Dataset Information

Association of plasma mitochondrial DNA with COPD severity and progression in the SPIROMICS cohort.

ABSTRACT:

Background

There is a lack of mechanism-driven, clinically relevant biomarkers in chronic obstructive pulmonary disease (COPD). Mitochondrial dysfunction, a proposed disease mechanism in COPD, is associated with the release of mitochondrial DNA (mtDNA), but plasma cell-free mtDNA has not been previously examined prospectively for associations with clinical COPD measures.

Methods

P-mtDNA, defined as copy number of mitochondrially-encoded NADH dehydrogenase-1 (MT-ND1) gene, was measured by real-time quantitative PCR in 700 plasma samples from participants enrolled in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Associations between p-mtDNA and clinical disease parameters were examined, adjusting for age, sex, smoking status, and for informative loss to follow-up.

Results

P-mtDNA levels were higher in participants with mild or moderate COPD, compared to smokers without airflow obstruction, and to participants with severe COPD. Baseline increased p-mtDNA levels were associated with better CAT scores in female smokers without airflow obstruction and female participants with mild or moderate COPD on 1-year follow-up, but worse 6MWD in females with severe COPD. Higher p-mtDNA levels were associated with better 6MWD in male participants with severe COPD. These associations were no longer significant after adjusting for informative loss to follow-up.

Conclusion

In this study, p-mtDNA levels associated with baseline COPD status but not future changes in clinical COPD measures after accounting for informative loss to follow-up. To better characterize mitochondrial dysfunction as a potential COPD endotype, these results should be confirmed and validated in future studies.

Trial registration

ClinicalTrials.gov NCT01969344 (SPIROMICS).

SUBMITTER: Zhang WZ

PROVIDER: S-EPMC8074408 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature

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Publications

Association of plasma mitochondrial DNA with COPD severity and progression in the SPIROMICS cohort.

Zhang William Z WZ Hoffman Katherine L KL Schiffer Kristen T KT Oromendia Clara C Rice Michelle C MC Barjaktarevic Igor I Peters Stephen P SP Putcha Nirupama N Bowler Russell P RP Wells J Michael JM Couper David J DJ Labaki Wassim W WW Curtis Jeffrey L JL Han Meilan K MK Paine Robert R Woodruff Prescott G PG Criner Gerard J GJ Hansel Nadia N NN Diaz Ivan I Ballman Karla V KV Nakahira Kiichi K Choi Mary E ME Martinez Fernando J FJ Choi Augustine M K AMK Cloonan Suzanne M SM

Respiratory research 20210426 1

<h4>Background</h4>There is a lack of mechanism-driven, clinically relevant biomarkers in chronic obstructive pulmonary disease (COPD). Mitochondrial dysfunction, a proposed disease mechanism in COPD, is associated with the release of mitochondrial DNA (mtDNA), but plasma cell-free mtDNA has not been previously examined prospectively for associations with clinical COPD measures.<h4>Methods</h4>P-mtDNA, defined as copy number of mitochondrially-encoded NADH dehydrogenase-1 (MT-ND1) gene, was meas ...[more]

PMID: 33902556

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Project description:BACKGROUNDMitochondrial dysfunction, a proposed mechanism of chronic obstructive pulmonary disease (COPD) pathogenesis, is associated with the leakage of mitochondrial DNA (mtDNA), which may be detected extracellularly in various bodily fluids. Despite evidence for the increased prevalence of chronic kidney disease in COPD subjects and for mitochondrial dysfunction in the kidneys of murine COPD models, whether urine mtDNA (u-mtDNA) associates with measures of disease severity in COPD is unknown.METHODSCell-free u-mtDNA, defined as copy number of mitochondrially encoded NADH dehydrogenase-1 (MTND1) gene, was measured by quantitative PCR and normalized to urine creatinine in cell-free urine samples from participants in the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Urine albumin/creatinine ratios (UACR) were measured in the same samples. Associations between u-mtDNA, UACR, and clinical disease parameters - including FEV1 % predicted, clinical measures of exercise tolerance, respiratory symptom burden, and chest CT measures of lung structure - were examined.RESULTSU-mtDNA and UACR levels were measured in never smokers (n = 64), smokers without airflow obstruction (n = 109), participants with mild/moderate COPD (n = 142), and participants with severe COPD (n = 168). U-mtDNA was associated with increased respiratory symptom burden, especially among smokers without COPD. Significant sex differences in u-mtDNA levels were observed, with females having higher u-mtDNA levels across all study subgroups. U-mtDNA associated with worse spirometry and CT emphysema in males only and with worse respiratory symptoms in females only. Similar associations were not found with UACR.CONCLUSIONU-mtDNA levels may help to identify distinct clinical phenotypes and underlying pathobiological differences in males versus females with COPD.TRIAL REGISTRATIONThis study has been registered at ClinicalTrials.gov ( NCT01969344).FUNDINGUS NIH, National Heart, Lung and Blood Institute, supplemented by contributions made through the Foundation for the NIH and the COPD Foundation from AstraZeneca/MedImmune, Bayer, Bellerophon Therapeutics, Boehringer-Ingelheim Pharmaceuticals Inc., Chiesi Farmaceutici S.p.A., Forest Research Institute Inc., GlaxoSmithKline, Grifols Therapeutics Inc., Ikaria Inc., Novartis Pharmaceuticals Corporation, Nycomed GmbH, ProterixBio, Regeneron Pharmaceuticals Inc., Sanofi, Sunovion, Takeda Pharmaceutical Company, and Theravance Biopharma and Mylan.

