Transient vs persistent cow's milk allergy and development of other allergic diseases

Elevated Cow's Milk-Specific IgE Levels Prior to Oral Immunotherapy Decrease the Likelihood of Reaching the Maintenance Dose

BACKGROUND

Food desensitization via oral immunotherapy (OIT) is gaining acceptance in clinical practice. Owing to adverse reactions, the duration of the buildup phase until a maintenance dose is achieved may be prolonged, and in a minority of cases, OIT is stopped.

OBJECTIVE

We aimed to assess factors associated with the probability of reaching the maintenance dose in cow's milk (CM) OIT.

METHODS

We collected data from patients undergoing CM OIT at the Montreal Children's Hospital, BC Children's Hospital, and Hospital for Sick Children. We compared univariable and multivariable Cox regressions to evaluate sociodemographic factors, comorbidities, clinical characteristics, and biomarkers at study entry associated with the likelihood of reaching a maintenance dose of 200 mL of CM.

RESULTS

Among 69 children who reached 4 mL of milk, the median age was 12 years (interquartile range, 9-15 years); 59% were male. Median duration of buildup phase from 4 to 200 mL was 24.0 weeks (interquartile range, 17.7-33.4 weeks). After adjusting for age and sex, higher baseline levels of specific IgE antibodies for α-lactalbumin (hazard ratio [HR] = 0.80; 95% confidence interval [CI], 0.67-0.95), β-lactoglobulin (HR = 0.86; 95% CI, 0.76-0.98), casein (HR = 0.82; 95% CI, 0.72-0.94), and total CM (HR = 0.79; 95% CI, 0.65-0.97) were associated with a decreased probability of reaching maintenance. In addition, for every 10-mL increase in CM tolerated at entry challenge, the probability of reaching maintenance increased by 10%.

CONCLUSIONS

The data suggest that higher levels of CM-specific IgE decreased the likelihood of reaching maintenance, whereas an increased cumulative CM dose at entry challenge increased the likelihood. Assessing these factors before therapy may assist in predicting the success of CM OIT.

Retinoic acid prevents immunogenicity of milk lipocalin Bos d 5 through binding to its immunodominant T-cell epitope

The major cow’s milk allergen Bos d 5 belongs to the lipocalin protein family, with an intramolecular pocket for hydrophobic ligands. We investigated whether Bos d 5 when loaded with the active vitamin A metabolite retinoic acid (RA), would elicit differential immune responses compared to the unloaded state. By in silico docking an affinity energy of −7.8 kcal/mol was calculated for RA into Bos d 5. Loading of RA to Bos d 5 could be achieved in vitro, as demonstrated by ANS displacement assay, but had no effect on serum IgE binding in tolerant or challenge-positive milk allergic children. Bioinformatic analysis revealed that RA binds to the immunodominant T-cell epitope region of Bos d 5. In accordance, Bos d 5 significantly suppressed the CD3+ CD4+ cell numbers, proliferative response and IL-10, IL-13 and IFN-γ secretion from stimulated human PBMCs only when complexed with RA. This phenomenon was neither associated with apoptosis of T-cells nor with the activation of Foxp3+ T-cells, but correlated likely with enhanced stability to lysosomal digestion due to a predicted overlap of Cathepsin S cleavage sites with the RA binding site. Taken together, proper loading of Bos d 5 with RA may suppress its immunogenicity and prevent its allergenicity.

Th2 related markers in milk allergic inflammatory mice model, versus OVA

Experimental studies on allergic asthma are limited by the high cost of the administrated allergens. In this study we tested the allergic potency of low fat milk as a cheap substitute to the widely used standard allergen, ovalbumin (OVA). BALB/c female mice (4 weeks old) were sensitized intraperitoneally with low fat milk/or OVA followed by intranasal challenge with the two allergens on days 28 and 29. At day 31, serum, bronchoalveolar lavage fluid (BALF), and lungs were harvested. Mice of the low fat milk model showed infiltration of eosinophils, macrophages, lymphocytes, and neutrophils in BALF comparable to that of the OVA model. Both allergic protocols led to the production of similar numbers of Th2 cells and induced comparable expression of Th2 cytokine (IL-13) as evident by real time PCR for IL-13 and GATA3 (Th2 transcription factor) and confirmed by immunofluorescence for Th2 surface markers (T1/ST2). In addition, both mouse models had similar elevated levels of allergen specific antibody, IgG1 and IgE. Notably, HE, PAS, and LUNA stained lung sections from low fat milk treated mice had higher average pathological scores as compared to OVA treated mice. In conclusion, this study suggests that the low fat milk-induced inflammation showed hallmarks of allergic airway inflammatory model such as eosinophilic influx in BALF, increased numbers of Th2 cells, augmented expression of IL-13, elevated levels of circulatory IgG1 and IgE, signs of robust pulmonary inflammation, and most importantly it is a cheap and promising model for studying acute allergic airway inflammation and acute asthma.

