Inflammatory reactions in progressive multifocal leukoencephalopathy afterhighly active antiretroviral therapy

Three patients with progressive multifocal leukoencephalopathy (PML) treate d with highly active antiretroviral therapy (HAART) worsened clinically and radiologically. At the time of deterioration all three had reduced HIV vir aemia and increased CD4 cell counts. Brain biopsy in all three disclosed PM L and marked perivascular lymphoplasmacytic infiltration. We reviewed the s lides of 28 brain biopsies diagnostic of PML. Inflammatory changes were obs erved in four out of nine patients on HAART and in one out of 19 patients n ot on HAART.