DALLAS—Correcting vitamin D deficiency early in the course of treatment with interferon beta-1b is likely to improve the outcome for patients with multiple sclerosis (MS), according to data presented at the 2014 Cooperative Meeting of CMSC and ACTRIMS. “The results of this study support the importance of identifying and correcting 25(OH)D insufficiency early in the course of MS,” said Alberto Ascherio, MD, DrPH, and colleagues. “The effects are likely additive to therapy with interferon beta-1b without decreasing its tolerability.”
Dr. Ascherio, from the Harvard School of Public Health in Boston, and colleagues sought to examine the predictive effect of serum 25(OH)D levels on disease activity and progression in patients with clinically isolated syndrome starting interferon beta-1b therapy. They also examined the effect of serum 25(OH)D levels on the occurrence of flu-like symptoms, a common side-effect of interferon beta-1b.
Drawing their study cohort from the BEtaferon/BEtaseron in Newly Emerging MS for Initial Treatment (BENEFIT) study, the researchers randomized patients with clinically isolated syndrome and two or more clinically silent brain MRI lesions to 250 mcg of interferon beta-1b (early treatment) or placebo (late treatment) subcutaneously every other day. Serum 25(OH)D concentration measurements were taken at baseline and at six, 12, and 24 months. Cox proportional hazard models or generalized mixed effects models were used to relate season-adjusted 25(OH)D concentrations to clinical and MRI outcomes up to five years. Occurrence of flu-like symptoms in the early treatment group with high or low serum 25(OH)D levels were compared by chi-square test.
Data from 216 patients in the early treatment group and 118 patients in the delayed treatment group were analyzed. When analyzed as a continuous variable, increases in 25(OH)D led to a lower probability of conversion to McDonald MS, with a trend toward lower probability of conversion to clinically definite MS. Increases in 25(OH)D also led to lower rates of newly active lesions, relapses, annual percent change in T2 volume, and annual percent change in brain volume. Dichotomous 25(OH)D levels were strongly and inversely associated with probability of conversion to clinically definite MS, cumulative number of new lesions on MRI, percent change in T2 volume, and percent change in brain volume. Occurrence of flu-like symptoms did not differ between patients in the early treatment group with high or low serum 25(OH)D levels at months 6, 12, and 24.
Dr. Ascherio and colleagues concluded that among patients who started interferon beta-1b treatment right after clinically isolated syndrome, incremental increases of 25(OH)D levels were associated with reduction of long-term MS disease activity and severity. “These results also suggest that early treatment with interferon beta-1b has an additive effect with 25(OH)D to reduce disease severity and progression on both clinical and imaging outcomes.”
Further research would be needed, the researchers said, to determine whether these results apply to patients with different MS subtypes or those treated with drugs other than interferon beta-1b.