Psychiatric disorders and symptoms severity in pre-school children with cow's milk allergy

BACKGROUND

Psychiatric disorders are seen frequently in atopic diseases. The present study aims to evaluate the frequency of psychiatric disorders and the severity of psychiatric symptoms in pre-school children with cow's milk allergy.

METHODS

The parents of the pre-school children with cow's milk allergy were interviewed in person and asked to fill out the Early Childhood Inventory-4 form.

RESULTS

The cow's milk allergy group included 40 children (27 male, 13 female) with mean age, 44.5±14.7 months, and the control group included 41 children (25 male, 16 female) with mean age, 47.6±15.2 months. It was established that 65% of the group with cow's milk allergy received at least one psychiatric diagnosis, while 36.6% of the control group received at least one psychiatric diagnosis, with a statistically significant difference (p=0.02). Within the psychiatric disorders, attention deficit hyperactivity disorders (odds ratio: 4.9, 95% CI: 1.472-16.856, p=0.006), oppositional defiant disorder (odds ratio: 5.6, 95% CI: 1.139-28.128, p=0.026), and attachment disorder (odds ratio: 4.8, 95% CI: 1.747-13.506, p=0.004) were found significantly higher compared with the healthy control group. When the groups were compared in terms of psychiatric symptom severity scores, calculated by using the Early Childhood Inventory-4 form, attention deficit hyperactivity disorders severity (p=0.006) and oppositional defiant disorder severity (p=0.037) were found to be higher in the cow's milk allergy group.

CONCLUSION

Psychiatric disorders are frequent and severe in pre-school children with cow's milk allergy.

Role of cellular immunity in cow's milk allergy: pathogenesis, tolerance induction, and beyond

Food allergy is an aberrant immune-mediated reaction against harmless food substances, such as cow's milk proteins. Due to its very early introduction, cow's milk allergy is one of the earliest and most common food allergies. For this reason cow's milk allergy can be recognized as one of the first indications of an aberrant inflammatory response in early life. Classically, cow's milk allergy, as is true for most other allergies as well, is primarily associated with abnormal humoral immune responses, that is, elevation of specific immunoglobulin E levels. There is growing evidence indicating that cellular components of both innate and adaptive immunity play significant roles during the pathogenesis of cow's milk allergy. This is true for the initiation of the allergic phenotype (stimulation and skewing towards sensitization), development and outgrowth of the allergic disease. This review discusses findings pertaining to roles of cellular immunity in allergic inflammation, and tolerance induction against cow's milk proteins. In addition, a possible interaction between immune mechanisms underlying cow's milk allergy and other types of inflammation (infections and noncommunicable diseases) is discussed.

Diagnosis and management of non-IgE-mediated cow's milk allergy in infancy - a UK primary care practical guide

The UK NICE guideline on the Diagnosis and Assessment of Food Allergy in Children and Young People was published in 2011, highlighting the important role of primary care physicians, dietitians, nurses and other community based health care professionals in the diagnosis and assessment of IgE and non-IgE-mediated food allergies in children. The guideline suggests that those with suspected IgE-mediated disease and those suspected to suffer from severe non-IgE-mediated disease are referred on to secondary or tertiary level care. What is evident from this guideline is that the responsibility for the diagnostic food challenge, ongoing management and determining of tolerance to cow’s milk in children with less severe non-IgE-mediated food allergies is ultimately that of the primary care/community based health care staff, but this discussion fell outside of the current NICE guideline. Some clinical members of the guideline development group (CV, JW, ATF, TB) therefore felt that there was a particular need to extend this into a more practical guideline for cow’s milk allergy. This subset of the guideline development group with the additional expertise of a paediatric gastroenterologist (NS) therefore aimed to produce a UK Primary Care Guideline for the initial clinical recognition of all forms of cow’s milk allergy and the ongoing management of those with non-severe non-IgE-mediated cow’s milk allergy in the form of algorithms. These algorithms will be discussed in this review paper, drawing on guidance primarily from the UK NICE guideline, but also from the DRACMA guidelines, ESPGHAN guidelines, Australian guidelines and the US NIAID guidelines.

