Daily baked egg intake may accelerate the development of tolerance to raw egg in egg-allergic children.

Recent studies suggest that egg-allergic children who tolerate baked egg (BE) are more likely to outgrow egg allergy than children that do not tolerate it. The question to be answered is whether regular ingestion of BE accelerates tolerance to other forms of egg (cooked and raw). Our aim was to determine if daily ingestion of BE would accelerate tolerance to raw egg in BE-tolerant patients compared to patients who tolerate BE at diagnosis but eliminated it from their diet and to patients who didn't tolerate it. We performed a retrospective analysis of all children diagnosed of IgE-mediated egg allergy at the Pediatric Allergy Unit of the Complejo Hospitalario Universitario A Coruña, from 2008 to 2014. Seventy children were included. At diagnosis, 33 patients tolerated BE and kept its daily ingestion, 16 patients tolerated BE and were recommended to avoid it, and 21 patients didn't tolerate it. Patients tolerating BE who kept daily ingestion achieved tolerance to raw egg significantly earlier (p < 0.05) than the other two groups.Conclusion: Our data suggest that daily intake of BE in BE-tolerant children accelerates tolerance to raw egg.What is Known:• It has been suggested that egg-allergic children who consume baked egg (BE) products on a regular bases are more likely to outgrow egg allergy than children that do not tolerate themWhat is New:• Patients who tolerated BE on diagnosis and followed an exclusion diet show a similar evolution than patients who initially did not tolerate BE. Daily ingestion of BE seems to accelerates tolerance to raw egg.

Decrease in antigen-specific CD63 basophil expression is associated with the development of tolerance to egg by SOTI in children.

BACKGROUND: In the last decade, there have been an increasing number of studies on achieving tolerance to foods by specific oral tolerance induction (SOTI). Still, the underlying mechanism of SOTI is unknown. Our aim was to describe changes in CD63 expression on basophils following in vitro Ag-specific stimulation by basophil activation test (BAT), after SOTI with egg in a pediatric population. METHODS: Ten children with persistent allergy to egg were included. Skin prick tests (SPTs) and open food challenges (OFCs) were performed before SOTI. Specific IgE determination and BAT with egg white (EW), ovomucoid (OM), and ovalbumin (OVA) were performed before and after 1 month of the buildup phase of SOTI. RESULTS: Total tolerance to egg was achieved in 9 cases and partial in one. After SOTI, there was a significant decrease in mean specific IgE levels (p < 0.05). CD63 expression also decreased (p < 0.05) in all patients. CONCLUSION: Decrease in Ag-specific basophil responsiveness is associated with the development of clinical tolerance by SOTI.

Mild to moderate hypersensitivity reactions to beta-lactams in children: a single-centre retrospective review.

OBJECTIVE: Beta-lactam (BL) antibiotics are the most reported drugs in hypersensitivity reactions in children. More than 90% of these children tolerate the suspected drug after diagnostic work-up. Skin tests (STs) show low sensitivity. Our aim was to assess the performance of drug provocation tests (DPTs) without previous ST in mild and moderate delayed reactions and to propose a new DPT protocol. DESIGN OF THE STUDY: Charts from 213 children under 15 years of age referred for suspected BL allergy from 2011 to 1013 were reviewed. Prick, intradermal and patch tests were performed with major determinant penicilloyl-polylysine, minor determinant mixture, amoxicillin (AMX), cefuroxime, penicillin G and AMX-clavulamate. Children with negative skin tests underwent DPT. After an initial full dose of antibiotic, DPT was carried on for 3 days at home in patients reacting within the first 3 days of treatment. If the reaction took place from day 4 on of treatment, patients took the antibiotic for 5 days. RESULTS: We included 108 girls and 105 boys. Mean age at the time of reaction was 3.66±3.06 years. 195 patients (91.5%) reacted to one BL. 154 reactions (67.2%) were non-immediate. Mild to moderate skin manifestations were most frequently reported. AMX-clavulanate was the most frequently involved (63.4%). DPT confirmed the diagnosis of drug hypersensitivity in 17 (7.3%) cases. These 17 patients had negative ST. CONCLUSION: In mild and moderate cases of BL hypersensitivity, diagnosis can be performed by DPT without previous ST.

Identification of sequential IgE-binding epitopes on bovine alpha(s2)-casein in cow's milk allergic patients.

BACKGROUND: Caseins are the major allergens responsible for cow's milk allergy (CMA). We have previously identified the IgE-binding epitopes of the major cow's milk (CM) proteins except for alpha(s2)-casein. METHODS: Overlapping decapeptides representing the entire length of alpha(s2)-casein were synthesized on a cellulose-derivatized membrane. Sera from 13 CM-allergic children, 4-15 years of age, with a median level of CM-specific IgE >100 kU/l (range 33.7 to > 100 kU/l) were used to identify IgE-binding epitopes. RESULTS: Four major and six minor sequential IgE-binding regions were identified on alpha(s2)-casein. The first major region is located in the middle of the protein at amino acids (AA) 83-100, and the other three major regions are located in the carboxy terminal portion of the protein at AA 143-158, 157-172 and 165-188. The minor IgE-binding regions were identified at AA 31-44, 43-56, 93-106, 105-114, 117-128, and 191-200. CONCLUSION: We identified 10 sequential IgE-binding regions on alpha(s2)-casein and performed the first crucial step in the development of immunotherapeutic interventions for CMA.

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.

Flow-cytometric cellular allergen stimulation test in latex allergy.

BACKGROUND: The use of flow-cytometric basophil activation to different allergens has been recommended in recent years. In this study, we analyzed the diagnostic reliability of the flow-cytometric allergen stimulation test (FAST) after latex-specific stimulation in vitro. The diagnostic reliability of the technique was assessed as well as its correlation with other in vitro diagnostic parameters. METHODS: 43 patients allergic to latex with a positive history and skin test participated in the study. Thirty subjects (20 of them exposed to latex) with a negative history, skin tests and serum-specific IgE determination to latex were used as controls. In FAST the percentage of basophils that express CD63 as an activation marker after in vitro stimulation with allergen (latex) is determined by flow cytometry, following double labelling with the monoclonal antibodies anti-CD63-PE and anti-IgE FITC. RESULTS: Intraclass correlation coefficient in FAST with latex was 0.995 (p < 0.0001), which demonstrates the excellent reproducibility of this technique. Taking a cutoff point of 10% by means of ROC curves, FAST yields a sensitivity of 93% and a specificity of 100%. The FAST positive predictive value in latex allergy was 100% and the negative predictive value was 99.9%. We found a positive and significant correlation between FAST and specific IgE (CAP) with the histamine release test and specific sulphidoleukotriene production [cellular allergen stimulation test (CAST); p < 0.05]. CONCLUSIONS: FAST is a highly reliable technique (93% sensitivity and 100% specificity) in the in vitro diagnosis of IgE-mediated latex allergy.