Background Household studies are crucial for understanding the transmission of SARS-CoV-2 infection, which may be underestimated from PCR testing of respiratory samples alone. We aim to combine assessment of household mitigation measures; nasopharyngeal, saliva and stool PCR testing; along with mucosal and systemic SARS-CoV-2 specific antibodies, to comprehensively characterise SARS-CoV-2 infection and transmission in households. Methods Between March and September 2020, we obtained samples from 92 participants in 26 households in Melbourne, Australia, in a 4-week period following onset of infection with ancestral SARS-CoV-2 variants. Results The secondary attack rate was 36% (24/66) when using nasopharyngeal swab (NPS) PCR positivity alone. However, when respiratory and non-respiratory samples were combined with antibody responses in blood and saliva, the secondary attack rate was 76% (50/66). SARS-CoV-2 viral load of the index case and household isolation measures were key factors that determine secondary transmission. In 27% (7/26) of households, all family members tested positive by NPS for SARS-CoV-2 and were characterised by lower respiratory Ct-values than low transmission families (Median 22.62 vs 32.91; IQR 17.06 to 28.67 vs 30.37 to 34.24). High transmission families were associated with enhanced plasma antibody responses to multiple SARS-CoV-2 antigens and the presence of neutralising antibodies. Three distinguishing saliva SARS-CoV-2 antibody features were identified according to age (IgA1 to Spike 1, IgA1 to nucleocapsid protein (NP), suggesting that adults and children generate distinct mucosal antibody responses during the acute phase of infection. Conclusion Utilising respiratory and non-respiratory PCR testing, along with measurement of SARS-CoV-2 specific local and systemic antibodies, provides a more accurate assessment of infection within households and highlights some of the immunological differences in response between children and adults.

Background: World-wide incidence and prevalence of both asthma and type 1 diabetes mellitus (T1DM) in children has been increasing in past decades. Association between the two diseases has been found in some but not other studies. Objective: We conducted a meta-analysis to verify such an association, and bidirectional Mendelian randomization analysis to examine the potential cause-effect relationships. Methods: Three databases (PubMed, Embase and Web of Science) were searched from their inception to February 1, 2021. Pooled hazard ratios (HR) or odds ratios (OR), and 95% confidence intervals, were calculated. Associations between single-nucleotide polymorphisms with childhood asthma and T1DM were selected based on genome-wide association studies. The outcome datasets were obtained from FinnGen study. We used the inverse variance-weighted, weighted median and MR-Egger methods to estimate causal effects. To assess robustness and horizontal pleiotropy, MR-Egger regression and MR pleiotropy residual sum and outlier test was conducted. Results: In meta-analysis, childhood asthma was associated with an increased risk of T1DM (HR=1.30, 95% CI 1.05-1.61, P=0.014), whereas T1DM was not associated with the risk of asthma (HR=0.98, 95% CI 0.64-1.51, P=0.941; OR=0.84, 95% CI 0.65-1.08, P=0.168). MR analysis indicated increased genetic risk of T1DM in children with asthma (OR=1.308; 95% CI 1.030-1.661; P =0.028). Analysis using the IVW method indicated not associated between T1DM and genetic risk of asthma (OR=1.027, 95%CI 0.970-1.089, P=0.358). Conclusion: Both meta-analysis and MR study suggested that childhood asthma was a risk factor for T1DM. No epidemiological or genetic evidence for an association of T1DM with asthma incidence. Further studies could be carried out to leverage this newfound insight into better clinical and experimental research in asthma and T1DM. Further studies could be carried out to leverage this newfound insight into better clinical and experimental research in asthma and T1DM.

