Oral immunotherapy in severe cow's milk allergic patients treated with omalizumab: Real life survey from a Spanish registry

BACKGROUND

Oral immunotherapy is a frequent treatment for the management of food allergies, but adverse events (AE) are common. This study assessed the outcome of cow's milk oral immunotherapy (MOIT) in severe cow`s milk-allergic patients treated with omalizumab in a real-life setting.

METHODS

OmaBASE was a national, multicenter, open, and observational registry that collected clinical, immunologic, and treatment from patients with food allergy receiving omalizumab.

RESULTS

Data derived from 58 patients aged 10.3 years (IQR 6.3-13.2) and median milk-specific IgE 100 kU_A /L at the start of omalizumab treatment. Most had experienced anaphylaxis by accidental exposures (70.7%) and had asthma (81.0%). Omalizumab in monotherapy induced tolerance to ≥6000 mg of cow's milk protein (CMP) to 34.8% of patients tested by oral food challenge. Omalizumab combined with MOIT conferred desensitization to ≥6000 mg of CMP to 83.0% of patients. Omalizumab withdrawal triggered more AE (P = .013) and anaphylaxis (P = .001) than no discontinuation. Anaphylaxis was observed in 36.4% of patients who discontinued omalizumab, and more in those with sudden (50.0%) rather than progressive (12.5%) discontinuation. At database closure, 40.5% of patients who had completed follow-up tolerated CMP without omalizumab (7.2% 1500-4500 mg; 33.3% ≥6000 mg).

CONCLUSION

Milk oral immunotherapy initiated under omalizumab allows the desensitization of subjects with severe cow's milk allergy even after omalizumab discontinuation. However, discontinuation of omalizumab can lead to severe AE and should be carefully monitored.

Egg OIT in clinical practice (SEICAP II): Maintenance patterns and desensitization state after normalizing the diet

BACKGROUND

It is unknown which are the most suitable maintenance pattern and egg consumption to maintain the desensitization state after ending the oral immunotherapy (OIT). This multicenter, randomized, controlled trial compared two OIT maintenance patterns with pasteurized egg white (PEW), evaluating the egg consumption effect on the desensitization state after ending the OIT.

METHODS

One hundred and one children with confirmed egg allergy were randomized: 25 to an egg-free diet (CG) and 76 to an OIT year with PEW and two maintenance patterns, 38 patients to daily 3.3 g proteins (AG) and 38 to every two days (BG). PEW challenge (DBPCFC), adverse reactions, and immune markers were assessed at baseline, at the end of the OIT, and at 6 and 12 months later on ad libitum egg consumption (T0, T12, T18, and T24). A questionnaire evaluated the egg consumption at T18.

RESULTS

At T12, 64 of 76 (84.21%) OIT patients had reached total desensitization (32 AG and 32 BG) vs 4 of 25 (16.00%) CG who passed the PEW DBPCFC. Thirty (93.75%) AG vs 25 (78.12%) BG patients completed an OIT year. At T18, 27 of 29 (93.1%) AG vs 20 of 24 (83.3%) BG passed the PEW DBPCFC, 96% consuming at least two egg servings/week. At T24, 97.43% OIT patients passed the challenge. Most patients had adverse reactions, more frequent in the BG patients; frequency and severity of reactions decreased through the study. PEW skin prick test wheal and sIgE antibody serum levels similarly decreased in AG or BG, but AG patients had greater increase in PEW sIgG4 (P < 0.05).

CONCLUSIONS

Daily OIT maintenance achieves better adherence, effectiveness, and safety. Two egg servings/week ensure maintained desensitization after the end of an OIT year.

Egg oral immunotherapy in children (SEICAP I): Daily or weekly desensitization pattern

BACKGROUND

Studies are required before incorporating egg oral immunotherapy (OIT) into clinical practice. The Spanish Society of Pediatric Allergy, Asthma and Clinical Immunology (SEICAP) conducted a multicenter, randomized controlled study assessing the effectiveness and safety of the OIT using pasteurized egg white (PEW) in egg-allergic children.

METHODS

One hundred and one egg-allergic children (6-9 years) were randomized for 1 year: 25 to an egg-free-diet (CG) and 76 to OIT (target dose 3.3 g PEW proteins), PI (30% weekly plus 5% daily increments) or PII (only 30% weekly increments) buildup patterns. Egg skin prick test, sIgE and sIgG4 serum levels, PEW double-blind placebo-controlled food challenge (DBPCFC), and dosing adverse reactions (DARs) were evaluated in all patients from inclusion (T0) until completing 1 year of follow-up (T12). At T12, egg-allergic control patients could start OIT. The effectiveness and safety of OIT and the effect of the buildup pattern were analyzed.

RESULTS

At T12, 4/25 (16.0%) CG patients passed the PEW DBPCFC vs 64/76 (84.2%) OIT that reached total desensitization (P = 0.000); 12 egg-allergic control patients started OIT. Finally, 72/88 (81.81%) patients reached total desensitization, 96.15% PI vs 75.80% on PII (P = 0.01). Induction period (121.12 ± 91.43, median 98.00 days) was longer in patients on PII buildup pattern, and those with allergic asthma, minor threshold dose, or higher egg sIgE (P < 0.05). Most patients (89.06%) developed DARs: 74.53% were mild; 21.90% moderate; and 3.5% requiring adrenaline-treatment. Moderate reactions and those requiring adrenaline were more frequent in patients with allergic asthma, PII pattern, or higher egg sIgE serum antibody levels (P < 0.05).

