Short Telomeres Are Associated with Genetic Instability and the Occurrence of High Risk Genomic Aberrations in Chronic Lymphocytic Leukemia.

Telomere length has been associated with the mutation status of the immunoglobulin variable heavy chain (VH) gene and the clinical course in chronic lymphocytic leukemia (CLL). In an unicentric CLL cohort of 108 patients, we have analyzed the telomere length by quantitative real time PCR, genomic aberrations by FISH with a comprehensive set of DNA probes (11q, 12q, 13q, 14q, 17p), the VH mutation status by DNA sequencing, ZAP-70 expression (clone 2F3.2, Upstate, according to Crespo et al., NEJM 2003) and CD38 expression by flow cytometry, to further study the prognostic impact and associations among these factors. A relative telomere-single-copy-gene ratio (T/S) was calculated for each sample, where low and high T/S values correspond to short and long telomere lengths, respectively. The median T/S value was 0.33 (range 0.06–1.18). There was an inverse correlation between telomere length and the following parameters: 1. VH homology (r=−0.56, p