No abstract

Background & Aims. T-cell receptor excision circles (TREC) and к-deleting recombination excision circles (KREC) are extrachromosomal DNA segments generated during V(D)J recombination process that characterize the diversity of the antigen repertoire of T- and B-cells. The aim of our study is to identify the prognostic value of the excision circles in the chronic lymphocytic leukemia (CLL) setting. Methods. The excision circles' levels were assessed by means of real time PCR in 109 patients with high-risk CLL and 16 matched healthy individuals. Results. KREC levels were significantly (p < 0.001) lower in CLL patients vs. the reference group. TREC levels were lower in groups with unmutated status of immunoglobulin heavy chain variable region genes (p < 0.05) and 11q deletions (p < 0.1). Moreover, the KREC levels were higher in NOTCH1 mutation carriers than in noncarriers (p < 0.05). The comparison of treatment outcomes demonstrated a correlation between a high TREC level and achievement of complete remission. The prognostic value of the bio-marker was confirmed by ROC-analysis: AUC_TREC = 0.713 (p = 0.001) Conclusion. Association between excision circles' le' and clinical/laboratory CLL prognostic factors, as well complete remission achievement, makes possible the plementation of the test for early prediction of the treatm outcome.