High viral loads of circulating Epstein-Barr virus DNA copy number in peripheral blood is associated with inferior prognosis in patients with mantle cell lymphoma

Mantle cell lymphoma (MCL) is a distinct subtype of B cell non-Hodgkin lymphoma. No research has yet documented to investigate the prognostic implications of Epstein-Barr virus (EBV) infection in MCL. The objective of this study was to determine whether EBV DNA load may influence the heterogeneity in the course of the disease in MCL patients. Eighty-eight MCL patients were retrospectively enrolled in the study. EBV DNA load was detected by real-time quantitative PCR for quantification. The univariate and multivariate Cox proportional hazards models were established for the estimation of prognostic factors. Twenty-seven patients were detected positive for EBV DNA and the median virus titer was 1.72×10(4) copies/mL (range, 8.20×10(2) to 4.14×10(5) copies/mL). With a median follow-up of 39 months (range, 9 to 120 months), patients in EBV DNA-positive group displayed unfavorable progression-free survival (PFS) (P=0.012) and overall survival (OS) (P=0.004) than patients in EBV DNA-negative group. Multivariate Cox regression analysis revealed that EBV DNA-positivity was an independent risk factor for both PFS (HR, 2.04; 95% CI, 1.07 to 3.92; P=0.031) and OS (HR, 2.68; 95% CI, 1.20 to 6.00; P=0.016). Reduction in EBV copies was significantly associated with therapy-response. Circulating EBV DNA load in whole blood proved to be a significant predictor of prognosis in patients with MCL, which needs further validation in large-scale clinical studies.