What does a blood test for RW show? How to take a blood test for the Wasserman reaction - test indications, preparation and interpretation of the results What does the Wasserman reaction test mean?

Syphilis is the name of a sexually transmitted disease that develops as a result of the penetration of a pathogen into the human body - the bacterium Treponema pallidum (treponema pallidum). In order to avoid serious consequences and begin treatment in a timely manner, it is necessary to recognize the disease as early as possible; this can be done by performing a blood test for RW.
Content

A blood test for syphilis is carried out to determine the presence in the patient’s blood of antibodies to the causative agent of syphilis or Treponema pallidum, as well as decay products of damaged cells.
It is important to remember what the blood test for syphilis is called - RW.

The Wasserman reaction is one of the most well-known methods used in diagnosing this disease; to carry it out, venous blood is taken from the suspected patient.
Diagnosing syphilis is quite difficult, since due to the characteristics of the disease, its presence can only be determined during certain periods.

This can be done from 3 to 5 weeks after infection, and from 7 to 10 days after the first signs of chancroid appear. If the results make it clear that there are an order of magnitude less antibodies, this may be a sign of secondary syphilis. As strange as it may sound, at a later stage a negative result may appear.

Reasons for appointment

When are blood tests prescribed for RW?

in case of planning a pregnancy and contacting an antenatal clinic (registration);
if inpatient treatment or diagnostic or therapeutic procedures are required;
conducting an annual survey;
if you suspect a sexually transmitted disease;
when donating blood;
to monitor the effectiveness of drugs used during the treatment of syphilis;
during casual sexual intercourse;
it is recommended to do a blood test for syphilis for varicose veins, lupus erythematosus and many other diseases;
people in prison.

Preparing for analysis

It is recommended to do a blood test for syphilis on an empty stomach, that is, not eat for at least 8-12 hours before the procedure.
Drinking tea, coffee, and alcohol is prohibited; drinking plain water is allowed.
The day before, you should refrain from eating fatty foods.

Positive reaction

If the presence of the causative agent of syphilis or its waste products is determined in a person’s blood, this means the presence of the disease. In this case, additional research methods are indicated.

The causative agent of syphilis is Treponema pallidum.

Negative reaction

If during the analysis the Wasserman RW reaction is negative, then there is no disease. However, in some cases the analysis may need to be repeated.

False positive reaction

The Wasserman reaction can be positive even in the absence of disease in the following cases:

within a year after cure of syphilis;
in the period after suffering serious illnesses: malaria, pneumonia, smallpox, typhus, etc.;
pregnancy period;
alcoholism and drug addiction;
presence of cancer;
viral hepatitis;
if the procedure is carried out incorrectly;
improper preparation of the patient.

Interpretation of the result

How to interpret the results of analysis on RW?

"-" negative reaction.
“+”, “++” weakly positive reaction.
“+++” positive reaction.
“++++” is a strongly positive reaction.

If the Wasserman reaction is positive, a person should immediately consult a venereologist to prescribe further research, and if the disease is confirmed, prescribe adequate treatment and observation.

Referral form for blood test Wasserman reaction

After all, with timely treatment, there is a greater chance of complete relief from the disease and prevents its transition to a chronic form. Moreover, a disease such as syphilis does not go away without a trace, it can cause serious consequences and threaten a person’s life.

RW positive

What tests are prescribed after RW + (positive)? If the result of a blood test for syphilis is positive, do not get upset ahead of time, as this does not always accurately indicate the presence of the disease. In order to confirm or refute the presence of a terrible diagnosis, it is necessary to undergo a number of additional studies.

We know that RW is a nonspecific test, that is, when it is carried out, it does not determine the presence of the bacterium itself, but only signs of its vital activity are visible, and this gives rise to the possibility of errors during diagnosis.

The final diagnosis of syphilis can only be made after three different tests: one nonspecific and two specific (treponemal) tests, which determine the presence of the pathogen.

Nowadays, blood can be tested for syphilis in almost any clinic or medical center. Due to the fact that the incidence of syphilis in the country ranks first among STDs, great assistance is provided in the diagnosis and prevention of this disease.

