[Allergology: what's new in 2022]. / Allergologie : ce qui a changé en 2022.

The study of reactions to SARS-CoV-2 vaccines has marked a large part of the literature in the last two years, using the basophil activation test (BAT) as a potential diagnostic tool for reactions to Covid-19 vaccines. In allergic rhinoconjunctivitis, lirentelimab (a humanised monoclonal antibody against lectin 8), reduces patients' symptoms and atopic comorbidities. In severe asthma, tezepelumab (human monoclonal antibody) reduces the annual asthma exacerbation rate over 52 weeks. In terms of diet, the new EAACI guidelines recommend avoiding cow's milk supplementation in infants during the first three days of life to reduce the risk of cow's milk allergy.

L'étude des réactions aux vaccins contre le SARS-CoV-2 a marqué une grande partie des publications de ces deux dernières années, en utilisant le test d'activation de basophiles (BAT) comme outil de diagnostic potentiel pour les réactions aux vaccins contre le Covid-19. Sur le plan de la rhinoconjonctivite allergique, le lirentélimab (anticorps monoclonal humanisé contre la lectine 8) diminue les symptômes des patients et ses comorbidités atopiques. Sur le plan de l'asthme sévère, le tézépélumab (anticorps monoclonal humain) en diminue le taux d'exacerbations annuelles sur 52 semaines. Sur le plan alimentaire, les nouvelles directives EAACI (Académie européenne d'allergie et d'immunologie clinique) recommandent d'éviter la supplémentation en lait de vache chez les nourrissons au cours des 3 premiers jours de vie pour en diminuer le risque d'allergie.

Protein and carbohydrate content of infant formula purchased in the United States.

BACKGROUND: The protein and carbohydrate composition of formula fed infants' diets in the United States (US) has not been described. The aims of this study were to characterize these dietary exposures in infant formula purchased in the US and to estimate the proportion of formula purchased which is hypoallergenic or lactose-reduced formula. METHODS: Powdered infant formula purchase data from all major physical stores in the US prior to the COVID-19 pandemic, between 2017 and 2019, were obtained from Information Resources, Inc. Protein and carbohydrate composition and scoop sizes for each formula were obtained from manufacturers. Ready to feed liquid products, products for premature infants and products for over 1 year old were not included. RESULTS: Total volumes of term formula purchased were 216 million kg of formula powder (equivalent to 1.65 billion litres) over 3 years. Intact protein formula was 67.9% of formula purchased, 26.6% was partially hydrolysed and 5.5% was hypoallergenic (5.2% extensively hydrolysed protein; 0.3% amino acid based). Soy protein formula represented 5.1% of formula purchased. Carbohydrate content overall was 52.7% lactose, 42.3% glucose polymers and 5.0% sucrose. 23.7% of formula purchased included sucrose as a carbohydrate. Of all formula purchased, 59.0% was lactose reduced, containing a non-lactose carbohydrate. Of 'standard' formula, defined as intact protein, non-thickened, cow's milk formula, 32.3% was lactose reduced. The proportion of hypoallergenic formula purchased significantly exceeded the prevalence of cow's milk protein allergy and increased over the 3-year study period from 4.9% to 7.6% of all formula sold. CONCLUSIONS: US infants are exposed to unnecessarily high levels of non-lactose carbohydrates and hypoallergenic formula, and this may represent a significant nutritional health risk.

Efficacy and safety of baked milk oral immunotherapy in children with severe milk allergy: A randomized, double-blind, placebo-controlled phase 2 trial.

BACKGROUND: Cow's milk allergy is the most common food allergy in young children and has no current treatment. Oral immunotherapy studies to date have shown efficacy but high rates of adverse reactions. OBJECTIVE: We sought to evaluate the safety and efficacy of baked milk oral immunotherapy (BMOIT) in children allergic to baked milk. METHODS: Participants (3-18 years) were randomized to receive BMOIT or placebo for 12 months. Efficacy was assessed by double-blind placebo-controlled food challenge after 12 months of treatment. Safety, quality of life, and mechanistic parameters were also evaluated. RESULTS: Eleven of 15 (73%) BMOIT participants reached the primary end point, tolerating 4044 mg of baked milk protein after 12 months of oral immunotherapy, compared with 0 of 15 (0%) on placebo. The median maximum tolerated dose and median change from baseline was significantly higher in the BMOIT group than in the placebo group (median maximum tolerated dose, 4044 mg vs 144 mg; P = .001; median change in maximum tolerated dose of 3900 mg vs 0 mg, P = .0001). Dose-related reactions were common, but more than 95% in both groups were mild. There was no significant change in cow's milk- or beta lactoglobulin-IgE from baseline for either group. Cow's milk-sIgG4 did significantly increase and casein IgE decreased in the BMOIT group. For proxy-reported food allergy quality of life, there was a significant difference in the emotional impact domain only, with more improving while on placebo compared with BMOIT. Most children and adolescents in the BMOIT group directly reported improvement in at least 1 domain. CONCLUSIONS: BMOIT was well tolerated and induced a substantial level of desensitization after 12 months of treatment.

Broad Cross-reactive IgA and IgG Against Human Coronaviruses in Milk Induced by COVID-19 Vaccination and Infection (preprint)

It is currently unclear if SARS-CoV-2 infection or mRNA vaccination can also induce IgG and IgA against common human coronaviruses (HCoVs) in lactating parents. Here we prospectively analyzed human milk (HM) and blood samples from lactating parents to measure the temporal patterns of anti-SARS-CoV-2 specific and anti-HCoV cross-reactive IgA and IgG responses. Two cohorts were analyzed: a vaccination cohort (n=30) who received mRNA-based vaccines for COVID-19 (mRNA-1273 or BNT162b2), and an infection cohort (n=45) with COVID-19 disease. Longitudinal HM and fingerstick blood samples were collected pre- and post-vaccination or, for infected subjects, at 5 time-points 14 - 28 days after confirmed diagnosis. The anti-spike(S) and anti-nucleocapsid(N) IgA and IgG antibody levels against SARS-CoV-2 and HCoVs were measured by multiplex immunoassay (mPlex-CoV). We found that vaccination significantly increased the anti-S IgA and IgG levels in HM. In contrast, while IgG levels increased after a second vaccine dose, blood and HM IgA started to decrease. Moreover, HM and blood anti-S IgG levels were significantly correlated, but anti-S IgA levels were not. SARS2 acute infection elicited anti-S IgG and IgA that showed much higher correlations between HM and blood compared to vaccination. Vaccination and infection were able to significantly increase the broadly cross-reactive IgG recognizing HCoVs in HM and blood than the IgA antibodies in HM and blood. In addition, the broader cross-reactivity of IgG in HM versus blood indicates that COVID-19 vaccination and infection might provide passive immunity through HM for the breastfed infants not only against SARS-CoV-2 but also against common cold coronaviruses.

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), ß-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.

COVID-19 Vaccines in Children with Cow's Milk and Food Allergies.

The COVID-19 pandemic is the most challenging global health crisis of our times. Vaccination against COVID-19 plays a key role to control the current pandemic situation. The risk of allergic reactions to new COVID-19 vaccines is low. However, there is a debate on the safety in allergic patients following post marketing findings by different agencies. Our aim is to understand from current experiences whether children with cow's milk or food allergy are at higher risk than a general population for allergic reactions to COVID-19 vaccines. Current data indicate that patients with a history of allergy to cow's milk or other foods, even if severe, should receive COVID-19 vaccine in a setting with availability of treatments for anaphylactic reactions and under medical supervision. Recipients should be discharged after a protracted observation period of 30 min if no reaction developed.