A novel mutation in SLC39A7 identified in a patient with autosomal recessive agammaglobulinemia

Severe RSV infection in infancy is associated with increased risk of recurrent wheezing in childhood. Both acute and long-term alterations in airway functions are thought to be related to inefficient anti-viral immune response. The airway epithelium, the first target of respiratory syncytial virus (RSV), normally acts as an immunological barrier able to elicit an effective immune reaction but may also be programmed to directly promote a Th2 response, independently from Th2 lymphocyte involvement. Recognition of RSV transcripts and viral replication intermediates by bronchial epithelial cells brings about release of TSLP, IL-33, HMGB1 and IL-25, dubbed “alarmins”. These epithelial cell-derived proteins are particularly effective in stimulating innate lymphoid cells 2 (ILC2) to release IL-4, IL-5, and IL-13. ILC2, reflect the innate counterparts of Th2 cells and, when activate, are potent promoters of airway inflammation and hyperresponsiveness in RSV bronchiolitis and childhood wheezing/asthma. Long-term epithelial progenitors or persistent epigenetic modifications of the airway epithelium following RSV infection, may play a pathogenetic role in the short and long-term increased susceptibility to obstructive lung diseases in response to RSV in the young. Additionally, ILC2 function may be further regulated by RSV-induced changes in gut microbiota community composition that can be associated with disease severity in infants. A better understanding of the alarmin-ILC interactions in childhood might provide insights into the mechanisms characterizing these immune-mediated diseases and indicate new targets for prevention and therapeutic interventions.

We describe a case of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) to multiple CFTR modulators and piperacillin in an 8 year old female with CF. To our knowledge this is the first reported case of delayed type, T-cell mediated hypersensitivity to multiple CFTR modulators described in literature. Our findings suggest possible cross-reactivity between CFTR modulators or multiple sensitisations, which should be taken into account in similar cases.

