ABSTRACT

I. INTRODUCTION B-cell chronic lymphocytic leukemia (CLL), the most common form of leukemia in Western countries, results from relentless accumulation of small mature, slowly dividing, monoclonal B lymphocytes (1). B-CLL cells are characterized by coexpression of pan B-cell markers CD5 and CD23, negativity for CD22 and FMC7 molecules, and low ex­ pression of the B cell receptor surface immunoglobulin and Ig associated molecule CD79b (2-4).