Maternofetal Transfer of Antibodies and the Influence of Maternal Atopic Status on the Neonate

Background

Epidemiologic evidence has shown that sensitization of allergic diseases develops early in life, even before birth. The gestational environment, including maternal atopic status and transplacentally transferred antibodies to allergens, may be of importance in the sensitization process.

Objective

To investigate maternofetal transfer of antibodies and the influence of maternal atopic status on the neonatal immune response.

Methods

Fifty-seven healthy pregnant women who underwent elective cesarean section (ECS) were recruited. Total and specific IgE (Phadiatop) levels in cord blood (CB) and maternal blood (MB) were determined using the ImmunoCAP assay. MB- and CB-specific IgG1 and IgA1 antibodies against ovalbumin and house dust mite were analyzed by enzyme linked immunosorbent assay. The cytokines, interleukin (IL)-13, interferon (IFN)-γ, and IL-10 in the supernatant of cultured CB mononuclear cells were quantified by enzyme linked immunosorbent assay. Two subgroups were defined based on the maternal levels of specific IgE (atopic group, Phadiatop IgE more than or equal to 0.35 kilo international units of allergen-specific antibody (KUA)/L; nonatopic group, Phadiatop IgE less than 0.35 KUA/L).

Results

Although total IgE was detectable in all MB samples, it could only be detected in 7% (4/57) of the CB samples. Specific IgE was detectable in all MB samples but undetectable in all CB samples. There was no correlation of total IgE between mothers and their neonates. The concentrations of IL-10, IL-13, and allergen-specific IgG1 and IgA1 in the CB samples did not differ significantly between the atopic and nonatopic groups. IFN-γ was undetectable in the CB samples.

Conclusions

Maternal IgE cannot be transferred to the child in utero. Maternal atopic status has no significant effect on neonatal immune responses.

Breastmilk from allergic mothers can protect offspring from allergic airway inflammation

OBJECTIVE

Breastfeeding is associated with a reduced risk of developing asthma in children. Using a murine model we previously demonstrated that mothers with Th1-type immunity to ovalbumin (OVA) transfer antigen-specific protection from OVA-induced allergic airway disease (AAD) to their offspring. The aim of this study was to evaluate the contribution of breastmilk and maternal B cell immunity from allergic mothers in the vertical transmission of protection from AAD.

METHODS

This was investigated using an adoptive nursing strategy. Naive offspring were nursed by allergic wild-type or B cell-deficient foster mothers with histories of Th2-type immunity to OVA. Following weaning, offspring were immunized with OVA-Al(OH)(3) and challenged with aerosolized OVA to induce AAD.

RESULTS

Offspring nursed by wild-type OVA-immune foster mothers demonstrated lower levels of OVA-specific immunoglobulin E, interleukin-5, and airway eosinophilia than progeny nursed by naive control mothers. In contrast, offspring nursed by B cell-deficient OVA-immune foster mothers had similar parameters of OVA-induced AAD as progeny nursed by naive control mothers.

CONCLUSIONS

These data demonstrate the ability of breastmilk from allergic mothers to protect offspring from AAD was dependent on intact maternal B cell immunity. Nursing alone, when done by wild-type mothers with AAD, was sufficient for offspring to acquire the antigen-specific protective factor(s) from breastmilk.

Serum ovalbumin-specific immunoglobulin G responses during pregnancy reflect maternal intake of dietary egg and relate to the development of allergy in early infancy

BACKGROUND

The value of allergen elimination diets during pregnancy for primary prevention of infant allergy has been questioned. However, dietary compliance may influence effectiveness.

OBJECTIVES

To monitor egg intake during a randomized controlled trial of egg avoidance throughout pregnancy and lactation by serial measurements of serum ovalbumin (OVA) IgG concentration in conjunction with dietary diary record and also, to analyse specific IgG concentrations at birth in relation to infant allergic outcome.

METHODS

Pregnant women, with personal or partner atopy, were randomized to complete dietary egg exclusion or an unmodified healthy diet before 20 weeks gestation. The infants were evaluated for atopy at 6 months of age. Serum food-specific IgG concentrations were determined by ELISA in maternal samples collected at study recruitment and during labour, and in infant samples at birth (umbilical cord).

RESULTS

Serum-specific IgG to OVA, but not the unrelated allergen, cow's milk beta-lactoglobulin, decreased over pregnancy in egg-avoiding women only (P<0.001). Cord OVA IgG concentration correlated with maternal IgG at delivery (r=0.944; P<0.001), and for infants born to atopic women, cord concentration was higher than that of their mother's (P<0.001). Infants with the lowest and highest cord IgG concentrations were the least likely, and those with mid-range concentrations were the most likely, to be atopic by 6 months of age (P=0.008).

CONCLUSION

Serum OVA IgG concentration reflects egg consumption, thereby indicating dietary allergen doses to which the developing immune system might be exposed. Trans-placental maternal IgG must be considered among early life factors that regulate infant atopic programming.

Effects of maternal allergen-specific IgG in cord blood on early postnatal development of allergen-specific T-cell immunity

BACKGROUND

A wide body of epidemiologic evidence indicates that as yet unknown maternal factor(s) can influence susceptibility to allergic disease in the offspring. It is also well established that the induction of allergen-specific T-cell memory is frequently initiated in utero, and it is likely that maternal factors exert their influence during this period.

