get into the mixture of T. pallidum antigens, which leads to false serodiagnosis of syphilis in patients with Escherichiosis or healthy people whose serum contains antibodies to Escherichia coli.

To a certain extent, incorrect interpretation of the results of the study should also be attributed to diagnostic errors.

Acute and chronic DM

In addition to technical errors when performing tests, decision makers can also be due to the characteristics of the body. Conventionally, decision makers are divided into sharp (<6 месяцев) и chronic(remain more than 6 months).

Acute decision makers can be observed during pregnancy and during menstruation, after vaccination, after a recent myocardial infarction, in many infectious diseases. Infections that may cause LPR - pneumococcal pneumonia, scarlet fever, infective endocarditis, tuberculosis, leprosy, venereal lymphogranuloma, chancroid (soft chancre), leptospirosis and other spirochetosis, HIV infection, infectious mononucleosis, malaria, chicken pox, viral hepatitis, mumps , measles, respiratory diseases, influenza and dermatoses.

Acute decision makers are unstable, their spontaneous negativity occurs within 4-6 months.

Chronic decision makers are possible in autoimmune diseases, systemic diseases of the connective tissue, oncological diseases, chronic pathology of the liver and biliary tract, in cardiovascular and endocrine pathologies, in blood diseases, in chronic lung diseases, injecting drugs, etc. In most of these conditions, anticardiolipin antibodies of the IgG and IgM classes ("reagins").

Chronic false-positive reactions may remain positive throughout life.

Chronic false-positive reactions may be preclinical manifestations of severe diseases. In malignant neoplasms, diffuse diseases of the connective tissue, the LPR titer can be very high.

Physiological conditions (old age) are distinguished among the causes of chronic positive reactions. With age, the number of LPR increases, in women they are observed 4.5 times more often than in men. In the age group of 80-year-olds, the prevalence of DM is 10%.

Frequent use of intravenous drugs, frequent transfusions and infusions can be the cause of DLL.

Chronic infections (tuberculosis, leprosy, infective endocarditis, malaria), myeloma can also cause DM.

Infection with other types of spirochetes

False-positive reactions of treponemal and non-treponemal tests can be observed in infectious diseases, the causative agents of which have antigenic similarity with pale treponema. These are relapsing fever, leptospirosis, tick-borne borreliosis, tropical treponematoses (yaws, bejel, pint), as well as inflammatory processes caused by saprophytic treponemas of the oral cavity and genitals.

The causative agents of endemic treponematoses (yaws, pinta, bejel) are treponemas that have genus-specific antigens similar to those of T.pallidum. In this regard, the antibodies formed against them are able to cross-react with the antigen of the causative agent of syphilis.

Russia is not a territory endemic for this group of diseases. These infections occur mainly in Africa, Latin America and South Asia, and cases are rare in the practice of medical institutions.

A patient with a positive serological test for syphilis coming from a country with endemic treponematoses should be tested for syphilis and given antisyphilitic treatment if not previously given.

Biological false positive Wasserman reaction

Beginning in 1938, and especially during World War II, screening serological tests for syphilis began to be widely carried out in the United States. The researchers compared the data obtained and found that a positive or doubtful reaction was found in people who did not have clinical and epidemiological signs of syphilitic infection or syphilis contacts. Moreover, such results occurred much more often than previously thought. Positive results of non-treponemal tests with lipid or cardiolipin antigens (VDRL, Colmer's tests, Kahn's tests) have been found in patients with various diseases, but who do not have signs of syphilitic infection. Biological false positive results have been identified in patients with autoimmune, inflammatory, and hematological diseases.

In the Russian-language medical literature, this phenomenon was called " biological false positive wasserman reaction» (B-LPRV), because these results were observed during the most common test of those times - the Wassermann reaction.

It turned out that B-LPRV can occur in two main variants - acute and chronic. In the first case, in patients who have had any, but not syphilitic infection, B-LPRV disappears in the process of recovery, and the duration of its detection does not exceed six months. In the second case, B-LPG can persist for many years in the absence of an obvious causative factor. In the early 1950s, it was found that chronic B-LPRV is most often detected in autoimmune diseases, especially SLE, in which the frequency of its detection reaches 30-44%

False positive non-treponemal (cardiolipin) tests

Lipid antigens of T. pallidum make up a significant part of the cell, however, lipids having the same structure can also be present in the body - autoantigens resulting from the destruction of organs and tissues (mainly lipids of mitochondrial membranes).

