Human herpesvirus-6B infection leading to hemophagocytic lymphohistiocytosis in an adult: a case report

BACKGROUND: Hemophagocytic lymphohistiocytosis (HLH) secondary to human herpesvirus-6B (HHV-6B) infection is rare in immunocompetent adults. CASE PRESENTATION: We report the case of a 43-year-old East Asian (Chinese) woman who developed HLH, presenting with persistent fever, jaundice, and cytopenias. Metagenomic next-generation sequencing (mNGS) identified HHV-6B in both peripheral blood and liver tissue, thereby establishing the etiologic diagnosis. Prompt initiation of antiviral therapy with ganciclovir, combined with corticosteroids and intravenous immunoglobulin, resulted in rapid clinical remission. CONCLUSIONS: This case highlights the critical importance of early pathogen identification using mNGS and timely immunomodulatory treatment for improving outcomes in adult patients with virus-associated HLH.