Molecular Diagnosis in House Dust Mite-Allergic Patients Suggests That Der p 23 Is Clinically Relevant in Asthmatic Children.

BACKGROUND: Patterns of sensitization to house dust mites depend on geographic area and are important in clinical practice. However, the role of molecular diagnosis is not currently defined. We sought to characterize a pediatric population by focusing on sensitization to different mite species and major mite components in order to assess the clinical relevance of sensitization to allergenic components in our practice. METHODS: Consecutive children with respiratory allergy sensitized to house dust mites (determined by skin prick test [SPT]) were recruited. We determined specific IgE to nDer p 1, rDer p 2, and rDer p 23 using ImmunoCAP and sIgE using ImmunoCAP-ISAC microarray. Patients were followed up for 3 years. RESULTS: A total of 276 children were recruited. The frequency of sensitization was 86.6% for nDer p 1, 79.3% for rDer p 2, and 75.8% for rDer p 23. Lepidoglyphus species was the most common storage mite detected by SPT. Twenty-six patients (9.4%) were not sensitized to Der p 1 or Der p 2. It is noteworthy that IgE binding to Der p 23 was positive in 14 (53.8%). Asthmatic patients, especially those with a persistent moderate-severe phenotype, more frequently recognized the 3 major allergens. CONCLUSIONS: Most patients with mite allergy were sensitized to the major allergens Der p 1, Der p 2, and Der p 23. Of the allergens evaluated, 5% were sensitized to Der p 23 but not to Der p 1 or Der p 2. Sensitization to Der p 23 should be considered in the diagnosis and treatment of mite allergy, especially in patients with moderate-severe asthma, because it may worsen the clinical phenotype.

'Real-life' experience in asthmatic children treated with omalizumab up to six-years follow-up.

INTRODUCTION AND OBJECTIVES: Omalizumab is present in international guidelines for the control of severe asthma, but data on the long-term effects in children are limited. Our objective was to perform a 'real-life' long-term trial of omalizumab in children with allergic asthma. MATERIALS AND METHODS: An observational single center 'real-life' study was performed. Data for treatment, lung function, side effect, asthma exacerbations and hospitalizations were recorded at six months and annually. RESULTS: Forty-eight patients <18 years of age were enrolled. Median treatment period was 2.9 (0.5-6). Fluticasone dose for the maintenance treatment decreases significantly at six months (452mcg/day to 329.89mcg/day, respectively). This difference was maintained throughout the follow-up. Nobody used oral corticosteroid after six months. The rate of hospital admissions and visits to the emergency department for asthma exacerbations decreased significantly in the third years and fourth years follow-up, respectively. There was an improvement in lung function. Mean values of FEV1 and FEF25-75% before treatment were 79.88 and 62.94, respectively; after six months of treatment a statistically significant change was seen with a mean FEV1 of 92.29 and FEF25-75% of 76.31 (p=0.0001). Lung function values were above normal throughout the six years of treatment. No side effects were reported. CONCLUSIONS: Overall in 'real life' omalizumab in children reduces asthma exacerbations and hospitalizations, improves lung function, and decreases the maintenance therapy. It is shown to be safe for up to six years of treatment in children.

Asymptomatic LTP sensitisation is common in plant-food allergic children from the Northeast of Spain.

BACKGROUND: The sensitisation profile at molecular level in plant-food allergy is complex. Several allergens may be involved, with different potential for severe reactions. lipid transfer proteins (LTP) are considered the most relevant plant-food allergens in adults in Mediterranean countries, but less is known in children. AIM: To describe the clinical pattern and sensitisation profile of children with plant-food allergy and LTP sensitisation from Northeast Spain. METHODS: Children with history of immediate reaction to plant-food(s), positive skin-prick-test to the culprit plant-food(s) and specific-IgE to plant-food LTPs were analysed. RESULTS: 130 children were included. 69.2% (90/130) had reacted to ≥2 taxonomically unrelated plant-foods. Peach, walnut, hazelnut and peanut were most frequently involved. Reactions severity ranged from anaphylaxis (45.4%, 59/130) to oral symptoms only. Sensitisation to a particular plant-food LTP not always caused clinical symptoms with that plant-food; 69% (40/58) and 63% (17/27) of peach- and walnut-tolerant subjects had positive rPru p 3 and nJug r 3 specific IgE, respectively. 65.4% (85/130) of children were also sensitised to storage proteins, which was associated to anaphylaxis and nut allergy. However, 60% of patients without nuts/seeds allergy were sensitised to storage proteins. Specific-IgE levels to LTPs and/or storage proteins were not useful to predict allergy (vs. tolerance) to peach, walnut, peanut or hazelnut. CONCLUSIONS: Sensitisation to LTP and/or storage proteins without clear clinical significance is relatively common. Prospective longitudinal studies are required to evaluate the relevance of these silent sensitisations over time. Caution is required when interpreting the results of molecular-based diagnostic tools in clinical practice.

