ORLANDO—Among patients with multiple sclerosis (MS), treatment with a disease-modifying therapy (DMT) may be associated with more rapid development of autoimmune disease than remaining untreated, according to data presented at the Fifth Cooperative Meeting of the Consortium of MS Centers and the Americas Committee for Treatment and Research in MS. In addition, irritable bowel syndrome (IBS) may be more prevalent among patients with MS who receive a DMT than among untreated patients.
Lynn Chouhfeh, MD, medical resident at the University at Buffalo, New York, and colleagues analyzed data from the New York State MS Consortium (NYSMSC) longitudinal registry to investigate the type and prevalence of comorbid autoimmune diseases in patients with MS treated with various DMTs. Eligible patients had at least five years of follow-up and clinically definite MS according to McDonald criteria. Patients with unknown DMT use before enrollment were excluded, as were patients with an autoimmune disease at the time of entry into the registry.
Of the 2,047 eligible patients, 281 developed an autoimmune disease after DMT initiation, and 33 patients who were DMT naïve developed an autoimmune disease. Autoimmune diseases included Crohn’s disease, myasthenia gravis, IBS, psoriasis, and rheumatoid arthritis, among others. DMT types included interferon beta-1a, interferon beta-1b, glatiramer acetate, and natalizumab, among others.
Rheumatoid Arthritis Was More Common Among Untreated Patients
The researchers found no demographic differences between the treated and untreated patients with MS. Approximately 91% of untreated patients were female, compared with 85% of treated patients. Mean age at registration was approximately 61 for untreated patients and 52 for patients who later received a DMT.
Thyroid disease was the most common autoimmune disease in both groups. The mean time from MS symptom onset to first comorbid autoimmune disease was significantly shorter among patients who received DMTs (192 months) than among untreated patients (262 months). The effect remained after adjusting for covariates in logistic regression modeling.
IBS was more common in the group of DMT users, compared with patients who were treatment naïve. Rheumatoid arthritis, however, was more common among untreated patients than among patients who received a DMT.
“Identifying risk factors associated with the development of autoimmune disease in the context of DMT use merits further understanding,” said Dr. Chouhfeh. “Our study results may contribute to identifying more appropriate personalized therapeutic management decisions for MS patients.”
Comorbid Autoimmune Disease May Increase Odds of MS Progression
A related study presented at the same meeting suggested that having a comorbid autoimmune disease significantly increases the odds of disease progression among patients with MS. Among individuals with relapsing-remitting MS, about 22% of patients with comorbid autoimmune disease developed secondary progressive MS, compared with 18% of patients without comorbid autoimmune disease. After adjusting for confounders, the investigators found that patients with comorbid autoimmune disease were 1.4 times as likely to develop secondary progressive MS than patients without comorbid autoimmune disease.
Katelyn S. Kavak, research scientist at the University at Buffalo, and colleagues analyzed data from the NYSMSC registry for 3,292 subjects with clinically definite relapsing-remitting MS and at least one follow-up. Eight types of autoimmune disease were reported in the database, including thryroid, lupus, psoriasis, and rheumatoid arthritis. Participants were considered to have a comorbid autoimmune disease if they ever reported having one or more such diseases at study enrollment or at follow-up.
The researchers compared subjects who reported having an autoimmune disease with those who did not to determine the effects of autoimmune disease on MS progression. The team conducted logistic regression analysis and controlled for age at symptom onset, sex, Expanded Disability Status Scale (EDSS) score at enrollment, and DMT use.
Progression Was More Prevalent Among Patients Using DMT
Compared with patients without comorbid autoimmune disease, patients with comorbid autoimmune disease were older at MS symptom onset (33 vs 31) and more likely to be female (84% vs 75%). EDSS score at enrollment did not differ between the two groups, but it was higher at the most recent follow-up among patients with comorbid autoimmune disease than among subjects without.
The researchers found no difference in race, education, or DMT use between the groups. But after results were stratified by DMT use, progression was significantly more prevalent in subjects using DMT than among subjects who did not use DMT.
“The increased susceptibility patients with MS have to other autoimmune diseases might be due to the effects of DMT use, as others have reported an increased susceptibility to thyroid issues in patients with MS after interferon treatment,” said Ms. Kavak. “Causality cannot be assumed in this study, and it has to be considered that subjects with a comorbid autoimmune disease might be different from those without a comorbid autoimmune disease. Subjects with a more severe form of relapsing-remitting MS may have a higher prevalence of medication use, which may not necessarily stop disease progression, but might induce autoimmune disease,” she added. “It would be of interest to investigate whether treating the autoimmune disease comorbidity would improve MS disease course.”