Search

RationaleIt has been suggested that patients with chronic obstructive pulmonary disease (COPD) experience considerable daily respiratory symptom fluctuation. A standardized measure is needed to quantify and understand the implications of day-to-day symptom variability.ObjectivesTo compare standard deviation with other statistical measures of symptom variability and identify characteristics of individuals with higher symptom variability.MethodsIndividuals in the SubPopulations and InteRmediate Outcome Measures In COPD Study (SPIROMICS) Exacerbations sub-study completed an Evaluating Respiratory Symptoms in COPD (E-RS) daily questionnaire. We calculated within-subject standard deviation (WS-SD) for each patient at week 0 and correlated this with measurements obtained 4 weeks later using Pearson's r and Bland Altman plots. Median WS-SD value dichotomized participants into higher versus lower variability groups. Association between WS-SD and exacerbation risk during 4 follow-up weeks was explored.Measurements and main resultsDiary completion rates were sufficient in 140 (68%) of 205 sub-study participants. Reproducibility (r) of the WS-SD metric from baseline to week 4 was 0.32. Higher variability participants had higher St George's Respiratory Questionnaire (SGRQ) scores (47.3 ± 20.3 versus 39.6 ± 21.5, p=.04) than lower variability participants. Exploratory analyses found no relationship between symptom variability and health care resource utilization-defined exacerbations.ConclusionsWS-SD of the E-RS can be used as a measure of symptom variability in studies of patients with COPD. Patients with higher variability have worse health-related quality of life. WS-SD should be further validated as a measure to understand the implications of symptom variability.

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).

Levels of iron and iron-related proteins including ferritin are higher in the lung tissue and lavage fluid of individuals with chronic obstructive pulmonary disease (COPD), when compared to healthy controls. Whether more iron in the extracellular milieu of the lung associates with distinct clinical phenotypes of COPD, including increased exacerbation susceptibility, is unknown. We measured iron and ferritin levels in the bronchoalveolar lavage fluid (BALF) of participants enrolled in the SubPopulations and InteRmediate Outcome Measures In COPD (SPIROMICS) bronchoscopy sub-study (n = 195). BALF Iron parameters were compared to systemic markers of iron availability and tested for association with FEV1 % predicted and exacerbation frequency. Exacerbations were modelled using a zero-inflated negative binomial model using age, sex, smoking, and FEV1 % predicted as clinical covariates. BALF iron and ferritin were higher in participants with COPD and in smokers without COPD when compared to non-smoker control participants but did not correlate with systemic iron markers. BALF ferritin and iron were elevated in participants who had COPD exacerbations, with a 2-fold increase in BALF ferritin and iron conveying a 24% and 2-fold increase in exacerbation risk, respectively. Similar associations were not observed with plasma ferritin. Increased airway iron levels may be representative of a distinct pathobiological phenomenon that results in more frequent COPD exacerbation events, contributing to disease progression in these individuals.

Background and purposeThe potential for adaptive plasticity in the post-stroke brain is difficult to estimate, as is the demonstration of central nervous system (CNS) target engagement of drugs that show promise in facilitating stroke recovery. We set out to determine if paired associative stimulation (PAS) can be used (a) as an assay of CNS plasticity in patients with chronic stroke, and (b) to demonstrate CNS engagement by memantine, a drug which has potential plasticity-modulating effects for use in motor recovery following stroke.MethodsWe examined the effect of PAS in fourteen participants with chronic hemiparetic stroke at five time-points in a within-subjects repeated measures design study: baseline off-drug, and following a week of orally administered memantine at doses of 5, 10, 15, and 20 mg, comprising a total of seventy sessions. Each week, MEP amplitude pre and post-PAS was assessed in the contralesional hemisphere as a marker of enhanced or diminished plasticity. Strength and dexterity were recorded each week to monitor motor-specific clinical status across the study period.ResultsWe found that MEP amplitude was significantly larger after PAS in baseline sessions off-drug, and responsiveness to PAS in these sessions was associated with increased clinical severity. There was no observed increase in MEP amplitude after PAS with memantine at any dose. Motor threshold (MT), strength, and dexterity remained unchanged during the study.ConclusionPaired associative stimulation successfully induced corticospinal excitability enhancement in chronic stroke subjects at the group level. However, this response did not occur in all participants, and was associated with increased clinical severity. This could be an important way to stratify patients for future PAS-drug studies. PAS was suppressed by memantine at all doses, regardless of responsiveness to PAS off-drug, indicating CNS engagement.

