Prognostic Significance of Circulating Epstein-Barr Virus (EBV) DNA in Non-Hodgkin's Lymphoma.

Epstein-Barr virus (EBV) is well-known as an etiologic agent of lymphoproliferative disorders. Almost all types of sporadic non-Hodgkin's lymphoma (NHL) of both B-cell and T-cell origins have been demonstrated to have EBV-infected tumor cells. However, the prognostic significance of EBV viral load has not been established yet. Methods: To monitor quantitative EBV DNA load, real time quantitative PCR of EBV BZLF1 DNA was done using RealArt® EBV LC PCR reagents (Artus) from whole blood samples drawn from newly diagnosed NHL patients at the time of diagnosis and during the follow-up. Results: Between July 2006 and March 2009, a total of 233 patients (including 120 [51.5%] diffuse large B-cell lymphoma [DLBCL]; 18 [7.7%] natural killer (NK)/T-cell lymphoma; and 11 [4.7%] peripheral T-cell lymphoma, unspecified) were reviewed and analyzed. Among them, 33 (14%) patients, had a detectable EBV DNA (positive group) while 200 (85%) patients did not (negative group). Those in positive group had a more advanced disease and a higher LDH level than those in negative group (P=0.003 and 0.007, respectively). With a median follow up of 11.3 months (range 1.2-34.9), 14 (42.4%) of the 33 patients in positive group had a progressive or relapsed disease while 30 (15%) of the 200 patients in negative group did (P<0.001). One-year overall survival (OS) rate was 72.5% in positive group while that was 82.9% in negative group (log-rank P=0.001). Interestingly, conversion to negative EBV DNA during the follow-up was associated with a lower probability of progressive or relapsed disease (P=0.004). NK/T-cell lymphoma patients having an EBV DNA survived shorter than those having not. However, in DLBCL patients, there was no difference in survival between those having an EBV DNA and those not. Conclusions: The presence of EBV DNA at diagnosis and the negative conversion of EBV DNA during the follow-up might have prognostic significance in patients with NHL.

No relevant conflicts of interest to declare.