Syphilitic infection is accompanied by the formation of immune complexes and an autoimmune response to cardiolipin, fibronectin, collagen, and muscle creatine kinase. In non-treponemal tests, a solution of three highly purified lipids (cardiolipin, stabilized with lecithin and cholesterol) in ethanol is used as an antigen. Cardiolipin is not a specific component for T. pallidum and is also described as one of the phospholipids in human biomembranes. Therefore, antibodies to this antigen are detected in serum in almost any alteration of human cells as a result of infections and under certain physiological and pathological conditions.

Since the antigen used in non-treponemal reactions is found in other tissues, tests may be positive in individuals without treponemal infection (1-2% in the general population).

The most common cause of biological false-positive non-treponemal tests is antiphospholipid syndrome, an autoimmune process that occurs in connective tissue diseases (systemic lupus erythematosus, dermatomyositis, scleroderma).

When using non-treponemal tests (RMP and its modifications), false-positive results may be due to the presence of antibodies to rheumatoid factor in the blood, cross-reacting antibodies in autoimmune pathology ("cress-reactors").

Some chronic bacterial infections (leprosy, etc.), diseases of viral etiology (infectious mononucleosis), and systemic connective tissue diseases are considered other factors in the occurrence of false positive results.

The reasons can also be in old age (over 70 years), pregnancy, extensive somatic pathology, lipid metabolism disorders, immunodeficiency states of various etiologies, systemic chronic diseases of the heart and lungs.

Other causes include cancer, tuberculosis, enterovirus infections, viral hepatitis, Lyme disease, pneumonia, alcoholism, drug addiction, diabetes, vaccination, other infections (malaria, chicken pox, measles, endo- and myocarditis), gout.

Under these conditions, the development of immunological disorders is noted, leading to abnormal production of antibodies that can cross-react with treponemal antigens.

Table. Biological causes of false positive reactions in non-treponemal serological tests.

False positive treponemal tests

The problem is exacerbated by the fact that treponemal tests can also be false positive. The causes may be autoimmune diseases, collagenosis, Lyme disease, pregnancy, leprosy, herpes, malaria, infectious mononucleosis, tumors, drug addiction. In recent years, immunoblotting, one of the most modern methods for diagnosing syphilis, has been actively used abroad to differentiate DM.

Preservation of antibodies after successful treatment

Specific diagnostic reactions remain positive for a long time even after full therapy. After effective treatment of syphilitic infection, in most patients, titers in nontreponemal tests are reduced by 4 times 6–12 months after treatment. However, with late initiation of therapy, titers even in non-treponemal tests may remain at the same level, but never increase.

False negative test results

Various diagnostic methods demonstrate different sensitivity and specificity depending on the form and stage of syphilis. The probability of an erroneous diagnosis increases, especially in cases of latent, latent, combined course of the disease.

False-negative serological reactions for syphilis can be observed in secondary syphilis due to the prozone phenomenon when testing undiluted serum, as well as when examining immunocompromised individuals, such as HIV-infected patients.

False-negative results of serological specific reactions (TPHA) caused by biological factors may be due to competition between specific IgM and IgG for binding to the antigen on the surface of erythrocytes, as well as the “prozone phenomenon”. In the latter case, agglutination does not occur due to overproduction of antibodies to pale treponema, since each antigen receptor on erythrocytes is associated with one molecule of agglutinin due to excess antibodies, which prevents the formation of a "lattice". Replacing RPGA with TPPA, i.e. erythrocytes on synthetic particles would presumably eliminate or minimize false-negative results.

In ELISA, such reactions can be explained by the presence of a seronegative phase in primary syphilis, and in secondary - immune deficiency, the presence of HIV infection. When obtaining a negative result of serological tests for syphilis, one should take into account the property of pale treponema to penetrate and multiply in various organs and tissues - the search for the pathogen in the lymph (lymph nodes) in some cases leads to a reliable result. It is advisable to repeat the analysis of samples that gave a positive result. Repeated, after 5-7 or more days, the study of sera, as a rule, allows you to obtain reliable results.

Practiced in medicine for more than a century, the Wassermann diagnostic reaction is one of the most well-known studies. Developed by the German physician August von Wassermann to facilitate the diagnosis of early and inactive forms of syphilis, this immunological reaction immediately entered the circle of therapeutic activity and proved to be useful.

What prompted such an unambiguously positive assessment of the use of a patient's blood sample for diagnosis?