Although interstitial lung disease (ILD) causes significant morbidity and mortality in rheumatoid arthritis (RA), it is difficult to predict the development or progression of ILD, emphasising the need for improved discovery through minimally invasive diagnostic tests. Aptamer-based proteomic profiling was used to assess 1321 proteins from 159 patients with rheumatoid arthritis with interstitial lung disease (RA-ILD), RA without ILD, idiopathic pulmonary fibrosis and healthy controls. Differential expression and gene set enrichment analyses revealed molecular signatures that are strongly associated with the presence and severity of RA-ILD and provided insight into unexplored pathways of disease. These warrant further study as non-invasive diagnostic tools and future therapeutic targets. [ABSTRACT FROM AUTHOR]

Primary clear cell renal cell carcinoma (ccRCC) has been previously characterized, but the genomic landscape of metastatic ccRCC is largely unexplored. Here, we performed whole exome sequencing (WES) in 68 samples from 44 patients with ccRCC, including 52 samples from a metastatic site. SETD2, PBRM1, APC and VHL were the most frequently mutated genes in the metastatic ccRCC cohort. RBM10 and FBXW7 were also among the 10 most frequently mutated genes in metastatic tissues. Recurrent somatic copy number variations (CNV) were observed at the previously identified regions 3p25, 9p21 and 14q25, but also at 6p21 (CDKN1A) and 13q14 (RB1). No statistically significant differences were found between samples from therapy-na€ıve and pretreated patients. Clonal evolution analyses with multiple samples from 13 patients suggested that early appearance of CNVs at 3p25, 9p21 and 14q25 may be associated with rapid clinical progression. Overall, the genomic landscapes of primary and metastatic ccRCC seem to share frequent CNVs at 3p25, 9p21 and 14q25. Future work will clarify the implication of RBM10 and FBXW7 mutations and 6p21 and 13q14 CNVs in metastatic ccRCC. [ABSTRACT FROM AUTHOR]

Background: Although acute respiratory distress syndrome (ARDS) is associated with high mortality, its direct causal link with death is unclear. Clarifying this link is important to justify costly research on prevention of ARDS.Objective: To estimate the attributable mortality, if any, of ARDS.Design: First, we performed a systematic review and meta-analysis of observational studies reporting mortality of critically ill patients with and without ARDS matched for underlying risk factor. Next, we conducted a survival analysis of prospectively collected patient-level data from subjects enrolled in three intensive care unit (ICU) cohorts to estimate the attributable mortality of critically ill septic patients with and without ARDS using a novel causal inference method.Results: In the meta-analysis, 44 studies (47 cohorts) involving 56 081 critically ill patients were included. Mortality was higher in patients with versus without ARDS (risk ratio 2.48, 95% CI 1.86 to 3.30; p<0.001) with a numerically stronger association between ARDS and mortality in trauma than sepsis. In the survival analysis of three ICU cohorts enrolling 1203 critically ill patients, 658 septic patients were included. After controlling for confounders, ARDS was found to increase the mortality rate by 15% (95% CI 3% to 26%; p=0.015). Significant increases in mortality were seen for severe (23%, 95% CI 3% to 44%; p=0.028) and moderate (16%, 95% CI 2% to 31%; p=0.031), but not for mild ARDS.Conclusions: ARDS has a direct causal link with mortality. Our findings provide information about the extent to which continued funding of ARDS prevention trials has potential to impart survival benefit.Prospero Registration Number: CRD42017078313. [ABSTRACT FROM AUTHOR]

