Comorbid Autoimmune Diseases In MS Patients May Influence Disease Progression

Background: Multiple Sclerosis (MS) has traditionally been viewed as an autoimmune disease, and recent studies have shown increased comorbidity with other autoimmune diseases. It is currently unknown if comorbid autoimmune diseases influence MS disease progression.

Objectives: This study aims to examine the association between comorbid autoimmune diseases and MS disease progression in Relapsing-Remitting MS (RRMS) subjects.

Methods: Subjects were part of the New York State Multiple Sclerosis Consortium (NYSMSC) registry. Of the 3293 participants, 762 (23.1%) reported ever having a comorbid autoimmune disease. During a mean follow up time of 5.0 years, 613 (18.6%) subjects converted from RRMS to Secondary Progressive MS (SPMS). Logistic regression analyses were performed with conversion to SPMS as the outcome and autoimmune disease as the predictor, while controlling for age at symptom onset, sex, Kurtzke Expanded Disability Status Scale (EDSS) at registration,  registration year, and disease modifying therapy.

Results: After controlling for confounders, having a comorbid autoimmune disease was significantly associated with MS disease progression from RRMS to SPMS. In adjusted models the effect was strongest for subjects who reported ever using a DMT, OR 1.4 (95% CI, 1.1-1.8) and was not significant in subjects who did not use DMT.  

Conclusions: Our findings suggest that the presence of comorbid autoimmune diseases may adversely influence MS disease progression. Further research between MS and other autoimmune diseases and its relationship with DMT is crucial, as it may influence the chosen treatment and give more insight into the underlying etiology.