Project description:RATIONALE:Rural residence is associated with poor outcomes in several chronic diseases. The association between rural residence and chronic obstructive pulmonary disease (COPD) exacerbations remains unclear. OBJECTIVE:To determine the independent association between rural residence and COPD-related outcomes including COPD exacerbations, airflow obstruction and symptom burden. METHODS:A total of 1684 Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) participants with FEV1/FVC<0.70 had geocoding-defined rural-urban residence status determined (N=204 rural and N=1480 urban). Univariate and multivariate logistic and negative binomial regressions were performed to assess the independent association between rurality and COPD outcomes including exacerbations, lung function, and symptom burden. The primary exposure of interest was rural residence, determined by geocoding of home address to the block level at time of study enrollment. Additional covariates of interest included demographic and clinical characteristics, occupation, and occupational exposures.The primary outcome measures were exacerbations determined over the one-year course after enrollment by quarterly telephone calls and at an annual research clinic visit. Odds ratio and incidence rate of exacerbations that required treatment with medications including steroids or antibiotics (total exacerbations), and exacerbations leading to hospitalization (severe exacerbations) were determined after adjusting for relevant covariates. RESULTS:Rural residence was independently associated with 70% increase in odds of total exacerbations [OR 1.70 (95% CI 1.13-2.56); p=0.012] and 46% higher incidence rate of total exacerbations [IRR 1.46 (95% CI 1.02-2.10); p=0.039]. There was no association between rural residence and severe exacerbations. Agricultural occupation was independently associated with increased odds and incidence of total and severe exacerbations. Inclusion of agricultural occupation to analysis attenuated the association between rural residence and odds and incidence rate of total exacerbations [OR 1.52 (95% CI 1.00-2.32; p=0.05) and IRR 1.39 (95% CI 0.97 - 1.99); p=0.07]. There was no difference in symptoms or airflow obstruction between rural and urban participants. CONCLUSIONS:Rural residence is independently associated with increased odds and incidence of total, but not severe COPD exacerbations. These associations are not fully explained by agriculture-related exposures, highlighting the need for future research into potential mechanisms of increased risk of COPD exacerbations in the rural population.

Project description:BackgroundThe biological mechanisms leading some tobacco-exposed individuals to develop early-stage chronic obstructive pulmonary disease (COPD) are poorly understood. This knowledge gap hampers development of disease-modifying agents for this prevalent condition.ObjectivesAccordingly, with National Heart, Lung and Blood Institute support, we initiated the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS) Study of Early COPD Progression (SOURCE), a multicenter observational cohort study of younger individuals with a history of cigarette smoking and thus at-risk for, or with, early-stage COPD. Our overall objectives are to identify those who will develop COPD earlier in life, characterize them thoroughly, and by contrasting them to those not developing COPD, define mechanisms of disease progression.Methods/discussionSOURCE utilizes the established SPIROMICS clinical network. Its goal is to enroll n=649 participants, ages 30-55 years, all races/ethnicities, with ≥10 pack-years cigarette smoking, in either Global initiative for chronic Obstructive Lung Disease (GOLD) groups 0-2 or with preserved ratio-impaired spirometry; and an additional n=40 never-smoker controls. Participants undergo baseline and 3-year follow-up visits, each including high-resolution computed tomography, respiratory oscillometry and spirometry (pre- and postbronchodilator administration), exhaled breath condensate (baseline only), and extensive biospecimen collection, including sputum induction. Symptoms, interim health care utilization, and exacerbations are captured every 6 months via follow-up phone calls. An embedded bronchoscopy substudy involving n=100 participants (including all never-smokers) will allow collection of lower airway samples for genetic, epigenetic, genomic, immunological, microbiome, mucin analyses, and basal cell culture.ConclusionSOURCE should provide novel insights into the natural history of lung disease in younger individuals with a smoking history, and its biological basis.