CONCLUSIONS

PEW OIT is an effective treatment for children with persistent egg allergy. A 30% weekly plus 5% daily increment pattern could be more effective and safer than one with only 30% weekly increments.

Anaphylaxis to hidden potato allergens in a peach and egg allergic boy

More than 170 foods have been identified as being potentially allergenic. However, a minority of these foods cause the majority of reactions. Sweets are frequently implicated in allergic reactions in children with cow's milk, egg, nuts or fruits allergy, and they are the most relevant foods investigated as responsible allergens. We report an anaphylactic reaction to candies in an egg and peach allergic boy. We performed a study to identify responsible allergens for the reaction. We investigated hidden egg and peach allergens in the candies, but they were not found. Finally, the causative allergen resulted to be a vegetable protein from potato peel. We diagnosed a new allergy in our patient and Sol t 4 was identified as the responsible allergen of the anaphylactic reaction. We conclude that responsible allergens should always be studied and identified in whatever allergic reaction in order to prevent new reactions.

Food allergy in breastfeeding babies. Hidden allergens in human milk

BACKGORUND

Food allergy is a rare disorder among breastfeeding babies.

OBJECTIVE

Our aim was to identify responsible allergens in human milk.

METHODS

We studied babies developing allergic symptoms at the time they were breastfeeding. Skin prick tests (SPT) were performed with breast milk and food allergens. Specific IgE was assessed and IgE Immunoblotting experiments with breast milk were carried out to identify food allergens. Clinical evolution was evaluated after a maternal free diet.

RESULTS

Five babies had confirmed breast milk allergy. Peanut, white egg and/or cow's milk were demonstrated as the hidden responsible allergens. No baby returned to develop symptoms once mother started a free diet. Three of these babies showed tolerance to other food allergens identified in human milk.

CONCLUSION

A maternal free diet should be recommended only if food allergy is confirmed in breastfed babies.

Anaphylactic reaction to probiotics. Cow's milk and hen's egg allergens in probiotic compounds

BACKGROUND

Probiotics are used in the treatment of allergic diseases. We investigated the safety of probiotics for subjects with food allergy.

MATERIAL AND METHODS

Labels of probiotics commercially available in Spain were examined to assess their content of cow's milk or hen's egg. Skin prick tests with these compounds (20 mg/ml) were performed in five children allergic to cow's milk, five children allergic to hen's white egg, and five control subjects non-allergic to food. Three serum pools: I (positive-specific IgE to cow's milk and hen's egg white proteins), II (positive-specific IgE to cow's milk and negative to hen's egg white proteins), and III (negative-specific IgE to cow's milk and positive to hen's egg white proteins) were used to detect cow's milk and hen's egg white allergens in probiotics. ImmunoCAP(®) (Phadia), in-house ELISA, SDS-PAGE immunoblotting, and inhibition studies of these assays were performed. Proteins were quantified by enzyme-immunoassay.

RESULTS

Eleven probiotics were studied. No label advertised about egg content, eight labels warned about lactose, lactic acid or cow's milk, one label claimed to be milk-free, and two gave no information. Cow's milk proteins were detected, by at least one lab technique, in 10/11 probiotics, three over 2.5 mg/kg (21, 52, 112 mg/kg). Hen's egg white proteins were detected in 3/11 probiotics, only one had more than 2.5 mg/kg (47 mg/kg).

CONCLUSION

Probiotic compounds may contain hidden allergens of food and may not be safe for subjects with allergy to cow's milk or hen's egg.

Bee pollen: a dangerous food for allergic children. Identification of responsible allergens

BACKGROUND

Bee pollen has been proposed as a food supplement, but it can be a dangerous food for people with allergy. We study an allergic reaction after ingestion of bee pollen in a 4-year-old boy who had developed rhinitis in the last spring and autumn.

METHODS

We performed a prick-by-prick test with bee pollen and skin prick tests with the most important local pollens, house dust mites, common fungi, and animal danders. The levels of serum tryptase, serum total IgE and specific IgE against bee venom and local pollen extracts were determined. The composition of the bee pollen was analysed and SDS-PAGE immunoblotting and blotting-inhibition were carried out.

RESULTS

Prick tests were positive to bee pollen and all local pollens extracts and negative to any other allergen sources. The bee pollen sample contained pollens from Quercus genus, and Asteraceae (Compositae) and Rosaceae families. Total IgE was 435 kU/l. Serum specific IgE to bee pollen was 6 kU/l and greater than 0.35 kU/L against pollens from Artemisia vulgaris, Taraxacum officinalis, Cupressus arizonica, Olea europaea, Platanus acerifolia and Lolium perenne as well as to n Art v 1 and other pollen marker allergens. Tryptase level was 3.5 mcg/mL. SDS-PAGE immunoblotting-inhibition points to Asteraceae pollen as the possible cause of the allergic reaction.