Rationale: The Sequential Organ Failure Assessment (SOFA) tool is a commonly used measure of illness severity. Calculation of the respiratory subscore of SOFA is frequently limited by missing arterial oxygen pressure (PaO2) data. Although missing PaO2 data are commonly replaced with normal values, the performance of different methods of substituting PaO2 for SOFA calculation is unclear. Objectives: The study objective was to compare the performance of different substitution strategies for missing PaO2 data for SOFA score calculation. Methods: This retrospective cohort study was performed using the Weill Cornell Critical Care Database for Advanced Research from a tertiary care hospital in the United States. All adult patients admitted to an intensive care unit (ICU) from 2011 to 2019 with an available respiratory SOFA score were included. We analyzed the availability of the PaO2/fraction of inspired oxygen (FiO2) ratio on the first day of ICU admission. In those without a PaO2/FiO2 ratio available, the ratio of oxygen saturation as measured by pulse oximetry to FiO2 was used to calculate a respiratory SOFA subscore according to four methods (linear substitution [Rice], nonlinear substitution [Severinghaus], modified respiratory SOFA, and multiple imputation by chained equations [MICE]) as well as the missing-as-normal technique. We then compared how well the different total SOFA scores discriminated in-hospital mortality. We performed several subgroup and sensitivity analyses. Results: We identified 35,260 unique visits, of which 9,172 included predominant respiratory failure. PaO2 data were available for 14,939 (47%). The area under the receiver operating characteristic curve for each substitution technique for discriminating in-hospital mortality was higher than that for the missing-as-normal technique (0.78 [0.77-0.79]) in all analyses (modified, 0.80 [0.79-0.81]; Rice, 0.80 [0.79-0.81]; Severinghaus, 0.80 [0.79-0.81]; and MICE, 0.80 [0.79-0.81]) (P < 0.01). Each substitution method had a higher accuracy for discriminating in-hospital mortality (MICE, 0.67; Rice, 0.67; modified, 0.66; and Severinghaus, 0.66) than the missing-as-normal technique. Model calibration for in-hospital mortality was less precise for the missing-as-normal technique than for the other substitution techniques at the lower range of SOFA and among the subgroups. Conclusions: Using physiologic and statistical substitution methods improved the total SOFA score's ability to discriminate mortality compared with the missing-as-normal technique. Treating missing data as normal may result in underreporting the severity of illness compared with using substitution. The simplicity of a direct oxygen saturation as measured by pulse oximetry/FiO2 ratio-modified SOFA technique makes it an attractive choice for electronic health record-based research. This knowledge can inform comparisons of severity of illness across studies that used different techniques. [ABSTRACT FROM AUTHOR]

The article presents the case study on Development and Prognosis of Acute Respiratory Distress Syndrome (ARDS) and effect of Neutropenic Illness by using patient level data from randomized controlled trials performed by the ARDS Network (ARDSNet). It also highlights the methods performed in three ongoing ICU cohorts of critically ill patients at New York-Presbyterian–Weill Cornell Medicine (WCM), Brigham and Women's Hospital (BWH), and Asan Medical Center (AMC) and also presents the results.

Background: Acute respiratory distress syndrome (ARDS) is heterogeneous. As an indication of the heterogeneity of ARDS, there are patients whose syndrome improves rapidly (i.e., within 24 hours), others whose hypoxemia improves gradually and still others whose severe hypoxemia persists for several days. The latter group of patients with persistent severe ARDS poses challenges to clinicians. We attempted to assess the baseline characteristics and outcomes of persistent severe ARDS and to identify which variables are useful to predict it. Methods: A secondary analysis of patient-level data from the ALTA, EDEN and SAILS ARDSNet clinical trials was conducted. We defined persistent severe ARDS as a partial pressure of arterial oxygen to fraction of inspired oxygen ratio (PaO2:FiO2) of equal to or less than 100 mmHg on the second study day following enrollment. Regularized logistic regression with an L1 penalty [Least Absolute Shrinkage and Selection Operator (LASSO)] techniques were used to identify predictive variables of persistent severe ARDS. Results: Of the 1531 individuals with ARDS alive on the second study day after enrollment, 232 (15%) had persistent severe ARDS. Of the latter, 100 (43%) individuals had mild or moderate hypoxemia at baseline. Usage of vasopressors was greater [144/232 (62%) versus 623/1299 (48%); p<0.001] and baseline severity of illness was higher in patients with versus without persistent severe ARDS. Mortality at 60 days [95/232 (41%) versus 233/1299 (18%); p<0.001] was higher, and ventilator-free (p<0.001), intensive care unit-free [0 (0–14) versus 19 (7–23); p<0.001] and non-pulmonary organ failure-free [3 (0–21) versus 20 (1–26); p<0.001] days were fewer in patients with versus without persistent severe ARDS. PaO2:FiO2, FiO2, hepatic failure and positive end-expiratory pressure at enrollment were useful predictive variables. Conclusions: Patients with persistent severe ARDS have distinct baseline characteristics and poor prognosis. Identifying such patients at enrollment may be useful for the prognostic enrichment of trials. [ABSTRACT FROM AUTHOR]

