Relationship between maternal and foetal specific IgE

Aim: A positive correlation between maternal and cord blood IgE levels is well documented for total IgEs, but not for specific IgEs. The difficulty in detecting specific cord blood IgEs is due to their low concentrations, which hinder their dosage by low-sensitivity methods. This study aimed to correlate maternal and fetal specific IgEs against individual cow's milk proteins, detected by highly sensitive and specific techniques. Methods: Cow’s milk specific IgE detection was performed by chemiluminescence on 52 specimens of maternal and cord blood after cow’s milk protein separation by 1D and 2D gel electrophoresis. Cow’s milk protein (CMP) antigens were identified by mass spectrometry techniques. Results: Specific IgEs for CMPs were found in 25/52 (48.1%) of maternal sera and in 19/52 (37%) of cord blood sera. In order of decreasing frequency, the proteins found were BSA, IgG heavy chain, caseins and, in a single case, b-lactoglobulin. Positive cord blood sera in all cases corresponded to a positive maternal result and maternal and fetal immunoreactivity patterns were closely correlated. Moreover, in no cases was there a positive cord blood response with a negative maternal response. Conclusion: The study demonstrates a close relationship between maternal and cord blood specific IgE patterns. The phenomenon observed could provide a model to elucidate the general production method of fetal IgEs, which might only be produced in the presence of both the corresponding maternal IgE and the related allergen.