Follow up study of cow's milk protein intolerant infants

Local atopy is more relevant than serum sIgE in reflecting allergy in childhood adenotonsillar hypertrophy

BACKGROUND

There was a lack of convincing evidence supporting the influence of allergy on the adenotonsillar hypertrophy (ATH). We investigated the presence of specific IgE (sIgE) in the serum and adenotonsillar tissues in children with ATH.

METHODS

A Pharmacia ImmunoCAP system was used to test sIgE against 31 allergens in the serum in 83 children with ATH before adenotonsillectomy. sIgE against 15 representative allergens were detected in adenotonsillar tissues from 20 of those children.

RESULTS

A total of 51 (61.45%) children had positive serum sIgE. 20 children with ATH had positive sIgE to more than two allergens at both tonsils and adenoids, although half of them were serum sIgE negative. The percentage of subjects with positive sIgE expression in adenoids and tonsils was 50.0% and 42.9%, respectively, among the subjects with positive serum sIgE expression. Of subjects with negative serum sIgE expression, local sIgE was detected in 36.0% of adenoids and 43.8% of tonsils, respectively. The rate of sIgE presence in local tissue (adenoids or tonsils) was significantly higher than that seen in the serum.

CONCLUSION

This study provided evidence that there was an important role for allergic inflammation in the ATH. The inconsistency in sIgE expression between adenotonsillar and serum suggests a role of local atopy in childhood ATH.

Natural course and risk factors for persistence of IgE-mediated cow's milk allergy

OBJECTIVE

To describe the natural course of IgE-mediated cow's milk allergy (IgE-CMA) and to determine risk factors for its persistence in a population-based cohort.

STUDY DESIGN

In a prospective cohort study, 54 infants with IgE-CMA were identified from a population of 13 019 children followed from birth. Diagnosis of IgE-CMA was based on history, skin prick test (SPT), and an oral food challenge (OFC) when indicated. Allergic infants were followed for 48-60 months. Families were contacted by telephone every 6 months and asked about recent exposures to milk. OFC was repeated to evaluate for recovery. Clinical characteristics, SPT, and OFC outcomes were compared between infants with persistent IgE-CMA and infants who recovered.

RESULTS

Thirty-one infants (57.4%) recovered from IgE-CMA during the study period. Most infants (70.9%) recovered within the first 2 years. Risk factors for persistence on multivariate analysis included a reaction to <10 mL of milk on OFC (or on first exposure as estimated by the guardian, if OFC was not performed) (P = .01), a larger wheal size on SPT (P = .014), and age of ≤30 days at time of first reaction (P = .05).

CONCLUSIONS

Resolution occurs in most infants with IgE-CMA. Infants reacting to <10 mL of milk or in the first month of life, and those with a larger wheal size on SPT, are at increased risk for persistence.

The multinational birth cohort of EuroPrevall: background, aims and methods

BACKGROUND/AIM

The true prevalence and risk factors of food allergies in children are not known because estimates were based predominantly on subjective assessments and skin or serum tests of allergic sensitization to food. The diagnostic gold standard, a double-blind placebo-controlled food provocation test, was not performed consistently to confirm suspected allergic reactions in previous population studies in children. This protocol describes the specific aims and diagnostic protocol of a birth cohort study examining prevalence patterns and influential factors of confirmed food allergies in European children from different regions.

METHODS

Within the collaborative translational research project EuroPrevall, we started a multi-center birth cohort study, recruiting a total of over 12 000 newborns in nine countries across Europe in 2005-2009. In addition to three telephone interviews during the first 30 months, parents were asked to immediately inform the centers about possible allergic reactions to food at any time during the follow-up period.

RESULTS

All children with suspected food allergy symptoms were clinically evaluated including double-blind placebo-controlled food challenge tests. We assessed sensitization to different food allergens by measurements of specific serum immunoglobulin E and skin prick tests, collect blood, saliva or buccal swabs for genetic tests, breast milk for measurement of food proteins/cytokines, and evaluate quality-of-life and economic burden of families with food allergic children.

CONCLUSIONS

This birth cohort provides unique data on prevalence, risk factors, quality-of-life, and costs of food allergies in Europe, leading to the development of more informed and integrated preventative and treatment strategies for children with food allergies.