Baseline specific IgE levels are useful to predict safety of oral immunotherapy in egg-allergic children.

BACKGROUND: Oral immunotherapy (OIT) is a promising treatment for food allergy but dose-related reactions are common. OBJECTIVE: To evaluate safety of egg-OIT. To identify predictors of dose-related reactions. METHODS: Fifty children aged 5-18 underwent egg-OIT after confirming IgE-mediated egg allergy by double-blind placebo-controlled challenge (DBPCFC). All dose-related reactions over a median period of 18 months on-OIT (range: 12-28) were registered. Children were retrospectively divided into three subgroups: (1) children who stopped reacting to OIT-doses over time (RR, Resolved Reactions); (2) children with ongoing dose-related reactions over the whole period on-OIT (PR, Persistent Reactions); (3) children who discontinued OIT within induction phase due to frequent reactions not improved by protocol re-adaptation and medication (ED, Early Discontinuation). Baseline clinical/immunological parameters associated with subgroups were investigated. RESULTS: Reactions occurred in 7.6% of doses. Adrenaline was required in 26% of children. The three subgroups corresponded to three different safety phenotypes: (1) twenty-four children (48%, RR) experienced infrequent and mainly mild reactions that resolved over time. None required adrenaline; (2) seventeen children (34%, PR) experienced more frequent and severe ongoing reactions over time; (3) nine children (18%, ED) discontinued OIT due to very frequent and mainly moderate reactions. Early discontinuation was associated with underlying asthma, higher specific IgE (sIgE) and lower threshold at DBPCFC. In contrast, lower sIgE and less severe reactions at DBPCFC were associated with subgroup RR. sIgE showed excellent performance in predicting belonging to subgroup RR. Levels below the optimal cut-off (ovomucoid-sIgE 8.85 kU/L) indicated 77% probability of belonging to subgroup RR, whereas levels above it indicated 95% probability of early discontinuation or ongoing reactions over time. CONCLUSIONS AND CLINICAL RELEVANCE: Egg-OIT involves substantial risks. However, baseline parameters, particularly sIgE, may help identify children in whom the procedure is more likely to be safe. Egg-OIT safety needs improvement in children with more severe and persistent egg allergy.

Tolerance to egg proteins in egg-sensitized infants without previous consumption.

BACKGROUND: Egg-sensitized infants who have never eaten egg may react at first ingestion. We sought to determine the association between skin prick test (SPT) and specific IgE (sIgE) to egg proteins (EP) and oral food challenge (OFC) outcomes to find cut-off points which can diagnose egg allergy. METHODS: One hundred and fifty-four infants up to 18 months, with cow's milk allergy (CMA) and/or atopic dermatitis (AD) without previous egg consumption, were recruited. SPT to EP were performed. If it was positive, sIgE was performed. If positive SPT and/or sIgE (n = 94), OFC was performed between 12 and 18 months. Receiver operating characteristic (ROC) curves were plotted, and the outcome of the OFC was related to SPT and sIgE. The cut-off points with the best diagnostic accuracy were found. RESULTS: Ninety-four patients were sensitized to egg (69%) and 60 nonsensitized (31%). Of the sensitized, 27 tolerated cooked (CE) and raw egg (RE) (28.7%). Sixty-seven were allergic (71.3%): 29 reacted to CE, seven to egg yolk (EY) and 22 to egg white (EW) and 38 reacted to RE. 69.2% tolerated CE. EW SPT and ovalbumin (OVA) sIgE have the best area under the curve (AUC). The higher positive predictive values (PPV) were obtained for EW SPT and EW sIgE. CONCLUSIONS: In egg-sensitized infants with EW SPT ≥8 mm and/or EW sIgE ≥8.36 KU/l, egg diagnostic OFC can be avoided as there is 94% probability of becoming positive. In the other patients, OFC should be performed safely and early to avoid unnecessary diets.

