Previous studies have demonstrated that some children with
spina bifida have
IgE to
proteins in
natural rubber. In this study we compare different sources of
latex antigen and identify possible antigenic
peptides by radioimmunoblotting technique. Sera were collected from 26 children with
spina bifida, tested by RAST with ammoniated
latex extract (AL), and frozen until use. Extracts were prepared from ammoniated and nonammoniated
latex, and the
proteins were separated by electrophoresis on a 15%
sodium dodecyl suflate-
polyacrylamide gel and transferred to polyvinylene difluoride (
PVDF). Strips of
PVDF were then incubated with individual sera and 125I-labeled rabbit antihuman
IgE before development by autoradiography; 18/26 sera were AL RAST positive; 0/8 AL RAST-negative patients had any binding to the
latex proteins on
PVDF. Sera from all patients were tested in a RAST with a nonammoniated
latex extract (NAL), and the results were comparable to the AL RAST. Liquid-phase AL and NAL were comparable in their ability to inhibit the binding of patient's
IgE to solid-phase AL and NAL. Sera from 14 RAST-positive patients were tested by immunoblotting with separated, reduced, and nonreduced AL and NAL. All 14 sera demonstrated
IgE binding to a 14 kd
peptide, which was more pronounced in reduced NAL. These results suggest that the 14 kd
peptide in NAL is a major
antigen in
rubber allergy but that AL is an acceptable
antigen source for in vitro diagnostic studies.