B-chronic lymphocytic leukaemia patients with stable benign disease show a distinctive membrane phenotype.

The circulating B cells of 98 patients with B-CLL were analysed with a panel of conventional markers and monoclonal antibodies including RFA-1 and RFA-4. A subgroup of patients was defined with a distinctive double membrane marker phenotype (RFA-1+, RFA-4+). These patients showed features of clinical stability. Their physical signs, haematological features and lymphocyte counts remained unchanged for 5-10 years: therefore, the RFA-1+, RFA-4+ membrane phenotype appears to identify a subgroup of B-CLL patients with a particularly non-progressive disease.