Purpose: To validate prognostic factors and determine the impact of obesity, hypertension, smoking and diabetes mellitus (DM) on risk of recurrence after surgery in patients with localized renal cell carcinoma (RCC). Materials and methods: We performed a retrospective cohort study among patients that underwent partial or radical nephrectomy at Weill Cornell Medicine for RCC and collected preoperative information on RCC risk factors, as well as pathological data. Cases were reviewed for radiographic evidence of RCC recurrence. A Cox proportional-hazards model was developed to determine the contribution of RCC risk factors to recurrence risk. Disease-free survival and overall survival were analyzed using the Kaplan-Meier method and log-rank test. Results: We identified 873 patients who underwent surgery for RCC between the years 2000–2015. In total 115 patients (13.2%) experienced a disease recurrence after a median follow up of 4.9 years. In multivariate analysis, increasing pathological T-stage (HR 1.429, 95% CI 1.265–1.614) and Nuclear grade (HR 2.376, 95% CI 1.734–3.255) were independently associated with RCC recurrence. In patients with T1-2 tumors, DM was identified as an additional independent risk factor for RCC recurrence (HR 2.744, 95% CI 1.343–5.605). Patients with DM had a significantly shorter median disease-free survival (1.5 years versus 2.6 years, p = 0.004), as well as median overall survival (4.1 years, versus 5.8 years, p<0.001). Conclusions: We validated high pathological T-stage and nuclear grade as independent risk factors for RCC recurrence following nephrectomy. DM is associated with an increased risk of recurrence among patients with early stage disease. [ABSTRACT FROM AUTHOR]

Background: Code status discussions (CSDs) can be challenging for many clinicians. Barriers associated with them include lack of education, comfort level, and experience. Objective: To conduct an educational intervention to improve knowledge and communication approaches related to CSDs. Design: A cross-sectional multidisciplinary educational intervention was conducted over one year consisting of an interactive presentation, live role-play, and pre- and post-intervention tests to measure impact of the formal training. Evaluations and comments were also collected. Setting/Subjects: Attending physicians, nurses, residents, fellows, and physician assistants (PAs) at an urban community teaching hospital of 500 beds serving an ethnically diverse population. Measurements: Data from pre- and post-intervention tests evaluating knowledge and communication approach regarding CSDs were collected. Participants completed a qualitative evaluation of the program. Results: There were 165 participants: 29 attending physicians, 26 residents, 17 fellows, 18 PAs, and 75 nurses. All (100%) completed the pre-intervention test and 154 (93.3%) completed the post-intervention test. There was an overall improvement in scores, 43.8% pre-intervention to 75.6% post-intervention (p-values <0.005). Attending physicians and fellows had the highest pre-intervention scores, while nurses and PAs had the lowest. Most participants (97%) reported they learned new information and 91% stated they would change patient management. Conclusions: Our study found that a brief educational intervention with multipronged teaching tools improved knowledge concerning CSDs. Participants felt it provided new insights and would change their practice. This study contributes to the literature by examining CSD training across different disciplines, allowing for cross-group comparisons. Future studies should try to correlate educational interventions and clinician knowledge with clinical practice outcomes. [ABSTRACT FROM AUTHOR]

