Multiple sclerosis and autoimmune diseases - a case control study.

Multiple sclerosis (MS) is one of the most common autoimmune diseases worldwide, and various autoimmune comorbidities have been reported with MS. The aim of this study was to estimate the prevalence of autoimmune disease comorbidity in patients with MS and their relatives in a Polish population. In this retrospective multicentre study, we investigated a group of patients with MS, and their relatives, in terms of age, gender, and the presence of simultaneous autoimmune diseases such as Graves's Disease, Hashimoto's thyroiditis, type 1 diabetes mellitus, myasthenia gravis, psoriasis, ulcerative enteritis, Crohn's Disease, coeliac disease, rheumatoid arthritis, autoimmune hepatitis and systemic lupus erythematous. This study included 381 patients with MS, of whom 52.23% were women. 27 patients (7.09%) had at least one autoimmune disease. The most common comorbidity was Hashimoto's thyroiditis (14 patients). 77 patients (21.45%) had relatives with an autoimmune disease, of which the most common was Hashimoto's thyroiditis. Our study revealed that the probability of autoimmune diseases co-occurring in patients with MS, and in their relatives, is higher and we found the greatest risk to be for Hashimoto's thyroiditis.