The diagnostic significance of IgG cow's milk protein antibodies re-evaluated

Consensus on the diagnosis and treatment of cow's milk protein allergy of the Latin American Society for Pediatric Gastroenterology, Hepatology and Nutrition

Cow's milk protein allergy (CMPA) is the most frequent cause of food allergy in the first months of life. Despite the fact that there are different guidelines and recommendations on the management of children with CMPA, there continues to be great variability in diagnostic and therapeutic criteria in Latin America. The Food Allergy Working Group of the Latin American Society for Pediatric Gastroenterology, Hepatology and Nutrition summoned a group of Latin American experts to reach a consensus and formulate a document to unify diagnostic and therapeutic criteria for CMPA. Three teams were formed, each with a coordinator, and the members of each team developed a series of statements for their corresponding module: a) clinical manifestations and diagnosis; b) diagnostic tools, and c) treatment. A search of the medical literature was carried out to support the information presented in each module and 28 statements were then selected. The statements were discussed, after which they were evaluated by all the experts, utilizing the Delphi method. Their opinions on statement agreement or disagreement were anonymously issued. The final statements selected were those with above 75% agreement and their corresponding recommendations were formulated, resulting in the document presented herein.

Gastrointestinal Food Allergies and Intolerances

Adverse reactions to food include immune-mediated food allergies, celiac disease, and nonimmune-mediated food intolerances. Differentiating between these many disorders is important to guide us toward appropriate testing and management. Double-blind placebo-controlled food challenges are the gold standard for food allergy diagnosis but are difficult and time-consuming. In place of this, strong clinical history, other supportive tests, and oral food challenges are helpful. Some commonly available tests for food allergy and intolerances lack sufficient evidence for efficacy. Food intolerance diagnosis is largely based on history and supported by symptom improvement with appropriate dietary manipulation.

Infant formulas containing hydrolysed protein for prevention of allergic disease

BACKGROUND

Infant formulas containing hydrolysed proteins have been widely advocated for preventing allergic disease in infants, in place of standard cow's milk formula (CMF). However, it is unclear whether the clinical trial evidence supports this.

OBJECTIVES

To compare effects on allergic disease when infants are fed a hydrolysed formula versus CMF or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective, including extensively or partially hydrolysed formula (EHF/PHF). To determine whether infants at low or high risk of allergic disease, and whether infants receiving early short-term (first few days after birth) or prolonged formula feeding benefit from hydrolysed formulas.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 11), MEDLINE (1948 to 3 November 2017), and Embase (1974 to 3 November 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles and previous reviews for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials that compared use of a hydrolysed formula versus human milk or CMF. Outcomes with ≥ 80% follow-up of participants from eligible trials were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed trial quality and extracted data from the included studies. Fixed-effect analyses were performed. The treatment effects were expressed as risk ratio (RR) and risk difference (RD) with 95% confidence intervals and quality of evidence using the GRADE quality of evidence approach. The primary outcome was all allergic disease (including asthma, atopic dermatitis, allergic rhinitis and food allergy).

MAIN RESULTS

A total of 16 studies were included.Two studies assessed the effect of three to four days infant supplementation with an EHF while in hospital after birth versus pasteurised human milk feed. A single study enrolling 90 infants reported no difference in all allergic disease (RR 1.43, 95% CI 0.38 to 5.37) or any specific allergic disease up to childhood including cow's milk allergy (CMA) (RR 7.11, 95% CI 0.35 to 143.84). A single study reported no difference in infant CMA (RR 0.87, 95% CI 0.52 to 1.46; participants = 3559). Quality of evidence was assessed as very low for all outcomes.No eligible trials compared prolonged hydrolysed formula versus human milk feeding.Two studies assessed the effect of three to four days infant supplementation with an EHF versus a CMF. A single study enrolling 90 infants reported no difference in all allergic disease (RR 1.37, 95% CI 0.33 to 5.71; participants = 77) or any specific allergic disease including CMA up to childhood. A single study reported a reduction in infant CMA of borderline significance (RR 0.62, 95% CI 0.38 to 1.00; participants = 3473). Quality of evidence was assessed as very low for all outcomes.Twelve studies assessed the effect of prolonged infant feeding with a hydrolysed formula compared with a CMF. The data showed no difference in all allergic disease in infants (typical RR 0.88, 95% CI 0.76 to 1.01; participants = 2852; studies = 8) and children (typical RR 0.85, 95% CI 0.69 to 1.05; participants = 950; studies = 2), and no difference in any specific allergic disease including infant asthma (typical RR 0.57, 95% CI 0.31 to 1.04; participants = 318; studies = 4), eczema (typical RR 0.93, 95% CI 0.79 to 1.09; participants = 2896; studies = 9), rhinitis (typical RR 0.52, 95% CI 0.14 to 1.85; participants = 256; studies = 3), food allergy (typical RR 1.42, 95% CI 0.87 to 2.33; participants = 479; studies = 2), and CMA (RR 2.31, 95% CI 0.24 to 21.97; participants = 338; studies = 1). Quality of evidence was assessed as very low for all outcomes.

