A Pilot Study of the Efficacy of Recombinant Alpha Interferon (IFN-A2b) and Zidovudine (AZT) in the Treatment of Progressive Multifocal Leukoencephalopathy (PML) Complicating HIV-1 Infection

Inclusion Criteria Patients must have: * HIV seropositivity by both ELISA and Western blot. * Biopsy proven progressive multifocal leukoencephalopathy (PML). Exclusion Criteria Co-existing Condition: Patients with the following conditions or symptoms are excluded: * Intolerant to interferon. * Prior or concomitant central nervous system disease (CNS) such as toxoplasmosis, multiple sclerosis (MS), or neurosyphilis. Patients with the following are excluded: * Intolerant to interferon. * Prior or concomitant central nervous system disease (CNS) such as toxoplasmosis, multiple sclerosis (MS), or neurosyphilis. Prior Medication: Excluded: * Patients receiving interferon for other reasons.