OKT4+ chronic lymphocytic leukaemia cells display different reactivity with selected monoclonal antibody combinations

Four cases of chronic T lymphocytic leukaemia are characterized by selected monoclonal antibody combinations and double-fluorescence studies. We found 3 possible combinations: OKT4++ Leu8++ Leu9+, OKT4++ Leu8+ Leu9- and the OKT4++ Leu9++ Leu8- phenotypes are correlated with different biological aspects of the disease. No markers of T cell activation were found, and serological examinations did not reveal anti-HTLV-I antibodies. In considering a larger number of patients, multiparametric analysis could be useful to better classify this heterogeneous type of leukaemia.