AUTHORS' CONCLUSIONS

We found no evidence to support short-term or prolonged feeding with a hydrolysed formula compared with exclusive breast feeding for prevention of allergic disease. Very low-quality evidence indicates that short-term use of an EHF compared with a CMF may prevent infant CMA. Further trials are recommended before implementation of this practice.We found no evidence to support prolonged feeding with a hydrolysed formula compared with a CMF for prevention of allergic disease in infants unable to be exclusively breast fed.

Unproven Diagnostic Tests for Food Allergy

The gold standard for diagnosis of immunoglobulin E (IgE)-mediated food allergy remains the oral food challenge, with serum IgE testing and skin prick testing serving as acceptable alternatives. However, the increase in prevalence of food allergy (both physician diagnosed and patient suspected) has led patients to pursue a variety of other alternative diagnostic procedures for suspected food allergy, which are reviewed in this article. These procedures (IgG testing, electrodermal testing, cytotoxic testing, provocation/neutralization, and applied kinesiology) have largely been unproven and may lead to unnecessary elimination diets.

WITHDRAWN: Infant formulas containing hydrolysed protein for prevention of allergic disease and food allergy

BACKGROUND

Allergy is common and may be associated with foods, including cow's milk formula (CMF). Formulas containing hydrolysed proteins have been used to treat infants with allergy. However, it is unclear whether hydrolysed formulas can be advocated for prevention of allergy in infants.

OBJECTIVES

To compare effects on allergy and food allergy when infants are fed a hydrolysed formula versus CMF or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective, including extensively or partially hydrolysed formula (EHF/PHF). To determine which infants at low or high risk of allergy and which infants receiving early, short-term or prolonged formula feeding may benefit from hydrolysed formulas.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group supplemented by cross referencing of previous reviews and publications (updated August 2016).

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials that compared use of a hydrolysed formula versus human milk or CMF. Trials with ≥ 80% follow-up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility of studies for inclusion, methodological quality and data extraction. Primary outcomes included clinical allergy, specific allergy and food allergy. We conducted meta-analysis using a fixed-effect (FE) model.

MAIN RESULTS

Two studies assessed the effect of three to four days' infant supplementation with an EHF whilst in hospital after birth versus pasteurised human milk feed. Results showed no difference in infant allergy or childhood cow's milk allergy (CMA). No eligible trials compared prolonged hydrolysed formula versus human milk feeding.Two studies assessed the effect of three to four days infant supplementation with an EHF versus a CMF. One large quasi-random study reported a reduction in infant CMA of borderline significance among low-risk infants (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.00).Prolonged infant feeding with a hydrolysed formula compared with a CMF was associated with a reduction in infant allergy (eight studies, 2852 infants; FE RR 0.82, 95% CI 0.72 to 0.95; risk difference (RD) -0.04, 95% CI -0.08 to -0.01; number needed to treat for an additional beneficial outcome (NNTB) 25, 95% CI 12.5 to 100) and infant CMA (two studies, 405 infants; FE RR 0.38, 95% CI 0.16 to 0.86). We had substantial methodological concerns regarding studies and concerns regarding publication bias, as substantial numbers of studies including those in high-risk infants have not comprehensively reported allergy outcomes (GRADE quality of evidence 'very low').Prolonged infant feeding with a hydrolysed formula compared with a CMF was not associated with a difference in childhood allergy and led to no differences in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy. Many of the analyses assessing specific allergy are underpowered.Subroup analyses showed that infant allergy was reduced in studies that enrolled infants at high risk of allergy who used a hydrolysed formula compared with a CMF; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF. Studies that enrolled infants at high risk of allergy; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF found a reduction in infant CMA.