OMALIZUMAB MAY FACILITATE DRUG DESENSITIZATION IN PATIENTS FAILING STANDARD PROTOCOLSTo the Editor,Nephrotic syndrome (NS) is a common glomerular disorder in children, for which steroids are the first-line treatment. While most children with NS respond to steroid therapy, 20% of children are resistant to steroids. Some children with steroid-responsive NS develop a frequently relapsing or steroid-dependent course and experience significant side effects of steroid therapy. Alternative medications such as calcineurin inhibitors, mycophenolate mofetil, cyclophosphamide, and rituximab, an anti-CD20 monoclonal antibody, are being considered for such patients with difficult-to-treat NS (1,2).Hypersensitivity reactions to monoclonal antibodies are quite limited in clinical practice, such as the release of cytokines that occur during intravenous infusion. However, IgE-mediated reactions may also occur. Life-threatening IgE-mediated reactions such as anaphylaxis lead to discontinuation of treatment or conversion to a less beneficial treatment. Rapid drug desensitization (RDD) is a therapeutic option that allows continuation of treatment with the causative drug (3). Omalizumab is a recombinant humanized anti-IgE monoclonal antibody. Treatment indications include severe asthma and idiopathic chronic urticaria. However, the efficacy of omalizumab has also been described in food allergy, as a bridge to oral immunotherapies, atopic dermatitis, idiopathic anaphylaxis, and mastocytosis (4). Previous studies have reported the use of omalizumab for rapid desensitization to chemotherapeutic agents (5). Here, we describe a patient with steroid-resistant NS who developed anaphylaxis on the first infusion of rituximab and subsequent type 1 hypersensitivity reactions during desensitization trials with rituximab using 12-, 16-, and 20-step protocols.A 4-year-old boy diagnosed with steroid-resistant NS and unresponsive to calcineurin inhibitors, either cyclosporine A or tacrolimus, and in their combination with mycophenolate mofetil, received rituximab. After premedication with methylprednisolone at a dose of 2 mg/kg, rituximab 375 mg/m2 was administered intravenously. During the infusion, he developed anaphylaxis (vomiting and dyspnea). The infusion was stopped and intramuscular epinephrine was administered, and a 12-step rapid desensitization protocol was planned for further infusions (Table 1). He was premedicated with H1 blockers and systemic steroids. However, the patient developed breakthrough reactions (urticaria) that required additional antihistamines at the 4th step. Infusion was resumed at a slower rate. Ten minutes after re-administration, generalized urticaria and angioedema developed. Montelukast was administered according to ENDA/EAACI recommendations for rapid desensitization in drug allergy (6). After 7 days, the protocol was modified to administer 375 mg/m2 rituximab in 16 steps with premedication (Table 2). The patient developed generalized urticaria and angioedema again at the 4th step. The next week, the desensitization protocol was designed with 375 mg/m2 rituximab in 20 steps (Table 3). Again, generalized urticaria and angioedema occurred in the 2nd step. A skin prick test was performed 3 weeks after the initial reaction. During the skin prick test, the patient developed generalized urticaria.In the absence of alternative treatment options for NS, desensitization with omalizumab treatment was suggested to prevent hypersensitivity reactions to rituksimab. Omalizumab (patient weight: 17.5 kg; total IgE:71 UI /ml; dose: 150 mg/ every 2 weeks) was added to treatment. The last omalizumab dose was administered 1 day before the following desensitization. After premedication, 375 mg/m2rituximab was administered in 20 steps. In the 5th step, the patient developed local urticaria requiring an antihistamine. The infusion was resumed and successfully completed. Under omalizumab treatment, the patient was administered 375 mg/m2 rituximab for the second time in a 20-step protocol. After the 6th dose, the interval of omalizumab treatment was changed to every 4 weeks. The rituximab dose was then increased to 750 mg/m2 at the third infusion. After premedication, the 20-step desensitization protocols were successfully applied in the following days.Rituximab is a chimeric monoclonal antibody that targets the CD20 antigen on the surface of B cells and causes elimination of B lymphocytes by complement- and antibody-dependent cellular cytotoxicity for 6-12 months (2). Efficacy has also been demonstrated in the treatment of steroid-resistant NS (7). Rituximab is one of the most common biologic agents with infusion-related reactions. Rituximab-associated hypersensitivity reactions can be classified as infusion-related reactions, cytokine release, IgE-mediated/non-IgE-mediated hypersensitivity reactions, mixed reactions, type 3 and type 4 hypersensitivity reactions (8).Omalizumab is a recombinant humanized IgG1 monoclonal antibody and prevents degranulation in effector cells by specifically binding to the FceRI receptor site of free IgE, causing a decrease in the level of free IgE in serum, and causing downregulation of FceRI receptors (9). Omalizumab has previously been used as a co-adjuvant in RDD along with insulin, the enzyme elosulfase alpha, chemotherapeutic agents, and aspirin (9). In a randomized, double-blind, placebo-controlled trial by Lang et al, desensitization was achieved after 16 weeks treatment with omalizumab. In other case reports, omalizumab treatment was generally started 7-14 days before RDD; only in one case report was the first omalizumab dose given 4 days before RDD (9). In previous studies, omalizumab dosing in allergic asthma was based on patient weight and total IgE. In our case, we administered 6 doses of omalizumab (150 mg/dose) every two weeks before desensitization and continued treatment once a month until completion of rituximab therapy. In patients with successful RDD on omalizumab, RDD steps can be reduced on subsequent infusions. Arroaberran et al. (10) presented a patient who tolerated elosulfase alpha enzyme without desensitization after omalizumab treatment.In conclusion, omalizumab may facilitate desensitization protocols and allow continuation of the preferred treatment.1Hatice Betul Gemici Karaaslan,

Several inborn errors of immunity are caused by defects in the general DNA repair machinery as exemplified by the T-B- RS-SCID condition owing to impaired resolution of programmed DNA double strands breaks introduced by RAG1/2 during V(D)J recombination. The genome instability generally associated with these conditions results in an increased propensity to develop malignancies requiring genotoxic based anti-cancer treatments. Moreover, the extent of immune deficiency often calls for hematopoietic stem cell transplantation as a definitive treatment, thus also demanding genotoxic based conditioning regimen prior to transplantation. In both cases, the underlying general DNA repair defects may result in catastrophic iatrogenic consequences. It is therefore of paramount importance to assess the functionality of the DNA repair apparatus prior to any genotoxic treatment when the exact molecular cause of the disease is unknown. For this purpose, two simple assays can be used on patient’s derived peripheral blood lymphocytes. 1) The PROMIDISα biomarker, based on the next generation sequencing analysis of the TCRα will highlight specific signatures of DNA repair deficiencies. 2) Direct analysis of the sensitivity of peripheral lymphocytes to ionizing radiations will formally identify patients at risk to develop toxicity towards genotoxic based treatments.