Preventive measures

But, despite all the measures taken by our medicine, this does not stop the spread of the disease completely, so every reasonable person must take care of his own health.

avoid casual sex;
eliminate the use of alcohol and drugs;
using a condom;
in case of unexpected contact, within two hours it is necessary to use an antiseptic, for example miramistin or cidipol. If more than 6 hours have passed, all measures will be in vain.

To prevent infection, you must adhere to several of the above rules. “Many diseases are much easier to prevent than to treat.” This statement, like nothing else, fits the disease - syphilis.

The Wassermann test (RW) is the most popular immunological test used to diagnose syphilis since its discovery in 1906. RW belongs to the group of complement fixation reactions (FFR) and is based on the ability of the blood serum of a syphilis patient to form a complex with the corresponding antigens. Modern RSC methods used to diagnose syphilis differ significantly in their antigens from the classical Wassermann reaction, however, the term “Wassermann reaction” is traditionally retained for them.

Antibodies produced by the immune system appear in the blood of an infected person. The causative agent of the disease, Treponema pallidum, contains the antigen cardiolipin, which causes the production of antibodies detected by RW. A positive Wasserman reaction indicates the presence of such antibodies in a person’s blood, and on this basis a conclusion is made about the presence of the disease.

The hemolysis reaction is an indicator of the result of the study in the RSC. The reaction involves two components: sheep red blood cells and hemolytic serum. Hemolytic serum is obtained by immunizing a rabbit with sheep red blood cells. It is inactivated for 30 minutes at a temperature of 56°C. The results of RSC are evaluated depending on the presence or absence of hemolysis in the test tubes. The presence of hemolysis is explained by the fact that if there are no syphilitic antibodies in the test serum, then the antigen-antibody reaction does not occur, and all the complement goes to the sheep erythrocyte-hemolysin reaction. And if there are specific antibodies, the complement is completely spent on the antigen-antibody reaction and hemolysis does not occur.

All ingredients for the Wasserman reaction are taken in the same volume - 0.5 or 0.25 ml. For strong fixation of complement on a specific complex, a mixture of the test serum, antigen and complement is placed in a thermostat at a temperature of 37° for 45-60 minutes. (phase I reaction), after which a hemolytic system consisting of sheep erythrocytes and hemolytic serum is added (phase II reaction). Next, the tubes are again placed in a thermostat for 30-60 minutes until hemolysis occurs in the control, in which the antigen is replaced with physiological solution, and instead of the test serum, physiological solution is added. Antigens for the Wasserman reaction are produced in finished form, indicating the titer and dilution method.

The maximum positivity of the Wasserman reaction is usually indicated by the number of crosses: ++++ (strongly positive reaction) - indicates a complete delay in hemolysis; +++ (positive reaction) - corresponds to a significant delay in hemolysis, ++ (weakly positive reaction) - evidence of a partial delay in hemolysis, + (doubtful reaction) - corresponds to a slight delay in hemolysis. Negative RW is characterized by complete hemolysis in all test tubes.

However, sometimes false positive results are possible - this is due to the fact that cardiolipin is also found in some quantities in the cells of the human body. The human immune system does not create antibodies against its “own” cardiolipin, but there are exceptions to this rule, due to which a positive Wasserman reaction occurs in a completely healthy person. This is especially often observed after severe viral and other diseases - pneumonia, malaria, liver and blood diseases, during pregnancy, i.e. in moments of severe weakening of the immune system.

If a doctor suspects a patient has a false positive result for the Wasserman reaction, he can prescribe a number of additional tests that are usually used in diagnosing sexually transmitted diseases.

Diseases and cases in which a doctor may prescribe a blood test for RW

Carrying out the procedure for taking a blood test for RW

Blood for RW is donated only on an empty stomach. The last meal should be no later than 6 hours before the test. The medical worker sits the patient down or places him on the couch and takes 8-10 ml of blood from the cubital vein.

If an analysis needs to be done on an infant, the sample is taken from the cranial or jugular vein.

Preparing for a blood test for RW

You should stop drinking alcohol 1-2 days before the test. It is also not recommended to eat fatty foods - they can distort the result. During the period of preparation for the analysis, you should refrain from taking digitalis medications.

Contraindications

The analysis result will be false if:

the person is sick with an infectious disease or has just recovered from it,
a woman is menstruating,
pregnant in the last weeks before giving birth,
the first 10 days after birth,
the first 10 days of a baby's life.

