American Board of Internal Medicine (ABIM) Certification Practice Exam

Fetuses of mothers with which antibodies are at risk for developing neonatal lupus erythematosus?

1. Anti-dsDNA and Anti-Smith antibodies

2. Anti-Ro/SSA or Anti-La/SSB antibodies

3. Anti-RNP and Anti-CCP antibodies

4. Anti-histone and Anti-ribosomal P antibodies

The correct answer is: Anti-Ro/SSA or Anti-La/SSB antibodies

Neonatal lupus erythematosus (NLE) is a condition that can arise in infants born to mothers who have specific autoimmune antibodies. The antibodies most commonly associated with NLE are Anti-Ro (also known as Anti-SSA) and Anti-La (also known as Anti-SSB). When these antibodies cross the placenta, they can affect the fetus, leading to complications such as skin rashes, congenital heart block, and other systemic signs of neonatal lupus. The pathogenesis of NLE is primarily linked to the presence of these antibodies because they can lead to damage in fetal tissues, particularly the heart and skin. In contrast, while other antibodies mentioned, such as Anti-dsDNA and Anti-Smith, are significant in diagnosing and managing systemic lupus erythematosus (SLE), they are not associated with neonatal lupus. Anti-RNP is also more related to mixed connective tissue disease, and Anti-CCP is primarily seen in rheumatoid arthritis. Neither of these antibody types is linked to the condition of neonatal lupus. Similarly, Anti-histone antibodies are commonly associated with drug-induced lupus and do not have the same association with neonatal lupus as the Anti-Ro and Anti-La antibodies do. Thus, the correct identification