Immunoglobulin Variable Region Gene Characteristics and Surface Membrane Phenotype Define B-CLL Subgroups with Distinct Clinical Courses

I. INTRODUCTION B cell chronic lymphocytic leukemia (B-CLL) cases are clinically heterogeneous, because some patients survive for prolonged periods without requiring definitive therapy, whereas others die rapidly despite aggressive treatment (1,2). However at the cellular level, the disease has been considered homogeneous, resulting from the accumulation of a leukemic clone derived from a normal CD5+ B lymphocyte (3). In addition, these B lymphocytes have been termed “ incompetent” (4).