Reversible complete atrioventricular block in a neonate with maternal anti-Sjögren's syndrome-associated antibody: atypical phenotype of autoimmune congenital heart block.

The fetus of anti-Sjögren's syndrome-associated antibody-positive mother developed complete atrioventricular block at 39 weeks of gestation and required urgent ventricular pacing after birth. Unexpectedly, the patient recovered from the atrioventricular block within a few days. Fraction analysis of maternal anti-Sjögren's syndrome-associated antibody revealed positivity for isolated anti-Ro/SSA 60 kDa antibody, which is abnormal as most patients with complete atrioventricular block present with anti-Ro/SSA 52 kDa positivity, which may indicate a potentially atypical late and reversible manifestation of an autoimmune congenital atrioventricular block in this patient.