Multiple sclerosis patients whose blood tests reveal elevated NfL, a biomarker of nerve damage, could see worsening disability one to two years later, according to a new study spearheaded by researchers at UC San Francisco.
In the study, published in JAMA Neurology on Nov. 6, 2023, and co-led by University Hospital and University of Basel, in Switzerland, the researchers looked at the incidence of disability worsening, defined as six months or more of increased impairment reflected in a higher score on the Expanded Disability Status Scale. They distinguished between disability worsening with relapse, which involves residual symptoms or the return of old ones following relapse, and gradual progression of symptoms without relapse.
The researchers tracked data spanning a 10-year period from approximately 4,000 patient visits to UCSF, comprising the EPIC study, and from approximately 9,000 patient visits to multiple sites in Switzerland, comprising the SMSC study. Together, the two studies included almost 1,900 patients. Among those, 570 patients were identified with disability that continued to worsen, of which the majority were independent of relapses.
Elevated NfL levels were associated with up to a 91% higher risk of worsening disability with relapse approximately a year later, and up to a 49% higher risk of worsening disability without relapse nearly two years later, the researchers found.
