Hypoimmunoglobulinaemia and aplastic anaemia.

Serum immunoglobulin levels were estimated in 19 patients with aplastic anaemia. Although the mean levels for IgG, IgA and IgM for the group as a whole were within the normal range, 8 individual cases showed low levels of one or more immunoglobulin class, suggesting a disturbance in immunoglobulin production. One of these patients had a thymoma, and another positive tests for anti-nuclear factor, but there was no evidence of auto-immune disease in the others. It is suggested that 'aplastic anaemia' may sometimes be a disease due to injury of a stem cell subserving both haemopoietic and immunological function.