Progressive multifocal leukoencephalopathy in a patient with systemic lupus erythematosus: Clues to early diagnosis.

A case of progressive multifocal leukoencephalopathy (PML) occurring on low dose immunosuppression for systemic lupus erythematosus (SLE) and Sjogren's syndrome (SS) is presented. Neurologic changes in patients with SLE or SS should not be assumed to be a disease manifestation. Importantly, serious opportunistic infections such as PML can occur in minimally immunosuppressed rheumatic patients. Early diagnosis, facilitated by scrutiny of MRI findings, should trigger measures to reconstitute immunity in an otherwise fatal disease.