A newborn has persistent bradycardia detected at birth. Electrocardiogram shows complete atrioventricular block. The mother reports having had a rash with photosensitivity last year. Which maternal antibodies are responsible for this condition?

• A Anti-dsDNA antibodies
• B Anticardiolipin antibodies
• C Anti-Smith antibodies
• D Anti-La (SSB) and anti-Ro (SSA) antibodies ✓

Explanation

Neonatal lupus results from transplacental passage of maternal anti-Ro/SSA and anti-La/SSB antibodies, which bind fetal cardiac conduction tissue and cause permanent congenital complete heart block, along with a photosensitive annular rash, thrombocytopenia, or hepatitis. Anti-dsDNA and anti-Smith define maternal SLE itself but do not cause congenital heart block, and anticardiolipin antibodies cause fetal loss rather than AV block.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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