Birth order and cord immunoglobulin E: results using a high-sensitivity immunoglobulin E protocol

Relationship of Cord Blood Immunoglobulin E and Maternal Immunoglobulin E with Birth Order and Maternal History of Allergy in Albanian Mother/Neonate Pairs

BACKGROUND

Previous studies reported that familial factors such as birth order and mothers atopy might influence cord blood levels and development of allergies.

AIM

The aim of the study was to evaluate the relationship of cord blood IgE and maternal IgE with birth order and mothers history of allergy in Albanian mother/neonate pairs.

MATERIAL AND METHODS

Study population represented 291 mother-infant pairs. Mothers were interviewed with a questionnaire for personal history of allergy and pregnancy history whereas serum IgE levels were determined using sandwich IRMA assay.

RESULTS

The mean level of cIgE in neonates with detectable levels was 1.59 (n = 78). No significant difference in means of cIgE was found between first born and later born neonates (p = 0.232) and between neonates of mothers with a negative and positive history of allergy (p = 0.125). Also, no significant difference was found between means of mIgE by birth order, whereas there was a significant difference of mIgE between mothers with and without a history of allergy (p = 0.01). In a group of neonates with detectable cIgE levels, maternal IgE levels were moderately correlated with cIgE levels.

CONCLUSION

Cord blood IgE is not affected by birth order and mothers history of allergy, whereas mothers IgE are affected by the history of allergy but not by birth order.

Sibling number and prevalence of allergic disorders in pregnant Japanese women: baseline data from the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Although an inverse relationship between number of siblings and likelihood of allergic disorders has been shown in many epidemiological studies, the biological mechanism underlying this phenomenon has not yet been identified. There is no epidemiological research regarding the sibling effect on allergic disorders in Japanese adults. The current cross-sectional study examined the relationship between number of siblings and prevalence of allergic disorders among adult women in Japan.

METHODS

Subjects were 1745 pregnant women. This study was based on questionnaire data. The definitions of wheeze and asthma were based on criteria from the European Community Respiratory Health Survey whereas those of eczema and rhinoconjunctivitis were based on criteria from the International Study of Asthma and Allergies in Childhood. Adjustment was made for age, region of residence, pack-years of smoking, secondhand smoke exposure at home and at work, family history of asthma, atopic eczema, and allergic rhinitis, household income, and education.

RESULTS

The prevalence values of wheeze, asthma, eczema, and rhinoconjunctivitis in the past 12 months were 10.4%, 5.5%, 13.0%, and 25.9%, respectively. A significant inverse exposure-response relationship was observed between the number of older siblings and rhinoconjunctivitis, but not wheeze, asthma, or eczema (P for trend=0.03); however, the adjusted odds ratio (OR) for having 2 or more older siblings was not significant although the adjusted OR for having 1 older sibling was statistically significant (adjusted OR=0.71 [95% CI: 0.56-0.91]). Number of total siblings and number of younger siblings were not related to wheeze, asthma, eczema, or rhinoconjunctivitis.

CONCLUSIONS

This study found a significant inverse relationship between the number of older siblings and the prevalence of rhinoconjunctivitis among pregnant Japanese women. Our findings are likely to support the intrauterine programming hypothesis; however, we could not rule out the hygiene hypothesis.