Systemic lupus erythematosus (SLE) and its treatment have been associated with progressive multifocal leukoencephalopathy (PML)1. We report a case of PML in a 58-year-old woman with SLE treated with belimumab, a biological therapy approved in 2011 for refractory SLE2. To the best of our knowledge, to date, 1 other such case has been described in the literature3. There was no …