American Board of Internal Medicine (ABIM) Certification Practice Exam

What autoantibody is commonly found in patients with CREST syndrome?

1. Anti-glutamic acid decarboxylase

2. Anti-basement membrane

3. Anti-centromere

4. Anti-phospholipase A2 receptor

The correct answer is: Anti-centromere

In patients with CREST syndrome, the presence of anti-centromere antibodies is a hallmark feature. CREST syndrome is considered a limited form of systemic sclerosis (scleroderma) and is characterized by the following symptoms: Calcinosis, Raynaud's phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasia. Anti-centromere antibodies are specifically associated with this variant of scleroderma and can be detected in a significant proportion of these patients. The antibodies target centromere proteins, which are involved in the management of chromosomes during cell division. Their presence is not only indicative of CREST syndrome but can also help in distinguishing it from other connective tissue diseases. In this context, other options like anti-glutamic acid decarboxylase, anti-basement membrane, and anti-phospholipase A2 receptor antibodies do not have a significant association with CREST syndrome. Anti-glutamic acid decarboxylase is primarily associated with Type 1 diabetes, anti-basement membrane antibodies are linked to Goodpasture's syndrome, and anti-phospholipase A2 receptor antibodies are often found in cases of primary membranous nephropathy. Therefore, anti