Cytomegalovirus-induced hemophagocytic lymphohistiocytosis revealing systemic lupus erythematosus: a case report.

INTRODUCTION AND

IMPORTANCE

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening hyperinflammatory syndrome caused by excessive immune activation. Secondary HLH may arise from infection, malignancy, or autoimmune disease. Cytomegalovirus (CMV) reactivation and systemic lupus erythematosus (SLE) are recognized triggers, but their coexistence as concurrent causes is extremely uncommon. Early recognition is critical, as delayed treatment significantly worsens outcomes.

CASE PRESENTATION: A 33-year-old woman presented with prolonged fever, oral ulcers, alopecia, arthralgia, and hepatosplenomegaly. Laboratory tests showed pancytopenia, hyperferritinemia (24 500 ng/mL), hypertriglyceridemia, and hypofibrinogenemia. Autoimmune evaluation confirmed new-onset SLE, while polymerase chain reaction verified CMV reactivation. She met six of eight HLH-2004 criteria, and her HScore was 301 (>99% probability), establishing secondary HLH triggered by CMV in the setting of SLE. Treatment included intravenous methylprednisolone followed by tapering oral prednisolone, cyclosporine, mycophenolate mofetil, hydroxychloroquine, and ganciclovir, with supportive antimicrobials and prophylaxis. The patient improved within 2 weeks, with normalization of ferritin and blood counts. Follow-up was weekly for 1 month, then biweekly, and monthly thereafter.

CLINICAL DISCUSSION: This case highlights CMV-associated secondary HLH presenting in the context of newly diagnosed SLE in a young woman. Overlapping infectious and autoimmune features, along with cytopenias, delayed recognition. Her prompt clinical, hematologic, and ferritin response illustrates the benefit of early diagnosis and immunosuppressive plus antiviral treatment.

CONCLUSION

Concurrent CMV-induced HLH and new-onset SLE are rare but should be considered in patients with unexplained fever and cytopenias. Maintaining a high index of suspicion and initiating prompt, targeted treatment are essential to achieve remission and prevent relapse.