To the EditorReply to Stefano Miceli SopoFirst of all we want to thank for giving us an opportunity to reply to this correspondence (1), acknowledging the correspondence authors important point about the recommendation of introducing well-cooked, but not raw or uncooked pasteurized hen’s egg as part of complementary feeding.We agree that the evidence-base is sparse, with just two trials about cooked egg contributing to the low to moderate certainty evidence in our review (2) and guideline (3). These studies were in different populations (4, 5). We highlighted these points in the guideline, and the subgroup analysis from the Perkin study (6) was used only as supporting material, and for estimating the amount of egg that could be used. It is correct that the Natsume study included infant at higher risk due to eczema, but that was the case for both groups, and outcome was assessed by controlled challenges as described in the systematic review (2).As set out in the guideline, the process took into account expert insight weighing up benefits and harms, costs, feasibility, standard practice and patient preferences, in addition to published evidence. Weighing up all of these factors, the task force decided that the potential benefits outweighed potential harms in the case of well-cooked egg. One relatively large study found a 29% absolute decrease in the proportion of high risk infants with egg allergy at 1 year when very small amounts of egg were introduced (RR 0.22, 95% CI 0.08 to 0.54) (4). And two trials found no adverse effects (4, 5). It is likely feasible for many families to introduce well-cooked egg as part of complementary feeding, including in baked goods. The potential benefits do not outweigh the harms for uncooked egg, so the task force did not suggest trying this approach.The task force included representatives from many countries and specialties, and followed a robust process when reviewing evidence and debating potential recommendations. As the correspondence authors note, this recommendation is in line with other key guidelines. Whilst the correspondence authors may not agree with specific recommendations, the process used to debate and vote on them was systematic and took into account perspectives from across the world, including those from organisations representing patients and their families. Furthermore, a public consultation process sought feedback prior to publication, which further reinforced consensus about this recommendation.As is the case with all guidelines, the EAACI food allergy prevention guideline provides suggestions for clinicians to consider, alongside the needs of individual patients and local contexts and customs. The guideline is not prescriptive and does not override clinical judgement ad individual circumstances. Given the lack of likely harm, the convenience of this approach and best available evidence to date, the task force stands by its suggestion that clinicians in countries where egg allergy is an issue discuss with families the potential and desire to introduce small amounts of well-cooked egg into the infant diet when appropriate as part of complementary feeding. This need not be from the beginning of complementary therapy and the amounts may be very small.The guideline suggests half of a well-cooked, small egg twice a week, which may be in the form of a hard-boiled egg, well-cooked egg pasta, bread or baked goods, for example (p. 850). There is no evidence of significant harm, and it is likely that infants in many parts of the world may be exposed to egg in their diet anyway. There is no need to avoid this to prevent egg allergy, and in the opinion of the EAACI task force, introducing it may have benefits.Susanne Halken, Professor a, ProfessorAntonella Maria Muraro b, ProfessorGraham Roberts c, ProfessorDebra de Silva d, ProfessorOn behalf of On behalf of the EAACI Prevention Guideline Task Forcea Hans Christian Andersen Children’s Hospital, Odense University Hospital, Odense, DenmarkbDepartment of Women and Child Health, Food Allergy Referral Centre Veneto Region, Padua University Hospital, Padua, Italyc Clinical and Experimental Sciences and Human Development in Health, Faculty of Medicine, University of Southampton, Southampton, UK. NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton, UK. The David Hide Asthma and Allergy Research Centre, St Mary’s Hospital, Newport, UKdThe Evidence Centre Ltd, London, UKReferencesStefano Miceli Sopo, Dario Sinatti, Francesco Mastellone, Giulia Bersani, Mariannita Gelsomino. Comment on Halken et al. Pediatr Allergy Immunol . 2022de Silva D, Halken S, Singh C, et al. Preventing food allergy in infancy and childhood: systematic review of randomised controlled trials. Pediatr Allergy Immunol . 2020;31(7):813-826Halken S, Muraro A, de Silva D, et al. EAACI guideline: Preventing the development of food allergy in infants and young children (2020 update). Pediatr Allergy Immunol. 2021;32(5):843-858.Natsume O, Kabashima S, Nakazato J, et al. Two-step egg introduction for prevention of egg allergy in high-risk infants with eczema (PETIT): a randomised, double-blind, placebo-controlled trial. Lancet. 92 2017;389(10066):276-286.Perkin MR, Logan K, Tseng A, et al. Randomized trial of introduction of allergenic foods in breast-fed infants. N Engl J Med. 2016;374(18):1733-1743.Perkin MR, Logan K, Bahnson HT, et al. Efficacy of the enquiring About Tolerance (EAT) study among infants at high risk of developing food allergy. J Allergy Clin Immunol. 2019;144(6):1606-1614.

