Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE mediated food allergy presenting with delayed onset of projectile vomiting in the absence of cutaneous and respiratory symptoms. The pathophysiology of FPIES remains poorly characterized. The first international consensus guidelines for FPIES were published in 2017 and provided clinicians with parameters on the diagnosis and treatment of FPIES. The guidelines have served as a resource in the recognition and management of FPIES, contributing to an increased awareness of FPIES. Since then, new evidence has emerged, shedding light on adult-onset FPIES, the different phenotypes of FPIES, the recognition of new food triggers, center-specific food challenge protocols and management of acute FPIES. Emerging evidence indicates that FPIES impacts both pediatric and adult population. As a result, there is growing need to tailor the consensus guidelines to capture diagnoses in both patient groups. Furthermore, it is crucial to provide food challenge protocols that meet the needs of both pediatric and adult FPIES patients, as well as the subset of patients with atypical FPIES. This review highlights the evolving clinical evidence relating to FPIES diagnosis and management published since the 2017 International FPIES Guidelines. We will focus on areas where recent published evidence may support evolution or revision of the guidelines.

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy with gastrointestinal symptoms such as vomiting and diarrhea. The development of international consensus guidelines for the diagnosis and management of FPIES in 2017 enabled us to compare patients worldwide, regardless of geographic variation in disease features. As a result, it has become clear that there is heterogeneity among patients with FPIES or that there are cases that partly fit the diagnostic criteria for FPIES but have different characteristics. This review highlights the heterogeneity in FPIES characteristics in terms of trigger foods, the age of onset, differences in geographic regions, and symptoms; it further proposes four disease entities, including acute FPIES in children, acute FPIES in adults, chronic FPIES, and early-onset neonatal FPIES, depending on the age of onset and presumed pathophysiology. The major symptoms at onset and trigger foods differ in acute FPIES in children, acute FPIES in adults, and chronic FPIES, whereas the disease entities may share a similar pathophysiology. Early-onset neonatal FPIES may have a different pathophysiology than acute or chronic FPIES, and may not necessarily fulfil the full diagnostic criteria for acute or chronic FPIES described in the international consensus guidelines. Due to the similarity in symptoms, early-onset neonatal FPIES may sometimes be misdiagnosed as necrotizing enterocolitis. We aim to increase awareness of FPIES among medical staff in pediatrics, neonatology, and internal medicine and promote research, to gain a better understanding of the heterogeneity and pathophysiology of FPIES.

Background: Multiple prolonged symptoms are observed in patients who recover from an acute COVID-19 infection, which is defined as long COVID. General fatigue is frequently observed in patients with long COVID during acute and post-acute phases. This study aimed to identify the specific risk factors for general fatigue in long COVID.

Methods: Hospitalized patients with COVID-19 aged over 18 years were enrolled in a multicenter cohort study at 26 medical institutions. Clinical data during hospitalization and patient-reported outcomes after discharge were collected from medical records, paper-based questionnaires, and smartphone apps.

Results: Among prolonged symptoms through 1-year follow-ups, general fatigue was the most interfering symptom in daily life. Patients with protracted fatigue at all follow-up periods had lower quality of life scores at the 12-month follow-up. Univariate logistic regression analysis of the presence or absence of general fatigue at the 3-month, 6-month, and 12-month follow-ups identified asthma, younger age, and female sex as risk factors for prolonged fatigue. Multivariable logistic regression analysis revealed that asthma was an independent risk factor for persistent fatigue during the 12-month follow-up period. Longitudinal changes in the symptoms of patients with or without asthma demonstrated that general fatigue, not cough and dyspnea, was significantly prolonged in patients with asthma.

Background: Asthma has been identified as different phenotypes due to various risk factors. Age differences may have potential effects on asthma phenotypes. Our study aimed to identify potential asthma phenotypes among adults divided by age as either younger or older than 65 years. We also compared differences in blood granulocyte patterns, occupational asthmagens, and asthma control-related outcomes among patient phenotype clusters.

