Infectious pathology, provoked by pale treponema, affecting most of the organs and systems of the individual's body, is called syphilis. A study on syphilis RPR is considered the main one for diagnosing the disease. Thanks to this test, nonspecific antibodies of class M and G immunoglobulins are detected. This analysis is recommended not only for monitoring the treatment of syphilis patients, but also for the initial detection of infected individuals.
Briefly about syphilis
This is a chronic infectious disease in which organs and systems of the body are affected. The causative agent of the disease survives well in biological environments - sperm, mucus, pus, and vaginal secretions. There are several ways of contracting this sexually transmitted disease:
- sexual;
- parenteral;
- domestic;
- transplacental.
After infection, two types of antibodies are synthesized in the body:
- Specific, or anti-treponemal, they are directed against the treponema itself.
- Nonspecific, or anticardiolipin, act against cellular components, which, being affected by the pathogen, are destroyed, as well as against body lipids that enter the bloodstream after cell death in a natural way. A study on syphilis RPR just reveals non-specific antibodies to lipid components.
The pathogen contains antigens to which the individual's immune system synthesizes antibodies. One of the antigens is similar to cardiolipin, due to which it is used to detect an immune response to treponema.
The incubation period averages 21 days. Syphilis is distinguished:
- Primary - from the moment of the appearance of hard chancre (sores appear at the site of the introduction of bacteria, they disappear on their own after two to six weeks) and until a rash forms. There is an increase in lymph nodes. During this period, antibodies have not yet been developed and cannot be detected in the blood.
- Secondary - symptoms such as general malaise, fever, headache, rash, come to light a month or two after the formation of ulcers. Soon the signs of the disease disappear, and the disease goes into a latent stage. Low immunity provokes relapses, since the pathogen does not disappear from the body. The clinical picture in this case is similar to secondary syphilis.
- Tertiary - occurs in the absence of therapy for a long period. The organs and systems of the body are affected.
The diagnosis is confirmed by laboratory diagnostics.
Study Overview
For the diagnosis of syphilis, two groups of tests are used - treponemal and nontreponemal. The latter include a study on syphilis RPR. The test is simple in setting up the reaction, the answer is ready in a short period of time. Sensitivity depends on the stage of the disease and amounts to syphilis:
- late - 73%;
- secondary - 100%;
- primary - 86%;
- hidden - 98%.
Among the advantages of this test are:
- quick response;
- high sensitivity among all other nontreponemal tests for late, primary and latent disease;
- the possibility of use in mass screenings;
- low price analysis;
- the availability of ready-made kits for research;
- high compatibility with treponemal tests.
The Ministry of Health of the Russian Federation recommends this analysis to monitor the treatment process and as a primary screening.
A positive reaction is observed after three to five weeks after infection or seven to ten days after the appearance of ulcers. In the secondary stage of the disease, titers are reduced. A decrease in titer of four or more times during the year indicates the effectiveness of the therapy.
Nontreponemal tests
Using them, antibodies are detected against a lipid entering the membrane of bacteria and mitochondria. They appear in the body of an individual a week after the formation of a solid chancre. The sensitivity of nontreponemal tests is high with primary and secondary syphilis, that is, if a person is infected, the result will be positive. However, false-positive results are not excluded, since antibodies against lipid are also formed in other pathological conditions. A feature of nontreponemal tests is the appearance of antibodies in the acute period of the disease. Thus, during recovery, their number decreases, which indicates the quality of treatment.
Microreaction of precipitation for syphilis
This study is based on the immunological reaction "antigen - antibody." The microreaction to syphilis RPR is a nontreponemal test, thanks to which reagin antibodies are detected in the blood, which are produced by the body of the individual against lipids of defective cells as a result of their damage by the spirochete, as well as lipoprotein proteins of the bacterial skin.
Due to the fact that antilipid antibodies are synthesized in other pathologies accompanied by tissue destruction, the precipitation microreaction is referred to as screening tests. A small amount of reagents and biomaterial (blood, cerebrospinal fluid) is required for the study, which is why it is called "microreaction".
