Journal of Investigational Allergology and Clinical Immunology最新文献

Background: An environmental exposure chamber (EEC) is a health facility that enables allergic symptoms to be induced in a controlled manner in persons sensitized to a dispersed allergen. We performed a study at our institution to technically and clinically validate an EEC in patients allergic to grass pollen.

Methods: We developed a new EEC inside a clean room (ISO-8 class) measuring 15.6 m². During the technical validation, the patient's exposure conditions were simulated by ensuring homogeneous distribution of the allergen with a particle disperser and monitoring both particle and pollen grain concentrations. Temperature, pressure, and humidity were also registered. A total of 31 volunteers were exposed to Phleum pratense pollen in the EEC. Of these, 25 were allergic (cases), with symptoms of rhinoconjunctivitis with or without asthma, and 6 were not (controls). One control and 2 cases were exposed twice to check reproducibility, generating a total of 34 challenges. The test was stopped once the positivity criterion was reached or the patient completed 90 minutes in the EEC.

Results: Both the stability of particle concentrations and approximation to the pollen sample concentration were guaranteed. All challenges with controls were negative. Among the cases, 15% of challenges were negative and 85% were positive. No severe or late reactions were observed. Volunteers exposed twice to the same pollen had the same result in both challenges.

Conclusion: Our EEC proved to be a specific, safe, and reproducible tool for the diagnosis of grass pollen allergy.

Background: To analyze causality between gut microbiota and chronic spontaneous urticaria (CSU) and to investigate the mediating effect of metabolic pathways.

Methods: We extracted genome-wide association study summary statistics for 211 microbiota taxa from the MiBioGen consortium (N=18 340), 205 microbiota metabolic pathways from the Dutch Microbiome Project (N=7738), and CSU from the FinnGen genomics initiative (N=450). Bidirectional Mendelian randomization (MR) was performed to detect genetic causality between gut microbiota, gut bacterial pathways, and CSU. Sensitivity analyses were performed to validate the robustness of the results. Mediation MR investigated mediators in the association between gut microbiota and CSU.

Results: MR analysis suggested that the family Peptococcaceae and its child taxon, the genus Peptococcus, were risk factors for CSU. In addition, the genera Collinsella, Lachnospiraceae UCG004, Ruminococcaceae UCG004, and Sellimonas were also risk factors for CSU, whereas Family XIII UCG001, Lachnospiraceae UCG010, and Methanobrevibacter had protective effects on CSU. As for metabolic pathways, NONMEVIPP-PWY, PWY-5022, and PWY-7221 were positively associated with CSU, although others, such as KDO-NAGLIPASYN-PWY, PWY- 6353, and PWY-7400 presented a suggestive association with CSU. Moreover, PWY-7400 was a mediator in causality between the family Peptococcaceae and CSU. These results were based on nominal significance (P<.05). None of the Bonferroni corrected P values were <.05.

Conclusions: Our study confirmed a causal association between gut microbiota and CSU, with the metabolic pathway being a potential mediator. Our findings provide new insights for further mechanistic and clinical studies in CSU.

Background and objectives: The Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines classify rhinitis as "intermittent" or "persistent" and "mild" or "moderate-severe". To assess ARIA classes in a real-world study in terms of phenotypic differences and their association with asthma.

Methods: We performed a cross-sectional real-world study based on users of the MASK-air® app who reported data for at least 3 different months. We assessed the frequency of users according to the ARIA classes and compared these classes in terms of rhinitis symptoms, use of comedication, frequency of comorbid asthma, and the association between comorbid asthma and rhinitis control.

Results: A total of 2273 users (180 796 days) were assessed. Most users had moderate-severe rhinitis (n=2003; 88.1%) and persistent rhinitis (n=1144; 50.3%). The frequency of patients with probable asthma was 35.7% (95%CI, 34.5%-37.0%) for intermittent rhinitis and 48.5% (95%CI, 47.1%-49.9%) for persistent rhinitis. The maximum values on the visual analog scale (VAS) for rhinitis symptoms and the combined symptom medication score were lower in patients with mild rhinitis than in those with moderate-severe rhinitis (irrespective of whether they had persistent or intermittent rhinitis). In most ARIA classes, VAS nose and VAS eye and rhinitis comedication were more frequent in patients with rhinitis+asthma than in those with rhinitis alone.

Conclusion: This study suggests that the presence of asthma is more closely related to persistence of rhinitis than to severity and that the presence of comorbid asthma may be associated with poorer control of rhinitis across the different ARIA classes.