Threshold and safe ingestion dose among infants sensitized to hen’s eggMasatoshi Mitomori,a Noriyuki Yanagida,aMakoto Nishino,a Kyohei Takahashi,aKen-ichi Nagakura,a Kiyotake Ogura,aMari Takei,b Sakura Sato,b Motohiro EbisawabaDepartment of Pediatrics, National Hospital Organization, Sagamihara National Hospital, Kanagawa, JapanbClinical Research Center for Allergy and Rheumatology, National Hospital Organization, Sagamihara National Hospital, Kanagawa, JapanRunning title: Threshold and safe ingestion dose of egg

Background: Genetic areas of FOXP3 TSDR, HLA-G upstream of CpG island 96, CpG41 and CpG73 islands of the HLA‐DRB1 and HLA-DQB1 genes respectively, previously documented to display immune modulatory properties, were subjected to epigenetic/genetic analysis to assess their influence in IgE-mediated food allergy (FA) development in children. Methods: 64 orally challenged and IgE- tested food allergic subjects together with 44 controls were recruited. Targeted pyrosequencing analysis, to detect DNA methylation status and genetic variations was utilized and experimental results obtained were analysed by statistical software platform and correlated to clinical data. Also, transcription factor (TF) binding sites at study areas were unmasked by the JASPAR prediction database. Results: Parents’ smoking was significantly correlated with aberrant methylation patterns, regardless food allergic or control status. HLA-G promoter region showed a trend for hypomethylation in food allergic subjects, with one of the CG sites displaying significantly decreased methylation values. Rs1233333, residing within HLA-G promoter region preserved a protective role towards DNA methylation. Variable methylation patterns were recorded for CpG41 of the HLA‐DRB1 gene and hypermethylation of the region was significantly correlated with the presence of (Single Nucleotide Polymorphisms) SNPs. TFs’ recognition sites, located at studied genetic areas and exerting pivotal regulatory biological roles, are potentially affected from divergent DNA methylation status. Conclusions: We propose that HLA-G expression is triggered by food derived allergens, providing a TregFoxP3-/HLA-G+ subpopulation generation and direct immune-tolerance. Furthermore, clear evidence is provided for the underlying co-operation of genetic polymorphisms with epigenetic events, mainly at CpG41 island of HLA-DRB1 gene, which need an extended investigation and elucidation.

Allergy related outcomes at 12 months in the CORAL Birth cohort of Irish children born during the first COVID 19 lockdown.Word count: 1248, References: 10

A document by Aastha Singh. Click on the document to view its contents.