Mutational analysis of immunoglobulin E-binding epitopes of ?-casein and ?-lactoglobulin showed a heterogeneous pattern of critical amino acids between individual patients and pooled sera

BACKGROUND

For immunotherapeutic approaches, 'critical' amino acids (AAs) within allergenic epitopes are replaced with alternate AAs to eliminate IgE antibody binding.

OBJECTIVE

To determine the critical AAs for IgE binding in beta-casein and beta-lactoglobulin (BLG).

METHODS

Peptides of 10-14 AAs in length were synthesized on a derivatized cellulose membrane with single AA substitutions (alanine or glycine) at each position. Membranes were incubated with a pool of sera from 15 cow's milk-allergic patients and individual sera from six of the 15 patients. In cases where no decrease in binding occurred with a single AA substitution, peptides with two AA substitutions were generated and labelled.

RESULTS

Using pooled patient sera, single AA substitutions led to complete elimination of binding to six of 11 peptides for beta-casein and to all six peptides for BLG. Substituting two AAs led to an elimination of binding to four of the remaining five beta-casein epitopes. However, in three of the 11 modified beta-casein peptides and five of the six BLG peptides, no decrease in IgE binding occurred in at least one individual patient. For these patients, critical AAs other than those defined by the patient serum pool were identified, indicating a heterogeneous pattern of IgE recognition.

CONCLUSION

These results indicate that AAs critical for IgE binding are more heterogeneous than initially defined by pooled milk-allergic patient sera. For future immunotherapeutic interventions with mutated peptides, critical AAs should also be identified with individual patient sera to account for heterogeneity of IgE binding between patients.

Clinical course and prognosis of cow's milk allergy are dependent on milk-specific IgE status

BACKGROUND

Large, prospective population-based studies on clinical course, development of tolerance, and risk for other atopy in children with cow's milk allergy (CMA) are lacking.

OBJECTIVE

We investigated the development of tolerance and the risk for asthma, rhinoconjunctivitis, atopic dermatitis, and sensitization in children with CMA followed to school age.

METHODS

We followed 118 children with CMA until recovery and repeatedly measured their sensitization to cow's milk (CM). At age 8.6 years, 94 allergic subjects and 80 control subjects from the same cohort were studied for atopic diseases and sensitization. In addition, the parents of 12 allergic subjects and 26 control children returned a questionnaire on atopy, respectively.

RESULTS

IgE-mediated CMA was detected in 86 (73%) children; at age 8.6 years, 13 (15%) had persistent CMA. All children with IgE-negative CMA were tolerant by age 5.0 years (P < .0001). Risk factors for persistent CMA at age 2.0 years were sensitization to CM at age 1.6 years (odds ratio, 6.3; 95% CI, 2.6-15.2), urticaria at diagnostic challenge (odds ratio, 3.3; 95% CI, 1.4-7.8), CM exposure at the maternity hospital (odds ratio, 3.2; 95% CI, 1.4-7.8), and early sensitization to egg (odds ratio, 2.8; 95% CI, 1.2-6.6). By age 8.6 years, children with IgE-positive CMA more frequently had asthma (31% vs 13%, P < or = .01), rhinoconjunctivitis (66% vs 21%, P < or = .001), atopic eczema (81% vs 26%, P < or = .001), and sensitization to any allergen (88% vs 39%, P < or = .001) than control subjects. CMA and family history of atopy were independent risk factors for atopic diseases, and CMA was also a risk factor for sensitization to inhalant allergens.

CONCLUSION

IgE-mediated CMA often persists to school age and is a risk factor for other atopy; non-IgE-mediated CMA, by contrast, is a benign infantile condition.

Prevalence and outcome of allergic colitis in healthy infants with rectal bleeding: a prospective cohort study

OBJECTIVES

Allergic colitis is often diagnosed clinically in healthy infants with rectal bleeding and often treated with costly hypoallergenic formula. The true prevalence of allergic colitis is unknown. We tested the hypothesis that allergic colitis is overdiagnosed in healthy infants with rectal bleeding. The authors also determined whether rectal bleeding in infants without allergic colitis would resolve without diet change.

