Prognostic significance of zap-70 in chronic lymphocytic leukemia

CLL is a disease with a variable prognosis. It is of crucial importance to determinepatients who will have an unfavorable course. Current clinical staging systems are incapableof predicting patients who would have a rapid progression after an initial diagnosis at an earlystage. In our study, we aimed to determine the association of ZAP-70 with other prognosticfactors and duration of treatment-free interval in CLL.Fifty-two CLL patients, diagnosed with standart moprhologic and immunophenotypicmethods, were included in the study. ZAP-70 and CD38 expressions were evaluated by flowcytometry. In 47 of the patients, 13q deletion, 11q deletion, p53 deletion and trisomy 12 werestudied with FISH.Out of 52 patients, 32 (61,5%) had ZAP-70 expression less than 20% and 20 (38,5%)had ZAP-70 expression more than 20%. The clinical stage of ZAP-70 positive patients weremore advanced (p= 0,02) and they had significantly lower hemoglobin levels (p= 0,02) and ashorter LDT (p= 0,04) compared to ZAP-70 negative patients. No association was observedbetween ZAP-70 and CD38 (>30%) and cytogenetic anomalies.The need for treatment was significantly higher in ZAP-70 positive group compared tonegative patients (p= 0,02). No correlation was observed between the need for treatment andCD38 expression and anomalies determined by FISH (p> 0,05). ZAP-70 was found to be anindependent variable of need for treatment in multivariate analysis (p= 0,03).As a conclusion, we demonstrated that patients who are ZAP-70 positive have a higherneed for treatment. Thus, determining ZAP-70 expression with flow cytometry at diagnosis isvery valuable in identifying patients in need for treatment beforehand.