Background Cold urticaria (coldU) is associated with substantial morbidity and risk of fatality. Data on coldU in children are sparse. We aimed to evaluate the clinical characteristics, management, risk of associated anaphylaxis, and resolution rate of coldU in a pediatric cohort. Additionally, we sought to compare these metrics to children with chronic spontaneous urticaria (CSU). Methods We prospectively enrolled children with coldU from 2013-2021 in a cohort study at the Montreal Children’s Hospital and an affiliated allergy clinic. Data for comparison with participants with solely CSU were extracted from a previous study. Data on demographics, comorbidities, severity of presentation, management, and laboratory values were collected at study entry. Patients were contacted yearly to assess for resolution. Results Fifty-two children with cold urticaria were recruited, 51.9% were female and the median age of symptom onset was 9.5 years. Most patients were managed with second generation H1-antihistamines (sgAHs). Well-controlled disease on sgAHs was negatively associated with concomitant CSU (adjusted odds ratio (aOR)=0.69 [95%CI: 0.53, 0.92]). Elevated eosinophils were associated with cold-induced anaphylaxis (coldA) (aOR=1.38 [95%CI: 1.04, 1.83]), which occurred in 17.3% of patients. The resolution rate of coldU was 4.8 per 100 patient-years, which was lower than that of CSU (adjusted hazard ratio=0.43 [95%CI: 0.21, 0.89], P<10-2). Conclusion Pediatric coldU bears a substantial risk of anaphylaxis and a low resolution rate. Absolute eosinophil count and co-existing CSU may be useful predictive factors.

Title:Comment on Halken et alAuthors :Stefano Miceli Sopo a, Dario Sinattia, Francesco Mastellone b, Giulia Bersani a, Mariannita Gelsomino b.