METHODS

For the purposes of this study, allergic colitis was defined histologically as colonic mucosa with >or= 6 eosinophils per high power field and/or eosinophils in colonic crypts or muscularis mucosae. We surveyed all 56 Ohio NASPGHAN members to determine standard practice regarding the evaluation of rectal bleeding in infants. In addition, infants <or= 6 months old with rectal bleeding were recruited from the referral area of Cincinnati Children's Hospital Medical Center. All infants underwent flexible sigmoidoscopy with biopsies at 5, 10 and 15 cm. Formula or maternal diet was changed only for infants with histologic findings of allergic colitis as defined. Study subjects were followed for 9 weeks.

RESULTS

In the survey of NASPGHAN members, 84% indicated they would empirically change the diet of an infant with rectal bleeding to treat presumed allergic colitis. In our study population, however, only 14 of 22 (64%; 95% confidence interval, 41-83) infants with rectal bleeding had allergic colitis. Five (23%) had normal biopsies and three (14%) had nonspecific colitis. Rectal bleeding in all infants with normal biopsies or nonspecific colitis resolved without diet change except for 1 infant subsequently diagnosed with infantile inflammatory bowel disease.

CONCLUSION

A significant proportion of infants with rectal bleeding may not have allergic colitis and may undergo unnecessary, expensive formula or maternal diet changes that may discourage breast-feeding.

Prediction of the development of tolerance to milk in children with cow's milk hypersensitivity

OBJECTIVES

To investigate whether the development of tolerance to cow's milk (CM) by aged 4 years can be predicted with a skin prick test (SPT) and measurements of total or specific immunoglobulin E (IgE) in the serum, taken at the time of diagnosis of cow's milk hypersensitivity (CMH).

STUDY DESIGN

Infants with immediate (n=95) or delayed (n=67) challenge reactions to CM were prospectively followed to aged 4 years. CMH status was assessed annually by CM challenges.

RESULTS

By aged 2, 3, and 4 years, children with delayed reactions developed tolerance to CM faster than those with immediate reactions: 64%, 92%, and 96% versus 31%, 53%, and 63%, respectively. A wheal size of <5 mm in SPT correctly identified 83% of 124 infants who developed tolerance to CM by aged 4 years, and a wheal size of >or=5 mm in SPT correctly identified 71% of 39 infants with persistent CMH. Milk-specific IgE <2 kU/L correctly identified 82% of infants who developed tolerance to CM, and milk-specific IgE >or=2 kU/L correctly identified 71% of infants with persistent CMH.

CONCLUSION

SPT and milk-specific IgE in the serum are useful prognostic indicators of the development of tolerance to CM in infants with CMH.

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.

B-cell epitopes as a screening instrument for persistent cow's milk allergy

BACKGROUND

Cow's milk is one of the most common causes of food allergy in the first years of life. We recently defined IgE-binding epitopes of all 6 major cow's milk proteins (alpha(s1)-, alpha(s2)-, beta-, and kappa-casein; alpha-lactalbumin; and beta-lactoglobulin) and had some evidence suggesting that IgE antibodies from patients with persistent cow's milk allergy (CMA) recognize different epitopes on cow's milk proteins than do those from patients who were likely to outgrow their allergy.

OBJECTIVE

In this study we sought to assess whether recognition of IgE antibodies of certain epitopes of cow's milk proteins would clearly separate the patients with life-long CMA from those who will become clinically tolerant to cow's milk.

METHODS

According to the known IgE-binding regions of cow's milk proteins, 25 decapeptides of alpha(s1)-casein, alpha(s2)-casein, kappa-casein, alpha-lactalbumin, and beta-lactoglobulin, comprising the core epitopes, were synthesized on a cellulose-derivatized membrane. Sera from 10 patients with persistent CMA and 10 patients who subsequently outgrew their milk allergy were used to investigate the differences in epitope recognition.

RESULTS

Five IgE-binding epitopes (2 on alpha(s1)-casein, 1 on alpha(s2)-casein, and 2 on kappa-casein) were not recognized by any of the patients with transient CMA but showed binding by the majority of the patients with persistent allergy. The presence of IgE antibodies against at least 1 of 3 epitopes (amino acid [AA] 123-132 on alpha(s1)-casein, AA 171-180 on alpha(s2)-casein, and AA 155-164 on kappa-casein) identified all patients with persistent CMA.

