Reduced T-colony forming capacity in B-chronic lymphocytic leukaemia.--II. Correlation with clinical stage and findings in B-prolymphocytic leukaemia.

The T-colony forming capacity of T-lymphocytes from 33 cases of B-chronic lymphocytic leukaemia (B-CLL) and five of B-prolymphocytic leukaemia (B-PLL) was studied. An absent or reduced (less than 50) colony growth was observed in 21 of the 33 B-CLL and in four of the five B-PLL studied. Seven of the nine stage 0 patients (77.7%) according to Rai's clinical staging) gave rise to more than 50 colonies, compared with five out of 24 (20.9%) in stages I-IV patients. Furthermore, the mean number of colonies was significantly (p less than 0.01) higher in stage 0 patients (57 +/- 33.6), compared with more advanced stages (22 +/- 29.9). Since in normal peripheral blood, T-colony formation appears to be a property of T mu lymphocytes, and T gamma cells are significantly increased in B-PLL and B-CLL, mainly in advanced disease, the T-colony growth was correlated with the percentage of T gamma cells. Despite a negative trend, a statistical correlation was not observed. Our findings are suggestive of a functional defect of the T-cell population in the majority of cases of B-CLL, with a partial sparing in stage 0 patients. This abnormality, apparently unrelated to the T mu: T gamma ratio, is probably due to an intrinsic defect of the T mu cell population.