American Board of Internal Medicine (ABIM) Certification Practice Exam

Which autoantibody is associated with pernicious anemia?

1. Anti-desmoglein

2. Anti-histone

3. Anti-parietal cell

4. Anti-GAD-65

The correct answer is: Anti-parietal cell

Pernicious anemia is an autoimmune disorder that affects the gastric mucosa, leading to a deficiency of intrinsic factor, which is essential for the absorption of vitamin B12. The presence of anti-parietal cell antibodies is a hallmark of this condition. These antibodies target the parietal cells in the stomach lining, which produce intrinsic factor. As a result, the destruction of these cells contributes to the development of vitamin B12 deficiency, ultimately leading to macrocytic anemia and neurologic complications. The association between anti-parietal cell antibodies and pernicious anemia is well-documented in clinical literature, making this choice the correct answer. Understanding this relationship helps clarify the mechanism behind pernicious anemia and its complications, reinforcing the importance of identifying these autoantibodies in affected patients for proper diagnosis and management.