CONCLUSIONS

The presence of IgE antibodies to distinct allergenic epitopes of cow's milk proteins can be used as a marker of persistent CMA. Prospective studies are needed to investigate the usefulness of these informative epitopes in predicting life-long CMA in young children.

Role of conformational and linear epitopes in the achievement of tolerance in cow's milk allergy

BACKGROUND

Cow's milk (CM) is one of the leading causes of food allergy in children. However, approximately 85% of milk-allergic children become clinically tolerant to CM within the first 3 years of life. The mechanisms involved in the achievement of tolerance remain unknown.

OBJECTIVE

To study whether IgE antibodies from children with persistent cow's milk allergy (CMA) differ from children who become clinically tolerant in their ability to recognize linear and conformational epitopes of alpha(s1)- and beta-casein.

METHODS

Thirty-six milk-allergic children were included in the study: 11 of the children became clinically tolerant, and 25 had persistent CMA. Blood was obtained from all patients during the time they showed clinical reactions to milk challenge. Six non-milk-allergic children served as controls. Specific IgE antibodies against linear (denatured) as well as conformational (native) milk proteins were determined by probing dot-blots with patients' sera. In addition, selected decapeptides from alpha(s1)- and beta-casein, previously found to be suggestive of persistent CMA, were synthesized on a cellulose-derivatized membrane and probed with individual sera from 10 patients who outgrew CMA and from 10 patients with persistent CMA.

RESULTS

Analysis of immunodot-blots showed that, in comparison to tolerant patients, milk-allergic children with persistent symptoms had a significantly higher ratio of specific IgE antibodies to linearized than to native alpha- and beta-casein (P < 0.005 and P < 0.02, respectively). Comparing the selected decapeptides, six of the 10 patients with persistent allergy recognized the peptide corresponding to amino acids 69-78 from alpha(s1)-casein while none of the patients who outgrew CMA had IgE binding to this epitope.

CONCLUSION

Patients with persistent milk allergy possess higher detectable levels of IgE antibodies to linear epitopes from alpha(s1)- and beta-casein than children who have achieved tolerance. Specific IgE binding to particular linear epitopes in alpha(s1)-casein may be a predictive factor for persistence of CMA.

Residual intestinal disease after milk allergy in infancy

BACKGROUND

The subsidence of cow's milk allergy (CMA) has been a subject of controversy. In this study the authors examined whether children with this condition in infancy developed full tolerance or whether they continue to have vague gastrointestinal (GI) symptoms relating to the consumption of milk or dairy products and/or signs of mucosal lesion in the GI tract.

METHODS

The authors reexamined 56 10-year-old subjects who manifested CMA before 1 year of age, and compared the results with a group of 204 randomly selected age-matched school children. Fifty-three and 90 subjects respectively attended a reexamination and were evaluated for growth, lactose tolerance, and immunoglobulin A (IgA)- and IgG-class antibodies to whole cow's milk. The subjects reporting milk-related GI symptoms were encouraged to do a 4-week blind elimination-challenge test with 1 week of low-lactose milk flour. Sixteen of the 25 children were able to complete the trial.

RESULTS

Approximately half the study subjects (45%) reported milk-related GI symptoms, whereas the respective figure among the control subjects was 10%. Three of six study subjects and seven of 10 control subjects, although completing the challenge, responded with intestinal symptoms. The growth of the former CMA subjects was retarded compared with the control subjects, and the difference in height was most striking in those subjects still reporting milk-related GI symptoms. However, all subjects had normal hemoglobin and whole-blood folic acid levels. The CMA subjects had significantly (P = 0.014) lower concentrations of milk antibodies compared with the control subjects. Lactose malabsorption, defined as high counts in a hydrogen breath test and related clinical symptoms, was found in eight CMA subjects (14%) and six control subjects (3%).

CONCLUSIONS

In a certain proportion of subjects with CMA in infancy, GI intolerance seems to persist even after small-dose tolerance has been achieved. The intestinal symptoms and the increased prevalence of lactose intolerance may be caused by a disturbance of the surface epithelial cells--a state to which the authors refer as residual intestinal disease.

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.

Persistent cow's milk protein intolerance in infants: the changing faces of the same disease

BACKGROUND

Recent research has shown that cow's milk protein intolerance (CMPI) often persists beyond 4 years of age.

