Immune Checkpoint Inhibitor-Associated Hemophagocytic Lymphohistiocytosis: Clinical Presentation and Outcomes in Three Patients.

Immune checkpoint inhibitor therapy has become increasingly recognized as a trigger for hemophagocytic lymphohistiocytosis, a life-threatening hyperinflammatory syndrome that may lead to organ failure without timely interventions. Given the rarity of this entity, patients are often misdiagnosed with more common oncologic complications. In the present series, we describe 3 patients with diverse clinical pictures evaluated at hospital admissions, who were ultimately diagnosed with immune checkpoint inhibitor-associated hemophagocytic lymphohistiocytosis. Treatment consisted of dexamethasone combined with an immunosuppressive agent such as anakinra, ruxolitinib, or tocilizumab, with variable clinical responses among patients. These cases highlight the importance of maintaining a high index of suspicion for hemophagocytic lymphohistiocytosis in patients presenting with systemic inflammation during immune checkpoint inhibitor therapy.