1. Doctors now have the opportunity to confirm the diagnosis of syphilis through a simple blood test for RW (Wasserman reaction).
2. The results of the treatment and its effectiveness can now be monitored using a specific indicator.
3. Based on the positive reaction of Wasserman, it was convincingly possible to establish not only the very fact of infection, but also approximately the time of the moment of infection.

Blood test for the Wasserman reaction

Over time, many shortcomings of the popular blood test came to light. If a negative Wasserman reaction was usually significant enough, then a positive result could often be due to other reasons. At the same time, the number of possible grounds for a false positive result steadily increased over time.

A positive reaction was noted in some diseases (malaria, tuberculosis, systemic, leptospirosis, leprosy, blood diseases). And even after vaccination or an acute viral infection.

In the USSR, since the second half of the fifties of the last century, the classical Wasserman reaction has always been duplicated by two additional mandatory studies - the Kahn reaction and the cytochole reaction.

Currently, the classical Wassermann reaction is not used. But, out of established habit, doctors often call so any reaction of a diagnostic blood test to syphilis.

False-positive serological tests for syphilis
False positive reaction to serological tests for syphilis

What are false positive reactions to syphilis

False-positive reactions for syphilis - positive test results for syphilis in the absence of disease. False-positive reactions must be distinguished from seropositivity and seroresistance after syphilis treatment. 2-5% of all tests performed (according to some authors, from 5 to 20%), much less often false positive reactions occur during treponemal tests. There are biological false positive reactions and erroneous false positive reactions associated with a violation of the technique of conducting tests in the laboratory.

What are the causes of false positive reactions to syphilis

False positive nontreponemal tests

The main reasons for biological false positive reactions are related to the fact that when conducting non-treponemal tests, antibodies to cardiolipin are determined (the main component of mitochondrial lipids, especially the heart muscle - hence the name), which appears in the body during tissue destruction in certain diseases and conditions. Thus, non-treponemal tests determine the so-called reagin antibodies that the body has developed not against the causative agent of syphilis - pale treponema, but against the consequences of a syphilitic infection. However, reagin antibodies are produced not only to lipids of destroyed tissues, but also to lipids of the membrane of pale treponema, but more than 200 antigens similar to in its composition on the lipid antigen of pale treponema.

False positive treponemal tests

The causes of false positive treponemal tests are unknown. The percentage of their occurrence is very low. It is noted that false positive treponemal tests are most common in systemic lupus erythematosus and in Lyme disease (borreliosis).
Since anti-treponemal antibodies are produced by immunological memory cells for quite a long time, there are hypotheses about a short-term contact of the body with pale treponema, which did not lead to infection with syphilis, but caused the production of anti-treponemal antibodies.

Undoubtedly, the appearance of positive non-treponemal and treponemal tests in non-venereal trepanematoses is not considered as a false positive biological reaction, but does not confirm the presence of syphilis.

When do false-positive reactions to syphilis occur?

The registered frequency of false-positive results of non-treponemal tests is, according to different authors, from 5 to 20%.

Main Causes of False Positive Nontreponemal Tests

The most common cause of biological false-positive non-treponemal tests is antiphospholipid syndrome (Hughes syndrome) - an autoimmune process that is most common in collagenoses (connective tissue diseases) - systemic lupus erythematosus (2.7% - 3.5%), dermatomyositis, scleroderma.

Among other reasons, the most common
Oncological diseases (for example, lymphoma up to 10%)
Tuberculosis, especially extrapulmonary forms (up to 3%)
Enteroviral infections
Infectious mononucleosis
Viral hepatitis
Lyme disease (borreliosis)
pneumonia
Alcoholism and drug addiction
Some skin diseases (for example, with psoriasis up to 1.1%)
Recently (up to 2-3 weeks) vaccination
Infections - malaria, chicken pox, measles
Endo and myocarditis
Diabetes mellitus (especially against the background of parenteral insulin compensation)
Gout
Age over 70 years.

What are false-positive seroreactions for syphilis in pregnant women

One of the common causes of false-positive tests for syphilis is pregnancy. The frequency of false-positive reactions during non-treponemal tests in pregnant women, according to different authors, ranges from 0.72% to 1.5%. .Differential diagnosis with biologically false positive seroreactions in pregnant women is carried out in the following cases:

• With conflicting, often weakly positive results of serological reactions
• With isolated positivity of one test among negative others
• With fluctuations in test results in repeated studies
• In the absence of anamnestic indications of syphilis in a pregnant woman and any objective signs of syphilis in sexual partners

What are false negative reactions to syphilis

False-negative (false-negative) results occur at high antibody concentrations, which inhibit agglutination (the prozone effect), which can be avoided with serial dilutions of serum. The average rate of false-negative non-treponemal tests (VDRL) in secondary syphilis is about 1%.
False-negative results of non-treponemal tests must be distinguished from negative non-treponemal tests at various periods of the course of syphilis, when the body has not yet developed antibodies or when the amount of antibodies is significantly reduced due to a decrease in the amount of lipid antigen.