Errors in the formulation of precipitation microreaction
Errors made during the study on syphilis RPR lead to false positive and false negative results:
- The presence of microorganisms in the emulsion.
- Use of disubstituted sodium citrate (disodium citrate) instead of trisodium citrate.
- Failure to comply with the conditions and shelf life of antigen, solutions, emulsion, biomaterial.
- Poor agitation, which leads to an uneven concentration of antigen in the emulsion.
- Violation of technology for taking blood from a finger.
- The use of dirty tubes, solutions, plates, pipettes.
Syphilis test
Using a laboratory blood test for syphilis (RPR, RW), antibodies to the causative agent of the infection, i.e., pale treponema, are detected.
This study is being conducted during a mass examination of some population groups for syphilis. In addition, analysis is shown:
- all individuals before surgery;
- persons with a partner with a diagnosed disease, and in the event of household contact with a patient with secondary syphilis;
- individuals with a confirmed diagnosis of another genital infection;
- babies born from matter suffering from syphilis;
- persons with clinical symptoms of syphilis;
- in order to confirm the screening results;
- women expecting a baby;
- to donors;
- persons who have illegible sexual intercourse;
- with pain in the bones;
- with abundant discharge from the genitals and the appearance of ulcerative lesions on the genitals, a rash on the dermis and mucous membrane, as well as with an increase in lymph nodes.
Syphilis RPR (Anticardiolipin Test)
The anticardiolipin test is one of the Wassermann reaction variants, more precisely, a more modern analysis, with the help of which immunoglobulins G and M are detected to phospholipids emerging from cells affected by the pathogen. It refers to non-specific tests, and false-positive results are possible, since antibodies to phospholipids are also detected in other diseases of an infectious and autoimmune nature. Recommend this study:
- when examining donors;
- diagnosis of latent syphilis;
- suspected disease.
Anticardiolipin bodies are detected in approximately eighty percent of individuals with primary and in one hundred percent with secondary syphilis. A positive test for syphilis RPR is recorded seven days after the occurrence of hard chancre, i.e., about a month after infection.
Study preparation
Special preparation for the analysis is not required. Biomaterial is delivered in the morning on an empty stomach. Twelve hours before going to the laboratory, coffee, tea, alcohol-containing drinks, as well as meals should be excluded. Allowed to drink plain water. The day before exclude the intake of fatty foods. Sixty minutes before delivery of the biomaterial, smoking is contraindicated. On the day of delivery of the analysis, it is undesirable to perform the following manipulations:
- fluorographic or radiological examination;
- Ultrasound
- physiotherapeutic procedures.
Deciphering the results
A negative RPR for syphilis means:
- No infection, no syphilis.
- Early primary and late tertiary syphilis is not excluded. If less than three weeks have passed since the introduction of the pathogen, then antibodies against cardiolopin may not be detected. For control, it is recommended to repeat the test after two weeks. After the secondary stage, the number of antibodies decreases and in some patients the result will be negative.
A positive result is to say the following:
- the first year after the disease has been cured;
- seropositive primary, secondary and tertiary syphilis.
Upon receipt of a positive response, the individual needs additional examination by a venereologist.
Due to the fact that the test is nonspecific, the probability of false positive results remains. Most often this occurs in the following conditions:
- pneumonia;
- diabetes mellitus;
- hepatitis of viral nature;
- tuberculosis;
- alcoholism;
- pregnancy;
- after vaccination;
- oncology;
- addiction.
Doctors evaluate syphilis therapy as effective, provided that the number of non-specific antibodies in the blood of an individual decreases by four times within twelve months. After complete completion of the course treatment, a blood test for syphilis RPR gives a negative result in ninety percent of patients.
Conclusion
A blood test makes it possible to detect antibodies to the causative agent of a sexually transmitted disease, that is, pale treponema. An analysis is made not only of individuals who prefer an active sex life, but also patients before surgery, expectant mothers and some other categories of citizens. For the reliability of the picture, doctors recommend preparing for the test.
A test for syphilis RPR is not conducted to diagnose the disease, and this should be remembered. Confirm the disease with treponemal tests. The final diagnosis is made only by the doctor.