Background: Intensive robot-assisted arm training in the chronic phase of stroke recovery can lead to clinical improvement. Combinatorial therapeutic approaches are sought to further optimize stroke recovery. Transcranial direct current stimulation (tDCS) is one candidate to combine with robotic training, as transient increases in excitability and improvements in motor behavior have separately been reported. Objective: To determine whether tDCS, delivered prior to robotic training, could augment clinical improvement. Methods: We conducted a dual-site, randomized controlled trial in 82 chronic ischemic stroke patients (inclusion > 6 m post-injury, dominant hemisphere, first stroke; residual hemiparesis) who were split into two groups to receive tDCS (M1-SO montage, anode ipsilesional, 5×7 cm electrodes, 2 mA, 20 mins) or sham tDCS, prior to robotic upper-limb training (12 weeks; 36 sessions; shoulder-elbow robot or wrist robot on alternating sessions). The primary end-point was taken after 12 weeks of training, and assessed with the Upper Extremity Fugl-Meyer impairment scale (FM). Corticomotor conduction was assessed with transcranial magnetic stimulation (TMS). Results: For the combined group (n = 82; post-training) robotic training increased the FM by 7.36 points compared to baseline (p < 0.0001). There was no difference in the FM increase between the tDCS and sham groups (6.97 and 7.73 respectively, p = 0.46). In both groups, clinically meaningful improvement (≥5 points) from baseline was evident in the majority of patients (56/77), was sustained six months later (54/72), and could be attained in severe, moderate and mild baseline hemiparesis. Clinical improvement was associated with increased excitability in the affected hemisphere as assessed by resting motor threshold (pre-post p = 0.029; pre-post 6 months p = 0.029), but not with threshold-adjusted assessment of MEP amplitude (pre-post p = 0.09; pre-post 6 months p = 0.15). Participants with motor evoked potentials were more likely to improve clinically than those without (17/18, 94%, versus 39/59, 66%, p = 0.018). Conclusions: Our study confirms the benefit of intensive robot-assisted training in stroke recovery, and indicates that conventional tDCS does not confer further advantage to robotic training. We also showed that corticospinal integrity, as assessed by TMS, is a predictor of clinically meaningful response to intensive arm therapy in chronic stroke. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine the extent to which robotic arm rehabilitation for chronic stroke may promote recovery of speech and language function in individuals with aphasia. Methods: We prospectively enrolled 17 individuals from a hemiparesis rehabilitation study pairing intensive robot assisted therapy with sham or active tDCS and evaluated their speech (N = 17) and language (N = 9) performance before and after a 12-week (36 session) treatment regimen. Performance changes were evaluated with paired t -tests comparing pre- and post-test measures. There was no speech therapy included in the treatment protocol. Results: Overall, the individuals significantly improved on measures of motor speech production from pre-test to post-test. Of the subset who performed language testing (N = 9), overall aphasia severity on a standardized aphasia battery improved from pre-test baseline to post-test. Active tDCS was not associated with greater gains than sham tDCS. Conclusions: This work indicates the importance of considering approaches to stroke rehabilitation across different domains of impairment, and warrants additional exploration of the possibility that robotic arm motor treatment may enhance rehabilitation for speech and language outcomes. Further investigation into the role of tDCS in the relationship of limb and speech/language rehabilitation is required, as active tDCS did not increase improvements over sham tDCS. [ABSTRACT FROM AUTHOR]

Objectives/hypothesis: To assess the long-term impact of vocal fold hemorrhage (VFH) on vocal function and health, and compare these parameters to those in similar patients who have not had VFH.Study Design: Retrospective cohort study.Methods: Patients with a history of VFH (N = 41) were characterized through a review of records and assessed by means of a survey for vocal health and professional functioning as well as the Voice Handicap Index-10 (VHI-10) and, if appropriate (n = 30, 73.2%), the Singing Voice Handicap Index (SVHI-10). They were compared to a group of demographically and occupationally similar patients without VFH (N = 25, 60.9%). Patients with multiple episodes of VFH (n = 9, 22.0%) were compared to patients with a single event.Results: After a median of 41 months follow-up, patients with VFH had favorable vocal function assessment and low median VHI-10 and SVHI-10 scores (4 and 6, respectively), substantially similar to patients without VFH (VHI-10, P = .905 and SVHI 10, P =.991). The two groups showed similarly low rates of change in occupation (7.3%vs. 8.0%, P =.999). Patients with VFH were more likely to have missed days of work due to a voice problem. Analysis of patients with one versus multiple VFH episodes showed no differences, except patients with multiple episodes had significantly greater confidence in their ability to address future VFH.Conclusions: Contrary to commonly held belief, VFH appears to have no significant long-term impact on vocational stability, subjective voice quality, or perceptions of vocal function. Moreover, among those with VFH, recurrence seems only to diminish anxiety over this transient injury.Level Of Evidence: 4 Laryngoscope, 127:900-906, 2017. [ABSTRACT FROM AUTHOR]