Predictive factors for the persistence of cow's milk allergy

Cow's milk allergy (CMA) is usually transient, but recent studies have shown a later acquisition of tolerance to CM. Our aims were to characterize a population of Portuguese children with CMA and to identify predictive factors for the persistence of this food allergy. Children with CMA observed in our Paediatric Allergy Clinic between 1997 and 2006 were selected. Demographic and clinical data were collected from medical records. The group of children who tolerated CM before the age of 2 was compared with the group of children who tolerated CM beyond that age or persisted with CMA until the end of the study. Multivariate logistic regression analysis was used to investigate independent predictive factors for the persistence of CMA beyond the age of 2. In the subgroup of children with IgE-mediated CMA, the acquisition of tolerance was analysed using Cox regression. In this population of 139 children, the majority presented more than one symptom (73%) affecting more than one organ (51%), with cutaneous (81%), gastrointestinal (55%), respiratory (16%) manifestations and/or anaphylaxis (3%). Thirty-two per cent developed asthma, 20% atopic eczema, 20% rhinoconjunctivitis and 19% other food allergies over time. The acquisition of tolerance was different in the whole population versus the subgroup with IgE-mediated CMA: 34%versus 0% at the age of 2, 55%versus 22% at the age of 5 and 68%versus 43% at the age of 10. Immediate allergic symptoms, asthma and other food allergies were independent factors for the persistence of CMA beyond the age of 2. Higher maximum weal diameter on skin prick test to CM and higher maximum level of specific IgE to CM were associated with reduced likelihood of acquiring tolerance in the subgroup of children with IgE-mediated CMA. In conclusion, children with IgE-mediated CMA acquire tolerance to CM at older age. Clinical parameters and allergy tests may be helpful in defining prognosis. CM-allergic children tend to develop other atopic conditions and need specialized follow-up in the long term.

Persistence of cow's milk allergy beyond two years of age

BACKGROUND

Cow's milk allergy (CMA) epidemiology seems to be changing over time, with an increase in prevalence and persistence. Our aim was to characterise a population of children with CMA beyond two years of age, followed up in a Paediatric Allergy Clinic at the tertiary care level.

METHODS

Retrospective study of children with persistent CMA diagnosed from January 1997 to June 2006. Medical records were analysed regarding: clinical presentation, follow-up, treatment and acquisition of tolerance. Data analysis was performed using Excel 2007 for Windows.

RESULTS

Seventy-nine children were included, with mean age at first symptoms of 3 months. The symptoms were immediate in 93%, with cutaneous (87.3%), gastrointestinal (55.7%) and respiratory (25.3%) manifestations. During the follow-up period, 30% developed atopic eczema, 52% asthma and 35% rhinoconjunctivitis. A family history of atopy was identified in 53%. The majority presented increased serum total IgE (376+/-723 KU/l) and positive skin prick test (SPT) to cow's milk (CM) (79%). SPT to goat's milk was positive in 2/3 of cases. Fifty-five percent had at least one accidental exposure to CM (severe reactions in 6%). During CM elimination diet, 35% were initially given an extensively hydrolysed formula, 17% a soy formula, and 48% both. By the age of 10 years, 44% of children persisted with CMA.

DISCUSSION

Our population of CM allergic children presented immediate symptoms with cutaneous expression in the majority. Severe reactions were common on accidental exposure. By the age of 10 years, 44% maintained CMA, highlighting the importance of a multidisciplinary follow-up.

Lessons from the clinical course of IgE-mediated cow milk allergy in Israel

Cow milk and milk products are the most common food products consumed in Israel; rates of allergy to cow milk exceed those of peanuts in infants and children. The aim of the present study was to evaluate retrospectively the clinical features and natural course of immunoglobulin (Ig) E-mediated cow milk allergy (CMA) in Israel. Data of children diagnosed with CMA from 1995 to 2003, were collected regarding age at first and most recent reactions, symptoms and signs, family history of atopy, other allergic diseases, emergency department visits, hospitalizations, and treatment. Patients with transient CMA were compared to those with persistent CMA (> or =3 yr old). The study group consisted of 105 patients, 43 with transient CMA (age range: 0.48-11 yr). The remaining 62 patients (age range: 3-16.5 yr) did not achieve tolerance to cow milk during the follow-up period. No differences were found between the groups in mean age and symptoms and signs at the first allergic reaction and family history of atopy. Patients with persistent CMA had a higher rate of asthma than patients with transient CMA (61.2% vs. 18.6%, p < 0.001). Fifty patients with persistent CMA had 137 subsequent allergic reactions after diagnosis, 25% of the reactions were due to oral milk challenge at the clinic and 75% due to accidental exposure, of which 13% required an emergency department visit and 8%, hospitalization. Only 19% of the reactions were treated with epinephrine injection. In conclusion, in our experience, less than half of the children diagnosed with IgE-mediated CMA during 9 yr, outgrew it. The patients with persistent CMA have a higher prevalence of asthma compared with the general population or to children with transient CMA. The high number of recurrent allergic reactions due to accidental exposure and the low rate of epinephrine usage in these patients point to a need for better education of patients and their families.