AUTHORS' CONCLUSIONS

We found no evidence to support short-term or prolonged feeding with a hydrolysed formula compared with exclusive breast feeding for prevention of allergy. Very low-quality evidence indicates that short-term use of an EHF compared with a CMF may prevent infant CMA.In infants at high risk of allergy not exclusively breast fed, very low-quality evidence suggests that prolonged hydrolysed formula feeding compared with CMF feeding reduces infant allergy and infant CMA. Studies have found no difference in childhood allergy and no difference in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy.Very low-quality evidence shows that prolonged use of a partially hydrolysed formula compared with a CMF for partial or exclusive feeding was associated with a reduction in infant allergy incidence and CMA incidence, and that prolonged use of an EHF versus a PHF reduces infant food allergy.

Infant formulas containing hydrolysed protein for prevention of allergic disease and food allergy

BACKGROUND

Allergy is common and may be associated with foods, including cow's milk formula (CMF). Formulas containing hydrolysed proteins have been used to treat infants with allergy. However, it is unclear whether hydrolysed formulas can be advocated for prevention of allergy in infants.

OBJECTIVES

To compare effects on allergy and food allergy when infants are fed a hydrolysed formula versus CMF or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective, including extensively or partially hydrolysed formula (EHF/PHF). To determine which infants at low or high risk of allergy and which infants receiving early, short-term or prolonged formula feeding may benefit from hydrolysed formulas.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group supplemented by cross referencing of previous reviews and publications (updated August 2016).

SELECTION CRITERIA

We searched for randomised and quasi-randomised trials that compared use of a hydrolysed formula versus human milk or CMF. Trials with ≥ 80% follow-up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

We independently assessed eligibility of studies for inclusion, methodological quality and data extraction. Primary outcomes included clinical allergy, specific allergy and food allergy. We conducted meta-analysis using a fixed-effect (FE) model.

MAIN RESULTS

Two studies assessed the effect of three to four days' infant supplementation with an EHF whilst in hospital after birth versus pasteurised human milk feed. Results showed no difference in infant allergy or childhood cow's milk allergy (CMA). No eligible trials compared prolonged hydrolysed formula versus human milk feeding.Two studies assessed the effect of three to four days' infant supplementation with an EHF versus a CMF. One large quasi-random study reported a reduction in infant CMA of borderline significance among low-risk infants (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.00).Prolonged infant feeding with a hydrolysed formula compared with a CMF was associated with a reduction in infant allergy (eight studies, 2852 infants; FE RR 0.82, 95% CI 0.72 to 0.95; risk difference (RD) -0.04, 95% CI -0.08 to -0.01; number needed to treat for an additional beneficial outcome (NNTB) 25, 95% CI 12.5 to 100) and infant CMA (two studies, 405 infants; FE RR 0.38, 95% CI 0.16 to 0.86). We had substantial methodological concerns regarding studies and concerns regarding publication bias, as substantial numbers of studies including those in high-risk infants have not comprehensively reported allergy outcomes (GRADE quality of evidence 'very low').Prolonged infant feeding with a hydrolysed formula compared with a CMF was not associated with a difference in childhood allergy and led to no differences in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy. Many of the analyses assessing specific allergy are underpowered.Subroup analyses showed that infant allergy was reduced in studies that enrolled infants at high risk of allergy who used a hydrolysed formula compared with a CMF; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF. Studies that enrolled infants at high risk of allergy; used a PHF compared with a CMF; used prolonged and exclusive feeding of a hydrolysed formula compared with a CMF; and used a partially hydrolysed whey formula compared with a CMF found a reduction in infant CMA.

AUTHORS' CONCLUSIONS

We found no evidence to support short-term or prolonged feeding with a hydrolysed formula compared with exclusive breast feeding for prevention of allergy. Very low-quality evidence indicates that short-term use of an EHF compared with a CMF may prevent infant CMA.In infants at high risk of allergy not exclusively breast fed, very low-quality evidence suggests that prolonged hydrolysed formula feeding compared with CMF feeding reduces infant allergy and infant CMA. Studies have found no difference in childhood allergy and no difference in specific allergy, including infant and childhood asthma, eczema and rhinitis and infant food allergy.Very low-quality evidence shows that prolonged use of a partially hydrolysed formula compared with a CMF for partial or exclusive feeding was associated with a reduction in infant allergy incidence and CMA incidence, and that prolonged use of an EHF versus a PHF reduces infant food allergy.

