The prognostic role of HBV infection in chronic lymphocytic leukemia.

PURPOSE: We attempt to assess the impact of hepatis-B virus (HBV) status on the prognosis of chronic lymphocytic leukemia (CLL) using a Chinese case cohort. METHODS: Five hundred and one consecutive newly diagnosed subjects with CLL were enrolled in this case cohort. HBV infection was defined as hepatitis B surface antigen (HBsAg) positive or hepatitis-B core antibody (HBcAb) positive. Univariate and stepwise multivariate Cox regression analyses were used to screen the prognostic risk factors associated with the end point of time-to-treatment (TTT) or overall survival (OS). Bootstrap re-sampling method was used to evaluate the model's internal validity. The discriminative ability of the models was evaluated using time-dependent receiver-operator characteristic (ROC) curves and corresponding areas under the curve (AUC). RESULTS: One hundred and twenty-one subjects (24%) among 501 patients were HBV positive. HBV infection was an independent predictor for the prognosis of TTT (HR = 1.37; 95% CI 1.04-1.80) or OS (HR =2.85; 95% CI 1.80-4.52). The AUCs for HBV infection were 0.62 (95% CI 0.58-0.66) for TTT and 0.69 (95% CI 0.66-0.72) for OS, respectively. When we combined HBV infection with the traditional clinical and biological factors, significant improvements for model's discrimination were observed for TTT [AUC: 0.81 (95% CI: 0.77-0.85) vs. 0.78 (95% CI: 0.74-0.82), P < 0.001] and OS [AUC: 0.81 (95% CI 0.76-0.86) vs. 0.76 (95% CI 0.71-0.82), P < 0.001). Further bootstrap re-sampling method revealed good internal consistence for the final optimal models (Average AUC: 0.78 for TTT and 0.79 for OS based on 1000 bootstraps). CONCLUSIONS: Our results indicated that HBV infection should be served as an important risk predictor for prognosis of CLL (TTT and OS).