Korean J Dermatol.
1975 Dec;13(4):271-279.
Serodiagnosis of Syphilis
Abstract
- The serodiagnostic test of syphilis employed with the greatest freguency in this country is the VDRL procedure which is one of the flocculation test utilizing cardiolipin-lecithin as an antigen. As well known, the immunologically nonspecific nature of this test relegates it only to screening test, so that all the sera displaying weakly reactive or reactive VDRL in the absence of definite evidence of present or past syphilis should be confirmed by using the specific treponemal antigen tests. However, there are only lirnited numbers of institutions at which the specific treponemal antigen tests are carried out, because the tests usually need quite coaiplicatnl technology and specifically trained personnel. The Treponema. pallidum hema.gglutination assay (TPHA) which was first described by Rathlev in 1965 and established as more improved and standardized procedure in serodia,gnosis of syphilis by Tornizaxva and Kasamatsu (1966) has been found to h as sensitive and specific as the technically more complicated Fluorescent treponemaI antibody absorption (FTA-ABS) or Treponema pallidum immobilization (TPI) po cedure by rnany investigators from different parts of the world during these 10 years. The TPHA has also been found to have definite advantage over the other tests because it is easy to perform and economic. The present authors felt. that the TPHA meight be the most reasonable method to be used in this country and decided to evaluate it in the serodiagnosis of problem cases. Sera from 516 presumed normal persons, 686 pregnant women ancl 1345 patients with various diseases other than syphilis were screened with the standard VDRL procedure as described and recommanded by USPHS. Out of these, 475 of t.he presumed normal persons, 646 of the pregnant women and 1243 of the patient group wit;h various diseases other than syphilis v;ere serologically nonreactive and 10, 12 and Rl sera from each of the above groups, respectively, were found to be true syphilitc with definite evidence of clinical signs or history of syphilis. Thirty-one out of the presumed normal persons, 28 out of the pregnant women and 71 out of the patient group with various diseases other than syphilis showed either weakly reactive or reactive VDRI, in undiluted sera without definite evidence of syphilis and these 130 sera from 130 persons were the subject of the present study. The TPHA was carried out on these 130 sera. according to the ma.nual MEA-TP instructed by National Institute of Health, Japan. The reagents used in this study rvere rnanufactured and supplied hy the Fujizoki Pharmaceutical Co. Ten (32.3%) out of the R1 sera from preaumed normal persons, 11 (39.4%) out of the 28 sera from pregna.nt women a.nd 28 (69.4%) out of the patient group with various disea ses other then syphilis showed reactive TPHA. Eighty-seven of the total 130 sera showed weakly reactive VDRL so called rough result and 19 (21.8%) Of these 87 sera showed reactive TPHA, while 30(69.8%) of the 43 sera which showed reactive VDRL were found to be TPHA reactive. These results arc in general agreement with those of other investigators confirmed by the more complicated FTA-ABS or TPI. The overall incidence of syphilis was 3.87%, 3.35% and 4.38% in presumed normal persons, in pregnant women and in patient group with various diseases other than syphilis respectively. Considering the relative lack of study concerning to the false positive reactions in this country, these results may be helpful to the clinician to rnake a cert.ain diagnostic decision when they meet such a patient whose VDRL is weakly reactive or reactive in the absence of definite evidence of syphilis. The authors concluded that: the MHA-TP technique is easy in performance, economic and highly specific in serodiagnosis and that this technique is highly recommanded in this country. * The authors thank Fujizoki Pharrnaceutical Company, Tokyo, Japan which provided the TPHA reagents used in this study.