Food-specific IgG Antibody-guided Elimination Diets Followed by Resolution of Asthma Symptoms and Reduction in Pharmacological Interventions in Two Patients: A Case Report

Asthma is one of the most common causes of office visits in the primary care and emergency care settings. Individuals are often able to maintain symptomatic control with long-term pharmacological therapy. Exacerbations of asthma commonly occur due to exposure to triggers such as viruses, pollutants, and allergens. While it is widely accepted that exposure to immunoglobulin E food allergens can exacerbate asthma symptoms, there is little evidence examining delayed immunoglobulin G-mediated reactions to food. Here we present two clinical cases of individuals who experienced a reduction in asthma symptoms, decreased dependence on pharmacological therapies, and increased quality of life by eliminating foods that demonstrated reactivity to immunoglobulin G levels identified through serum testing.

Formulas containing hydrolysed protein for prevention of allergy and food intolerance in infants

BACKGROUND

Allergies and food reactions are common and may be associated with foods including adapted cow's milk formula. Formulas containing hydrolysed proteins have been used to treat infants with allergy or food intolerance. However, it is unclear whether hydrolysed formula can be advocated for prevention of allergy and food intolerance in infants without evidence of allergy or food intolerance.

OBJECTIVES

To determine the effect of feeding hydrolysed formulas on allergy and food intolerance in infants and children compared to adapted cow's milk or human breast milk. If hydrolysed formulas are effective, to determine what type of hydrolysed formula is most effective including extensively and partially hydrolysed formulas. To determine which infants benefit, including infants at low or high risk of allergy and infants receiving early, short term or prolonged formula feeding.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. The review was updated with searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2006), MEDLINE (1966-March 2006), EMBASE (1980-March 2006) and CINAHL (1982-March 2006) and previous reviews including cross references.

SELECTION CRITERIA

Randomised and quasi-randomised trials that compare the use of a hydrolysed infant formula to human milk or cow's milk formula. Trials with >80% follow up of participants were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eligibility of studies for inclusion, methodological quality and data extraction were assessed independently by each review author. Primary outcomes included clinical allergy, specific allergies and food intolerance. Meta-analysis was conducted using a fixed effects model.

MAIN RESULTS

Two trials compared early, short term hydrolysed formula to human milk feeding. No significant difference in infant allergy or childhood cow's milk allergy (CMA) were reported. No eligible trial compared prolonged hydrolysed formula to human milk feeding. Two trials compared early, short term hydrolysed formula to cow's milk formula feeding. No significant benefits were reported. One large quasi-random study reported a reduction in infant CMA of borderline significance in low risk infants (RR 0.62, 95% CI 0.38, 1.00). Ten eligible studies compared prolonged feeding with hydrolysed formula versus cow's milk formula in high risk infants. Meta-analysis found a significant reduction in infant allergy (seven studies, 2514 infants; typical RR 0.79, 95% CI 0.66, 0.94), but not in the incidence of childhood allergy (two studies, 950 infants; typical RR 0.85, 95% CI 0.69, 1.05). There was no significant difference in infant eczema (eight studies, 2558 infants, typical RR 0.84, 95% CI 0.68, 1.04), childhood eczema incidence (two studies, 950 infants, typical RR 0.83, 95% CI 0.63, 1.10), childhood eczema prevalence (one study, 872 infants; RR 0.66, 95% CI 0.43, 1.02), or infant or childhood asthma, rhinitis and food allergy. One study reported a significant reduction in infants with CMA with confirmed atopy (RR 0.36, 95% CI 0.15, 0.89). Subgroup analysis of trials blinded to formula found no significant difference in infant allergy (four studies, 2156 infants; typical RR 0.87, 95% CI 0.69, 1.08) or childhood allergy incidence (one study, 872 infants; RR 0.91, 95% CI 0.73, 1.14). No eligible trial examined the effect of prolonged hydrolysed formula feeding on allergy beyond early childhood. There is evidence that preterm or low birthweight infants fed a hydrolysed preterm formula have significantly reduced weight gain, but not in other growth parameters (head circumference or length). Studies in term infants report no adverse effects on growth. Subgroup analysis of trials of partially hydrolysed versus cow's milk formula found a significant reduction in infant allergy (six studies, 1391 infants; typical RR 0.79, 95% CI 0.65, 0.97) but not childhood allergy, or infant or childhood asthma, eczema or rhinitis. Methodological concerns were the same as for the overall analysis. Analysis of trials of extensively hydrolysed formula versus cow's milk formula found no significant differences in allergy or food intolerance. Infants fed extensively hydrolysed formula compared with partially hydrolysed formula had a significant reduction in food allergy (two studies, 341 infants; typical RR 0.43, 95% CI 0.19, 0.99), but there was no significant difference in all allergy or any other specific allergy incidence. Comparing extensively hydrolysed casein containing formula with cow's milk formula, one study (431 infants) reported a significant reduction in childhood allergy incidence (RR 0.72, 95% CI 0.53, 0.97). Meta-analysis found a significant reduction in infant eczema (three studies, 1237 infants; typical RR 0.71, 95% CI 0.51, 0.97). One study reported a significant reduction in childhood eczema incidence (RR 0.66, 95% CI 0.44, 0.98) and prevalence (RR 0.50, 95% CI 0.27, 0.92).