METHODS

This study examines the relationship between maternally derived allergen-specific IgG subclass antibodies and cellular immune responses (lymphoproliferation and cytokine production) against the same allergens in 49 subjects tested at birth and at 2 years of age. Polyclonal production of the Th1 cytokine IFN-gamma was also examined in the cord-blood samples.

RESULTS

At birth, there were positive correlations between both house-dust mite (HDM)- and ovalbumin (OVA)-specific IgG subclass levels in cord blood, maternal atopy, and the magnitude of perinatal lymphoproliferative responses to respective allergens. Inverse relationships were also observed between cord-blood IgG antibody titres and allergen-specific production of some Th2 cytokines. However, there were no consistent relationships between cord-blood allergen-specific IgG antibodies and subsequent immune responses to allergens when the same subjects were retested at 2 years of age. An inverse relationship was observed between maternal history of atopy and perinatal IFN-gamma production capacity.

CONCLUSIONS

Our results suggest that transplacental transfer of allergen-specific IgG antibody is unlikely to be a major mechanism for maternal regulation of allergen-specific immunity in infancy. An alternative possibility is that maternal effects may operate by influencing IFN-gamma production by T cells in the offspring.

Cord blood levels of immunoglobulin G subclass antibodies to food and inhalant allergens in relation to maternal atopy and the development of atopic disease during the first 8 years of life

BACKGROUND

Factors that either protect from or enhance the development of atopic disease appear to be acting early in life. The gestational environment, including maternal immune responses, such as transplacentally transferred immunoglobulin (Ig) G antibodies to allergens, may be of importance in this respect, since allergen-specific immunity has been demonstrated to develop in utero.

OBJECTIVE

To evaluate the relation between cord blood IgG subclass antibodies to allergens, maternal atopy and development of atopic disease in the children.

MATERIAL AND METHODS

The study group comprised a cohort of 96 children participating in a prospective study up to 8 years of age. Cord blood IgG subclass antibodies to ovalbumin, beta-lactoglobulin, Bet v 1 and cat dander were analysed by ELISA.

RESULTS

The levels of all IgG subclass antibodies to ovalbumin and rBet v 1 were higher in newborn infants with an atopic mother, as compared with babies with nonatopic mothers. IgG1 antibody levels to cat and IgG4 antibody levels to beta-lactoglobulin and cat were also higher in atopic than in nonatopic mothers, whereas the other subclass antibody levels to those allergens were similar. High levels of cord blood IgG antibodies to cat and birch, but not to the food allergens, were associated with less atopic symptoms in the children during the first 8 years of life. Moreover, children who developed IgE antibodies to cat had lower levels of IgG antibodies to that allergen at birth.

CONCLUSIONS

High levels of cord blood IgG subclass, especially IgG4, antibodies to food and inhalant allergens are associated with maternal atopy. High levels of IgG antibodies to inhalant, but not food, allergens are associated with less development of atopy in the children.

Prospective estimation of IgG, IgG subclass and IgE antibodies to dietary proteins in infants with cow milk allergy. Levels of antibodies to whole milk protein, BLG and ovalbumin in relation to repeated milk challenge and clinical course of cow milk allergy

Prospectively, serum levels of IgE, specific IgE antibodies (AB) to whole cow milk protein (CMP), bovine se-albumin, bovine immunoglobulin, bovine lactoferrin, bovine lactalbumin and beta-lactoglobulin (BLG), IgG and IgG subclass antibodies to ovalbumin (OA) and BLG, and IgG4 RAST to CMP (bovine whey) were measured in 39 infants with cow milk protein allergy (CMPA) at birth (cord blood), at time of diagnosis and before and after milk challenge at the age of 12 months. Immunological measurements were also undertaken in 33 control infants without CMPA at birth, at 6 months and at 18 months. At no time, were differences found between the levels of IgG and IgG subclass AB to OA and BLG in control versus infants with CMPA. In the 39 infants with CMPA no correlation was found between the levels of IgE, IgG and IgG subclass AB in cord blood and subsequent levels of these values, irrespective of the type of CMPA (IgE-mediated (CMA) or non-IgE-mediated (CMI)), and irrespective of whether remission had occurred. In cord blood 25/33 (76%) of the infants with CMPA had specific IgE-AB to one or more of the bovine milk proteins indicating a prenatal intrauterine sensitization to cow milk protein. At 6 months the frequency of specific IgE-AB to bovine milk proteins was significantly (p less than 0.05) higher in infants with CMA versus CMI, and at 12 months total serum-IgE and the increase of these specific IGE-AB and RAST to CMP were significantly higher (p less than 0.05) in infants with persistent CMA. From 6 to 12 months withholding milk resulted in a significant fall in specific IgE-AB to CMP, and IgG, IgG1 and IgG4 anti-BLG followed by an increase after milk challenge. Decreasing levels of IgG anti-OA from birth to 6 months reflect passive maternal transfer of IgG through the placenta, and increasing levels of IgG anti-BLG, already from birth to 6 months, may represent an early exposure to CMP in all infants. Significantly higher levels (p less than 0.05) of IgG anti-OA AB, IgG1 and IgG4 anti-BLG AB were found in infants with persistent CMA, indicating a close relation between the synthesis of IgE and IgG and between IgE and IgG subclasses (IgG1 and IgG4) in symptomatic cow milk-allergic individuals.(ABSTRACT TRUNCATED AT 400 WORDS)