Abstract
Epstein-Barr virus (EBV) is a ubiquitous virus and is related to various diseases. Primary EBV infection is usually asymptomatic, and it sometimes progresses to infectious mononucleosis, which resolves spontaneously after the emergence of EBV-specific immunity. But, in some apparently immunocompetent hosts, chronic infections can develop. Chronic active EBV infection (CAEBV) is characterized by chronic or recurrent infectious mononucleosis-like symptoms, such as fever, extensive lymphadenopathy, hepatosplenomegaly, and pancytopenia. Patients with CAEBV have high viral loads in their peripheral blood and/or an unusual pattern of EBV-related antibodies. This disease is rare but severe with high morbidity and mortality. Recent advances in technology have increased our understanding of CAEBV pathophysiology, indicating that the clonal expansion of EBV-infected T or natural killer (NK) cells plays a central role in the pathogenesis of CAEBV. However, it remains unclear whether CAEBV is truly a monoclonal lymphoproliferative disorder. In this review, I summarize the clinical feature of CAEBV and discuss our current understanding of the pathogenicity of the disease.