With primary syphilis, the Wasserman reaction becomes positive at 6-8 weeks of the disease (in 90% of cases), and the following dynamics are noted:

in the first 15-17 days after infection, the reaction in most patients is usually negative;
at the 5-6th week of the disease, in approximately 1/4 of the patients the reaction becomes positive;
at the 7-8th week of the disease, RW becomes positive in the majority.

In secondary syphilis, RW is always positive. Together with other serological reactions (RPGA, ELISA, RIF), it allows not only to detect the presence of the pathogen, but also to find out the approximate duration of infection.

With the development of a syphilitic infection in the 4th week of the disease, after the onset of primary syphiloma, the Wasserman reaction passes from negative to positive, remaining so both in the secondary fresh and in the secondary recurrent period of syphilis. In the latent secondary period and without treatment, RW can turn negative so that when a clinical relapse of syphilis occurs, it becomes positive again. Therefore, in the latent period of syphilis, a negative Wasserman reaction does not indicate its absence or cure, but only serves as a favorable prognostic symptom.

With active lesions of the tertiary period of syphilis, positive RW occurs in approximately 3/4 of cases of the disease. When the active manifestations of the tertiary period of syphilis disappear, it often turns negative. In this case, a negative Wasserman reaction in patients does not indicate that they do not have a syphilitic infection.

In early congenital syphilis, RW is positive in almost all cases and is a valuable method for verifying the disease. In late congenital syphilis, its results correspond to those obtained in the tertiary period of acquired syphilis.

The study of the Wasserman reaction in the blood of patients with syphilis undergoing treatment is of great practical importance. In some patients, despite vigorous anti-syphilitic therapy, the Wasserman reaction does not turn negative - this is the so-called seroresistant syphilis. In this case, it makes no sense to carry out endless antisyphilitic therapy, achieving the transition of positive RW to negative.

From the above it follows that a negative Wasserman reaction is not always a sign of the absence of a syphilitic infection in the body.

A positive Wasserman reaction is possible in people with a number of other diseases and conditions not related to syphilis:

All of the above indicates that a positive result of the Wasserman reaction is not yet unconditional evidence of the presence of a syphilitic infection.

Recovery after testing

After taking a blood test, doctors recommend a proper and balanced diet, as well as plenty of fluids. You can afford warm tea and chocolate. It will be useful to refrain from physical activity and under no circumstances drink alcohol.

Norms

Normally, hemolysis should be observed in the blood - this is considered a negative reaction to syphilis (Wassermann reaction is negative). If hemolysis is absent, the degree of reaction is assessed, which depends on the stage of the disease (marked with “+” signs). However, you should be aware that in 3-5% of completely healthy people the reaction may be false positive. At the same time, in the first 15-17 days after infection, the reaction in sick people may be false negative.

The Wasserman reaction is the basis for diagnosing a disease such as syphilis. The classic version of this study has not been used in the Russian Federation since the 1980s, but the laid foundation is used in analogues.

Syphilis is a disease of infectious etiology that is caused by Treponema pallidum (treponema pallidum). Infection with syphilis occurs predominantly through sexual contact; vertical transmission of infection is also possible (during childbirth from an infected mother to a child).

The course of the disease is characterized by constant progression, the presence of relapses, the frequency of clinical symptoms and the ability to affect all organs and systems of the body.

To diagnose syphilis, special tests are used:

non-treponemal (precipitation microreaction (RPR - anticardiolipin test), Wasserman reaction, microscopic VDRL test, syphilis AgCL and others),
treponemal (ELISA, RIF, RPHA, treponemal immobilization reaction, immunoblotting, etc.).

The most “classical” test is the Wasserman reaction.

For reference. The Wasserman reaction is an immunological method for diagnosing syphilis, based on the complement fixation reaction.

The essence of RW is that the blood of a patient with syphilis, when a special aggressor protein is added to it, is capable of forming complexes with it that absorb complement, which will precipitate.

How is a Wasserman blood test performed?

That is, an artificial analogue of treponema (cardiolipin antigen) and a special binding protein (compliment) are added to the patient’s blood serum. If antibodies (specific protective proteins) to Treponema pallidum are present in the blood, then the binding of cardiolipin antigen and these antibodies occurs with the participation of complement. The resulting compound precipitates, assessed as ++++.

