Age-Dependent Seroprevalence of JCV Antibody in Children.

Progressive multifocal leukoencephalopathy (PML) is an opportunistic central nervous system infection, caused by the John Cunningham virus (JCV). PML may occur during treatment with immunosuppressive agents or monoclonal antibodies such as natalizumab. The JCV seroprevalence increases with age with a seropositivity of 60% in the adult human population. In this study, we analyzed sera from 109 pediatric multiple sclerosis (MS) patients (mean age 14 years) as well as sera from 162 patients with a wide range of suspected neurologic disorders (mean age 6.3 years). Our results showed a considerably lower seroprevalence for JCV in our pediatric cohort with 33.3% and equal distribution in both subgroups, compared with reported seropositivity in adult population. This could result in a lower risk for drug-induced PML in pediatric patients compared with adult patients and can influence the indication for natalizumab therapy in pediatric MS patients.