Biopsy-proven PML in an HIV-negative patient with discoid lupus: Failure to detect JC virus in CSF.

Abstract We present a case of a 58-year-old man with a history of severe discoid lupus erythematosus and acute encephalopathy and incoordination. Antinuclear antibody testing was weakly positive but all other laboratory tests for systemic lupus erythematosus were negative and serum quantitative immunoglobulins and lymphocytes were normal. MRI brain showed T2/FLAIR hyperintensities within the bilateral parietal and temporal lobes with involvement of subcortical U fibers. CSF PCR was negative for varicella-zoster virus, herpes simplex, JCV and BK virus. However, JCV antibody index was elevated (3.88; reference: