Chen, C.‐C.

Key points Staphylococcus aureus showed a significant increase in relative abundance in CRSwNP patients following endoscopic sinus surgery compared to pre‐surgery samples. Other Staphylococcus species were found to correlate positively with S. aureus in patients with nasal polyps; among those, S. caprae correlated strongly while being the most represented in samples. Patients with recurrent nasal polyp growth exhibited a substantially greater postoperative increase in the relative abundance of S. aureus .

ABSTRACT Nonsteroidal anti‐inflammatory drugs (NSAID)‐exacerbated respiratory disease (N‐ERD) is a mainly type 2 inflammatory condition that combines asthma, nasal polyps, and hypersensitivity to NSAIDs. Its pathogenesis involves both upper and lower airways, yet most studies to date have examined these compartments separately. It remains unclear whether the molecular mechanisms in the nose, sinuses, and lungs are distinct or overlapping—an important gap, given that clinical manifestations of N‐ERD involve both sites. In this review, we summarize available omics studies—transcriptomics, proteomics, metabolomics, and epigenomics—performed on upper and lower airways in patients with N‐ERD. While omics approaches have revealed new molecular insights, comparisons across studies are limited by heterogeneity in design, controls, and methodology. We emphasize the need for integrated multi‐omics analyses and standardized frameworks to better characterize the disease across airways. Such efforts are essential for identifying robust biomarkers and therapeutic targets and for moving toward a systems‐level understanding of N‐ERD.

AbstractBackgroundExposure to aeroallergens induces eosinophilic airway inflammation in patients with asthma and allergic airway diseases. The circulating number of eosinophils in peripheral blood is relatively small, leading us to hypothesize that bone marrow needs to be engaged quickly to meet the demands of the tissues.MethodsTo investigate the communication between the lungs and bone marrow, we used acute allergen exposure and airway inflammation models in mice. Gene‐deficient mice and cytokine reporter mice as well as in vitro cell culture models were used to dissect the mechanisms.ResultsNaïve BALB/c mice produced increased numbers of eosinophil precursors and mature eosinophils in the bone marrow when their airways were exposed to a common fungal allergen, Alternaria alternata. Expression of IL‐5 and IL‐33 increased rapidly in the lungs, but not in the bone marrow. Sera from allergen‐exposed mice promoted eosinophilopoiesis in bone marrow cells from naïve mice, which was blocked by anti‐IL‐5 antibody. Mice deficient in the IL‐33 receptor ST2 (i.e., Il1rl1−/− mice) were unable to increase their serum levels of IL‐5 and allergen‐induced eosinophilopoiesis in the bone marrow after allergen exposure. Finally, group 2 innate lymphoid cells (ILC2s) in the lungs showed robust expression of IL‐5 after Alternaria exposure.ConclusionsThese finding suggests that lung IL‐33, through innate activation of ILC2s and their production of IL‐5, plays a key role in promoting acute reactive eosinophilopoiesis in the bone marrow when naïve animals are exposed to airborne allergens. Therefore, bone marrow eosinophilopoiesis may be affected by atmospheric environmental conditions.