The special serological test for Treponema TPHA is used for the laboratory diagnosis of syphilis.
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Syphilis is a systemic, infectious disease caused by the spirochete Treponema pallidum. The microorganism is transmitted mainly through direct sexual contact and also through the placenta from the mother to the fetus. If syphilis is not treated, infected individuals can develop irreversible complications such as chronic joint inflammation, cardiovascular problems such as valvular diseases, and central nervous system problems such as mental illness and paralysis.
The laboratory diagnosis of syphilis can be made through direct and indirect tests. Direct tests include scraping from the syphilis lesions and identifying the causative organism. In indirect tests, they determine antibodies against Treponema. These antibodies do not appear in the serum until 3 to 4 weeks after the appearance of the syphilitic ulcer, an ulcer located where the organism first enters the body.
Serological testing for syphilis includes the VDRL (Venereal Disease Research Laboratory), RPR (Rapid Plasma Reagin), TPHA (Treponema pallidum Haemagglutination Assay), and FTA-ABS (Fluorescent Treponemal antibodies-absorbed test) tests, as well as testing for IgM antibodies with enzyme immunoassay techniques (EIA). The VDRL and RPR are screening tests. Both of these tests have high false positive rates. Conditions that may cause false-positive results include vaccination in children, antinuclear antibodies, blood loss (with multiple transfusions), brucellosis, ulcerative colitis, chickenpox, cirrhosis, common cold, diabetes mellitus, fever, the first week of life, hepatitis (infectious), hypergammaglobulinemia, leprosy, leptospirosis (Weil's disease), Lyme disease, lymphogranuloma venereum, lymphoma, infection (chronic), malaria, measles, infectious mononucleosis, mycoplasma pneumonia, nonsyphilitic treponema diseases (bejel, pinta, yaws), periarteritis nodosa, pneumococcal pneumonia, pregnancy, rheumatic fever, rheumatoid arthritis, scarlet fever, scleroderma, aging, subacute bacterial endocarditis, systemic lupus erythematosus, tuberculosis (pulmonary advanced), trypanosomiasis, typhoid fever, vaccinia.
Because of the high false-positive rate, any positive VDRL or RPR test should be followed up with a confirmatory test, such as TPHA and FTA-ABS. These tests determine the specific antibodies against Treponema pallidum. The FTA-ABS test is the most sensitive test used to diagnose syphilis. This test will remain positive for life, even if the patient receives appropriate treatment.
Important Note
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. The correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings, and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
At Diagnostiki Athinon we answer any questions you may have about the test you perform in our laboratory and we contact your doctor to get the best possible medical care.
