A new study suggests that pediatric-onset multiple sclerosis is not protective against disability worsening even in the absence of relapses. Progression independent of relapse activity can occur at any age, and although pediatric onset is not fully protective against progression, the findings suggest that patients with pediatric onset are less likely to exhibit progression independent of relapse activity over a decade of follow-up.

Researchers in Italy set out to assess the incidence of and factors linked to progression independent of relapse activity and relapse-associated worsening in pediatric-onset MS compared with typical adult-onset MS and late-onset MS. They wanted to know what proportion of disability worsening happens in conjunction with relapses versus independent of relapse activity in pediatric-onset MS, and how it differs from adult-onset disease.

Although up to 20 percent of patients with MS experience onset before 18 years of age, it has been suggested that people with pediatric-onset MS are protected against disability because of the greater capacity for repair.

This study on prospectively acquired data from the Italian MS Register was performed from June 1, 2000, to September 30, 2021. At the time of data extraction, longitudinal data from 73, 564 patients from 120 MS centers were available in the register. The main outcomes included age-related cumulative incidence and adjusted hazard ratios for progression independent of relapse activity and relapse-associated worsening and associated factors.

This multicenter cohort study of 16,130 patients with MS found that although progression independent of relapse activity was rarely detectable before 18 years of age, pediatric onset was not protective against progression independent of relapse activity. Progression independent of relapse was observed in 40.4 percent of patients with pediatric-onset MS even while they were still young (i.e., approximately a single decade of follow-up), and delay in DMT initiation and less time receiving therapy were both linked to a higher risk of progression independent of relapse activity in pediatric-onset MS.

These data sets reinforce the benefit for DMT initiation in patients with pediatric-onset MS, as treatment was linked to reduced occurrence of both progression independent of relapse activity and relapse-associated worsening regardless of age at onset.

The findings were published in the journal JAMA Neurology.