Allergology International最新文献

Background: We investigated the efficacy and safety of dupilumab in Japanese patients aged ≥6 months to <18 years old with moderate-to-severe atopic dermatitis not adequately controlled with existing therapies.

Methods: In this randomized, double-blind, phase 3 study, patients received dupilumab (n = 30) or placebo (n = 32) with concomitant topical corticosteroids for 16 weeks, then all patients received dupilumab from 16 to 52 weeks. The primary endpoint was the proportion of patients with ≥75% improvement in Eczema Area and Severity Index (EASI) score from baseline (EASI-75) to Week 16. Key secondary endpoints included changes in EASI score, proportion of patients with investigator global assessment (IGA) scores of 0/1, and changes in worst daily itch numerical rating scale (NRS) scores (evaluated in patients aged ≥6 to <12 years [n = 35]).

Results: At Week 16, more patients achieved EASI-75 with dupilumab than placebo (43.3% vs 18.8%; P = 0.0304), and the least squares mean (LSM) difference in percent change in EASI scores at Week 16 of dupilumab vs placebo was -39.4% (P = 0.0003). However, no significant difference in the proportion of patients achieving IGA scores of 0/1 at Week 16 with dupilumab versus placebo were seen (10.0% vs 9.4%; P = 0.8476). The percent change in worst daily itch NRS scores at Week 16 was higher with dupilumab (LSM difference: -33.3%; nominal P = 0.0117). Dupilumab was well tolerated; no new safety signals were identified.

Conclusions: Dupilumab showed consistent efficacy and was well tolerated in Japanese patients aged ≥6 months to <18 years with moderate-to-severe atopic dermatitis previously insufficiently controlled with existing therapies.

Background: Diagnosing perioperative anaphylaxis (POA) is often challenging. Although a guideline recommends measuring tryptase rather than histamine, there is little evidence for this. We aimed to examine the diagnostic performance and appropriate timing of tryptase and histamine measurements for diagnosing anaphylaxis, and the association between Hypersensitivity Clinical Scoring Scheme (HCSS) scores and elevated biomarkers.

Methods: We measured tryptase and histamine levels thrice: 30 min, 2 h, and at least 24 h after an anaphylactic event for patients with suspected anaphylaxis, and at the induction of general anesthesia and 30 min and 2 h after the start of surgery for control patients without a reaction. Absolute values and the magnitude and rate of change from baseline were evaluated. We determined the thresholds of tryptase and histamine levels with the best diagnostic performance and compared their performance.

Results: Forty-five patients with perioperative anaphylaxis were included in this study. The control group included 30 patients with uneventful general anesthesia and 12 patients with a suspected but unconfirmed diagnosis of perioperative anaphylaxis. Comparison at the same measurement timings showed that tryptase generally had better diagnostic performance than histamine. Both showed better diagnostic performance when assessed using multiple measurements rather than a single measurement. The best diagnostic performance was seen with the percentage change in the higher tryptase value, whether measured at 30 min or 2 h after anaphylaxis onset, as compared to baseline. However, neither tryptase nor histamine levels correlated with HCSS scores.

Conclusions: Overall, tryptase showed better diagnostic performance than histamine. When multiple tryptase measurements are possible, parameters calculated using two acute phase measurements and the baseline level have better diagnostic performance.

Background: Basal cell hyperplasia is commonly observed in nasal polyp epithelium of eosinophilic chronic rhinosinusitis (eCRS). We examined the function and mechanisms of basal cell hyperplasia in the pathophysiology of eCRS.

Methods: We found that normal human bronchial epithelial (NHBE) cells obtained basal cell characteristics when cultured with PneumaCult™-Ex Plus Medium. Most of the cells passaged three times expressed basal cell surface markers CD49f and CD271 by flow cytometry, and basal cell nuclear marker p63 by immunohistochemical staining. We named these NHBE cells with basal cell characteristics cultured Basal-like cells (cBC), and NHBE cells cultured with BEGM™ cultured Epithelial cells (cEC). The characteristics of cBC and cEC were examined and compared by RNA sequencing, RT-PCR, ELISA, and cell proliferation studies.

Results: RNA sequencing revealed that cBC showed higher gene expression of thymic stromal lymphopoietin (TSLP), IL-8, TLR3, and TLR4, and lower expression of PAR-2 compared with cEC. The mRNA expression of TSLP, IL-8, TLR3, and TLR4 was significantly increased in cBC, and that of PAR-2 was significantly increased in cEC by RT-PCR. Poly(I:C)-induced TSLP production and LPS-induced IL-8 production were significantly increased in cBC. IL-4 and IL-13 stimulated the proliferation of cBC. Finally, the frequency of p63-positive basal cells was increased in nasal polyp epithelium of eCRS, and Ki67-positive proliferating cells were increased in p63-positive basal cells.

Conclusions: Type 2 cytokines IL-4 and IL-13 induce basal cell hyperplasia, and basal cells exacerbate type 2 inflammation by producing TSLP in nasal polyp of eCRS.

