Immunotherapy-related secondary hemophagocytosis in a glioblastoma patient: response to cytokine-directed therapy.

Hemophagocytic Lymphohistiocytosis (HLH) is a severe and potentially life-threatening condition characterized by an excessive and uncontrolled activation of the immune system. ICI-related hemophagocytic lymphohistiocytosis (irHLH) is a rare immune-related adverse event with an incidence of 0.03% to 0.4%. Although rare, it can be potentially lethal, with a high mortality rate of up to 50% in some cases. We present a patient with recurrent glioblastoma who developed Hemophagocytic Lymphohistiocytosis s a result of nivolumab treatment and was subsequently managed with cytokine-directed therapy (tocilizumab). Early diagnosis and treatment of Hemophagocytic Lymphohistiocytosis (HLH) associated with immune checkpoint inhibitors (ICIs) are indeed crucial due to the potentially life-threatening nature of the condition.Cytokine-based treatments (such as anti-IL-6) may be appropriate for patients who do not respond to high-dose steroids.