Differential antibody responses to rubella virus infection in males and females.

Specificities of human rubella virus (RV)-specific IgG, IgM, and IgA antibodies for RV structural proteins (envelope E1 and E2 and capsid) and an E1 domain represented by a synthetic peptide (BCH-178) were determined by immunoblot and ELISA techniques in sera from rubella-infected individuals. Sequential sera were obtained from 67 females and 32 males during acute and convalescent infection phases. Males and females had differences in all antibody classes, especially during the early acute infection phase. At no time during follow-up were IgA anti-E2 antibodies detected in males, in contrast to the case in females. Significantly lower levels of IgG antibody directed to E2 were also observed in males. Males had earlier onset of E1-specific IgG and IgM antibodies with a greater proportion of total RV antibody response directed to E1 (IgG) or E1 peptide (IgM). These differences suggest there are hormonal and genetic influences on immune recognition of RV proteins that may be related to the increased incidence of rubella-associated arthropathy in females.