Macrophage Activation Syndrome Secondary to Hepatitis B in a Kidney Transplant Recipient: A Case Report and Regional Literature Review

Background

Macrophage activation syndrome (MAS), also known as hemophagocytic lymphohistiocytosis (HLH), is a rare but potentially fatal hyperinflammatory disorder characterized by excessive activation of macrophages and cytotoxic lymphocytes, leading to a cytokine storm and multiorgan failure. Kidney transplant recipients are particularly vulnerable due to chronic immunosuppression and increased susceptibility to systemic infections. Viral infections, including hepatitis B and C, are recognized triggers of MAS in this population. Case Presentation: We report the case of a 21-year-old male kidney transplant recipient who developed MAS secondary to hepatitis B and C coinfection. The patient presented with fever, cervical and axillary lymphadenopathy, splenomegaly, and pancytopenia. Laboratory findings revealed hypertriglyceridemia, hypofibrinogenemia, elevated LDH, and hepatic cytolysis. Bone marrow aspiration confirmed hemophagocytosis. Six of the eight HLH-2004 diagnostic criteria were met, establishing the diagnosis of MAS. Hepatitis B PCR was >8 log10, and the patient was treated with entecavir, with favorable clinical and biological improvement.