No abstract

No abstract

Reference materials were produced to standardize the immunoglobulin class specificity and potency of immunofluorescent anti-IgM conjugates used for diagnostic tests for congenital syphilis. In attempting to mimic essential immunologic characteristics of syphilitic and nonsyphilitic infant sera, we evaluated these sera in comparison with processed adult sera. We were quite surprised to discover that some syphilitic babies do not produce significant quantities to IgM antibody to T. pallidum in response to their infection, as would be expected; instead, they make relatively large amounts of IgM anti-IgG. We found this to be true also for newborns and infants infected with cytomegalovirus, rubella, and toxoplasmosis. To our knowledge, this observation has not been previously reported. However, it could have been predicted from the knowledge that older infants and young children normally produce IgM antibodies to maternal IgG allotypes (Gm factors). We are disturbed that these findings suggest that currently recommended indirect immunofluorescence IgM tests for perinatal infection may not be disease specific. Our observations may be important for a better understanding of basic immunologic mechanisms of fetal-maternal to tolerance and fetal response to life-threatening infection.

Whole-cell sonicates of Treponema pallidum, Nichols strain, were evaluated in an enzyme-linked immunosorbent assay (ELISA) for syphilis, and results were read in a Dynatek Microelisa Reader. The antigen was evaluated with sera from patients with syphilis, persons presumed normal, and biological false-positives. Two hundred and ninety-seven sera were tested by the ELISA with T. pallidum antigens, the Venereal Disease Research Laboratory (VDRL) slide test, the fluorescent treponemal antibody absorption (FTA-Abs) test, and the microhemagglutination assay for T. pallidum antibodies (MHA-TP). The results of all of the tests were compared. The ELISA, with 89.3% sensitivity, was less sensitive than the VDRL (93.3%) and FTA-Abs (100.0%) tests but more sensitive than the MHA-TP (76.0%). The ELISA was considerably more sensitive in primary syphilis than ttie MHA-TP. Specificity was as follows: ELISA, 98.5%; FTA-Abs test, 97.8%; MHA-TP, 98.2%; and VDRL test, 92.7%. The ELISA has good potential as a confirmatory test in the serodiagnosis of syphilis.

No abstract