Cellular immunity in primary hypogammaglobulinaemia: evidence for a generalised lymphocyte defect in some patients with "common" variable hypogammaglobulinaemia.

In vivo and in vitro T lymphocyte function was studied in 64 patients with X-linked and common "variable" primary hypogammaglobulinaemia. Lymphopenia, splenomegaly, depressed in vitro lymphocyte transformation to mitogens and failure to manifest delayed hypersensitivity skin reactions occurred frequently in the common "variable" group, particularly those with adult onset disease. However, relative circulating T lymphocyte numbers and in vitro lymphocyte transformation in a mixed lymphocyte reaction with the CLA4 lymphoid cell line were normal. Antibody mediated and PHA induced lymphocytotoxicity were also normal. These findings indicate the presence of a generalised lymphocyte defect which is selective for certain T lymphocyte functions. Despite these apparent T lymphocyte defect, none of the patients suffered from the unusual opportunistic parasitic, viral or fungal infections which tend to occur in infants with severe primary defects of both T and B lymphocytes.