Normally, hemolysis of red blood cells occurs in the serum of healthy people. That is, there are no antibodies in the blood with which the cardiolipin antigen can react, and, therefore, the adsorption and complement fixation reaction does not occur in the serum. Free complement is involved in hemolysis, the appearance of which is assessed as a negative Wassermann reaction, that is, “-“.

The blood test for the Wasserman reaction has five answer options:

– (indicates that complete hemolysis of red blood cells has occurred in the serum, which means the test for syphilis is negative);
+ (such an answer is interpreted as doubtful, one + evaluates a mild delay in hemolysis);
++ (observed with partial delay of hemolysis and is regarded as a weakly positive Wasserman reaction);
+++ (this result is regarded as a positive RW, indicating a significant delay in hemolysis);
++++ (sharply positive RW, complete absence of hemolysis and precipitation indicates the patient has syphilis or other diseases that caused a false positive RW).

The first response indicates a negative RW and does not require further investigation. When obtaining other results, it should be borne in mind that the Wasserman reaction is not highly accurate and specific.

Attention. When performing a blood test for the Wasserman reaction, false positive results are quite often observed.

In this regard, when receiving questionable, weakly positive and strongly positive Wasserman reactions, treponemal tests are performed to clarify the diagnosis.

False-positive results may be associated with consumption of fatty foods, alcoholic beverages, pregnancy, menstruation, malaria, systemic lupus erythematosus, etc.

Modern understanding of the Wasserman reaction

In modern laboratories, the “classical” Wasserman reaction is considered obsolete and is not used. However, RW is still often written on the answer sheet and assignment form.

Currently, this term refers to modified modern RW.

The most common analogue of the Wassermann reaction is the RPR (nonspecific antiphospholipid test). It is also a non-treponemal test (that is, it does not have high specificity), but is more sensitive and has a lower risk of false-positive results than the classic Wasserman test.

The RPR test is a screening test that detects antibodies (IgG and IgM) to cardiolipin.

To carry out the analysis, as well as for the classic Wassermann reaction, venous blood is used.

It is advisable to take the analysis on an empty stomach. Smoking should be avoided one hour before blood collection. Although the risk of false-positive results with RPR is lower than with RW, ideally, it is preferable not to consume alcoholic beverages or fatty foods on the eve of the test.

Where to donate blood and how much does the examination cost?

For reference. The estimated cost of RРР ranges from 330 to 400 rubles and depends on the laboratory where the tests are performed.

Also, a specific treponemal test (RPGA or IgG/IgM ELISA for syphilis) can be used. This test detects specific antibodies in the blood exclusively to Treponema pallidum, and therefore can be used to clarify the results after non-treponema tests. Its cost ranges from 320 to 380 rubles.

Indications for the study

Positive RPR can be detected within seven to ten days after the patient develops primary syphilitic chancre or three to five weeks after infection.

The Wasserman reaction has a sensitivity of 70 to 80% for the diagnosis of primary syphilis and almost one hundred percent sensitivity for early latent and secondary syphilis.

After the onset of the secondary stage, titers begin to decrease. It should be borne in mind that about thirty percent of late syphilis may be false negative by RPR.

Therefore, conducting treponemal tests in order to clarify the diagnosis is mandatory.

However, the Wasserman reaction (RPR) can be effectively used to monitor ongoing treatment for syphilis.

The main indications for analysis are:

casual sex;
drug use;
contact with a patient with syphilis;
suspicion of syphilis (the most specific is the appearance of chancroid);
control of syphilis treatment;
pregnancy, donation, work in medical institutions (included in the list of standard examinations);
mental disorders and damage to the nervous system (neurosyphilis).

Also, children born from infected mothers are subject to mandatory examination.

Analysis during pregnancy

False-positive Wasserman reaction. Causes

Important. When conducting the initial examination, it should be taken into account that non-treponemal tests do not have specificity. This is due to the fact that antibodies to cardiolipin can appear not only during infection with syphilis.

