Maternal autoantibody profiles at risk for autoimmune congenital heart block: a prospective study in high-risk patients.

OBJECTIVE This prospective study aimed to identify antibody profiles characterising mothers with fetuses developing congenital heart block (CHB) by comparing their antibody frequencies and levels with those in unaffected mothers. METHODS Eighty-one consecutive pregnant patients positive to anti-Ro±anti-La antibodies, at high risk of developing fetal CHB were prospectively studied. The 16 patients with fetal CHB outcome were considered the study population and the 65 patients with normal pregnancy outcomes were considered the control cohort. Anti-Ro52, anti-Ro60, anti-p200 and anti-La antibodies were assayed using home-made ELISA assays. RESULTS The prevalence of anti-p200 antibodies was significantly higher in the fetal CHB affected patients than in the controls (p=0.03). Combinations of anti-p200 with anti-Ro52 and anti-Ro60 antibodies were significantly more frequent in the women with fetuses developing CHB than in the controls (p=0.03 for all combinations). The women with fetal CHB had significantly higher mean anti-Ro52, anti-Ro60 and anti-p200 levels than the controls (p=0.003, p=0.0001 and p=0.04, respectively); mean anti-La/SSB level was not significantly different in the two cohorts (p=0.25). CONCLUSIONS Since anti-p200, anti-Ro52 and anti-Ro60 antibodies, especially at high level, seem to identify patients at increased risk of developing fetal CHB, their detection could recognise anti-Ro/La positive women at risk for having an infant with this rare, potentially dangerous disorder.