Increase in T gamma lymphocytes in B-cell chronic lymphocytic leukaemia. II. Correlation with clinical stage and findings in B-prolymphocytic leukaemia.

The proportion of T gamma and T mu lymphocytes was studied in 40 cases of B-chronic lymphocytic leukaemia (B-CLL) and six of B-prolymphocytic leukaemia (B-PLL). The significant increase in T gamma cells, previously reported in two small B-CLL series, was confirmed and shown to be directly correlated with the clinical stages of the disease (P less than 0.01 to less than 0.001). The normal T mu:T gamma ratio (2.3:1) was reversed in B-CLL (1:1.4) and B-PLL (1:1.9). The proportion of T mu cells was decreased but was not related to stage. Our findings suggest that the increase in T gamma cells may be responsible for the hypogammaglobulinaemia of B-CLL. This is supported by two sets of observations. First, serum Ig levels were more often normal in cases in Stages 0 and I than in Stages II-IV (P less than 0.05), while the levels of two or three Ig classes were below normal in Stages II-IV twice as frequently. Secondly, splenic irradiation in one case was followed by a fall in the absolute number of T gamma lymphocytes, a reversion to normal of the T mu: T gamma ratio and an improvement in serum Ig levels. Thus, the imbalance in ;the regulatory T-cell subsets may provide an important clue to understand the pathogenic mechanism of the immunodeficiency in the chronic B-cell leukaemias.