Methods: We recruited nonelderly (<65 years old) (n = 726) and elderly adults (≥65 years old) (n = 201) with mild-to-severe asthma. We conducted a factor analysis to select 17 variables. A two-step cluster analysis was used to classify subjects with asthma phenotypes, and a discriminant analysis was used to verify the classification of cluster results.

Results: There were three clusters with different characteristics identified in both the nonelderly and elderly asthmatic adults. In the nonelderly patient group, cluster 2 (obese, neutrophilic phenotypes) had a 1.85-fold significantly increased risk of asthma exacerbations. Cluster 3 (early-onset, atopy, and smoker with an eosinophil-predominant pattern) had a 2.37-fold risk of asthma exacerbations and higher oral corticosteroid (OCS) use than cluster 1 (late-onset and LMW exposure with paucigranulocytic blood pattern). Among elderly patients, cluster 2 had poor lung function and more ex-smokers. Cluster 3 (early-onset, long asthma duration) had the lowest paucigranulocytic blood pattern percentages in the elderly group.

Conclusions: The novelty of the clusters was found in age-dependent clusters. We identified three distinct phenotypes with heterogeneous characteristics, asthma exacerbations and medicine use in nonelderly and elderly asthmatic patients, respectively. Classification of age-stratified asthma phenotypes may lead to precise identification of patients, which provides personalized disease management.

Background: Maintaining good asthma control minimizes the risk of exacerbations and lung function decline and is a primary goal of asthma management. The Japanese Pediatric Asthma Guidelines (JPGL) employs different classification criteria for control status from other guidelines, stressing a higher level of control. Based on JPGL, we previously developed a caregiver-completed questionnaire for assessing and achieving best asthma control in preschoolers. In this study, we aimed to develop a questionnaire for school-age children and adolescents.

Methods: A working questionnaire comprising 14 items for patients and 34 items for caregivers was administered to 362 asthma patients aged 6-15 years and their caregivers. Separately, physicians filled out a questionnaire to determine JPGL-defined control. Logistic regression analysis was performed to construct a model to predict control levels using data from a randomly selected set of completed questionnaires from two-thirds of the subjects. Validation was performed using the remaining questionnaires.

Results: A set of 7 questions, encompassing self-assessed control status at the time of the visit and in the past month, and nocturnal/early morning asthma symptoms for patients and frequency of asthma symptoms, dyspnea, rescue beta-agonist use, and asthma hospitalization for caregivers, were selected and the 7-item model showed a good statistical fit with AIC of 110.5. The model has been named the Best Asthma Control Test for School Children and Adolescents (Best ACT-S). Best ACT-S scores differed significantly in the hypothetical direction among the groups of different JPGL-defined control levels, step-up/down treatment decisions, and presence/non-presence of exacerbations in the previous year.

Conclusions: The Best ACT-S is a valid questionnaire for children/adolescents aiming for best asthma control.

Background: Obstructive sleep apnea (OSA) is one of the major co-morbidities and aggravating factors of asthma. In OSA-complicated asthma, obesity, visceral fat, and systemic inflammation are associated with its severity, but the role of bronchial hyperresponsiveness (BHR) is unclear. We investigated the involvement of BHR and mediastinal fat width, as a measure of visceral fat, with OSA severity in patients with OSA and asthma-like symptoms.

Methods: Patients with OSA who underwent BHR test and chest computed tomography scan for asthma-like symptoms were retrospectively enrolled. We evaluated the relationship between apnea-hypopnea index (AHI) and PC₂₀ or anterior mediastinal fat width, stratified by the presence or absence of BHR.

Results: OSA patients with BHR (n = 29) showed more obstructive airways and frequent low arousal threshold and lower mediastinal fat width, and tended to show fewer AHI than those without BHR (n = 25). In the overall analysis, mediastinal fat width was significantly positively correlated with AHI, which was significant even after adjustment with age and gender. This was especially significant in patients without BHR, while in OSA patients with BHR, there were significant negative associations between apnea index and airflow limitation, and hypopnea index and PC₂₀.