Most often, a false-positive Wasserman reaction is detected in patients with:

DM (diabetes mellitus);
tuberculosis;
malignant neoplasms;
autoimmune pathologies (systemic damage to connective tissue);
viral hepatitis;
enterovirus infection;
severe pneumonia;
infectious mononucleosis;
scarlet fever;
malaria;
gout;
alcoholism;
(if syphilis has been previously excluded (using the treponemal test), RW can be used to confirm this syndrome);
eosinophilic infiltrate in the lungs.

Also, false-positive results are possible in children on the seventh to tenth day of life, pregnant women, patients after vaccination and carriers of non-syphilitic treponemas. In people taking narcotic drugs, the Wasserman reaction will also be false positive.

It should also be taken into account that with a very high titer of syphilitic antibodies, false negative results can be diagnosed.

In this regard, RW should be carried out in combination, using specific treponemal tests. Most often, ELISA or RPGA is used for Treponema pallidum IgG/IgM,

Positive Wasserman reaction

Positive RPR is observed in syphilis:

primary (if the infection occurred one to three months ago);
secondary (infection more than three months ago);
tertiary (infection more than three years ago).

Also, a positive response can be detected within a year after treatment and with the formation of seroresistance (also after treatment).

If a negative answer is received, early seronegative primary or late tertiary disease cannot be excluded.

Wasserman's diagnostic reaction has long occupied a separate place in medical science. Its inventor was the German physician August von Wasserman, the creator who developed this widely known study. This Wasserman reaction is aimed at diagnosing and treating the initial stage of syphilis, which is not so easy to determine using conventional research processes. Most patients still do not know about the existence of such a medical concept. In this article we will reveal what the Wasserman reaction is, and in what area of medicine is it used?!

What is the Wasserman reaction?

The beginning of the existence of the Wasserman reaction is considered to be 1906. It was during this period that this research was applied for the first time, and until today, it has been constantly improved. This concept relates to the field of venereology; it is these specialists who use it in their medical research. The Wasserman reaction is a list of laboratory processes that quickly and accurately diagnose syphilis and determine the causative agent of this disease - Treponema pallidum.

Let's consider the main factors that caused a positive assessment of the blood test for syphilis:

A blood test for rw makes it possible to fully confirm the presence of a disease such as syphilis in a patient;
Specific outcome measures not only confirm the presence of the disease, but also the effectiveness of its treatment;
A positive analysis gives doctors the opportunity to clearly establish not only the fact of infection, but also its exact time.

The practice of such diseases shows that the earlier the disease was diagnosed, the greater the chance of positive results during treatment. If the blood on RW showed positive dynamics, then the antibodies have already actively reacted, and this indicates the presence of syphilis. This disease can occur in patients who have suffered severe viral illnesses or pneumonia. This disrupts the normal functioning of the body, and the risk of syphilis increases.

Analysis process

In order for the results of the study to be accurate, experts recommend donating blood on an empty stomach. At least 7 hours must pass since the last meal, otherwise there can be no talk about the accuracy of the results. There are a number of circumstances when taking blood for analysis is strictly prohibited, namely:

When the patient experiences a significant increase in body temperature;
The presence of an infectious disease or its consequences;
During menstrual periods in women;
At the final stage of pregnancy, namely, two weeks before and after birth;
If the patient consumed alcoholic beverages or other psychotropic and narcotic drugs the day before blood sampling for analysis;
In infants in the first weeks of their life.

During the analysis, medical workers must adhere to all antiseptic rules that are regulated by the medical institution. Blood sampling in adult patients is taken from the ulnar vein, in an amount of 8-10 ml, no more. Babies have a completely different procedure. Using a special scalpel, an incision is made on the child's heel, from which the required amount of blood is taken. For children, the required blood volume is much less than for adults. Next, the collected blood should be placed in a special tube, with a temperature no higher than 3-4? C, and sent for laboratory testing within two days.

If tests are delivered later than the specified time, the effectiveness and reliability of the results may be affected and the procedure will have to be repeated.

Conducting laboratory testing also has a clear structure. First, I make a special serum from the collected blood. At a temperature of 37? C, the blood is placed in a thermostat for about 20 minutes. The resulting lump of blood is processed in a centrifuge until transparent bloody serum is formed, which is necessary for further research. If laboratory diagnostics reveal red blood cells in the serum, it is sent again to a centrifuge to separate them. The prepared blood should be stored in the refrigerator for a week.