Project description:BackgroundThrombocytosis has been associated with COPD prevalence and increased all-cause mortality in patients with acute exacerbation of COPD (AECOPD); but whether it is associated with morbidity in stable COPD is unknown. This study aims to determine the association of thrombocytosis with COPD morbidity including reported AECOPD, respiratory symptoms and exercise capacity.MethodsParticipants with COPD were included from two multi-center observational studies (SPIROMICS and COPDGene). Cross-sectional associations of thrombocytosis (platelet count ≥350 × 109/L) with AECOPD during prior year (none vs. any), exertional dyspnea (modified Medical Research Council (mMRC) score ≥ 2), COPD Assessment Test (CAT) score ≥ 10, six-minute-walk distance (6MWD), and St. George Respiratory questionnaire (SGRQ) were modeled using multivariable logistic or linear regression. A pooled effect estimate for thrombocytosis was produced using meta-analysis of data from both studies.ResultsThrombocytosis was present in 124/1820 (6.8%) SPIROMICS participants and 111/2185 (5.1%) COPDGene participants. In meta-analysis thrombocytosis was associated with any AECOPD (adjusted odds ratio [aOR] 1.5; 95% confidence interval [95% CI]: 1.1-2.0), severe AECOPD (aOR 1.5; 95% CI: 1.1-2.2), dyspnea (mMRC ≥ 2 aOR 1.4; 95% CI: 1.0-1.9), respiratory symptoms (CAT ≥ 10 aOR 1.6; 95% CI: 1.1-2.4), and higher SGRQ score (β 2.7; 95% CI: 0.5, 5). Thrombocytosis was also associated with classification into Global Initiative for Chronic Obstructive Lung Disease (GOLD) group D (aOR 1.7 95% CI: 1.2-2.4).ConclusionsThrombocytosis was associated with higher likelihood of prior exacerbation and worse symptoms. Platelet count, a commonly measured clinical assay, may be a biomarker for moderate-severe COPD symptoms, guide disease classification and intensity of treatment. Future longitudinal studies investigating the role of platelets in COPD progression may be warranted.Trial registrationClinicalTrials.gov: NCT01969344 (SPIROMICS) and NCT00608764 (COPDGene).

Project description:BackgroundThe Global Initiative for Chronic Obstructive Lung Disease (GOLD) considers blood eosinophil counts < 100 cells/μL (BEC≤100) in people with COPD to predict poor inhaled corticosteroid (ICS) responsiveness. However, the BEC≤100 phenotype is inadequately characterized, especially in advanced COPD.Research questionAre there differences between GOLD group D patients with high BEC and those with low BEC regarding baseline characteristics and longitudinal outcomes?Study design and methodsWe used multivariable mixed models and logistic regression to contrast clinical characteristics and outcomes of BEC≤100 vs BEC > 100 (BEC100+) in all subjects with COPD (n = 1,414) and GOLD group D subjects (n = 185) not receiving ICS.ResultsWe identified n = 485 with BEC≤100 (n = 61 GOLD group D) and n = 929 people with BEC100+ (n = 124 GOLD group D). BEC≤100 status was stable at 6 weeks and approximately 52 weeks (intraclass correlations of 0.78 and 0.71, respectively). Compared with BEC100+, BEC≤100 comprised more women, with greater current smoking, and less frequent childhood asthma. Among all analyzed participants, the two BEC-defined subsets showed similar rates of lung function decline (mean slope, BEC≤100 vs BEC100+, -50 vs -39 mL/y; P = .140), exacerbations (0.40 vs 0.36/y; P = .098), subsequent ICS initiation (2.5% vs 4.4%; P = .071), and mortality (7.8% vs 8.4%; P = .715). However, in GOLD group D, people with BEC≤100 showed higher exacerbation rates within 365 days of enrollment (0.62 vs 0.33/y; P = .002) and total follow-up (1.16 vs 0.83/y; P = .014). They also had greater lung function decline (mean slope of -68 mL/y vs -23 mL/y; P = .036) and had greater emphysema at baseline (voxels < 950 Hounsfield units at total lung capacity of 7.46% vs 4.61%; P = .029).InterpretationIn non-ICS-treated GOLD group D COPD, people with BEC≤100 had more baseline emphysema, prospective exacerbations, and lung function decline. Our analysis has identified a particularly vulnerable subpopulation of people with COPD, suggesting the need for studies focused specifically on their therapeutic treatment.Clinical trial registrationClinicalTrials.gov; No.: NCT01969344; URL: www.Clinicaltrialsgov.

Dataset Information

Association of plasma mitochondrial DNA with COPD severity and progression in the SPIROMICS cohort.

Background

Methods

Results

Conclusion

Trial registration

Publications

Association of plasma mitochondrial DNA with COPD severity and progression in the SPIROMICS cohort.

Similar Datasets

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