Women with multiple sclerosis (MS) and people diagnosed with the disease at a younger age are more likely to have a benign course of MS, remaining fully functional for decades after disease onset, according to researchers at the School of Medicine and Biomedical Sciences in New York. Disease modifying drugs were also found to help maintain this benign state.
The results were published in the journal BMC Neurology, in the study, “Factors associated with benign multiple sclerosis in the New York State MS Consortium (NYSMSC).”
MS is known for following a highly heterogeneous course. Some patients have what is called benign MS (BMS), experiencing little disease progression and minimal disability, sometimes even decades after disease onset. But patients with BMS can only be diagnosed retrospectively, 10 or more years after MS onset.
Although the general recommendation is that newly diagnosed MS patients immediately start treatment, it is not known whether BMS patients might also benefit from earlier treatment with disease modeling drugs (DMDs).
Researchers analyzed more than 6,258 patients enrolled in The New York State MS Consortium (NYSMSC) to study the prevalence of BMS, the prognostic factors associated with BMS, and whether DMDs can maintain a benign status in people diagnosed with BMS at baseline.
Because there is no consensus as to a definition of BMS, the researchers used three distinct but common criteria to identify this condition: 1. patients who had an Expanded Disability Status Scale (EDSS) equal to or lower than 2, and disease duration greater than 10 years; or, 2. patients with an EDSS of 3 or lower, and disease duration greater than 15 years; or, 3. patients with an EDSS of 3 or lower, but disease duration of 10 or more years.
Depending on the classification criteria used, 19.8% to 33.3% of patients were characterized as having BMS at the time of enrollment.
Findings showed that female sex and younger age at disease onset were positive prognostic factors of having BMS at baseline. Conversely, African-American race and progressive MS at onset were negative prognostic factors, meaning that a lower percentage of patients with those characteristics had a disease that followed a benign course.
Among the 1,237 BMS patients identified with the most conservative criteria (No. 1), 742 were followed for a median of four years to examine the effect of DMD on BMS maintenance. The majority of patients who were on DMDs at enrollment or follow-up were receiving IFN-β1a (Avonex), IFN-β1b (Betaseron), or glatiramer acetate (Copaxone). One hundred and nine patients (14.7%) had no history of DMD use at enrollment and did not use DMD during the course of the study.
Investigators found that both DMD use and longer disease duration significantly predicted the maintenance of BMS status at follow-up. This protective effect was particularly obvious in patients who were taking DMD both at baseline and follow-up.
These findings suggest that early initiation and continued treatment with DMDs is beneficial for BMS patients, increasing their likelihood of maintaining a benign status.