Concentration of autoantibodies to native 60‐kd ro/ss‐a and denatured 52‐kd ro/ss‐a in eluates from the heart of a child who died with congenital complete heart block

Objective. To determine the serologic specificity of acid eluates from tissues of a child who died with congenital complete heart block (CCHB). Methods. Tissues were extracted, acid eluted, and the IgG and antibody titers determined on the eluates by enzyme‐linked immunosorbent assay. Results. Antibodies to native 60‐kd and denatured 52‐kd Ro/SS‐A were found to be enriched only in the heart eluate, and not in the eluates from brain, kidney, and skin. Conclusion. These findings indicate a major role for anti–native 60‐kd Ro/SS‐A in the immunopathogenesis of CCHB.