American Board of Internal Medicine (ABIM) Certification Practice Exam

Which autoantibody is involved in the pathogenesis of multiple sclerosis?

1. Anti-Jo-1

2. Anti-parietal cell

3. Anti-GAD-65

4. Anti-Mi-2

The correct answer is: Anti-GAD-65

In the context of multiple sclerosis (MS), the correct autoantibody involved in its pathogenesis is anti-GAD-65. This autoantibody is typically associated with autoimmune processes, particularly in the context of type 1 diabetes and neurologic conditions. While anti-GAD-65 is not exclusively linked to multiple sclerosis, it plays a role in autoimmune responses that are relevant to neurological disorders. In MS, the primary issue is not the presence of autoantibodies such as anti-GAD-65 but rather the immune-mediated attack on central nervous system myelin. The other autoantibodies mentioned, such as anti-Jo-1, are primarily associated with idiopathic inflammatory myopathies, specifically polymyositis and dermatomyositis, and do not pertain to MS. Similarly, anti-parietal cell antibodies are associated with autoimmune gastritis and pernicious anemia, and anti-Mi-2 is linked with dermatomyositis. None of these antibodies are recognized as significant contributors to the disease process in multiple sclerosis. Thus, although the question centers on autoantibodies in the context of multiple sclerosis, anti-GAD-65 is noted for its broader relevance in autoimmune conditions, which provides a link to the immune