Secondary Hemophagocytic Lymphohistiocytosis Mimicking Sepsis in Adults: A Case Series

Background and Clinical Significance: Secondary hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that can closely resemble sepsis in adults, potentially delaying recognition and treatment. Because infection may trigger or coexist with HLH, persistent or disproportionate inflammation despite appropriate antimicrobial therapy should prompt reassessment for concomitant HLH and investigation of the underlying trigger; Case Presentation: We describe three adults initially managed for presumed sepsis or severe infection at a referral hospital in Colombia. All developed persistent fever, cytopenias, organomegaly, and marked hyperferritinemia. HScore values were 222, 246, and 248, respectively; the score in Case 3 was calculated retrospectively from available pretreatment data. Bone marrow hemophagocytosis was demonstrated in Cases 1 and 2 but not in Case 3. The underlying triggers were acute myeloid leukemia, disseminated histoplasmosis in the setting of advanced HIV infection, and visceral leishmaniasis. The malignancy-associated case had an unfavorable outcome. Both infection-associated cases improved after pathogen-directed therapy combined with corticosteroids to control hyperinflammation, without escalation to an etoposide-based regimen; Conclusions: Sepsis and secondary HLH should not be regarded as mutually exclusive diagnoses. Persistent or disproportionate inflammation accompanied by progressive multilineage cytopenias, splenomegaly, markedly elevated or rising ferritin levels, hypertriglyceridemia, and/or decreasing fibrinogen should prompt early HScore calculation, assessment of HLH-2004 criteria, and concurrent investigation for an underlying trigger. Recognition of the clinical pattern and individualized treatment of both the trigger and hyperinflammatory state may facilitate timely management.