Fatal ruxolitinib-related JC virus meningitis.

We report a possible association between ruxolitinib and JC virus meningitis. A 72-year-old man with myelofibrosis started treatment with ruxolitinib. Fourteen days later, the patient presented to the emergency department with fever and nausea. HIV test was negative. Ruxolitinib was suspended. Symptoms progressed with neck stiffness, cognitive impairment, and motor aphasia. CSF was positive for JC virus. MRI showed nonspecific abnormal findings. Five days after the clinical debut, the patient died. The clinical picture, MRI imaging, and positive JC virus PCR in CSF strongly suggest ruxolitinib-related JC virus meningitis.