In situ evidence of JC virus control by CD8+ T cells in PML-IRIS during HIV infection.

Objective: To determine the pathophysiologic features of progressive multifocal leukoencephalopathy (PML) associated with immune reconstitution inflammatory syndrome (PML-IRIS) in HIV-infected patients.

Methods: In a cross-sectional study, we retrospectively analyzed 11 HIV-infected patients with a firm diagnosis of PML-IRIS. Brain biopsies were collected from 5 patients and their histopathologic features were compared to those of 4 HIV-infected patients with classic PML.