Background: Asthma is characterized by phenotypes of different clinical, demographic, and pathological characteristics. Identifying the profile of exhaled volatile organic compounds (VOCs) in asthma phenotypes may facilitate establishing biomarkers and understanding asthma background pathogenesis. This study aimed to identify exhaled VOCs that characterize severe asthma phenotypes among patients with asthma.

Methods: This was a multicenter cross-sectional study of patients with severe asthma in Japan. Clinical data were obtained from medical records, and questionnaires were collected. Exhaled breath was sampled and subjected to thermal desorption gas chromatography-mass spectrometry (GC/MS).

Results: Using the decision tree established in the previous nationwide asthma cohort study, 245 patients with asthma were divided into five phenotypes and subjected to exhaled VOC analysis with 50 healthy controls (HCs). GC/MS detected 243 VOCs in exhaled breath samples, and 142 frequently detected VOCs (50% of all samples) were used for statistical analyses. Cluster analysis assigning the groups with similar VOC profile patterns showed the highest similarities between phenotypes 3 and 4 (early-onset asthma phenotypes), followed by the similarities between phenotypes 1 and 2 (late-onset asthma phenotypes). Comparisons between phenotypes 1-5 and HC revealed 19 VOCs, in which only methanesulfonic anhydride showed p < 0.05 adjusted by false discovery rate (FDR). Comparison of these phenotypes yielded several VOCs showing different trends (p < 0.05); however, no VOCs showed p < 0.05 adjusted by FDR.

Conclusions: Exhaled VOC profiles may be useful for distinguishing asthma and asthma phenotypes; however, these findings need to be validated, and their pathological roles should be clarified.

Background: Intestinal bacteria may play a role in the development of food allergies. This study aimed to analyze and compare the gut microbiota of food-allergic children with that of healthy children of the same age.

Methods: Stool samples were collected from one-and-a-half-year-old food-allergic (FA group, n = 29) and healthy controls (HC group, n = 19). A questionnaire was provided to examine the children's birth, dietary, medical, and social histories. The gut microbiota was profiled by 16S rRNA sequencing. Differences in taxonomic composition were assessed using linear discriminant analysis effect size (LEfSe), and microbial functional profiles were predicted with Tax4Fun2.

Results: No significant difference in the alpha diversity index between the two groups; however, a negative correlation was observed between the Shannon diversity index and the relative abundance of Bacteroides. A significant difference was observed in beta diversity (permutational multivariate analysis of variance) in the bacterial composition between the FA and HC groups (P < 0.05). The FA group had a higher abundance of Escherichia and Anaeromassilibacillus and a lower abundance of Bacteroides, Oscillibacter, Ruminococcus, Hungateiclostridium and Anaerotaenia than the HC group (LEfSe: linear discriminant analysis score >2). The FA group showed a predicted increase in the expression levels of genes associated with intestinal pathogenicity compared with that in the HC group.

Conclusions: The gut microbiota of food-allergic children has a higher abundance of bacteria involved in intestinal inflammation and a lower abundance of bacteria involved in immune tolerance than that of healthy children. This dysbiosis may also be associated with food allergies.

Background: Oxaliplatin is commonly used to treat gastrointestinal malignancies. However, its applications are limited due to potential adverse drug reactions (ADRs), particularly severe anaphylactic shock. There is no method to predict or prevent ADRs caused by oxaliplatin. Therefore, we aimed to investigate the genetic HLA predisposition and immune mechanism of oxaliplatin-induced ADRs.

Methods: A retrospective review was performed for 154 patients with ADRs induced by oxaliplatin during 2016-2021 recorded in our ADR notification system. HLA genotyping was conducted for 47 patients with oxaliplatin-induced ADRs, 1100 general population controls, and 34 oxaliplatin-tolerant controls in 2019-2023. The in vitro basophil activation test (BAT) was performed and oxaliplatin-specific IgE levels were determined.

Results: The incidence of oxaliplatin-induced ADRs and anaphylactic shock in our cohort was 7.1% and 0.15%, respectively. Of the 154 patients, 67.5% suffered rash/eruption; 26.0% of the patients who could not undergo oxaliplatin rechallenge were considered to show oxaliplatin-induced immune-mediated hypersensitivity reactions (HRs). The genetic study found that the HLA-DRB∗12:01 allele was associated with oxaliplatin-induced HRs compared to the general population controls (sensitivity = 42.9%; odds ratio [OR] = 3.4; 95% CI = 1.4-8.2; P = 0.008) and tolerant controls (OR = 12; 95% CI = 2.3-63.7; P = 0.001). The in vitro BAT showed higher activation of CD63⁺ basophils in patients with oxaliplatin-induced HRs compared to the tolerant controls (P < 0.05). Only four patients (8.5%) with oxaliplatin-induced ADRs were positive for oxaliplatin-specific IgE.

Conclusions: This study found that 26.0% of patients with oxaliplatin-induced ADRs could not undergo oxaliplatin rechallenge. HLA-DRB∗12:01 is regarded as a genetic marker for oxaliplatin-induced hypersensitivity.