To the Editor,Food protein-induced enterocolitis syndrome (FPIES) is a non-immunoglobulin E (IgE) mediated food allergy that predominantly affects infants and is characterized by repetitive vomiting that occurs 1–4 h after the ingestion of causative food. The etiology and underlying mechanisms of FPIES are not well understood. Recently, egg yolk (EY) has been recognized as a major causative food of FPIES.1,2 Most FPIES patients achieve tolerance with age;3 however, the practice management of EY-associated FPIES (EY-FPIES) has yet to be established. In a preliminary analysis of EY-FPIES, we found that the patients who acquired tolerance to EY had been diagnosed at a significantly younger age than non-tolerated patients despite no difference in the age of onset between both patients. This suggested that the early diagnosis and intervention is beneficial for tolerance acquisition in EY-FPIES. To investigate this further, we compared clinical outcomes between the early and late diagnosis of EY-FPIES.The present study enrolled 21 patients with EY-FPIES (1) diagnosed by positive oral food challenge (OFC) tests at our hospital between April 2018 and April 2021 who (2) subsequently underwent OFC to evaluate tolerance acquisition (re-OFC) at least once. The open OFC was performed by ingestion of a single dose once or three divided doses every 30 minutes. OFC was considered positive for FPIES based on delayed abdominal reactions without immediate skin or respiratory reactions. After confirmation by OFC, we instructed all patients to continue complete elimination of EY, regardless of threshold doses of OFC. We retrospectively collected data from electronic medical records on sex, age of first ingestion of EY, disease onset, first visit to our hospital, diagnosis, specific IgE (sIgE) to EY measured by ImmunoCAP test at diagnosis, asymptomatic histories of EY consumption before onset, the number of symptomatic episodes before diagnosis, the period between the first ingestion of EY and diagnosis of EY-FPIES, and age of tolerance acquisition. Tolerance acquisition was defined by (1) negative OFC and (2) the ability of daily EY consumption without FPIES reactions for three months at home. We divided the patients into the following two groups according to their age at the time of diagnosis: the early diagnosis (ED) group (<12 months) and the late diagnosis (LD) group (≥12 months), and compared the clinical features between both groups. A sIgE value higher than 0.35 UA/ml was defined as positive. Statistical analyses were performed using GraphPad Prism 9. The Mann-Whitney U test was used to compare nonparametric independent samples between the groups. Tolerance acquisition during follow-up was analyzed using a Kaplan–Meier survival curve and the log-rank test. P-value <0.05 was considered statistically significant. This study was approved by the Institutional Review Board of the KKR Sapporo Medical Center (2021-06).Patients’ characteristics are shown in Table 1. The ED group consisted of 12 patients (57.1%), 10 (83.3%) of whom acquired tolerance to EY, and the LD group consisted of nine patients (42.9%), three (33.3%) of whom acquired tolerance to EY. Among 21 patients with EY-associated FPIES, a total of 35 re-OFCs were performed, with a median interval of seven months (interquartile range [IQR], 6–11 months) (Figure 1). The median ages that re-OFC proved negative in ED and LD groups were 16 and 26 months, respectively (p = 0.014) (Table 1). The time to tolerance acquisition was significantly longer in the LD group than that in the ED group, as shown in the Kaplan–Meier analysis (log-rank, p = 0.0015) (Figure 2). The median ages of onset and first visit to our hospital were significantly younger in the ED group than those in the LD group (Table 1). All patients had a history of three episodes (IQR 2–6) of asymptomatic consumption before onset. Although the median age of the first introduction of EY in the ED group was younger than that in the LD group (six months vs. eight months, p = 0.004), there was no significant difference in the median number of asymptomatic consumptions before onset and the period between the first introduction and onset between the groups. The period between the first introduction of EY and FPIES diagnosis was shorter in the ED group than that in the LD group (2.5 months vs. 7 months, p = 0.0002).We demonstrated that the ED group achieved tolerance at a higher rate than the LD group, suggesting that early diagnosis and intervention predict favorable prognosis in EY-FPIES. Consistent with a previous report,4 all patients with EY-FPIES had histories of asymptomatic consumption before disease onset. Involvement of both innate and adaptive immunities with resultant proinflammatory cytokine production has been suggested in the pathology of acute FPIES.5 Our results suggest that the development of EY-FPIES requires sensitization of the adaptive immune system. T helper (Th)2 and Th17 cells are considered as key players of the immune response in FPIES,6 which is reflected by local infiltration of eosinophils and neutrophils, respectively. Adaptive immunity of infants shows dynamic changes with a rapid decline of regulatory T cells and maturation of Th17, while Th2 dominance is preserved.7 Additionally, the intestinal barrier function immaturity was also observed, resulting in a higher permeability of antigens across the intestines.8 Thus, early infants may be predisposed to FPIES because of immunological as well as anatomical immaturity. Although both ED and LD groups shared a similar interval between the first introduction of EY and onset, the period between the onset and diagnosis in the ED group was significantly shorter than that in the LD group. Our results suggest that an earlier elimination of EY after onset prevents the complete development of EY-FPIES.The median age at onset in the 21 patients with EY-FPIES was 8 months (IQR, 7–9 months), which is comparable to previous reports.9 Similar to another report,9 13 patients (65.0%) achieved tolerance at the median age of 16 months. This is earlier than the median age reported in a European series that demonstrates a 50% cumulative probability of resolution at the age of 41 months.10Notably, the median age of diagnosis is older (12 months) in that study compared with that in our series. Thus, the different clinical courses may attribute to differences in age of diagnosis. Otherwise, the clinical course may depend on ethnicity. In 2017, the Japanese Society of Pediatric Allergy and Clinical Immunology recommended the early introduction of EY to infants with a high risk for IgE-mediated egg allergy. This might have increased the number of early-onset EY-FPIES in Japan. Our results suggest that a first re-OFC seven months after the diagnosis is reasonable for preventing unnecessary food avoidance in EY-FPIES.Our study is limited by a retrospective review of a small number of patients from a single institute. Additionally, accidental exposures after diagnosis occurred in one patient in the LD group, influencing the scheduling of re-OFC. Moreover, we evaluated solely patients with a confirmational diagnosis by OFC, which might be insufficient to reflect the whole heterogeneity of EY-FPIES.Conclusively, the ED group achieved tolerance in EY-FPIES earlier compared with the LD group. Early diagnosis and complete elimination of EY may be beneficial for EY-FPIES.

