Colchicine ultrasensitivity of lymphocytes in chronic lymphocytic leukaemia.

It has been previously reported that, in comparison with normal lymphocytes, the lymphocytes in chronic lymphocytic leukaemia (CLL) are ultrasensitive in culture to the cytocidal action of colchicine. In this report the results of 240 colchicine studies in 87 patients with CLL are presented and analysed in terms of the diagnostic, clinical and haematological significance of colchicine ultrasensitivity (CUS) in CLL. All patients with CLL showed very significantly increased CUS of lymphocytes. The CUS did not vary with clinical and haematological status or time and only very rarely with treatment. There was no correlation between % CUS and subsequent course or survival. The results in CLL and in other forms of lymphocytosis and in non-Hodgkin's lymphoma are compared. It is concluded that the test is of considerable diagnostic value, particularly in identifying low-count and treated CLL and in the exclusion of non-CLL lymphocytosis. It appears to have no prognostic value but may have future application in monitoring treatment which selectively eliminates the abnormal cell population.