AUTHORS' CONCLUSIONS

There is no evidence to support feeding with a hydrolysed formula for the prevention of allergy compared to exclusive breast feeding. In high risk infants who are unable to be completely breast fed, there is limited evidence that prolonged feeding with a hydrolysed formula compared to a cow's milk formula reduces infant and childhood allergy and infant CMA. In view of methodological concerns and inconsistency of findings, further large, well designed trials comparing formulas containing partially hydrolysed whey, or extensively hydrolysed casein to cow's milk formulas are needed.

Gastroesophageal reflux and cow milk allergy: is there a link?

Gastroesophageal reflux (GER) and cow milk allergy (CMA) occur frequently in infants younger than 1 year. In recent years, the relation between these 2 entities has been investigated and some important conclusions have been reached: in up to half of the cases of GER in infants younger than 1 year, there may be an association with CMA. In a high proportion of cases, GER is not only CMA associated but also CMA induced. The frequency of this association should induce pediatricians to screen for possible concomitant CMA in all infants who have GER and are younger than 1 year. With the exception of some patients with mild typical CMA manifestations (diarrhea, dermatitis, or rhinitis), the symptoms of GER associated with CMA are the same as those observed in primary GER. Immunologic tests and esophageal pH monitoring (with a typical pH pattern characterized by a progressive, slow decrease in esophageal pH between feedings) may be helpful if an association between GER and CMA is suspected, although the clinical response to an elimination diet and challenge is the only clue to the diagnosis. This article reviews the main features of GER and CMA, focusing on the aspects in common and the discrepancies between both conditions.

A similar high level of immunoglobulin A and immunoglobulin G class milk antibodies and increment of local lymphoid tissue on the duodenal mucosa in subjects with cow's milk allergy and recurrent abdominal pains

In previous studies, we have reported endoscopic and histological alterations locally on the gastrointestinal (GI) tract associated with a gastrointestinal type of cow's milk allergy. In this study, we sought to further characterize endoscopic, and immunological findings in these children. We also hypothesized that the same type of immune responses might also be found in children with unexplained and recurrent abdominal pains. We did a gastroduodenoscopy for persistent GI symptoms, examined the mucosal histology of the small intestine and measured the antibodies to whole cow's milk and its fractions with an enzyme-linked immunosorbent assay (ELISA) in a consecutive series of 22 subjects with untreated and 14 with treated cow's milk allergy (CMA) and 44 with recurrent abdominal pains (RAP). The immunological findings of the study subjects were compared with 54 controls. Lymphonodular hyperplasia (LNH) of the duodenum was the main endoscopic finding in 11 subjects (50%) with untreated and 5 (36%) with treated CMA. It was also found in 6 of 44 subjects with RAP. Compared with the controls, the patients with CMA showed significantly higher levels of IgA class antibodies to whole milk (p = 0.003) and betaLG (p < 0.0001). Of the IgG class antibodies to betaLG (p = 0.032), BSA (p < 0.0001) and alphaCAS (p < 0.0001) were significantly higher. The patients with LNH of the duodenal bulb as the main endoscopic finding showed significantly higher values of IgG class antibodies to betaLG (p = 0.01) and alphaCAS (p = 0.005). Interestingly, the patients examined for RAP showed a similar increment in the pattern of whole milk and specific milk protein antibodies as the CMA children. In conclusion this study showed that gastrointestinal CMA beyond infancy is significantly associated with high levels of IgG and IgA class antibodies to milk and its fractions. As high levels of these antibodies and LNH of the duodenal bulb were also found in subjects with RAP, the study further suggests that gastrointestinal CMA might be one major reason for RAP.