Clinical-Hematological Changes and Predictors of Severity in Acute Food Protein-Induced Enterocolitis Syndrome Reactions at Oral Food Challenge: A Multicenter Observational Study.

BACKGROUND: Oral food challenge (OFC) is the criterion standard for diagnosis of acute food protein-induced enterocolitis syndrome (FPIES). No diagnostic/prognostic biomarkers are available, and OFC assessment criteria are not validated. OBJECTIVE: To assess clinical-hematological changes and predictors of severity of FPIES reactions at OFC. METHODS: This was an observational multicenter prospective study. Children aged 0 to 18 years diagnosed with acute FPIES were recruited at follow-up OFC in 12 tertiary centers in Spain and Italy. OFC outcomes (as positive/negative/inconclusive and mild/moderate/severe) were assessed on the basis of published "2017 FPIES Consensus" criteria. Clinical characteristics were recorded, and full blood cell count was done at baseline, reaction onset, and 4 hours later. Regression analysis was performed to assess predictors of severe reactions at OFC. RESULTS: A total of 81 children had positive OFC (mild in 11% [9 of 81], moderate in 61% [49 of 81], and severe in 28% [23 of 81]). Increase in neutrophils and reduction in eosinophils, basophils, and lymphocytes were observed (P < .05). OFC was inconclusive in 19 cases despite objective signs or neutrophilia. Regression analysis showed that a 2-day OFC protocol where only 25% of an age-appropriate portion is given on day 1 (not sex, age, culprit food, cumulative dose, and previous reaction severity) was associated with reduced odds of severe reaction compared with giving multiple doses in a single day. CONCLUSIONS: Distinct hematological changes may help support FPIES diagnosis. Current OFC assessment criteria may not capture the broad spectrum of acute FPIES presentations. This 2-day protocol may be associated with a reduced risk of severe reactions. Future work should aim to develop safer OFC and non-OFC diagnostics for FPIES.

[Hypersensitivity reactions to non-steroidal anti-inflammatory drugs and tolerance to alternative drugs]. / Reacciones de hipersensibilidad a antiinflamatorios no esteroideos y su tolerancia a fármacos alternativos.

INTRODUCTION: Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) are the most common reactions to drugs. The prevalence varies from 0.6 to 5.7% in general population, but there are no data available in children. The aim of this study is to determine the frequency of patients diagnosed with hypersensitivity to NSAIDs, and describe their clinical characteristics, type of hypersensitivity, and tolerance to alternative drugs. METHODS: Retrospective study was conducted on children with suspected hypersensitivity to NSAIDs from January 2012 to December 2013. The diagnosis was confirmed by oral drug provocation test (DPT) to the drug involved in the group with a history of one episode, while in the group with a history of more than one episode with the same drug the diagnosis was based on clinical data. Subsequently, a DPT with acetylsalicylic acid (ASA) was done in order to classify hypersensitivity into selective or multiple. In those cases with a positive result, a DPT was performed with alternative drugs. RESULTS: Out of a total of 93 children studied, 26 were diagnosed with hypersensitivity to NSAIDs: 7 confirmed by oral DPT, and 19 based on clinical data. Multiple hypersensitivity was diagnosed in 50% of patients. Ibuprofen was involved in all reactions. The most common clinical manifestation was angioedema (44%). Acetaminophen was the best tolerated alternative drug. CONCLUSIONS: More than one quarter (28%) of the population studied was diagnosed with hypersensitivity to NSAIDs, and 50% had multiple hypersensitivity. Acetaminophen is a safe alternative in children with hypersensitivity to NSAIDs. Meloxicam may be an alternative in cases that do not tolerate acetaminophen.