Anti-Ro (SSA) and anti-La (SSB) antibodies and complete congenital heart block.

Complete congenital heart block (CCHB) is the most severe manifestation of neonatal lupus syndrome, associated with a mortality rate of up to 31%. It is caused by irreversible damage to the cardiac conduction system due to the transplacental passage of maternal antibodies to the fetus. Anti-Ro (SSA) and anti-La (SSB) antibodies are usually detected in sera of mothers of children with prenatally diagnosed CCHB and in cardiac tissues of affected newborns. Their pathogeneic role in the development of CCHB has been established in several studies. When CCHB is detected during pregnancy, careful monitoring and delivery are needed before heart failure is developed. Treatment strategies are debatable and may include prophylactic therapy for high-risk pregnant women and a combination of intrauterine plasmapheresis with plasma exchange or with corticosteroids. Pacemaker insertion is required in most infants during the first three months of life. Assays for anti-Ro (SSA) and anti-La (SSB) antibodies should be performed on sera of pregnant women with SLE and newborns with CCHB.