Serum total IgE level during pregnancy and postpartum

Background: Studies on serum IgE levels during pregnancy are limited. Objective: To investigate the course of serum total IgE levels during pregnancy and postpartum. Methods: 159 pregnant subjects provided 218 serum samples during various stages of pregnancy and the postpartum period. Serum total IgE geometric means were compared at various trimesters and postpartum. In addition, the postpartum IgE data were analysed according to the method of delivery. Analysis was also done according to history of allergy. Results: The geometric mean serum total IgE was 20.5 IU/ml in the first trimester, 20.8 IU/ml in the second and 22.2 IU/ml in the third. Postpartum serum IgE level showed a lower mean, 14.9 IU/ml during the early postpartum period (less than 30 days) compared to 30.3 IU/ml during the late postpartum period (30 days-25 weeks). However this was not statistically significant. Serum IgE in the postpartum period also did not differ according to method of delivery. A history of allergy was positive in 98 samples, negative in 61 and unclear in 59. Using analysis of variance, none of these three groups showed significant change in serum total IgE level during pregnancy or postpartum. Conclusion: In this cross-sectional study, serum total IgE levels showed no statistically significant changes during pregnancy or postpartum. This finding would be of greater weight if reproduced in a larger number of subjects with multiple serial samples at fixed regular time intervals during pregnancy and postpartum (AU)

Does heredity determine the allergy manifestation or the sensitisation to a specific allergen?

Background: The role of genetics in allergy development is well accepted. However, studies could not delineate the mode of inheritance or what is specifically being inherited. The purpose of this study was to determine the effect of genetics on the development of allergy manifestation, serum IgE level, and sensitization to specific allergens. Methods: Fifty-eight twin sets (age 7 months to 11 years) were evaluated for allergy by medical history, family history, physical examination, serum total IgE level, and percutaneous testing to selected common allergens. Results: In 25 monozygotic (MZ) sets, concordance of atopy was significantly higher than in 33 dizygotic (DZ) sets (84.6% vs 62.5%). The age at onset tended to be earlier when the mother was allergic than when the father was (23.5 months vs 30.5 months). When both twins were allergic, the intra-pair difference in age at onset was within <6 months in 50% of MZ sets versus 31.8% in DZ sets. Total IgE level in twins showed a very strong correlation in MZ sets (r 0.92), but only a moderate correlation among DZ sets (r 0.57). Skin test positivity to specific allergens did not show a significant concordance between twins in either group. Conclusion: Our study indicates that the genetic influence was strongest on the inheritance of IgE phenotype, the development of the atopic tendency, the age of onset, and to some extent on the specific allergy manifestation. The effect seemed less on determining the specific offending allergen(s), suggesting possible roles of epigenetic and environmental factors