The frequency of negative non-treponemal tests in different periods of syphilis

Where can I get more information

This study is necessary in order to confirm the presence or absence of a disease such as syphilis in a person.

Wasserman reaction, what is it?

Blood test for the Wasserman reaction is based on the ability of treponema, which is the causative agent of syphilis, to produce cardiolipin antigen. In response to its appearance in the blood, the human immune system produces antibodies that bind to this antigen and form a strong complex.

If antibodies are not formed in the blood, then cardiolipin binds to red blood cells and causes their destruction - hemolysis.

The evaluation criteria are blood test titers for the Wasserman reaction. Simply put, titer is a way of expressing the concentration of antibodies and antigens at which there is a significant or complete delay in hemolysis. If there is syphilis, then the titer begins to increase around the fourth week after infection and reaches its maximum in the secondary period of the disease.

But in the tertiary, on the contrary, it decreases.

You can talk about the presence of the disease if the antibody titers in the analysis are in the range from 1:2 to 1:800. In this case, the maximum dilution rate is important, at which a sharply positive reaction is still preserved.

Why donate blood for the Wasserman reaction?

The study can be carried out not only if syphilis is suspected. Mandatory handover blood for the Wasserman reaction during pregnancy. And three times: when they are registered, for a period of thirty weeks and before childbirth.

This study is also assigned to:

• On admission to the hospital and before surgery.
• When applying for a job, for example, in cafes, restaurants, children's institutions or shops.
• Donors who donate sperm or blood.
• If other diseases that are sexually transmitted are detected, for example, chlamydia or trichomoniasis.
• With pain in the joints, the appearance of painless sores, prolonged, more than one month, fever and with an increase in regional lymph nodes.

A blood test for the Wasserman reaction, how to take it?

This analysis does not require any special preparations from you. However, in order to minimize the risk of erroneous results, it is better to follow simple rules.

If you are to donate blood for the Wasserman reaction, then:

• Stop taking medication three days before the test.
• If this is not possible, be sure to tell your doctor what medications you are taking.
• For 12 hours, give up coffee, strong tea and alcohol.
• Refrain from eating 8 hours before the test. Better blood for the Wasserman reaction hand over on an empty stomach, since fatty, protein foods can distort the results.
• Avoid cigarettes at least one hour before visiting the laboratory. Be sure to tell your doctor if you have any chronic conditions, such as diabetes.

If you are planning to submit blood test for Wasserman reaction, then price will be determined by which region and institution you choose to do so. In public clinics, this can be done for free. In private, the cost can range from 300 to 1000 rubles.

What might be the results of the study?

Normally, a blood test should give a negative result, which means that there is no syphilis.

A person has to take an analysis for the determination of syphilis almost most often: hiring, medical examinations, preventive examinations, pregnancy. These studies are necessary - they allow you to identify the disease in the early stages, when the treatment will be most effective.

The resulting positive result often confuses a person, especially in the absence of any reasons. The detection of false-positive syphilis is a fairly common occurrence, and therefore you should not panic ahead of time. According to information from various sources, up to 30% of primary studies may give an incorrect result. There are a lot of reasons for this phenomenon: a change in the state of the body, somatic diseases. To better understand why there are false data, it is worth taking a closer look at the issue of conducting a study.

Types of tests for syphilis

Clinical research methods are rapidly improving every year. With the development of new diagnostic methods, a false positive reaction to syphilis is becoming less common. If necessary, diagnostics can include several different methods - this allows you to get the most reliable result.

Non-treponemal research methods

These techniques are aimed at identifying proteins that are formed as a result of the activity of the pale spirochete. They are aimed at determining the "traces" of the pathogen. Such methods have a relatively high percentage of error (up to 10%). Such techniques are non-specific, but allow the degree of infection to be determined by the antibody titer.

Wasserman reaction RW

The most common test that is performed to detect pale treponema is a serological blood test. The Wasserman reaction allows you to determine the presence of the disease in just a few minutes. Therefore, this technique is used in laboratories most often - it does not require much time and has a relatively low cost.

