Therapy of progressive multifocal leukoencephalopathy (PML) in AIDS with Cidofovir (Vistide (R)). Review of the literature and two case reports

The progressive multifocal leukoencephalopathy (PML),a complication of the acquired immunodeficiency syndrome (AIDS) in 4%-5% of all cases, is an ence phalitis caused by the JC papovavirus. The prognosis is very poor with a me an survival time after diagnosis of 3 to 6 months. No effective therapy is known to date. Therapeutic trials in small groups of patients with alpha-in terferon, didanosine, and arabinoside were of mi nor success. A controlled study with cytarabine did not show any efficacy. Single case reports on a t herapy with cidofovir (Vistide(R)),an approved nucleotide-analogone in the therapy of cytomegalovirus-retinitis in AIDS-patients without renal dysfunc tion,showed positive results. We describe 2 more cases of a therapy of cido fovir in AIDS-associated PML. Out of 22 cases described in the literature, including these 2 cases, with a thera py of cidofovir in AIDS-associated PM L, 16 patients improved under therapy, 2 remained stable,and only 4 patient s still worsened fulminantly. These results indicate an additive antiviral effect of cidofovir against JC-virus. Th is may be used in the therapy of P ML in AIDS-patients because no alternative antiviral therapy of PML is avai lable at present. The efficacy of cidofovir for the therapy of PML is sugge sted by case reports. The exact mechanisms leading to an improvement under a therapy with cidofovir in the 16 cases described so far should be evaluat ed in a randomised, controlled study with an adequate size of cohorts.