Abstract Background: The level of pollen in Korea has increased over recent decades. Research suggests that pollen-food allergy syndrome (PFAS) may be more frequent in childhood than previously recognized. We aimed to investigate the prevalence and characteristics of PFAS in children aged 6–10 years from a general population-based birth cohort. Methods: We analyzed 930 children from the COhort for Childhood Origin of Asthma and allergic diseases (COCOA) birth cohort. Allergic diseases were diagnosed annually by pediatric allergists. The skin prick tests were performed with 14 common inhalant allergens and four food allergens for children aged 3 and 7 years. Results: Of the 930 eligible children, 44 (4.7%) aged 6–10 years were diagnosed with. The mean age at onset was 6.74 years. PFAS prevalence was 7.2% among children with allergic rhinitis (AR) and 19.1% among those with pollinosis, depending on comorbidity. PFAS was more prevalent in schoolchildren with atopic dermatitis, food allergy, and sensitization to food allergens and grass pollen in early childhood. In schoolchildren with AR, only a history of food allergy before 3 years increased the risk of PFAS (aOR 2.971, 95% CI: 1.159–7.615). Conclusion: Food allergy and food sensitization in early childhood was associated with PFAS in schoolchildren with AR. Further study is required to elucidate the mechanism by which food allergy in early childhood affects the development of PFAS.

Background: Previous studies reported controversial results regarding the association between allergic disorders and ADHD/ASD. The aim of this article is to investigate whether allergic disorders are associated with ADHD/ASD in a large cohort of pediatric patients. Methods: A retrospective study using the pediatric (0-18 year) database (ICD-9-CM codes) of Clalit Health Services during the years (2000-2018). Diagnosis of all disorders was made by specialist physicians. Results: 117,022 consecutive non-selective allergic children diagnosed with one or more allergic disorder (asthma, rhinitis. conjunctivitis, skin, food, or drug allergy) and 116,968 non-allergic children were enrolled to our study. The mean follow-up period was 11±6 years. The presence of allergic disorders in early childhood (mean age of allergic diagnosis 4.5± 4.3 years) in boys as well as in girls, significantly increased the risk to develop ADHD (O.R 2.45, CI 2.39-2.51; P<0.0001), ASD (O.R 1.17, CI 1.08-1.27; P<0.0001) or both ADHD+ASD (O.R 1.5, CI 1.35-1.79; P<0.0001). Children with more than one allergic comorbidity revealed a much higher risk. In a multivariable analysis (adjusted for age at study entry, number of yearly visits and gender) the risk of allergic children to develop ADHD and ADHD+ASD, but not ASD alone, remained significantly higher. Conclusion: Allergic disorder in early childhood significantly increased the risk to develop ADHD, and to a less extend ASD, in later life.

Background: Cross-reactivity between wheat and other cereals is an essential issue in the management of wheat allergy. Few studies have reported in vitro cross-reactivity in immediate-type wheat allergy. This study aimed to examine cross-reactivity of the three fractions (albumin/globulin, gliadin, and glutenin fractions) among cereals in children with wheat allergy. Methods: Sera from 128 children with immediate-type wheat allergy were collected. We measured specific immunoglobulin E (sIgE) levels against each fraction of wheat, barley, and rye by using an enzyme-linked immunosorbent assay (ELISA). Cross-reactivities of each fraction among wheat, barley, and rye were examined via inhibition ELISA. Results: All subjects were sensitized to all the fractions of wheat, and also those of barley and rye. The wheat sIgE levels were significantly higher than those of barley and rye in all the fractions (p ≤ 0.001) and were significantly correlated with sIgE levels to them in each fraction (r = 0.887–0.969, p < 0.001). On inhibition ELISA, wheat inhibited the IgE binding to most of the solid phases at the lower protein levels compared to barley and rye in all fractions. Conclusions: In children with immediate-type wheat allergy, sensitization to all the three fractions of wheat was observed. In addition, they showed sensitization to barley and rye caused by in vitro cross-reactivity with wheat in each fraction. When managing children with wheat allergy, sensitization to barley and rye caused by the cross-reactivities should be considered.