IgM antibody to Treponema pallidum in cerebrospinal fluid of infants with congenital syphilis

Congenital syphilis in neonates with nonreactive nontreponemal test results

OBJECTIVE

Infants whose mothers had syphilis during pregnancy were studied to determine how often exposed newborns with normal physical examinations and nonreactive nontreponemal serologic tests had abnormal laboratory or radiographic studies.

STUDY DESIGN

Retrospective analysis of prospectively collected data from infants born to mothers with syphilis and had a normal examination and a nonreactive nontreponemal test. Some infants had IgM immunoblotting, PCR testing or rabbit infectivity testing (RIT) performed.

RESULTS

From 1984 to 2002, 115 infants had a nonreactive serum Venereal Disease Research Laboratory (VDRL)/rapid plasma reagin (RPR) test and a normal physical examination at birth. Among 87 infants born to mothers who had untreated syphilis, 4 had a positive serum IgM immunoblot or PCR test, but none had spirochetes recovered by RIT. Two infants had anemia, one had an elevated serum alanine aminotransferase concentration and one with Down's syndrome had direct hyperbilirubinemia. Among 14 infants born to mothers treated <4 weeks before delivery, none had abnormal laboratory or radiographic tests, although 1 of 11 had a reactive serum IgM immunoblot. Among 14 infants born to mothers treated ⩾4 weeks before delivery, none had abnormal laboratory or radiographic tests.

CONCLUSION

Newborns with normal physical examination and nonreactive nontreponemal test results are unlikely to have abnormalities detected on conventional laboratory and radiographic testing.

Neurosyphilis: epidemiology, pathogenesis, clinical course and laboratory diagnostics

The article describes the key achievements and problems related to studying neurosyphilis. It also shows the dynamics of neurosyphilis incidence in Russia and abroad from the early twentieth century and up to present. The article also describes issues related to the pathogenesis, clinical course and pathomorphism of the disease. The authors present current approaches to the laboratory diagnostics of neurosyphilis.

Laboratory diagnosis of congenital syphilis by immunoglobulin M (IgM) and IgA immunoblotting

We screened cord blood or serum samples from 101 infants at risk for congenital syphilis and serum samples from their mothers for immunoglobulin G (IgG), IgM, and IgA antibodies to Treponema pallidum by western blotting (immunoblotting). Clinical evaluation showed that six infants had signs and/or symptoms consistent with congenital syphilis. The sera from five of these infants were IgM blot positive, and four were IgA blot positive. Four asymptomatic infants had serologic evidence of congenital syphilis. The sera from three of these infants were IgM blot positive, and two were IgA blot positive. However, the IgM reactivity of the serum from one asymptomatic infant, which was also IgA positive, was abolished by protein G treatment. An IgM capture enzyme-linked immunosorbent assay corroborated the presence of IgM antibodies in six of seven IgM blot-reactive sera. Overall, for detection of symptomatic congenital syphilis, a sensitivity of 83% for IgM blotting and 67% for IgA blotting was obtained. The significance of positive IgM or IgA Western blots for asymptomatic infants requires further study to confirm infection in these infants.