Multiplex Ligation-Dependent Probe Amplification Versus Multiprobe Fluorescence in Situ Hybridization To Detect Genomic Aberrations in Chronic Lymphocytic Leukemia : A Tertiary Center Experience

Abstract

Cytogenetic abnormalities play a major role in the prognosis of patients with chronic lymphocytic leukemia (CLL). Several methods have emerged to try to best identify these abnormalities. We used fluorescence in situ hybridization (FISH) to determine the frequency of cytogenetic changes in our CLL patient population. We also evaluated the effectiveness of multiplex ligation-dependent probe amplification (MLPA) in detecting these abnormalities. Sixty-two B-CLL patients and 20 healthy controls were enrolled, and FISH and MLPA analyses were performed on peripheral blood samples. Using FISH, genomic aberrations were found in 73% of patients and presented as follows: single 13q14.3 deletion (60%), trisomy 12 (7%), ATM deletion (6%), 17p13.1 deletion (2%). MLPA analyses done on 61/62 patients showed sensitivity and specificity values of 90% and 100% respectively. MLPA revealed several additional copy number changes, the most common being 19p13 (LDLR and CDKN2D). Moreover, the cost for MLPA analysis, including technical time and reagents, is 86% less than FISH. In conclusion, cytogenetic abnormalities are a common finding in CLL patients, and MLPA is a reliable approach that is more cost effective and faster than FISH. Despite MLPA limitations of sensitivity, it can be used as a first-line screen and complementary test to FISH analysis.