Conclusions: Risk factors for greater AHI differed depending on the presence or absence of BHR in OSA patients with asthma-like symptoms. In the presence of BHR, severity of asthma may determine the severity of concomitant OSA.

Background: Asthma in the elderly needs more attention in an aging society. However, it is likely to remain underdiagnosed and undertreated. This study aimed to clarify clinical characteristics of new-onset asthma in the elderly, describing the prevalence, predictive factors, and comorbidities after asthma diagnosis of new-onset asthma in the elderly in the general population.

Methods: This community-based prospective cohort study enrolled 9804 generally healthy participants (30-74 years old) in Nagahama City, and conducted a follow-up assessment after 5 years. Elderly participants were those aged ≥65 years at baseline. Patients with new-onset asthma were defined as participants without asthma at baseline assessment and with asthma at the follow-up assessment.

Results: Among the 7948 participants analyzed in this study, 28 (1.4%) elderly and 130 (2.2%) non-elderly had new-onset asthma. Multiple logistic regression analysis revealed low forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) and high blood eosinophil counts at baseline as predicting factors for new-onset asthma in the elderly. Additionally, subsequent incidence of new-onset asthma was higher in elderly participants with both predictors (high blood eosinophil counts and low FEV₁/FVC at baseline) than those with none or one of the predictors before asthma diagnosis. Lastly, elderly patients with new-onset asthma had more frequent comorbidity of moderate to severe sleep disordered breathing than those non-elderly.

Conclusions: Eosinophilic inflammation and airflow obstruction may predict subsequent new-onset asthma after the age of 65 years. Revealing the characteristics of new-onset asthma in the elderly can aid in the prevention of underdiagnosed asthma.

Background: Atopic dermatitis and autoimmune diseases are highly heritable conditions that may co-occur from an early age.

Methods: The primary study is a national administrative cohort study involving 499,428 children born in 2002, tracked until 2017. Atopic dermatitis was defined as five or more principal diagnoses of atopic dermatitis and two or more topical steroid prescriptions. We estimated the risks for the occurrence of 41 autoimmune diseases, controlling for risk factors. In addition, we sourced a gene library from the National Library of Medicine to conduct a comprehensive gene ontology. We used Gene Weaver to identify gene set similarity and clustering, and used GeneMania to generate a network for shared genes.

Results: Exposed and unexposed groups included 39,832 and 159,328 children, respectively. During a mean follow-up of 12 years, the exposed group had an increased risk of autoimmune disease (hazard ratio, 1.27 [95 % confidence interval, 1.23-1.32]) compared to the unexposed group. The hazard ratios of autoimmune illnesses consistently increased with two- and five years lag times and alternative atopic dermatitis definitions. Shared genes between atopic dermatitis and autoimmune diseases were associated with comorbidities such as asthma, bronchiolitis, and specific infections. Genetic interactions of these shared genes revealed clustering in Th1, Th2, Th17, and non-classifiable pathways.

Conclusions: Atopic dermatitis was significantly associated with an increased risk of subsequent autoimmune disease. we identified the genetically associated disease in atopic dermatitis patients comorbid with autoimmune disease and demonstrated a genetic network between atopic dermatitis and autoimmune diseases.

Background: In clinical research on multifactorial diseases such as atopic dermatitis, data-driven medical research has become more widely used as means to clarify diverse pathological conditions and to realize precision medicine. However, modern clinical data, characterized as large-scale, multimodal, and multi-center, causes difficulties in data integration and management, which limits productivity in clinical data science.

Methods: We designed a generic data management flow to collect, cleanse, and integrate data to handle different types of data generated at multiple institutions by 10 types of clinical studies. We developed MeDIA (Medical Data Integration Assistant), a software to browse the data in an integrated manner and extract subsets for analysis.

