For patients with primary progressive MS, age is a particularly important factor that predicts disease activity.
At the AAN 2023 Fall Conference, Ilana Katz Sand, MD, discussed recent developments in primary progressive MS (PPMS). Dr. Katz Sand is a clinician and researcher in the Corinne Goldsmith Dickinson Center for Multiple Sclerosis at Mount Sinai.
A recent systematic review and meta-analysis published in Frontiers in Neurology examined PPMS, assessing disease activity and its predictors for this MS subtype. Katelijn M. Blok, a clinical researcher and PhD student at Erasmus Medical Center in the Netherlands, and colleagues reviewed 34 articles with 7,109 patients in total.
At the time of study inclusion, the midpoint age ranged from 38.5 to 55.8, midpoint disease duration ranged from 3.0 to 11.7 years, and the percentage of women in a study ranged from 0% to 73.3%. Most studies included data on relapses (n=20) and radiologic disease activity (n=23).
Identifying Variables that Predict Disease Activity
Blok and colleagues reported that radiologic disease activity was more frequent than clinical disease activity (31.9% vs 9.2%). The researchers examined studies that assessed only clinical outcomes and found the weighted estimated proportion of overall disease activity across all studies was 26.8% (95% CI, 20.6 to 34.0%).
Univariable analyses resulted in no significant predictors for overall disease activity. In multivariable analyses that included predefined variables, only midpoint age at the time of study inclusion was a significant negative predictor of overall disease activity (P=0.031). “This finding is in line with studies comparing active versus non-active PPMS, reporting a younger age of onset in active PPMS,” the researchers wrote.
A sensitivity analysis showed that lower midpoint age at the time of study inclusion predicted higher disease activity (P=0.007). This analysis also found that longer radiological follow-up predicted a higher prevalence of radiological disease activity (P=0.005).
Selecting Patients for Immunomodulating Therapies
The pooled estimate of inflammatory disease activity—26.8%—indicates that “about a quarter of [people with PPMS] could benefit meaningfully from [immunomodulating therapies],” Blok and colleagues wrote.
“Especially when treating relatively young [people with PPMS], clinicians should remain vigilant for inflammatory disease activity,” they continued, noting the importance of follow-up. “This follow-up should include a customized program of clinical and MRI monitoring to not overlook possible indications for [immunomodulating therapies].”
Finally, they noted that the age of patients “should be carefully considered when interpreting trial results.”
For more coverage of the AAN 2023 Fall Conference, please click here.
