Journal Articles
Permanent URI for this collectionhttps://mro.massey.ac.nz/handle/10179/7915
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Item Exploring geographic differences in IgE response through network and manifold analyses(Elsevier Inc. on behalf of the American Academy of Allergy, Asthma & Immunology, 2026-01-01) Cucco A; Pearce N; Simpson A; Pembrey L; Mpairwe H; Figueiredo CA; Cooper PJ; Douwes J; Brooks C; Adcock IM; Kermani NZ; Roberts GDM; Murray CS; Custovic A; Fontanella S; WASP Study Group; STELAR/UNICORN Consortium; U-BIOPRED ConsortiumBackground: Component-resolved diagnostics allow detailed assessment of IgE sensitization to multiple allergenic molecules (component-specific IgEs, or c-sIgEs) and may be useful for asthma diagnosis. However, to effectively use component-resolved diagnostics across diverse settings, it is crucial to account for geographic differences. Objective: We investigated spatial determinants of c-sIgE networks to facilitate development of diagnostic algorithms applicable globally. Methods: We used multiplex component-resolved diagnostics array to measure c-sIgE to 112 proteins in an international collaboration of several studies: WASP (World Asthma Phenotypes; United Kingdom, New Zealand, Brazil, Ecuador, and Uganda), U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes; 7 European countries), and MAAS (Manchester Asthma and Allergy Study, a UK population-based birth cohort). Hierarchical clustering on low-dimensional representation of co-occurrence networks ascertained sensitization and c-sigE clusters across populations. Cross-country comparisons focused on a common subset of 18 c-sIgEs. We investigated sensitization networks across regions in relation to asthma severity. Results: Sensitization profiles shared similarities across regions. For 18 c-sIgEs shared across study populations, the response structure enabled differentiation between different geographic areas and study designs, revealing 3 clusters: (1) Uganda, Ecuador, and Brazil, (2) U-BIOPRED children and adults, and (3) New Zealand, United Kingdom, and MAAS. Spectral clustering identified differences between clusters. We observed constant, almost parallel shifts between severe and nonsevere asthma in each country. Conclusions: Patterns of c-sIgE response reflect geographic location and study design. However, despite geographic differences in c-sIgE networks, there is a remarkably consistent shift between networks of subjects with nonsevere and severe asthma.Item Asthma inflammatory phenotypes on four continents: most asthma is non-eosinophilic(Oxford University Press on behalf of the International Epidemiological Association, 2023-04) Pembrey L; Brooks C; Mpairwe H; Figueiredo CA; Oviedo AY; Chico M; Ali H; Nambuya I; Tumwesige P; Robertson S; Rutter CE; van Veldhoven K; Ring S; Barreto ML; Cooper PJ; Henderson J; Cruz AA; Douwes J; Pearce N; WASP Study GroupBACKGROUND: Most studies assessing pathophysiological heterogeneity in asthma have been conducted in high-income countries (HICs), with little known about the prevalence and characteristics of different asthma inflammatory phenotypes in low-and middle-income countries (LMICs). This study assessed sputum inflammatory phenotypes in five centres, in Brazil, Ecuador, Uganda, New Zealand (NZ) and the United Kingdom (UK). METHODS: We conducted a cross-sectional study of 998 asthmatics and 356 non-asthmatics in 2016-20. All centres studied children and adolescents (age range 8-20 years), except the UK centre which involved 26-27 year-olds. Information was collected using questionnaires, clinical characterization, blood and induced sputum. RESULTS: Of 623 asthmatics with sputum results, 39% (243) were classified as eosinophilic or mixed granulocytic, i.e. eosinophilic asthma (EA). Adjusted for age and sex, with NZ as baseline, the UK showed similar odds of EA (odds ratio 1.04, 95% confidence interval 0.37-2.94) with lower odds in the LMICs: Brazil (0.73, 0.42-1.27), Ecuador (0.40, 0.24-0.66) and Uganda (0.62, 0.37-1.04). Despite the low prevalence of neutrophilic asthma in most centres, sputum neutrophilia was increased in asthmatics and non-asthmatics in Uganda. CONCLUSIONS: This is the first time that sputum induction has been used to compare asthma inflammatory phenotypes in HICs and LMICs. Most cases were non-eosinophilic, including in settings where corticosteroid use was low. A lower prevalence of EA was observed in the LMICs than in the HICs. This has major implications for asthma prevention and management, and suggests that novel prevention strategies and therapies specifically targeting non-eosinophilic asthma are required globally.
