PREVALENCE OF MATERNAL Ro (SS-A) AND La (SS-B) AUTOANTIBODIES IN RELATION TO CONGENITAL HEART BLOCK

Abstract

The prevalence of autoantibodies to ribonucleoprotein antigens in cases of congenital heart block was established using immunofluorescence, counterimmunoelectrophoresis, double immunodiffusion and Western blots. All of 35 mothers of babies with congenital heart block, none of five mothers of babies with other types of heart block, 10 of 29 women with connective tissue disease but no babies with heart block, four of 445 normal pregnant women and two of 109 healthy nonpregnant women had either Ro (SS-A) or La (SS-B) antibodies. Of 15 babies with congenital heart block, 10 of 10 who were less than 3 months old possessed antibody. Antibody titres in affected but not in normal infants were lower compared with their mothers' titres, suggesting deposition of antibodies in the baby's tissues. The findings indicate that placental transfer of anti-Ro (SS-A) or anti-La (SS-B) is essential for development of congenital complete heart block.

Evaluation of Transplacental Treatment for Fetal Congenital Bradyarrhythmia

“…26, 27 Interestingly, these antibodies are relatively common and are detected in 1-2% of randomly tested pregnant women. 28 Currently, the outcome of anti-Ro/SSA-positive pregnancies is very good when prospectively followed by multidisciplinary teams with experience in this field. 1 Transplacental passage of anti-Ro/SSA antibodies from mother to fetus, however, is associated with a risk of development of neonatal lupus erythematosus (NLE).…”

Identification of mothers at risk for congenital heart block and other neonatal lupus syndromes in their children. comparison of enzyme‐linked immunosorbent assay and immunoblot for measurement of anti–ss‐a/ro and anti–ss‐b/la antibodies

“…Antibodies to SS-A/Ro and SS-B/La ribonucleoproteins in maternal sera have been almost universally demonstrable when neonatal lupus is identified in a child (4)(5)(6). These autoantibodies are found with high frequency in the sera of individuals with Sjogren's syndrome (SS) or systemic lupus erythematosus (SLE), in some of their clinically normal relatives, and occasionally in otherwise healthy individuals (7,8).…”

Protein heterogeneity in the human Ro/SSA ribonucleoproteins. The 52- and 60-kD Ro/SSA autoantigens are encoded by separate genes.

“…Autoantibodies to Ro/SSA are found in the sera of30-50% ofpatients with systemic lupus erythematosus (SLE)' and in at least 50% of patients with primary Sjogren's syndrome (3,5). These autoantibodies occur in a higher percentage in patients with subacute cutaneous lupus erythematosus, and in essentially all neonatal lupus erythematosus patients with congenital heart block (6,7). The presence of anti-Ro/SSA antibodies is associated with lymphopenia, photosensitive dermatitis, pulmonary disease, and renal disease in lupus patients (8)(9)(10)(11)(12)(13), suggesting a pathogenic role for these antibodies in this disease.…”