To perform the analysis, cerebrospinal fluid or blood is used. The test material can be taken from a finger (if there is only one analysis) or from a vein (if several studies are required). When conducting an analysis, there can be not only a false positive, but also a false negative result. It is possible under the following circumstances:

• the early stage of infection, when the number of treponema in the body is still low;
• chronic disease in the stage of remission, when the number of antibodies decreases.

Note! A false negative result is extremely rare, and therefore, if there is at least one plus out of four, an additional examination is necessary.

Recipitation microreaction (MR)

This research technique is based on the antigen-antibody reaction. It requires a small amount of material to complete. It is aimed at identifying antilipid antibodies that are produced in the process of destruction of treponema cells. For research, both the patient's blood and cerebrospinal fluid are used.

Since cell destruction can occur not only with syphilis, the analysis is used as a screening test, not a confirmatory one. There are two versions of this technique:

• Microscopic test (VDRL). To perform the analysis, inactivated blood serum is used. If the nervous system is suspected to be affected by syphilis, cerebrospinal fluid is used as the test material.
• Macroscopic test (RPR). It is considered a method of express diagnostics. A visual calculation of plasma reagins is used.

This reaction, if the necessary sterility is not observed, may show a false positive result. The appearance of such an analysis is also possible with non-specific tissue damage, which entails the destruction of lipids. If there is a positive result, a mandatory treponemal test is recommended for confirmation.

Treponemal research methods

This category of analyzes provides the most accurate data, and there are rarely false positive results. Research is aimed at identifying specific proteins that are secreted by the body in response to infection. These methods have a higher cost, and therefore are used as confirming, rather than qualifying.

Specific antibodies begin to be produced by the body only a few weeks after infection with treponema. They can persist for a long period after the disease has been cured. Therefore, specific tests may show positive results for a long time after remission.

Note! With a positive RW-analysis and a negative treponemal test, a second study is performed after a few weeks.

ELISA (ELISA, EIA)

Based on the assessment of the level of immunoglobulins of the IgA, IgB and IgM classes. The first two types of proteins are produced in the body from the 2nd week of infection, and IgM - a month after infection.

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The interpretation of the analysis is based on the ratio of the presence of immunoglobulins:

• only IgA was detected - no more than 14 days have passed since the infection;
• IgA and IgB detected - infection occurred 14 to 28 days ago;
• all three types were found - syphilis in the body for more than 28 days;
• found only IgM - late syphilis.

The presence of IgM may be a sign of already cured syphilis - the synthesis of IgM immunoglobulins may continue for several months after remission.

Immunofluorescence reaction (RIF, FTA)

Used to confirm infection at the earliest stages. For research, blood is taken from a finger or a vein. The result is similar to the RW analysis, where a minus is indicated, or from 1 to 4 pluses. If there is at least one plus, an additional study may be prescribed.

False-positive results are extremely rare when performing RIF - they can be in pregnant women, as well as in patients with connective tissue diseases.

Passive agglutination reaction (TPHA, TPHA)

The antibody titer allows you to determine the presence of syphilis and its stage. This technique gives reliable data from the 28th day after infection. For evaluation, blood from a finger or vein is used. An increase in the number of antibodies means a later stage of the disease.

The most accurate research methods

The analyzes of this group are highly sensitive, and therefore the error in their results is extremely low. They are distinguished by a higher cost, in comparison with other methods, and a more complex technique.

Polymerase chain reaction (PCR)

PCR analysis is considered one of the most accurate. It aims to identify sections of pathogenic DNA in the human body. The method requires the availability of specialized equipment and reagents, and therefore is used in rare cases.

Immunoblotting

Combined research method. Aimed at the determination of immunoglobulins in the patient's blood serum. The analysis checks for the presence of a complex of antibodies, according to which the diagnosis is established. This technique uses electrophoresis, which separates immunodeterminants, and an ELISA reaction, which shows separated dots.

Treponema pallidum immobilization reaction (RIBT)

Highly specific analysis that determines the reaction of blood serum to pale treponema. It is widely used all over the world because it has a high probability of an accurate result. Special antibodies (immunomobilizins) in a patient with syphilis are able to immobilize treponema. There are no such antibodies in the blood of a healthy person. It is on the presence / absence of this ability that the research methodology is based.

RIBT is used to identify those varieties of syphilis in which the Wasserman reaction gives negative results - damage to the nervous system, internal organs, and a latent form of the disease. A false positive result in the CIS countries is extremely rare. The cause of its appearance may be sarcoidosis, leprosy.