Results: MeDIA integrates and visualizes data and information on research participants obtained from multiple studies. It then provides a sophisticated interface that supports data management and helps data scientists retrieve the data sets they need. Furthermore, the system promotes the use of unified terms such as identifiers or sampling dates to reduce the cost of pre-processing by data analysts. We also propose best practices in clinical data management flow, which we learned from the development and implementation of MeDIA.

Conclusions: The MeDIA system solves the problem of multimodal clinical data integration, from complex text data such as medical records to big data such as omics data from a large number of patients. The system and the proposed best practices can be applied not only to allergic diseases but also to other diseases to promote data-driven medical research.

Background: Non-IgE-mediated gastrointestinal food allergies (non-IgE-GIFAs) seem to be increasing rapidly worldwide. However, nationwide studies have been limited to food-protein-induced enterocolitis (FPIES) and food-protein-induced allergic proctocolitis (FPIAP), with little attention to other non-IgE-GIFA subgroups. The aim of this study was to elucidate the clinical features of all patients with non-IgE-GIFAs, not just certain subgroups.

Methods: We conducted a nationwide cross-sectional survey of non-IgE-GIFAs in Japan from April 2015 through March 2016. A questionnaire was sent to hospitals and clinics throughout Japan. The questionnaire asked about the number of physician-diagnosed non-IgE-GIFA patients, the status of fulfillment of the diagnostic criteria, tentative classification into 4 clusters based on the initial symptoms, the day of onset after birth, complications, and the suspected offending food(s).

Results: The response rate to that questionnaire was 67.6% from hospitals and 47.4% from clinics. Analyses were conducted about “diagnosis-probable” patient cohort (n = 402) and the “diagnosis-confirmed” patients (n = 80). In half of the reported non-IgE-GIFA patients, onset occurred in the neonatal period. The patients were evenly distributed among 4 non-IgE-GIFA clusters. In Cluster 1, with symptoms of vomiting and bloody stool, the onset showed a median of 7 days after birth, which was the earliest among the clusters. Cow's milk was the most common causative food.

Conclusions: In half of the patients, the onset of non-IgE-GIFAs was in the neonatal period. This highlights the importance of studying the pathogenesis in the fetal and neonatal periods.

Background: Adults with food-protein-induced enterocolitis syndrome (FPIES) often develop severe abdominal symptoms after eating seafood. However, no investigation of a food elimination strategy for adult FPIES patients has been performed to date.

Methods: We conducted a retrospective cohort study of seafood-avoidant adults by telephone interview, based on the diagnostic criteria for adult FPIES reported by González et al. We compared the clinical profiles, abdominal symptoms, and causative seafoods between FPIES and immediate-type food allergy (IgE-mediated FA) patients. We also profiled the detailed intake-status of seafoods in adult FPIES patients.

Results: Twenty-two (18.8 %) of 117 adults with seafood-allergy were diagnosed with FPIES. Compared with the IgE-mediated FA patients, FPIES patients had an older age of onset, more pre-existing gastrointestinal and atopic diseases, more episodes, longer latency and duration of symptoms, more nausea, abdominal distention, and severe abdominal pain, and more frequent vomiting and diarrhea. In particular, abdominal distention—reflecting intestinal edema and luminal fluid retention—may be the most distinctive characteristic symptom in adult FPIES (p < 0.001). Bivalves, especially oysters, were the most common cause of FPIES. Strikingly, intake-status profiling revealed that many FPIES patients can safely ingest an average of 92.6 % of seafood species other than the causative species.

Conclusions: There are many differentiators between FPIES and IgE-mediated FA, which may reflect differences in the underlying immunological mechanisms. Although seafood FPIES is unlikely to induce tolerance, many patients can ingest a wide variety of seafood species after a long period from onset.

Background: N-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory properties and are expected to prevent the onset of allergies. However, epidemiological studies investigating the relationship between child allergies and maternal intake of n-3 PUFAs or fish have yielded inconsistent results.

