Abstract: Objective To analyze the differences of Epstein-Barr virus (EBV) DNA in peripheral blood mononuclear cells (PBMCs) of patients with non-Hodgkin's lymphoma (NHL), and to discuss its clinical applications in prognosis. Methods A retrospective analysis of 421 NHL patients from the Western Branch of the First Affiliated Hospital of University of Science and Technology of China between April 2017 and September 2020 were conducted. The following clinical information was collected: age, sex, pathological type, clinical stage, lymphoma B symptoms, NHL international prognostic index (IPI), the results of blood routine and biochemical. Ninety-seven NHL patients were followed up regularly to analyze the changes of EBV DNA load before and after treatment to discuss its significance in the prognosis. Results The positive rate of EBV DNA from PBMCs in 421 NHL patients was 41.8%. The EBV DNA positive rate increased with age. Among them, NHL patients with T and NK cells and with lymphoma B symptoms were more susceptible to EBV infection, and the infection rate of patients with different tissue sources was also significantly different.According to International prognostic index, 97 NHL patients were divided into four groups. After treatment, EBV DNA load in the low-risk group, low-medium-risk group and middle-risk group decreased significantly, while the load in the high-risk group did not change significantly. The prealbumin(PA), albumin(ALB), and retinol binding protein (RBP) in NHL patients after EBV infection are significantly lower than those in uninfected patients, and the risk was higher and the survival time was shorter. Among the clinical indicators, pathological types, EBV infection, lymphoma B symptoms, bone marrow infiltration, PA and CysC were significantly correlated with the prognosis of patients. And pathological types, EBV infection, bone marrow infiltration and CysC were found to be independent prognostic factors in NHL. Patients with NHL derived from mature T and NK cells had poor prognosis. Conclusion Different types of NHL patients had differences in EBV DNA in PBMCs. Regular EBV DNA load monitoring before and after therapy could be clinical application value for prognosis monitoring.

Key words: Epstein-Barr virus DNA, Non-Hodgkin's lymphoma, Clinical features prognosis