Severe cytokine release syndrome resulting in purpura fulminans despite successful response to nivolumab therapy in a patient with pleomorphic carcinoma of the lung: a case report.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have provided more options in the treatment of lung cancer. However, ICIs can cause several unfavorable reactions generally referred to as immune-related adverse effects. CASE PRESENTATION: In this report, we present the case of a 52-year-old woman with successful regression of pleomorphic carcinoma of the lung following nivolumab therapy. She developed purpura fulminans (PF) ultimately resulting in amputation of both lower extremities. Blood tests revealed thrombocytopenia with increased serum soluble IL-2 receptor, ferritin, and triglyceride levels suggesting hemophagocytic lymphohistiocytosis (HLH). In addition, serum A disintegrin-like and metalloproteinase with thrombospondin type 1 motifs 13 activity was decreased, suggesting thrombotic thrombocytopenic purpura (TTP). Further detailed analysis revealed severe hypercytokinemia including increased levels of IL-1ß, IL-6, IL-10, TNFα, IFNγ, and G-CSF. CONCLUSION: The severe systemic inflammatory reaction and impaired peripheral circulation in this patient was attributed to excessive immunological effect induced by nivolumab resulting in cytokine release syndrome (CRS). This is the first report of a patient with multiple pathological conditions including HLH, TTP-like condition, and PF presumably arising from ICI-induced CRS. Further accumulating thoroughly investigated cases would lead to better understanding of the disease and development of reliable cancer immunotherapy.