Impaired antibody responses to a pneumococcal polysaccharide vaccine in patients with non-Hodgkin's lymphoma in remission.

Eight patients with non-Hodgkin's lymphoma who have been in complete clinical remission for the mean of 23.3 months were evaluated for their antibody responses to a pneumococcal vaccine. The results were correlated with lymphocyte subpopulations, serum immunoglobulin levels, and in vitro mitogenic responses to phytohemagglutinin, concanavalin and pokeweed mitogen. Two patients with normal antibody responses had immunoglobulin levels and mitogenesis within the range of controls. Impaired antibody responses in the remaining six patients were correlated either with marked depressed mitogenesis to phytohemagglutinin or with low levels of IgA. Impaired humoral immune responses seem to persist in these patients even after several months of sustained clinical remission.