SEROLOGY OF SYPHILIS Assist Prof Dr. Syed Yousaf Kazmi

SEROLOGY OF SYPHILIS OBJECTIVES Perform Rapid Plasma Reagin Test Understand the principle of screening test of syphilis Learn different conditions giving rise to false positive serology of screening test of syphilis Interpret results of screening test in different

SYPHILIS INTRODUCTION The name "syphilis" was coined by Italian physician and poet Girolamo Fracastoro in his Latin written poem “Syphilis sive morbus gallicus” ("Syphilis or The French Disease") in 1530 The genus name, Treponema, is derived from the Greek term for "turning thread“ One of the oldest disease known to mankind

SYPHILIS INTRODUCTION Genus Treponema include –Treponema pallidum subspp pallidum (syphilis) –Treponema pallidum subspp pertenue (yaws) –Treponema pallidum subspp endemicum (bejel) –Treponema carateum (pinta) All subspp are indistinguishable serologically from each other

SYPHILIS INTRODUCTION Highly contagious Penetrate unbroken skin/ through abrasions Never been cultured on artificial media/ tissue culture Only human host Organism survives 4 o C temp for 24 hours-important for blood transfusion

SYPHILIS INTRODUCTION A.ACQUIRED SYPHILIS  Primary syphilis  Secondary syphilis  Latent syphilis  Early latent  Late latent  Tertiary syphilis B.CONGENITAL SYPHILIS C.SYPHILIS RELATED DISEASE  Yaws, Pinta, Bejel Yaws

PRIMARY SYPHILIS IP: 9-90 days, usually ~21 days. Develops at site of contact/inoculation. Classically: single, painless, clean-based, indurated ulcer, with firm, raised borders Mostly ano-genital, but may occur at any site (tongue, pharynx, lips, fingers, nipples, etc...) Non-tender regional adenopathy Very infectious

SECONDARY SYPHILIS 6 wks to 6 months after primary chancre Diffuse non-pruritic indurated rash on body including palms & soles. Fever, malaise, headache, sore throat Highly infectious

LATENT SYPHILIS Positive syphilis serology without clinical signs of syphilis begins with the end of secondary syphilis and may last for a lifetime Early(infectious) and late phase(Non-infectious) Untreated syphilis –30% cure –30% latent –30% tertiary phase

TERTIARY SYPHILIS Years/ decades later Granulomatous lesion called Gumma Skin, bones, liver Destructive lesions in CNS-stroke, paresis, tabes, neuropsychiatric symptoms etc.) CVS-Aortitis, aneurysm, valvular insufficiency Non infectious

SEROLOGICAL TESTS Non Treponemal Tests –VDRL, RPR –Treponemal infection induce formation of two types of antibodies Reagin (that react with non-treponemal Cardiolipin) Specific anti-treponemal antibodies Treponemal Tests –TP-PA (Treponema pallidum particle agglutination) –TPHA (Treponema pallidum heam-agglutination) –ELISA –FTA-ADS test

NON-TREPONEMAL SCREENING TESTS Widely available Cheap Easy to perform Rapid results in minutes Correlate with disease activity (become negative with successful treatment) False positivity-Preg, autoimmune dis, EBV inf, May be false negative in early Prim syphilis

NON-TREPONEMAL SCREENING TESTS Rapid Plasma Reagin test Cardiolipin-cholesterol- lecithin acts as antigen Reagins are mixture of IgG/IgM Colored compound is attached with antigen Visible clumping occurs in minutes Antigen antibody complex visible on card

RPR TEST

Positive 2-3 weeks in Prim untreated Syphilis Highly positive in secondary syphilis Becomes negative 6-8 months after treatment Quantitative test- response to therapy Positive RPR late after therapy means ineffective treatment/ re-infection False positivity in viral infections (infectious mononucleosis), bacterial infections (e.g., pneumonia, TB), chronic disease (e.g., RA, SLE), elderly, Pregnancy

TREPONEMAL TESTS Use Treponema pallidum antigen Detects specific anti- Treponemal antibodies Specific tests for syphilis Once positive-remain positive for life Do not revert to negative with treatment Expensive Laborious, time consuming Expertise req

INTERPRETATION OF SEROLOGICAL TESTS FOR SYPHILIS Possible ExplanationTreponemal Tests (TP-PA/ FTA-ADS) Non- Treponemal tests (RPR/ VDRL) Syphilis - recent or previous Yaws or pinta ++ No syphilis False positive –+ Consistent with previously treated or untreated Syphilis Yaws, Pinta, Bejel +– No syphilis Syphilis in incubation period ––