Usefulness of CD45 density in the diagnosis of B-cell chronic lymphoproliferative disorders

Although many B-cell chronic lymphoproliferative disorders (BCLPDs) including B-cell chronic lymphocytic leukemia (B-CLL) have characteristic clinical and biological features, the overlapping morphologic and immunophenotypic profiles of various BCLPDs, is still the main problem.

Our aim was to evaluate the usefulness of CD45 expression in the immunological classification of BCLPDs.

A prospective study was set in a university hospital to investigate the CD45 intensity, particularly in B-CLL.

The expression of CD45 in 37 patients with BCLPD including typical B-CLL (Group I), atypical B-CLL and CLL/PLL (II), and hairy cell leukemia (HCL), B-prolymphocytic leukemia (B-PLL), and B-non Hodgkin's lymphoma (B-NHL) as non-CLL BCLPDs (III) and in eight healthy age matched controls (IV) was quantitatively compared by flow cytometric CD45/RALS gating strategy.

The mean, median, and peak channel scores of CD45 obtained for the four groups were compared using one-way analysis of variance test. A P value

Lower CD45 density is associated highly with typical CLL and differences between typical CLL and other groups were significant (P< 0.001, 0.001, and 0.001). Non-CLL cases had significantly brighter CD45 expression than atypical CLL (P=0.014). No differences were found between normal lymphocytes and non-CLL BCLPD cases.

CD45 is a useful marker, to discriminate the typical CLL from the non-CLL BCLPD and from atypical CLL.