Hemophagocytic lymphohistiocytosis in a rheumatoid arthritis patient treated with infliximab.

Hemophagocytic lymphohistiocytosis (HLH) is a rare condition with high mortality. We report a case of a 74-year-old woman with rheumatoid arthritis who developed HLH secondary to pyelonephritis due to Escherichia coli infection following infliximab treatment. Bone marrow aspiration showed proliferation of histiocytes with hemophagocytosis. The patient died despite treatment with intravenous antibiotics intravenous methylprednisolone and intravenous immunoglobulin. Cytokine levels were measured and are discussed.