Evaluation of telomerase activity in patients with chronic B lymphocytic leukemia versus age matched controls. Correlation between telomerase activity and bone marrow infiltration

Abstract

Telomerase is a ribonucleoproteic enzyme associated with cellular immortality and malignancy. This enzyme, besides the catalytic subunit bearing reverse transctiptase activity, contains an RNA template complementary to TTAGGG telomeric repeats, thus permitting de novo synthesis of telomeric DNA onto chromosomal telomeric ends. Increased telomerase activity has been reported in Chronic Lymphocytic Leukemia (CLL) by many authors. In order to investigate the telomerase activity in patients with CLL and its correlation to commonly used morphologic prognostic markers, 38 frozen blood lymphocyte samples from patients with CLL and 47 age-matched controls were investigated for telomerase activity using the Telomerase PCR ELISA-plus kit from Roche. Trepanobiopsies from the same patients were analysed for the type of bone marrow infiltration as well. Analysis showed highly variable Relative Telomerase Activity (RTA) in B-CLL patients, ranging from comparable or even lower than the mean RTA of controls (in Binet A stage patients) to manifold increase in the majority of patients with advanced stage disease. The sex and age of the patients showed no influence on RTA in CLL patients, in contrast to the control group, where the age influenced telomerase activity. We found a positive correlation between the RTA and disease stages (Binet), as well as between RTA and the type of BM infiltration.