Concomitant multiple sclerosis and another autoimmune disease: Does the clinical course change?

Multiple Sclerosis is a demyelinating disease that can cause different symptoms by the autoimmune involvement of myelin. CD4+ and CD8+ T-cells as well as B-cells play important roles in MS pathophysiology. Co-existence of other autoimmune diseases and multiple sclerosis has been reported previously in the literature. It is not clear whether this co-existence may change the clinical course of MS or not. In this study we aim to evaluate the prevalence of other autoimmune diseases among patients with MS and if they may play any role in the clinical course of the patients.

Twenty four patients with multiple sclerosis and another simultaneous autoimmune disease were detected among 1700 patients referred to the MS clinic of Sina Hospital during two years. Sex, age, duration of MS and the autoimmune disease as well as the type of the latter were recorded. For evaluation of disease progression a control group was randomly selected from the same patients referred to the clinic. EDSS was measured and recorded in both groups.

The prevalence of concomitant autoimmune disease and multiple sclerosis was 0.014. The mean age of the patients was 35.04±6.45years. There were 18 different autoimmune diseases in the first group. The mean duration of MS and concomitant autoimmune disease were 5.91 and 9.80±7.1years respectively. The mean of EDSS in these patients was 1.62±1.12 and in the control group was 3.33±1.89. One patient had developed secondary progressive course in the first group. The statistical difference between these groups based on EDSS, was significant (P-value: <0.001). The median of EDSS in the first group was 1.5 and in the second one was 2.5. The mean of annual relapse rate in the first group was 0.60 and in the second one was 0.62 (P-value: 0.71).

The present study shows that several other autoimmune diseases may coexist with MS and their presence may modify the course of the disease. This should be re-evaluated in multicenter prospective long term studies.