To carry out the Wasserman reaction, three test tubes with already treated serum are used. Each of them is partially filled with blood and diluted 1:5 with additional components needed for the study. 0.25 ml of treponemal antigen is added to the first tube, the serum is mixed with 0.25 ml of cardiolipin in the second, and the third is filled with 0.25 ml of sodium chloride solution. After these procedures, complement is added to all three tubes in the same amount.

Important! Practice shows that it is impossible to mix all these components in advance; this will disrupt the imbalance and negatively affect the overall results.

The next procedure is the process of incubating the finished tubes with serum. They are placed in a thermostat for further heat treatment for about an hour. After the first incubation, 0.5 ml of hemolytic composition is added to each tube, and after that I place it in the thermostat again. The RW analysis is almost ready. Two additional tubes are used to establish the final results. The first is filled with blood that tests positive for syphilis, the second with the blood of a healthy person. The result is obtained by comparing the finished analyzes with the last two samples.

Evaluation of Wasserman reaction assays

It is worth noting that laboratory tests can either confirm the presence of the disease or show negative results. The severity of a disease in medicine is usually denoted by “+” signs. If there is one sign, the reaction can be considered weakly positive, but if studies show “++++” or “4+”, the reaction is considered strongly positive.

In medicine, there is also such a type of reaction as questionable; in practice, it is indicated by the “+/-” sign.

With such results, the test should be repeated to confirm or simplify the presence of syphilis. During the entire period of the Wasserman reaction, experts were convinced that infection with Treponema pallidum in the first 18 days may show unreliable results. For example, in 6% of completely healthy people, the reaction may show a false positive result, since 20% of infected patients have a false negative result. And only with time can an accurate diagnosis be determined. Over the course of 3-4 weeks, the disease progresses, and a false-negative reaction quickly develops into a positive one.

Treatment of this disease today gives quite positive results. But sometimes there are also hidden diseases, tests for which have shown the absence of the disease. And if in such cases doctors have any doubts, they conduct the study again.

After the first set of treatment procedures, a new blood sample is taken from the patient for reaction. Its positive dynamics indicate proper treatment and a speedy recovery. But there are cases when the treatment process still leads to a negative reaction. This syndrome is commonly called sero-resistant syphilis. Then specialists are looking for new, more effective treatment methods that will result in positive and favorable dynamics.

One of the important studies that is carried out during routine medical examinations, as well as during the registration of a pregnant woman, is a blood test for RW. Many patients do not know what it is needed for. This article will discuss what kind of analysis it is and when it is prescribed.

Wasserman reaction

An RW test is a serological blood test to determine the presence or absence of antibodies to Treponema pallidum, which is the causative agent of such a dangerous disease as syphilis. This pathogenic microorganism is also called a spirochete. It is resistant to environmental conditions and exists for up to four days outside the body.

If there is treponema in the patient's body, the immune system begins to produce antibodies. During this, red blood cells are destroyed. This is what this study defines.

This diagnostic method also makes it possible to assess how long ago the infection occurred and to identify the activity of the pathogenic microorganism.

The founder of the method is August Wasserman, which is why the name of this diagnostic is named after him. The test can be done at any medical institution.

When is the test ordered?

It is mandatory to donate blood for RV in the following cases:

during preventive medical examinations;
during pregnancy planning or while bearing a child;
if necessary, treatment in a hospital setting.

Diagnostics are also prescribed in preparation for surgery.

It is also important to do a timely test if a person has signs indicating a sexually transmitted disease.

Clinical manifestations of syphilis in adults include the following symptoms:

enlarged lymph nodes (particular attention should be paid to the inguinal lymph nodes);
specific discharge from the penis or vagina (with an unpleasant odor and color);
headache;
dizziness;
high body temperature;
profuse discharge from the genital tract;
bone tenderness and joint pain;
the appearance of rashes or ulcers on the skin and mucous membranes.

Experts recommend testing during casual unprotected sexual intercourse. This is explained by the fact that syphilis may not have clinical symptoms for a long time, so an infected person in the initial stages does not even suspect the disease.

Due to the fact that the disease has a latent period for a long time, it is necessary to donate biomaterial and carry out this method of blood testing:

persons working in the medical field;
catering or educational workers;
donors who donate blood, sperm or plasma;
patients with drug addiction;
HIV-infected;
persons suffering from alcohol addiction;
people who have had contact with patients suffering from syphilis.