Bovine beta-casein antibodies in breast- and bottle-fed infants: their relevance in Type 1 diabetes

BACKGROUND

Bovine beta-casein is a cow's milk protein that targets both humoral and cellular immune responses in patients with Type 1 diabetes and, to a lesser degree, also in normal subjects. In this study we aimed to determine whether the avoidance of cow's milk consumption early in life could prevent the development of antibody response to bovine beta-casein despite the mother being exposed on a daily basis to cow's milk consumption.

MATERIALS AND METHODS

We measured the antibody response to bovine beta-casein using an ELISA method in 28 healthy infants under 4 months of age, of whom 16 were exclusively breast-fed and 12 were bottle-fed with cow's milk. In addition, beta-casein antibodies were measured in 37 prepubertal children with Type 1 diabetes and in 31 healthy children who were exposed to cow's milk or dairy products to see whether differences in antibody titers exist in this young age group. Antibodies binding to beta-casein were also evaluated by immunoblotting analysis.

RESULTS

Elevated levels of beta-casein antibodies were found in bottle-fed infants compared to breast-fed infants (p<0.0001). Antibody levels to bovine beta-casein were also significantly higher in children with Type 1 diabetes compared to age-matched controls (p=0.03). By western blot analysis we confirmed specific binding to bovine beta-casein in bottle-fed infants, in children with Type 1 diabetes and in controls exposed to cow's milk, but not in infants who were exclusively breast-fed.

CONCLUSIONS

The results of this study indicate that breastfeeding within the first 4 months of life prevents the generation of antibody response to bovine beta-casein despite the mothers' consumption of cow's milk during the breastfeeding period. These findings may have relevance for disease prevention.

Milk-induced reflux in infants less than one year of age

Cow's milk allergy (CMA) and gastroesophageal reflux are considered to be among the most common disturbances in infants less than 1 year of age. In recent years, the relationship existing between these two entities has been investigated and some important conclusions have been reached: In just under half the cases of GER in infants less than 1 year of age there is an association with CMA; in a high proportion of cases, GER is not only CMA-associated but also CMA-induced; the frequency of this association should induce pediatricians to screen for possible concomitant CMA in all infants with GER less than 1 year old; with the exception of some patients with mild typical CMA manifestations (diarrhea, dermatitis, or rhinitis), the symptoms of GER associated with CMA are the same as those observed in primary GER; immunologic tests are useful in a suspected association between GER and CMA; and subjects with GER secondary to CMA show a typical pH-monitoring tracing pattern, characterized by a progressive, slow decrease in esophageal pH between feedings. This article reviews the main features of the two diseases, stressing the aspects in common between them and comments on all the listed points.

Allergenicity of major cow's milk and peanut proteins determined by IgE and IgG immunoblotting

BACKGROUND

Specific IgG antibodies are frequently observed in food-allergic patients. However, the allergen-fraction specificity of IgG antibodies in relation to IgE antibodies is not well defined. Our aim was to determine the IgE and IgG antibody profile to major cow's milk and peanut-antigen fractions in food-allergic patients and tolerant individuals.

METHODS

Sera were collected from 10 patients allergic to cow's milk and 10 patients allergic to peanuts, as well as from 20 control subjects. Cow's milk and peanut proteins were migrated on SDS-PAGE and immunoblotted for IgE, IgG, and IgG4 antibodies. Food-specific IgE concentrations were measured by CAP System FEIA, and IgG and IgG4 concentrations by ELISA.

