Poor myelin repair may be behind worsening progressive MS

Remyelination appears to be less effective in people who developed multiple sclerosis (MS) in later life, according to new research.

MS onset usually occurs between the ages of 20 and 40. Anyone who develops their first symptoms after the age of 50 is considered to have late-onset MS (LOMS). Researchers from the University Medical Centre Gottingen, Germany, found people with LOMS have significantly fewer oligodendrocyte cells, which are responsible for making myelin in the spinal cord and brain, than people who develop MS earlier.

People who have LOMS also seem to have poorer relapse recovery, faster disease progression, and their response to disease-modifying therapies seems to be worse. When the myelin sheath is damaged by disease activity, some repairing by oligodendrocytes is possible, occurring in around 23-50% of the lesions in patients with normal onset MS.

People with LOMS are three times more likely to present with a progressive disease at the onset, with symptoms worsening regardless of relapses. The reductions in oligodendrocytes “could influence the efficacy of the reparative process, in particular remyelination, in patients with late-onset MS,” and noting this could be one factor driving greater disability progression in these people. “Therapeutic approaches to improve remyelination are thus necessary,” the researchers wrote.