High anti‐IgE levels at birth are associated with a reduced allergy prevalence in infants at risk: a prospective study

Abstract

Development of atopic disease was prospectively studied in 148 children from birth to the age of 18 months and related to serum levels of IgG anti-IgE antibody. Children with a dual heredity of allergy, but remaining healthy, had significantly higher IgG anti-IgE levels at birth than children with a similar predisposition to allergy, who became allergic. Children with increased allergy risk, defined by elevated IgE levels at birth (> = 0.53 kU/l) and with probable allergy symptoms had also significantly higher IgG anti-IgE levels at birth than children of the same risk group, developing definite allergy. Independent of allergy risk, there was a significantly lower prevalence of atopic disease in children with cord serum levels of IgG anti-IgE above 350 AU/l than in children with lower levels. Additionally, we showed that the allergy predictive capacity of IgE levels in cord serum was slightly improved in specificity, sensitivity and efficiency by including not only the family history of allergy, but also cord serum levels of IgG anti-IgE. Our results thus raise the possibility that high levels of IgG anti-IgE protect children of increased allergy risk from early development of atopic disease and reduce the severity of symptoms.

Disproportional Distribution of Isotype and Non-lsotype-Specific IgG Subclass Anti-lgE Autoantibodies in Human Cord Serum

“…IS IgG a-E Ab mainly belonged to the IgGl and IgG4 subclass in median concentrations of < 4 (range: <4-36.6) and 0.32 ng/ml (range:<0.1-!3), respectively (table 2). Wc have shown that IgG a-E Ab are commonly detected in cord scrum in agreement with previous data on a few samples [4] and a recent extended study [26]. We further demonstrate that IgG a-E Ab in randomly collected cord se ra may belong to all four IgG subclasses although with dif ferent prevalences.…”

“…Particularly noteworthy is the appar ent preponderance of IS a-E Ab of the lgG4 subclass which normally constitutes only a minor part of serum IgG [27]. lgG4 Ab may have some scavenger or blocking function since it does not activate complement, is functionally mono valent and thereby form small immune complexes [37], Our findings need consideration when interpreting the interesting data of Vassella et al [26]. Their results, also obtained by ELISA but with a different IgE myeloma pro tein (lgE NDa), suggest that an increased IgG a-E Ab level in cord serum may protect high-risk infants with dual hered ity [parcnt(s) or sibling] against the development of subse quent allergy.…”

“…It also raises justified questions on the definition of a-E Ab and may in part explain the difficulties in establishing any physiological role for a-E Ab. Recently, increased IgG a-E Ab levels in cord serum were suggested to protect high-risk infants from developing subsequent allergy [26], but no dis tinction was made between NIS and IS a-E Ab. neither were the individual IgG subclasses evaluated.…”

Early Immune Responses to Allergens

“…One possibility could be to prevent mucosal absorption of allergen; alternatively, high levels of IgG antibodies could possibly modify the neonatal immune response. Another possibility was indicated by a study re porting that elevated levels of IgG anti-IgE antibodies in the cord blood were associated with a lover incidence o f allergy during the first 18 months of life [13]. This was particularly obvious in babies with a strong family history o f allergy.…”

Is Allergy a Preventable Disease?

“…Birth at this time of the year would provide low levels of cord serum IgG antibodies. Furthermore, high levels of IgG anti-IgE antibodies in cord blood are associated with less allergy during the first 18 months of life, particularly in babies with a strong family history of allergy 35 .…”