Receptors for immunoglobulin isotype on T and B lymphocytes from untreated patients with chronic lymphocytic leukaemia.

Peripheral blood lymphocytes from eighteen untreated patients with chronic lymphocytic leukaemia (CLL) were analysed for the proportions of T and B lymphocytes with receptors for IgM, IgG or IgA. T lymphocytes with Fc receptors for IgM (T mu cells) or IgA (T alpha) cells were found in proportions comparable to those found in the controls. However, the proportion of T lymphocytes with receptors for IgG (T gamma cells) was significantly increased (P < 0.001) resulting in an abnormally low ratio of T mu/T gamma (P < 0.001), when compared with normal controls. The proportion of B cells bearing Fc receptors for IgM, IgG or IgA was determined simultaneously. No significant differences were found between the normal controls and the patients with CLL. In vitro treatment of the purified T and B lymphocyte preparations with human leucocyte interferon, did not alter the proportions of the lymphocytes expressing Fc receptors for various immunoglobulin isotypes. The significance of these findings is discussed.