AIMS

To evaluate the clinical and immunological characteristics of a group of infants with persistent CMPI.

PATIENTS AND METHODS

Twelve infants (6 m, 6f) with persistent CMPI were followed up from birth until a median age of 5 years. The patients underwent CMP challenge each year to evaluate CMP-tolerance. As controls we followed 26 infants (12 m, 14 f) with CMPI that resolved within 1-2 years.

RESULTS

A family history of atopic disease was found in 10/12 patients with persistent CMPI and in 10/26 controls (P<0.01). Clinical presentation changed over time: at onset symptoms were prevalently gastrointestinal, while at the end of the study there was an increased frequency of wheezing and constipation and a higher frequency of delayed reactions to CMP-challenge than at study commencement (9/12 vs 2/12; P<0.007). 11/12 infants with persistent CMPI and 3/26 controls (P<0.0001) presented multiple food intolerance. During the observation period 9/12 infants with persistent CMPI and 2/26 controls showed atopic disease: asthma, rhinitis, eczema (P < 0.0001).

CONCLUSIONS

Persistent CMPI forms are characterized by: (a) considerable importance of familial atopic disease; (b) change in CMPI manifestations over time and more prolonged delay between CMP consumption and manifestation of symptoms; (c) very high frequency of multiple food intolerance and allergic diseases.

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

The effect of different feeding regimens, notably the use of hydrolysed cow's milk formulas, on the development of allergic reactions and the development of cow's milk protein-IgG antibodies is still disputed. We prospectively compared the development of allergic manifestations and cow's milk protein-IgG antibodies in a total of 702 infants who were divided into six groups: 1. exclusively breast milk for at least 4 weeks (n = 206). 2. Breast milk plus initial partially hydrolysed formula (n = 104). 3. Breast milk plus extensively hydrolysed formula (n = 50). 4. Breast milk plus initial conventional cow's milk formula (n = 73). 5. Conventional cow's milk with or without breast milk throughout (n = 187). 6. Extensively hydrolysed cow's milk formula for 2 months, followed by conventional cow's milk (n = 82). Cow's milk protein antibodies were determined by an indirect immunofluorescent test. Antibody titres rose slowly in groups 1, 3 and 6. Children in group 5 showed two high peaks. There were no significant differences in the frequency and type of allergic manifestations between the groups. Introduction of cow's milk formula during the first trimenon resulted in elevated antibody titres in all breast fed infants compared with introduction at a later date.

CONCLUSION

In contrast to a previous study from the same laboratory, there is no diagnostic significance of cow's milk protein-IgG antibodies for allergic manifestations. The occurrence of these antibodies is a physiological phenomenon: the shorter the breast feeding period and the earlier cow's milk formula is introduced, the higher the antibody levels.

Cow's milk protein intolerance in infants under 1 year of age: a prospective epidemiological study

Incidence and clinical manifestation of cow's milk protein intolerance (CMPI) were studied in 1158 unselected newborn infants followed prospectively from birth to 1 year of age. No food changes were required in 914 infants who were used as healthy controls. When CMPI was suspected (211 infants), diagnostic dietary interventions according to a standard protocol were performed. After exclusion of lactose intolerance, two positive cow's milk elimination/challenge tests were considered diagnostic of CMPI. Two hundred and eleven symptomatic infants were examined for possible CMPI. A large group of 80 infants improved on a lactose reduced formula. In 87/211 infants CMPI was excluded (sick controls). Finally CMPI was proven in 26 infants. The calculated incidence rate for CMPI was 2.8%. The principal symptoms in infants with CMPI were gastrointestinal, dermatological and respiratory in 50%, 31% and 19% respectively. A positive family history for atopy (first or second degree relatives) was more frequent in either CMPI infants (65%), or sick controls (63%) when compared to either healthy controls (35%) or infants improving on a low lactose formula (51%). Differences between patients with CMPI and sick controls were only found for the presence of atopy in at least 2 first degree relatives [(5/26 in CMPI infants and 4/87 in sick controls (P < 0.05)] and for multiorgan involvement [10/26 infants with CMPI as opposed to 12/87 in the sick control group (P < 0.02)]. These statistical differences are too weak to be of clinical value.