Immunological competence of patients in remission from acute leukaemia: apparently normal T cell function but defective pokeweed mitogen-driven immunoglobulin synthesis.

Immunological function of 62 patients in remission from acute leukaemia has been evaluated using peripheral blood mononuclear cells in vitro assays. T cell function, as indicated by proliferation in response to polyclonal activation (by phytohaemagglutinin) and antigen-specific stimulation (allogeneic cells), was normal in these patients. In contrast, pokeweed mitogen-driven Ig synthesis was significantly decreased for all immunoglobulin classes measured (IgM, IgG and IgA) in the case of adult and childhood acute lymphocytic leukaemia patients, and for IgA in the case of adult acute non-lymphocytic leukaemia patients. The defects in humoral immunological responses may contribute to the increased susceptibility to infection of these patients.