Antibody reactivity to alpha-enolase in mothers of children with congenital heart block.
OBJECTIVE
To evaluate the frequency of anti-alpha-enolase antibodies in the sera of mothers whose children have congenital heart block (CHB), given provocative results in which alpha-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 alpha-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-alpha-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-alpha-enolase reactivity.


CONCLUSIONS
The low frequency of anti-alpha-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 alpha-enolase.
Llanos
Carolina
C
Department of Medicine, New York University School of Medicine, New York, NY 10016, USA.
Chan
Edward K L
EK
Li
Songqing
S
Abadal
Grant X
GX
Izmirly
Peter
P
Byrne
Caroline
C
Clancy
Robert M
RM
Buyon
Jill P
JP
D001323:Autoantibodies / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D006327:Heart Block / Q000151:congenital* / Q000276:immunology; D006801:Humans; D007231:Infant, Newborn; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D010751:Phosphopyruvate Hydratase / Q000276:immunology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000276:immunology*
D001323:Autoantibodies; D010751:Phosphopyruvate Hydratase