During the latent period of pathology, those included in these groups pose a potential danger to others.

Preparing for the study

In order for the results to be accurate and reliable, it is important to know how to properly prepare for the study. To do this, doctors recommend adhering to the following rules:

Seven days before donating blood, it is important not to drink alcoholic beverages. Usually, if this recommendation is violated, the analysis shows a positive reaction.
Before submitting biological material, you are not allowed to drink very strong drinks (both coffee and tea).
A few hours before the test, stop smoking.
It is correct to donate blood on an empty stomach. Therefore, they take it early in the morning so that the interval between food intake and blood sampling is at least ten hours.
The day before diagnosis, experts do not recommend eating fried or fatty foods.
Before the study, it is necessary to exclude any psychological or physical stress.
A few days before the procedure, the patient should not take any medications. If this is not possible, then you should definitely warn a specialist about the use of medications.

It is not advisable to carry out the procedure after radiography, rectal examination, ultrasound diagnostics or physiotherapeutic manipulations. Otherwise, it is better to postpone the blood test to another day.

Execution technique

In this study, blood is collected in two ways:

from a vein;
from a finger.

In the first case, after disinfecting the skin on the elbow, a vein is pierced using a medical needle and syringe. Blood is drawn into a special tube with a specific reagent.

In the second option, the pad of the ring finger is carefully treated with an antiseptic solution and a puncture is made with an instrument called a scarifier. After this, the blood is drawn into a test tube using a special device, similar to a large pipette.

Experts say that venous blood testing is more informative and reliable..

The duration of the analysis ranges from five to fifteen minutes.

After drawing blood, a specialist, using reagents and specific markers of syphilis, determines the reaction and enters it into a form.

Decoding the result

When preparing the results of the study, the results can be of several options:

positive;
weakly positive;
negative;
false positive.

The interpretation of the results depends on the professionalism and experience of the specialist, the correct preparation for the diagnosis, as well as the presence of certain factors that may affect the outcome.

Positive result

If antibodies are detected that the human immune system produces against the causative agent of syphilis, the result is said to be positive.

A positive reaction signals syphilis of various forms and degrees of progression. Also, this result is determined within one year after treatment of this venereal disease.

This reaction is indicated by pluses in the form. The fewer advantages, the lower the likelihood of contracting the disease.

The results may be deciphered as follows:

a sharply positive result with four pluses;
positive reaction - three pluses;
a weakly positive result is indicated by two plus signs on the form;
only one plus indicates an uncertain reaction.

Thus, the more pluses, the more likely it is that the patient has syphilis. In the third and fourth options, a repeat blood test is necessary.

Negative result

If the analysis transcript shows a negative result, this indicates that the causative agent of the disease has not been detected. This means the absence of syphilis in the body.

However, in some cases, such a reaction may occur in the late tertiary form of the disease or indicate early primary syphilis.

Therefore, it is important to remember that the result may not be reliable if the patient is in the seronegative window stage, in which infection has already occurred, but antibodies have not yet been produced by the body.

False or weak positive result

In some cases, decoding may result in a false positive reaction, which indicates an unreliable result. The reasons for this option are:

oncological processes occurring in the body;
drug use;
alcohol abuse;
vaccination done the day before.

This reaction is observed in diseases of the respiratory system, liver or endocrine system, namely pneumonia, tuberculosis, hepatitis or diabetes mellitus.

It is also possible with arthritis of various origins and systemic connective tissue disease.

An inaccurate test result can be given by a vaccination that was given a few days before diagnosis.

This result is often determined in women during pregnancy..

A weakly positive reaction is found in rare cases. Typically, this phenomenon is possible when the patient is in the early stages of the disease.

Diagnosis during pregnancy

A blood test for syphilis should be done when planning a pregnancy. Women need to donate blood for analysis when carrying a child and when registering.

In addition, the study is carried out during pregnancy. This is because during this period the infected mother can infect the fetus.

Often women in this position may have a false positive reaction. If such a phenomenon is observed in the analysis transcript, then the procedure is repeated.

Thus, the RW test is an important diagnosis of syphilis. It allows you to determine the stage and form of this dangerous disease. Therefore, analysis is mandatory for people of certain categories.