JC VIRUS AND MULTIPLE-SCLEROSIS - A REFUTATION

Polyomavirus JC (JCV) has been implicated in the etiology of multiple sclerosis (MS), because it causes progressive multifocal leukoencephal opathy (PML), a multifocal demyelinating disease with many microscopal similarities to MS. During childhood, the virus establishes a latent infection in the kidneys, which can be reactivated in immunocompromise d patients. During reactivation, the virus is shed in the urine. The k idney is the only known site of latent infection and reactivation. The refore, excretion of the virus in the urine of MS patients is to be ex pected, if reactivated JCV is involved in the etiology of MS. We studi ed urine samples of 53 patients with definitive MS and of 53 controls matched for age and sex. We found no evidence of active JCV infection in MS. The hypothesis of a polyomaviral etiology of MS is not supporte d by the results of this study.