%0 Journal Article %A Carolina Llanos %A Edward K.L. Chan %A Songqing Li %A Grant X. Abadal %A Peter Izmirly %A Caroline Byrne %A Robert M. Clancy %A Jill P. Buyon %T Antibody Reactivity to α-Enolase in Mothers of Children with Congenital Heart Block %D 2009 %R 10.3899/jrheum.080860 %J The Journal of Rheumatology %P jrheum.080860 %X Objective To evaluate the frequency of anti-α-enolase antibodies in the sera of mothers whose children have congenital heart block (CHB), given provocative results in which α-enolase, a membrane protein, was recognized by monoclonal antibodies reactive with the peptide p200 of 52 kDa Ro/SSA in a neonatal rat heart library. Methods An ELISA using a recombinant α-enolase protein was developed. Sera from 100 anti-Ro52+ CHB mothers in the Research Registry for Neonatal Lupus, 50 patients with systemic lupus erythematosus (SLE; 7 anti-Ro52+), and 48 healthy controls were tested for anti-α-enolase reactivity. Results There were no significant differences in the median values obtained from CHB mothers, patients with SLE, or controls at each of the dilutions tested. Only 7 (7%) at 1:100 dilution and 2 (2%) at 1:1000 dilution of 100 CHB sera were 3 standard deviations above the mean value obtained for controls. Preincubation with recombinant Ro52 did not inhibit anti-α-enolase reactivity. Conclusion The low frequency of anti-α-enolase antibodies in the sera of CHB mothers and the absence of apparent cross-reactivity with Ro52 suggest that antibodies to Ro52 are not likely to mediate CHB via binding to α-enolase. %U https://www.jrheum.org/content/jrheum/early/2009/02/04/jrheum.080860.full.pdf