- Title
- Airway surfactant protein D deficiency in adults with severe asthma
- Creator
- Mackay, Rose-Marie A.; Grainge, Christopher L.; Lau, Laurie C.; Barber, Clair; Clark, Howard W.; Howarth, Peter H.
- Relation
- Chest Vol. 149, Issue 5, p. 1165-1172
- Publisher Link
- http://dx.doi.org/10.1016/j.chest.2015.11.012
- Publisher
- American College of Chest Physicians
- Resource Type
- journal article
- Date
- 2016
- Description
- Background: Surfactant protein D (SP-D) is an essential component of the innate immune defense against pathogens within the airways. SP-D also regulates allergic inflammation and promotes the removal of apoptotic cells. SP-D dysregulation is evident in several pulmonary diseases. Our aim was to investigate whether airway and serum levels of SP-D are altered in treatment-resistant severe asthma. Methods: SP-D concentrations were measured in matched serum and BAL samples collected from 10 healthy control subjects (HC) and 50 patients with asthma (22 with mild asthma [MA] and 28 with severe asthma [SA]). These samples were also evaluated by using Western blot analysis to investigate variations in SP-D size. Results: SP-D levels in BAL samples were significantly lower in SA compared with HC and MA (P < .001) and inversely correlated with BAL eosinophil cationic protein concentrations in SA (P < .01). Serum SP-D was significantly increased in SA compared with HC and MA (P < .001), and BAL/serum ratios were significantly lower in SA compared with HC and MA (P < .001). Reduced SP-D levels in BAL samples, with concomitant increases in serum in SA, were associated with degraded fragments of SP-D in the serum and increased BAL neutrophil counts and lipopolysaccharide levels. Conclusions: These findings suggest defective innate immunity within the airways in SA, as reflected by low BAL SP-D concentrations and altered bacterial presence with airway neutrophilia. Furthermore, BAL SP-D leakage into the serum in patients with SA may provide a peripheral blood biomarker, reflecting increased epithelial damage and/or epithelial permeability within the peripheral airways.
- Subject
- asthma; biomarkers; bronchoalveolar lavage; eosinophilic inflammation; immunology asthma; immunology (lung); neutrophilic inflammation; severe asthma; surfactant protein D
- Identifier
- http://hdl.handle.net/1959.13/1329183
- Identifier
- uon:26089
- Identifier
- ISSN:0012-3692
- Language
- eng
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