Methods: Following exclusions from a dataset comprising 103,057 records from the Japan Environment and Children's Study, 72,105 participants were divided into five groups according to mothers' intake of n-3 PUFAs or fish during pregnancy to assess the risk of their children being diagnosed with allergy by 3 years old. Adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for child allergies were calculated using multivariable logistic regression analyses with reference to the lowest intake group.

Results: Levels of maternal intake of n-3 PUFAs or fish showed inverted associations (i.e., reduced risk) with the incidence of physician-diagnosed allergic rhinoconjunctivitis or parent-reported symptoms of current rhinitis with eye symptoms at different time points and the cumulative incidence from birth to 3 years of age. Inverted associations were also found for current wheeze at 1-<2 years of age and current eczema at 1-<2 and 0-<3 years of age. However, for food allergies, no significant associations were observed in the incidence in each group compared with the lowest intake group at any age.

Conclusions: The findings suggest that n-3 PUFA intake during pregnancy may reduce the risk of developing allergic diseases and symptoms in children. In addition, consumption of n-3 PUFAs or fish is very unlikely to increase the risk of allergy given that the results are from a country with high fish consumption. Trial registration: UMIN000030786 https://rctportal.niph.go.jp/detail/um?trial_id=UMIN000030786.

Background: Allergen immunotherapy (AIT) is the only disease-modifying treatment for immunoglobulin (Ig) E-mediated allergy. Owing to the high prevalence and early onset of hay fever and pollen-food allergy syndrome (PFAS), a safer and simpler treatment method than conventional AIT is needed. To develop a local nasal immunotherapy using an ointment containing hypoallergenic pollen and assess its efficacy in mice and healthy humans.

Methods: Hypoallergenicity was achieved by combining pollen and galactomannan through the Maillard reaction to create birch pollen-galactomannan conjugate (BP-GMC). The binding of galactomannan to Bet v 1 was confirmed using electrophoresis and Western blotting (WB). Binding of specific IgE antibodies to BP-GMC was verified using enzyme-linked immunosorbent assay (ELISA) and basophil activation test (BAT). The localization of BP-GMC absorption was confirmed using a BALB/c mouse model. BP-GMC mixed with white petrolatum was intranasally administered to 10 healthy individuals (active drugs, 8; placebo, 2) for 14 days.

Results: In electrophoresis and WB, no 17-kDa band was observed. In ELISA and BAT, BP-GMC did not react to specific IgE but was bound to IgA and IgG. In the mouse model, BP-GMC was detected in nasopharyngeal-associated lymphoid tissues. In the active drug group, the salivary-specific IgA level significantly increased on day 15 (p = 0.0299), while the serum-specific IgG level significantly increased on day 85 (p = 0.0006).

Conclusions: The BP-GMC ointment rapidly produced antagonistic antibodies against IgE; it is safe and easy to use and might serve as a therapeutic antigen for hay fever and PFAS.

Background: Lactobacillus paracasei has been known to reduce airway resistance and inflammation in asthma. However, the therapeutic effect of its extracellular vesicles (EVs) in patients with asthma remains unclear.

Methods: To validate the clinical relevance of L. paracasei-derived EVs (LpEV) in asthma, the composition of gut microbial EVs was verified by metagenomics in LPS-induced C57BL/6 mice. The components of proteins and metabolites in LpEV were identified by peptide mass fingerprinting and metabolomic analysis. The serum levels of specific IgG1 or IgG4 antibodies to LpEV were compared by ELISA between patients with eosinophilic asthma (EA, n = 10) and those with neutrophilic asthma (NA, n = 10) as well as with healthy controls (HCs, n = 10). Finally, therapeutic effects of LpEV and their metabolites in asthma were validated in vivo/in vitro.

