Treatment Options for the Comorbidity of Multiple Sclerosis with Other Chronic Inflammatory Diseases

Approximately 280 000 people in Germany suffer from multiple sclerosis (MS), an autoimmune disease of the central nervous system. Of these, approximately 5% have a comorbid chronic inflammatory disease: the more common ones are psoriasis, rheumatoid arthritis (RA), and chronic inflammatory bowel diseases (IBDs, of which the main types are ulcerative colitis and Crohn's disease).

This narrative review is based on pertinent publications retrieved by a literature search in PubMed, as well as relevant guidelines. All statements in this article reflect a consensus among the authors, who represent different medical disciplines.

As the data from clinical trials to date are limited, judgments about the proposed treatments are a matter of expert opinion. In general, TNFα blockers should not be used in patients with MS, as they can worsen the disease. In patients with MS and psoriasis, dimethyl fumarate is a useful option for mild disease activity. In MS with comorbid RA, azathioprine and leflunomide/teriflunomide are suitable for mild disease activity. For more severe disease activity, anti-CD20 antibodies have been approved for both diseases and should be used. In MS with comorbid IBD, azathioprine is suitable for mild disease activity. Ozanimod has been approved for patients who have MS and comorbid ulcerative colitis with more severe disease activity, especially those who are JCnegative; it shares its mechanism of action (VLA-4 blockade) with natalizumab.

The treatment of patients who have both MS and another chronic inflammatory disease should be interdisciplinary and personalized, and treatments must be planned with due attention to potential adverse effects. Further studies of treatment for this group of patients are needed.