Isolated congenital complete heart block: longterm outcome of mothers, maternal antibody specificity and immunogenetic background.

Objective: To assess the longterm outcome of mothers of children with isolated congenital complete heart block (CCHB), and the maternal specific immunoblot pattern and HLA antigens.

Methods: Fifteen mothers of 16 children with isolated CCHB were investigated; their followup extended up to 15.8 years on average after the index delivery. Anti-Ro and La antibodies were detected by counterimmunoelectrophoresis and ELISA; anti-Ro antibodies were studied by immunoblot. HLA typing was done using a microcytotoxicity test.

Results: One mother has systemic lupus erythematosus (SLE) before the index delivery. The other mothers developed only minor symptoms (arthralgia, dry eyes and photosensitivity) resembling primary Sjögren's syndrome more than classic lupus. All 15 mothers were anti-Ro and 9 were also anti-La positive, a mean of 12.5 years after the index delivery. Eight mothers reacted with the 52 kDa SSA(Ro) component, and 2 also with the 60 kDa SSA(Ro) component. The prevalence of the DR3 antigen and of the B44/DR5, DR3/DQ2 and A1/Cw7/B8/DR3/DQ2 haplotypes was significantly increased.

Conclusion: The longterm outcome for the mothers of children with CCHB is more reassuring than generally assumed. All the mothers were anti-Ro positive by sensitive ELISA: Reactivity to the denaturated 52 kDa SSA(Ro) component seems characteristic of these mothers, who presented a particular immunogenetic background.