Circulating immune complexes containing rubella antigens in late-onset rubella syndrome.

Eight infants with late-onset rubella syndrome were investigated. All patients had been infected by rubella virus during gestation but had minimal clinical symptoms at birth and during a latent period of several months. They presented secondarily an acute phase characterized by a severe multisystem disease. Antirubella antibody titers were present at low levels before and during the first weeks of the acute phase, contrasting with high serum levels of IgM. The percentage of T lymphocytes was very low and an increase of B lymphocytes was observed. The presence of circulating immune complexes which appeared to contain rubella antigens was demonstrated. These findings suggest that the lesions observed in late-onset rubella syndrome are partly due to CIC, and that suscepibility to infection can be related to a peripheral T and B lymphocyte disequilibrium.