Distinct Clinical and Prognostic Features of Acute and Chronic Active Epstein-Barr Virus-Associated Hemophagocytic Lymphohistiocytosis in Adults: A Scoping Review.

Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is a major subtype of secondary HLH and is increasingly recognized as a heterogeneous entity. However, the clinical differences between acute EBV-HLH (AEBV-HLH) and chronic active EBV infection-associated HLH (CAEBV-HLH) have not been systematically characterized. We conducted a scoping review of PubMed up to December 7, 2024, and identified 168 eligible articles involving 714 adult patients with EBV-HLH, including 584 with AEBV-HLH and 130 with CAEBV-HLH. Epidemiologic features, clinical manifestations, treatment patterns, and prognostic factors were summarized and compared between the two subgroups. Patients with AEBV-HLH showed more severe HLH-related abnormalities, including lower blood counts and higher ferritin, triglyceride, lactate dehydrogenase, and plasma EBV-DNA levels, whereas central nervous system involvement was more frequent in CAEBV-HLH. The median overall survival was significantly longer in CAEBV-HLH (8.9 months) than AEBV-HLH (2.4 months, P=0.005). In the overall cohort, ferritin >5000 μg/L, soluble CD25 >10000 U/mL, EBV-DNA >10000 copies/mL, and receiving hematopoietic stem cell transplantation (HSCT) were independently associated with better overall survival. In subgroup analyses, soluble CD25, EBV-DNA, and HSCT remained independent predictors in AEBV-HLH, whereas undergoing HSCT was the only independent prognostic factor in CAEBV-HLH. These findings support distinct clinical and prognostic characteristics between AEBV-HLH and CAEBV-HLH, especially in adults. AEBV-HLH is characterized by a more fulminant inflammatory presentation, whereas CAEBV-HLH more often follows a chronic course with greater extensive organ. HSCT appears to be central to long-term outcome in both subtypes.