Reiter protein complement fixation test; a preliminary comparison of the TPI test with the complement fixation test employing a soluble protein antigen derived from the Reiter strain

A comparative study of the specificity of the Reiter protein complement fixation (RPCF) test and the Treponema pallidum immobilization (TPI) test on 180 sera showed that the results in 178 instances or 98.9 per cent were in agreement. The sensitivity of the RPCF test, when compared to the TPI test, on 189 sera from patients known to have syphilis was in agreement in 182 or 96.3 per cent, assuming a correlation exists between positive TPI and both the "reactive" or "weakly reactive" RPCF test results. As to reproducibility of results, the RPCF test results agreed in 84 of the 87 sera tested (95.4 per cent). The sera were tested at least three times on different days. Anticomplementary reactions were observed in three of 91 normal sera.     

Serological diagnosis of syphilis: comparison of the Trep-Chek IgG enzyme immunoassay with other screening and confirmatory tests

The Trep-Chek IgG Enzyme Immunoassay (Trep-Chek IgG EIA) was evaluated with 604 serum specimens submitted for syphilis serology from patients across Canada against a battery of conventional syphilis serology tests, including the Rapid Plasma Reagin (RPR) test, the Venereal Disease Research Laboratory (VDRL) test, the Treponema pallidum passive particle agglutination (TP-PA) test, the fluorescent treponemal antibody absorption (FTA-ABS) test, and the newer confirmatory test, Innogenetics INNO-LIA. On the basis of a consensus result derived from these serologic tests, 34 specimens were found to be syphilis-positive (28 active and six past infections), and 570 were syphilis-negative (including 12 biological false positives). When the test results on this set of samples were compared to those obtained with the conventional tests RPR, VDRL, TP-PA, and FTA-ABS, the sensitivity and specificity of the Trep-Chek IgG EIA were found to be 85.3% and 95.6%, respectively. Without further evaluation, we do not recommend use of the Trep-Chek IgG EIA as a stand-alone test for either screening or confirmatory syphilis serology.