Inflammation should be considered as a factor in any auto-immune disease. Try reading MS and Inflammation. Vitamin D deficiency is strongly linked with MS and other inflammatory diseases. Have you had your serum (25(OH)D) levels checked? I’d guess your doctor would’ve already covered that.
Other big sources of inflammation are dysbiosis, e.g. candida overgrowth, diet, stress and lack of exercise. Following the protocol here may be helpful in treating the first two. Read the blog in the link for advice on balancing fats to reverse inflammation.