Hemophagocytic lymphohistiocytosis caused by dual mutations in UNC13D and STX11 induced by HHV-7: a case report and review of the literature.

Abstract

Hemophagocytic lymphohistiocytosis (HLH) is a severe disorder caused by excessive activation of the immune system and is characterized by hyperinflammation and life-threatening multiple organ failure. We report a case of a 39-year-old female patient with rapidly progressive disease who presented with pancytopenia, coagulopathy, hepatic dysfunction, and hyperlipidemia. Laboratory tests revealed marked cytopenia, hypofibrinogenemia, hypertriglyceridemia, hyperferritinemia, elevated soluble CD25 levels, decreased natural killer cell activity, and hemophagocytosis in the bone marrow, meeting the diagnostic criteria for HLH. The HLH in this case was triggered by human herpesvirus 7 (HHV-7), which has rarely been reported. Genetic analysis revealed compound heterozygous mutations in two HLH-related genes, UNC13D (c.1232G > A) and STX11 (c.121 C > A), which were inherited from the mother and father, respectively, indicating a diagnosis of familial HLH. Hematopoietic stem cell transplantation remains the most effective treatment for this condition. This case highlights the importance of incorporating genetic testing into the early diagnostic workflow for HLH. Early identification of genetic predisposition is crucial for prognosis assessment and the selection of appropriate treatment strategies to improve clinical outcomes.