An increased number of individuals with clinically recognized monoclonal B-cell lymphocytosis characterizes a recent database of chronic lymphocytic leukemia Rai stage 0

摘要

The incidence and presenting features of chronic lym-phocytic leukemia (CLL) have changed significantly in the last 30 years [1-3]. Both tjje introduction of automated blood counters in routine'clinical practice and the evolution of flow cytometry have led to a lowering of the absolute lymphocyte count (ALC) required for a diagnosis of CLL (i.e. >5.0 X 10~9/1) [4]. Furthermore, after recognition of monoclonal B lymphocytosis (MBL) and the publication of the 2005 MBL diagnostic criteria, which were based on B-cell counts rather than ALC, there was initially an overlap between the diagnostic criteria for CLL and MBL. Accordingly, some individuals with an ALC >5 X 10~9/1 who have B cell counts <5 X 10~9/lmay fulfill both the MBL and the CLL diagnostic criteria [5]. Although this initially appeared to affect a small proportion of patients, subsequent studies from the Mayo Clinic indicated that up to 40% of individuals with newly diagnosed Rai stage 0 CLL according to the 1988 and 1996 criteria fell in this area of overlap [6].