Black carbon content in airway macrophages is associated with increased severe exacerbations and worse COPD morbidity in SPIROMICS.

TitleBlack carbon content in airway macrophages is associated with increased severe exacerbations and worse COPD morbidity in SPIROMICS.
Publication TypePublication
Year2022
AuthorsTejwani V, Woo H, Liu C, Tillery AK, Gassett AJ, Kanner RE, Hoffman EA, Martinez FJ, Woodruff PG, R Barr G, Fawzy A, Koehler K, Curtis JL, Freeman CM, Cooper CB, Comellas AP, Pirozzi C, Paine R, Tashkin D, Krishnan JA, Sack C, Putcha N, Paulin LM, Zusman M, Kaufman JD, Alexis NE, Hansel NN
JournalRespir Res
Volume23
Issue1
Pagination310
Date Published2022 Nov 14
ISSN1465-993X
KeywordsAir Pollutants, Carbon, Cotinine, Humans, Macrophages, Morbidity, Particulate Matter, Pulmonary Disease, Chronic Obstructive, quality of life, Soot
Abstract

BACKGROUND: Airway macrophages (AM), crucial for the immune response in chronic obstructive pulmonary disease (COPD), are exposed to environmental particulate matter (PM), which they retain in their cytoplasm as black carbon (BC). However, whether AM BC accurately reflects environmental PM exposure, and can serve as a biomarker of COPD outcomes, is unknown.METHODS: We analyzed induced sputum from participants at 7 of 12 sites SPIROMICS sites for AM BC content, which we related to exposures and to lung function and respiratory outcomes. Models were adjusted for batch (first vs. second), age, race (white vs. non-white), income (<$35,000, $35,000~$74,999, ≥$75,000, decline to answer), BMI, and use of long-acting beta-agonist/long-acting muscarinic antagonists, with sensitivity analysis performed with inclusion of urinary cotinine and lung function as covariates.RESULTS: Of 324 participants, 143 were current smokers and 201 had spirometric-confirmed COPD. Modeled indoor fine (< 2.5 μm in aerodynamic diameter) particulate matter (PM) and urinary cotinine were associated with higher AM BC. Other assessed indoor and ambient pollutant exposures were not associated with higher AM BC. Higher AM BC was associated with worse lung function and odds of severe exacerbation, as well as worse functional status, respiratory symptoms and quality of life.CONCLUSION: Indoor PM and cigarette smoke exposure may lead to increased AM BC deposition. Black carbon content in AMs is associated with worse COPD morbidity in current and former smokers, which remained after sensitivity analysis adjusting for cigarette smoke burden. Airway macrophage BC, which may alter macrophage function, could serve as a predictor of experiencing worse respiratory symptoms and impaired lung function.

DOI10.1186/s12931-022-02225-0
Alternate JournalRespir Res
PubMed ID36376879
PubMed Central IDPMC9664618
Grant ListP30 ES005605 / ES / NIEHS NIH HHS / United States
F32HL149258-01 / HL / NHLBI NIH HHS / United States
MS#: 
MS271
Manuscript Full Title: 
Black carbon content in airway macrophages is associated with increased severe exacerbations and worse COPD morbidity in SPIROMICS.
Manuscript Lead/Corresponding Author Affiliation: 
Clinical Center: Baltimore (Johns Hopkins University)
ECI: 
Manuscript Status: 
Published and Public