Inflammatory reactions in progressive multifocal leukoencephalopathy after highly active antiretroviral therapy.

Three patients with progressive multifocal leukoencephalopathy (PML) treated with highly active antiretroviral therapy (HAART) worsened clinically and radiologically. At the time of deterioration all three had reduced HIV viraemia and increased CD4 cell counts. Brain biopsy in all three disclosed PML and marked perivascular lymphoplasmacytic infiltration. We reviewed the slides of 28 brain biopsies diagnostic of PML. Inflammatory changes were observed in four out of nine patients on HAART and in one out of 19 patients not on HAART.