Serum Th2 cytokine profiles in mould sensitised adults from a large population-based cohort

Abstract

Background: Sensitisation to moulds is strongly associated with severe asthma but the immunopathogenesis is poorly understood. Identifying factors associated with mould sensitisation and asthma may shed light on its aetiology.

Aim: To elucidate mechanisms for the development of asthma in mould sensitised adults by examining serum Th2 cytokine profiles in a large respiratory cohort.

Methods: Serum cytokines (IL-4, IL-5, IL-6, IL-8, IL-10, TNF-α) in 1,157 44 year old subjects from the population-based Tasmanian Longitudinal Health Study (TAHS) were measured using lincoplex assays. Skin prick testing was performed for HDM, cat, grasses and moulds; Aspergillus fumigatus, Penicillium notatum, Cladosporium herbarum and Alternaria alternate. Serum Th2 cytokine profiles for atopic adults sensitised to a specific allergen were compared to non-atopic subjects using multivariable linear regression, adjusting for gender, current smoking and inhaled corticosteroid use.

Results: Serum Th2 cytokine profiles for 645 atopic adults sensitised to HDM, cat or grasses were significantly increased compared with non-atopic adults. In contrast, Th2 cytokine profiles were reduced for adults sensitised to Cladosporium [ratio of geometric means (GMs) for IL-4, IL-5 and IL-6 were 0.25 (p=0.002), 0.55 (p=0.046) and 0.55, p=0.06, respectively] and Aspergillus [ratio of GM for IL-4 was 0.34 (p=0.03)] compared with non-atopic adults. Sensitisation to any mould was significantly associated with current asthma (Odds ratios ranged from 9–23; p<0.001).

Conclusion: The underlying biological mechanisms driving allergic inflammatory responses in adults sensitised to moulds may differ from those sensitised to other aeroallergens.