Details

Autor(en) / Beteiligte

• Lugogo, Njira
• Francisco, Dave
• Addison, Kenneth J.
• Manne, Akarsh
• Pederson, William
• Ingram, Jennifer L.
• Green, Cynthia L.
• Suratt, Benjamin T.
• Lee, James J.
• Sunday, Mary E.
• Kraft, Monica
• Ledford, Julie G.

Titel

Obese asthmatic patients have decreased surfactant protein A levels: Mechanisms and implications

Ist Teil von

• Journal of allergy and clinical immunology, 2018-03, Vol.141 (3), p.918-926.e3

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Eosinophils are prominent in some patients with asthma and are increased in the submucosa in a subgroup of obese patients with asthma (OAs). Surfactant protein A (SP-A) modulates host responses to infectious and environmental insults. We sought to determine whether SP-A levels are altered in OAs compared with a control group and to determine the implications of these alterations in SP-A levels in asthmatic patients. Bronchoalveolar lavage fluid from 23 lean, 12 overweight, and 20 obese subjects were examined for SP-A. Mouse tracheal epithelial cells grown at an air-liquid interface were used for mechanistic studies. SP-A−/− mice were challenged in allergen models, and exogenous SP-A therapy was given after the last challenge. Eosinophils were visualized and quantitated in lung parenchyma by means of immunostaining. Significantly less SP-A (P = .002) was detected in samples from OAs compared with those from control subjects. A univariable regression model found SP-A levels were significantly negatively correlated with body mass index (r = −0.33, P = .014), whereas multivariable modeling demonstrated that the correlation depended both on asthma status (P = .017) and the interaction of asthma and body mass index (P = .008). Addition of exogenous TNF-α to mouse tracheal epithelial cells was sufficient to attenuate SP-A and eotaxin secretion. Allergen-challenged SP-A−/− mice that received SP-A therapy had significantly less tissue eosinophilia compared with mice receiving vehicle. SP-A functions as an important mediator in resolving tissue and lavage fluid eosinophilia in allergic mouse models. Decreased levels of SP-A in OAs, which could be due to increased local TNF-α levels, might lead to impaired eosinophil resolution and could contribute to the eosinophilic asthma phenotype.