Reasons for false positive results

The Wasserman reaction can determine "acute" and "chronic" false positive results. Its severity depends on the nature of the changes in the person's condition. RW can show the stage of exacerbation in such cases:

• infectious diseases in the acute stage;
• traumatic injuries;
• myocardial infarction;
• the introduction of any vaccine a few days before the test;
• food poisoning.

These conditions are characterized by an increased work of the immune system, which leads to an increased production of antibodies. They are mistakenly recognized in the reaction as antibodies to treponema, and therefore a positive result occurs.

In the presence of pathologies of a chronic nature, the immune system produces a large number of non-specific antibodies that can cause a reaction. In RW, this condition may show a false positive result. Therefore, it is worth warning the doctor about the following diseases:

• chronic pathologies of connective tissues;
• tuberculosis;
• chronic diseases of viral etiology: HIV, hepatitis B, C, D;
• chronic liver diseases;
• autoimmune pathologies.

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With age, redox reactions slow down in the patient's body. Tissue aging can also show a false positive result, and therefore more accurate research methods are prescribed for elderly patients.

Note! With a positive Wasserman reaction, an additional study is carried out, which allows you to get a more accurate picture, for example, enzyme immunoassay.

Recheck

A second test for syphilis is performed when the results of the screening study are questionable. It is assigned in the presence of one or two crosses - such an analysis requires additional verification. The study can give false positive results in several cases:

• Early stage of the disease. Before the appearance of hard chancre, the amount of immunoglobulins in the body is quite low.
• late stage of the disease. More than 2 years have passed since the infection, and the antibody titer gradually began to decline.

A re-analysis, which is carried out after 2-3 weeks, shows exactly whether there is a disease. If there is a positive result for the second time, additional clarifying methods are used.

Tests during pregnancy

One of the most unexpected may be a positive test result for syphilis in pregnant women, especially if the woman has not changed her partner. This situation often terrifies expectant mothers, since treponema can negatively affect the intrauterine development of the baby.

Screening during pregnancy is carried out several times:

• upon registration, at 12 weeks;
• the beginning of the 3rd trimester, at 30 weeks;
• before childbirth.

This is the amount of research that is considered the minimum. A false positive test for syphilis may occur due to the restructuring of the body that occurs during pregnancy. When a woman carries a child, her immune system produces a large number of antibodies - this is an evolutionary adaptation to protect the baby in the first year of life.

During pregnancy, an additional clarifying analysis is prescribed, which is characterized by greater accuracy. If a control study shows the presence of a pathogen in the body, treatment is mandatory. The effect of therapy on a growing organism is significantly less than the possible harm from treponema.

How to prepare for analysis?

One of the ways to prevent an incorrect result is to prepare for the test. Due to improper preparation, reactions may occur that are accompanied by the production of non-specific antibodies, which leads to an incorrect result.

• The analysis must be taken on an empty stomach. You can use only pure water.
• A day before blood sampling, it is worth completely eliminating alcohol - it creates an additional burden on the liver, which can lead to a positive result.
• It is recommended the day before to stop eating fatty and fried foods, spicy dishes and a lot of spices.
• At least 60 minutes before the analysis, it is recommended to refrain from smoking.
• Before taking blood from a vein, you need to rest for 10-15 minutes in the emergency room.
• Women are not recommended to donate blood during menstruation.
• It is impossible to carry out an analysis after an x-ray examination, physiotherapy procedures.
• It is forbidden to donate blood for syphilis during an exacerbation of infectious diseases.

Note! If the patient is taking any medication, he should consult a doctor before the study, it may be necessary to take a break of several days between taking the drugs and the analysis.

What to do if syphilis is confirmed?

There is no need to worry about getting a positive initial screening. False syphilis is easily determined by repeated examination. If, however, the diagnosis was confirmed, you need to take action:

• examination of the sexual partner by a dermatovenereologist;
• examination of close relatives;
• implementation of preventive treatment to prevent infection in loved ones;
• registration of a sick leave for the period of treatment - the sick leave does not contain information about the diagnosis, guaranteeing confidentiality;
• at the end of the course of treatment, a special certificate is issued - you need to have it with you in order to avoid questions about false positive results in the next few months.

A positive result for syphilis is not always reliable. Therefore, do not worry and it is recommended to wait for additional research. Proper treatment, which was started on time, guarantees a quick recovery with a minimum of residual effects.

Higher medical education, venereologist, candidate of medical sciences.