Disease modifying therapies use associated with comorbid autoimmune diseases in multiple sclerosis patients

Background The relation between the use of disease modifying therapies (DMT's) and the occurrence of comorbid autoimmune diseases (AID's) in multiple sclerosis (MS) patients is still unclear. Objective To investigate the difference in duration from MS symptom onset to first reported AID in subjects using DMT's vs. DMT naïve. Type and prevalence of comorbid AID's was also investigated. Methods Data was extracted from the New York State MS Consortium (NYSMSC) registry and comprised of MS patients with a minimum of 5 years follow-up. After exclusion, 1792 patients were enrolled in the study, 1478 had no AID, and 314 patients had comorbid AID's that developed after the initial enrollment. Patients who had an AID were divided into two groups: those with an AID after DMT initiation (n=281) and patients with an AID who were DMT naïve (n=33). Logistic regression analysis was used to test differences in duration between MS symptom onset and the development of AID between the two groups while adjusting for confounders Results DMT use did not change the frequency of self-reported AID (17.2 vs. 20.4%). However, the duration between first MS symptom onset and the initial reported occurrence of a comorbid AID was significantly shorter in the DMT user group (192 months±115) compared to the DMT naïve group (262 months±107, p=.002). Conclusion There were no group differences between DMT users vs. DMT naïve subjects with regards to AID frequency. The DMT user group reported the development of an AID earlier than the DMT naïve group. Further studies that can identify patients with higher risk for developing AID's is warranted.