Results: Significantly lower proportions of EVs derived from Lactobacillus at the genus level were noted in mice with NA than in control mice. Moreover, the serum levels of LpEV-specific IgG4, but not IgG1, were lower in patients with NA than in those with EA or in HCs and positively correlated with FEV₁ (%) values. In addition, oral administration of LpEV reduced airway resistance and inflammation in mice with NA. Finally, LpEV and their 3 metabolites (dodecanoic acid, palmitoleic acid, and D-(-)-tagatose) significantly inhibited JNK phosphorylation/IL-8 production in airway epithelium in vitro.

Conclusions: These findings suggest that LpEV may have a therapeutic potential targeting NA by suppressing the JNK pathway and proinflammatory cytokine production in airway epithelium.

Background: Ozone is one of the triggers of asthma, but its impact on the pathophysiology of asthma, such as via airway inflammation and airway hyperresponsiveness (AHR), is not fully understood. Thymic stromal lymphopoietin (TSLP) is increasingly seen as a crucial molecule associated with asthma severity, such as corticosteroid resistance.

Methods: Female BALB/c mice sensitized and challenged with house dust mite (HDM) were exposed to ozone at 2 ppm for 3 h. Airway inflammation was assessed by the presence of inflammatory cells in bronchoalveolar lavage fluid and concentrations of cytokines including TSLP in lung. Anti-TSLP antibody was administered to mice to block the signal. Survival and adhesion of bone marrow-derived eosinophils in response to granulocyte colony-stimulating factor (G-CSF) were evaluated.

Results: Ozone exposure increased eosinophilic airway inflammation and AHR in mice sensitized and challenged with HDM. In addition, TSLP, but not IL-33 and IL-25, was increased in lung by ozone exposure. To confirm whether TSLP signaling is associated with airway responses to ozone, an anti-TSLP antibody was administered, and it significantly attenuated eosinophilic airway inflammation, but not AHR. Interestingly, G-CSF, but not type 2 cytokines such as IL-4, IL-5, and IL-13, was regulated by TSLP signaling associated with eosinophilic airway inflammation, and G-CSF prolonged survival and activated eosinophil adhesion.

Conclusions: The present data show that TSLP contributes to ozone-induced exacerbations of eosinophilic airway inflammation and provide greater understanding of ozone-induced severity mechanisms in the pathophysiology of asthma related to TSLP and G-CSF.

Background: Selective activator protein (AP)-1 inhibitors are potentially promising therapeutic agents for atopic dermatitis (AD) because AP-1 is an important regulator of skin inflammation. However, few studies have investigated the effect of topical application of AP-1 inhibitors in treating inflammatory skin disorders.

Methods: Immunohistochemistry was conducted to detect phosphorylated AP-1/c-Jun expression of skin lesions in AD patients. In the in vivo study, 1 % T-5224 ointment was topically applied for 8 days to the ears of 2,4 dinitrofluorobenzene challenged AD-like dermatitis model mice. Baricitinib, a conventional therapeutic agent Janus kinase (JAK) inhibitor, was also topically applied. In the in vitro study, human epidermal keratinocytes were treated with T-5224 and stimulated with AD-related cytokines.

Results: AP-1/c-Jun was phosphorylated at skin lesions in AD patients. In vivo, topical T-5224 application inhibited ear swelling (P < 0.001), restored filaggrin (Flg) expression (P < 0.01), and generally suppressed immune-related pathways. T-5224 significantly suppressed Il17a and l17f expression, whereas baricitinib did not. Baricitinib suppressed Il4, Il19, Il33 and Ifnb expression, whereas T-5224 did not. Il1a, Il1b, Il23a, Ifna, S100a8, and S100a9 expression was cooperatively downregulated following the combined use of T-5224 and baricitinib. In vitro, T-5224 restored the expression of FLG and loricrin (LOR) (P < 0.05) and suppressed IL33 expression (P < 0.05) without affecting cell viability and cytotoxicity.

Conclusions: Topical T-5224 ameliorates clinical manifestations of AD-like dermatitis in mice. The effect of this inhibitor is amplified via combined use with JAK inhibitors.