High expression of lipoprotein lipase in poor risk B-cell chronic lymphocytic leukemia

Abstract

We investigated the pattern of lipoprotein lipase (LPL) expression in B-cell chronic lymphocytic leukemia (B-CLL) and assessed its prognostic relevance. Expression of LPL mRNA as well as protein was highly restricted to leukemic B cells. The intensity of intracellular immunoreactivity of LPL was higher in samples of patients with unmutated immunoglobulin heavy-chain variable region genes (IGV_H) compared to those with mutated IGV_H genes. LPL mRNA levels in peripheral blood mononuclear cells (PBMNC) from 104 CLL patients differed by 1.5 orders of magnitude between cases with mutated (N=51) or unmutated (N=53) IGV_H (median: 1.33 vs 45.22 compared to normal PBMNC). LPL expression correlated strongly with IGV_H mutational status (R=0.614; PH status with an odds ratio of 25.90 (Pvs 96 months, P=0.001) and a trend for a shorter median overall survival (105 months vs not reached). Our data establish LPL as a prognostic marker and suggest functional consequences of LPL overexpression in patients with B-CLL.