EBV-positive T/NK lymphoproliferative diseases: analysis of prognostic factors for patients in China.

The Epstein-Barr virus (EBV) is a ubiquitous lymphotropic herpesvirus that infects the human body through the respiratory tract. Usually, primary infection with EBV is asymptomatic and occurs early in life, however adolescents or young adults are more likely to develop a self-limited symptomatic infection, which manifests as acute infectious mononucleosis (IM). Systemic EBV-positive lymphoproliferative disease (EBV + T/NK-LPD) has been described as a disease related to chronic or persistent EBV infection after acute EBV infection, with severe IM-like symptoms. EBV + T/NK-LPD is associated with high mortality and morbidity with life-threatening complications. Information on its prognostic factors remains limited, therefore in this study, we aimed to evaluate the association between prognostic factors and mortality and complications of EBV + T/NK-LPD in China by retrospectively reviewing 173 EBV + T/NK-LPD cases. We observed that the high mortality rate of EBV + T/NK-LPD was mainly due to serious and fatal complications. Fever, lymphadenopathy, hepatosplenomegaly, EBV-encoded RNA (EBER) > 50/HPF, Ki-67 > 30%, and other visible complications were closely associated with EBV + T/NK-LPD prognosis. In addition, fever, hepatosplenomegaly, decreased WBC count, and a Ki-67 index of > 30% were risk factors for complications. Thus, disease prognosis should be based on a comprehensive analysis of pathological and clinical data. Such data will help pathologists and clinicians to pay close attention to the changes in the clinical condition of the patients as well as take precautionary measures against the occurrence of fatal complications.