RESULTS

In food-allergic children, similar fraction-specific IgE, IgG, and IgG4 antibody-binding profiles to the major cow's milk or peanut antigens were found. In nonallergics, the presence of fraction-specific IgG antibodies was mostly dependent on regular ingestion of the food. The presence of specific antibody on immunoblots correlated with their quantitative measurement. The mean value for specific IgE in cow's milk-allergic patients was 450 +/- 1,326 IU/ml, and 337 +/- 423 IU/ml in peanut-allergic patients. Specific IgG antibody values in milk-allergic patients were not different (median OD 1.5, range 0.3-2.3) from controls (median OD 1, range 0.2-1.8). However, in peanut-allergic patients, IgG concentrations were significantly higher than in controls (OD 1.2 [0.5-1.3] vs 0.5 [0.3-0.7]; P< 0.01).

CONCLUSIONS

Similar fraction-specific IgE and IgG antibody profiles in allergic individuals suggest a common switching trigger involving both isotypes. Intrinsic allergenicity might explain identical IgG antibody fraction specificity in nonallergics and in allergics. The presence of IgG antibodies in nonallergics was related to regular ingestion of the food.

Development of immunoglobulin G and immunoglobulin E antibodies to cow's milk proteins and ovalbumin after a temporary neonatal exposure to hydrolyzed and whole cow's milk proteins

The ingestion of food antigens usually results in the induction of oral tolerance, but the clinical and immunologic consequences of brief exposure to cow's milk proteins during the neonatal period are not well-documented. The aim of this work was to study immunoglobulin (Ig)E and IgG responses to cow's milk proteins and ovalbumin after exposure during the first three days of life in infants who were otherwise exclusively breast-fed. A group of 129 infants was randomly assigned at birth to one of three feeding regimens: human milk (HM), cow's milk formula (CMF), or a casein hydrolysate formula (CHF), during the first three days of life. They were then all exclusively breast-fed for a varying period of time and followed for two years. Serum IgG and IgE antibodies to cow's milk proteins and ovalbumin (OVA) were analyzed in blood samples obtained at birth, at 4 days and at 2, 4, 8, 12 and 24 months of age. The levels of IgG antibodies to beta-lactoglobulin (IgG-BLG) and bovine serum albumin (IgG-BSA) were higher in the CMF and the HM groups than in the CHF group for up to two years. This was particularly obvious for IgG-BLG in infants who started weaning before two months. The levels of IgG antibodies to casein (IgG-CAS) were higher in the CMF group, as compared with the CHF group at 8 and 12 months. The levels of IgG antibodies to OVA were similar in all three feeding groups. The levels of IgE antibodies to CAS or OVA were similar in the three feeding groups. Exposure to cow's milk during the first three days of life stimulated IgG antibody production to cow's milk proteins and this was still obvious at 2 years of age, while feeding with a casein hydrolysate during the first three days of life was associated with low levels of IgG antibodies to cow's milk proteins.

Fecal alpha 1-antitrypsin in newborn infants

BACKGROUND

Fecal alpha 1-antitrypsin is used as a marker for intestinal protein loss reflecting increased intestinal permeability. Exact data of fecal alpha 1-antitrypsin in newborn infants are not available.

METHODS

30 healthy mature neonates and three infants with impaired gastrointestinal passage due to stenoses and atresia respectively, were investigated during the first days of life. The amniotic fluid of 13 and the serum of 17 infants was available. alpha 1-antitrypsin was determined using the radial immunodiffusion method.

RESULTS

Normal newborns showed mean fecal alpha 1-antitrypsin levels (+/-SD) of 2061 +/- 817 mg/dl (day 1), 1186 +/- 720 mg/dl (day 2), 308 +/- 380 (day 3), 35 +/- 27 (day 5), and 27 +/- 21 mg/dl (day 6). Two infants with esophageal atresia presented a much lower pattern, and one with annular pancreas had a fecal alpha 1-antitrypsin pattern comparable with that of normal babies. Serum alpha 1-antitrypsin was normal (275 +/- 52 mg/dl), and amniotic fluid contained 20 +/- 12 mg/dl alpha 1-antitrypsin.

CONCLUSIONS

The pattern of neonatal fecal alpha 1-antitrypsin content appears to reflect the meconium clearance of the gut rather than intestinal permeability and "gut closure." We hypothesize that the origin of increased fecal alpha 1-antitrypsin is the result of accumulated secretions from bile, the pancreas, and the duodenum, but alpha 1-antitrypsin originating from swallowed amniotic fluid during pregnancy may play an additional role.