Progressive multifocal leukoencephalopathy in patients with AIDS receivinghighly active antiretroviral therapy

Recent reports suggest that human immunodeficiency virus (HIV)-associated p rogressive multifocal leukoencephalopathy (PML) may improve with highly act ive antiretroviral therapy (HAART). We observed three patients who develope d PML while receiving HAART. All patients received HAART for 4-11 months an d had low plasma levels of HIV-1 RNA before the onset of symptoms of PML. A ntiretroviral therapy was changed in two patients, and their plasma HIV-1 R NA levels declined significantly. Despite this virologic response, PML did not improve in these patients. The third patient's HIV-1 RNA level became u ndetectable while he was receiving HAART, and his symptoms of PML improved after the addition of interferon alpha. Our observations suggest that PML c an develop in patients who have shown clinical response to HAART. Furthermo re, PML may not improve despite an adequate virologic response to HAART. De finitive therapy is still needed for PML.