Silent maternal autoimmunity unmasked by neonatal atrioventricular block: a case of neonatal lupus

Abstract

Neonatal lupus erythematosus (NLE) is a rare autoimmune condition resulting from transplacental transfer of maternal autoantibodies, most commonly anti-Ro/SSA and anti-La/SSB, and may present with cardiac, cutaneous, or hematological manifestations. We report a late preterm male neonate who presented on day one of life with respiratory distress and persistent bradycardia. Electrocardiogram revealed atrioventricular block with 2:1 conduction, while echocardiography showed no structural cardiac abnormalities. Autoimmune evaluation demonstrated elevated antinuclear antibodies, anti-Ro, anti-La, and anti-dsDNA antibodies, confirming the diagnosis of neonatal lupus. The neonate was managed with isoprenaline infusion followed by oral beta-blocker therapy, resulting in stabilization of heart rate. In view of these findings, the asymptomatic mother was evaluated and found to have elevated ANA, anti-Ro, and anti-La antibodies, suggestive of subclinical systemic lupus erythematosus. The infant remained clinically stable on follow-up, with appropriate neurodevelopment and later development of hypopigmented skin lesions, and is planned for pacemaker insertion at a later stage. This case highlights the importance of considering neonatal lupus in cases of unexplained neonatal bradycardia and emphasizes the need for evaluation of maternal autoimmune status even in the absence of symptoms.