CONCLUSION

Foods derived from bees can be dangerous to people with allergy to pollen.

Exercise-induced asthma in asthmatic children. Predisposing factors

BACKGROUND

Exercise-induced bronchoconstriction (EIB) has a high prevalence in children with asthma, and this is a common problem, even in case of controlled asthma, because of the high levels of physical activity in the childhood.

OBJECTIVES

The aim of our study was to identify factors associated with the development of EIB in children with controlled asthma.

METHODS

We studied children evaluated for asthma. A personal and familiar history was collected from each patient to estimate asthma severity, precipitating factors, exercise ability, immunotherapy treatment and atopic familiar disorders. Skin prick tests for inhalant allergens, pulmonary function tests (PFTs) and exercise challenge test (ECT) measurements were realized in every patient. We used the Chi Squared test to compare qualitative variables, the Student's-t test for quantitative variables and a logistic regression analysis to estimate the independent effect of the variables.

RESULTS

We evaluated 132 asthmatic patients. Eighty-two, 6 to 14 years old (average 110 +/- 36.9 months), were included in the study. Forty one have coughing or wheezing with exercise at least three months ago, in addition to a positive ECT; 9 of these children had solitary EIB (group A), and 32 (group B) had controlled chronic asthma, 27 intermittent and 5 moderately persistent. Forty one controlled asthmatic children, 39 intermittent, 1 mildly persistent and 1 moderately persistent (group C) had a good tolerance for exercise with a negative ECT. No differences were found in familiar history, asthma severity or evolution time in B vs C group. We found that 35 patients (42,68 %) patients were sensitized to indoor allergens: 24 (58,53 %) were patients suffering EIB and 11 (26,8 %) allowed to group C. Precipitating factors of asthma were in group B: respiratory infections in 19 cases, pollen in 20 and in 10 indoor allergens exposure. In group C: 14 patients had asthmatic symptoms with viral respiratory infections, 32 with pollen and 2 with indoor allergens exposure. A patient from group A had allergy rhinitis after exposure to cats. Allergy to indoor allergens demonstrated an direct association to EIB suffering (p = 0,026). Twenty six patients with allergic asthma followed pollen immunotherapy treatment, 7 of group B (33,3 %) and 19 (59,3 %) of group C. This treatment was inversely associated with EIB suffering (p = 0,048). A logistic regression analysis confirmed the independence of both variables as predisposing and protecting factors in EIB suffering.

CONCLUSIONS

Allergy to indoor allergens might be considered a risk factor for EIB. Immunotherapy treatment could be a protective factor against the development of EIB in children with allergic asthma.

Cow's milk-specific immunoglobulin E levels as predictors of clinical reactivity in the follow-up of the cow's milk allergy infants

BACKGROUND

IgE-mediated cow's milk proteins (CMPs) allergy shows a tendency to disappear with age. The sooner tolerance is detected, the earlier the substitute diets can be suspended and the quicker family emotional hardship is alleviated.

OBJECTIVE

To analyse the specific IgE levels to cow's milk and its proteins, which help to separate tolerant from no tolerant children in the follow-up of infants with allergy to cow's milk.

PATIENTS AND METHODS

Sixty-six infants diagnosed with IgE-mediated allergy to CMPs were included in this prospective follow-up study. Periodic reassessments were carried out every 6 months until they were 2-years old and then, annually, until tolerance arose or until the last reassessment in which tolerance had not been achieved. Non-tolerant infants were followed, at least, for a period of 3 years. In each visit, the same skin tests and determination of specific IgE (CAP System FEIA) for milk and its proteins were carried out. The open challenge test was repeated unless a clear transgression to milk, which came to be positive, had taken place within the previous 3 months in each of the follow-up visits. Specific IgE levels to milk and its proteins, in different moments of the follow-up were analysed by means of the receiver-operating characteristic curve to predict clinical reactivity.

RESULTS

Throughout the follow-up 45 (68%) infants became tolerant. The follow-up mean for tolerant infants was 21.2 months whereas for non-tolerant infants it was 58 months. The specific IgE levels which were predictors of the clinical reactivity (positive predictive value (PPV)> or =90%), grew as the age of the infants increased: 1.5, 6 and 14 kU(A)/L for milk in the age range 13-18 and 19-24 months and in the third year, respectively. Specific IgE levels to casein: 0.6, 3 and 5 kU(A)/L, respectively, predicted clinical reactivity (PPV> or =90%) in the different analysed moments of the follow-up. The cut-off points: 2.7, 9 and 24 kU(A)/L for milk and 2, 4.2 and 9 kU(A)/L for casein, respectively, predicted clinical reactivity with an accuracy > or =95% corresponding to a specificity of 90%.

CONCLUSIONS

Monitorization of specific IgE concentration for milk and casein by means of the CAP system in allergic children to CMPs allows us to predict, to a high degree of probability, clinical reactivity. Age factor must be taken into account to evaluate the specific IgE levels which are predictors of tolerance or clinical reactivity.