American Board of Internal Medicine (ABIM) Certification Practice Exam

Which autoantibody is associated with bullous pemphigoid?

1. Anti-hemidesmosome

2. Anti-desmoglein

3. Anti-histone

4. Anti-centromere

The correct answer is: Anti-hemidesmosome

Bullous pemphigoid is a chronic autoimmune blistering skin condition characterized by the presence of large, tense blisters on the skin, particularly affecting the elderly. It is primarily associated with autoantibodies targeting proteins that are crucial for the integrity of the epidermis and dermis junction. The specific autoantibodies found in bullous pemphigoid are directed against hemidesmosome proteins, primarily BP180 (also known as type XVII collagen) and BP230. These components play a vital role in anchoring the epidermis to the dermis. The presence of these autoantibodies results in a disruption of this anchoring, leading to the formation of blisters when there is shearing stress on the skin. In contrast, the other autoantibodies mentioned are associated with different autoimmune blistering or connective tissue diseases. For instance, anti-desmoglein antibodies are typically associated with pemphigus vulgaris, which targets a different component of the skin (desmosomes responsible for cell adhesion). Anti-histone antibodies are often seen in drug-induced lupus erythematosus, while anti-centromere antibodies are associated with limited scleroderma, particularly CREST syndrome. Thus, the correct identification of