Although interstitial lung disease (ILD) causes significant morbidity and mortality in rheumatoid arthritis (RA), it is difficult to predict the development or progression of ILD, emphasising the need for improved discovery through minimally invasive diagnostic tests. Aptamer-based proteomic profiling was used to assess 1321 proteins from 159 patients with rheumatoid arthritis with interstitial lung disease (RA-ILD), RA without ILD, idiopathic pulmonary fibrosis and healthy controls. Differential expression and gene set enrichment analyses revealed molecular signatures that are strongly associated with the presence and severity of RA-ILD and provided insight into unexplored pathways of disease. These warrant further study as non-invasive diagnostic tools and future therapeutic targets., Competing Interests: Competing interests: The authors have reported the following conflicts of interest, all outside the submitted work: ST reports medical advisory group membership of Novo Nordisk and board membership at Droobi Health, Qatar. RG receives grant support from Canon Medical Systems. HH reports grants from Canon Medical Systems and Konica Minolta, and personal fees from Mitsubishi Chemical Co and Canon Medical Systems Inc. MN reports grants from AstraZeneca, Daiichi Sankyo, Canon Medical Systems, Merck investigator studies program; personal fees from Daiichi Sankyo and AstraZeneca. MEW receives research support from Amgen, Bristol Myers Squibb and Eli Lilly and consultation fees from AbbVie, Aclaris, Amgen, Arena, Bayer, Bristol Myers Squibb, Corvitas, Eqrx, Genosco, GSK, Gilead, Horizon, Johnson & Johnson, Kiniksa, Lilly, Novartis, Pfizer, Rami Therapeutics, R Pharma, Roche, Sanofi, Scipher, Sci Rhom, Set Point and Tremeau. He holds stock/stock options of CanFite, Inmedix, Vorso and Scipher. NAS reports grants and other support from Bristol-Myers Squibb, grants from Mallinckrodt, Sanofi, Crescendo Biosciences, Lilly and Amgen. PFD reports grants from Bristol-Myers Squibb and Genentech, and other support from Boehringer Ingelheim. AMKC is a cofounder and equity stock holder for Proterris, which develops therapeutic uses for carbon monoxide, and also has a use patent on CO and a patent in chronic obstructive pulmonary disease. EYK is a member of the steering committees for and receives no financial remuneration from NCT04409834 (Prevention of arteriovenous thrombotic events in critically ill COVID-19 patients, TIMI group) and REMAP-CAP ACE2 renin–angiotensin system modulation domain, and receives unrelated research funding from Bayer AG, Roche Pharma Research and Early Development, Windtree Therapeutics, the US National Institutes of Health, the US Agency for International Development, the American Heart Association, American Lung Association and the Bell Family Fund. IOR reports grants from Genentech. FJM reports personal fees, non-financial support and other support from AstraZeneca, other support from Afferent/Merck, personal fees, non-financial support and other support from Boehringer Ingelheim, other support from Bristol Myers Squibb, other support from Chiesi, personal fees and non-financial support from the Canadian Respiratory Society, personal fees and non-financial support from CME Outfitters, personal fees and non-financial support from CSL Behring, personal fees from Dartmouth University, personal fees from France Foundation, personal fees from Gala, personal fees and non-financial support from Genentech, grants, personal fees, non-financial support and other support from GlaxoSmithKline, personal fees and non-financial support from Inova Fairfax, personal fees and non-financial support from MD Magazine, personal fees and non-financial support from NYP Methodist Hospital Brooklyn, personal fees and non-financial support from Miller Communications, personal fees and non-financial support from National Association for Continuing Education/Integritas, other support from Nitto, personal fees and non-financial support from Novartis, personal fees from New York University, personal fees and non-financial support from Patara/Respivant, personal fees from Pearl, personal fees and non-financial support from Peer View, personal fees from Physicians Education Resource, personal fees from ProMedior, personal fees and non-financial support from Rare Diseases Healthcare Communications, personal fees from Rockpointe Communications, personal fees and non-financial support from Sanofi/Regeneron, other support from Biogen, personal fees and non-financial support from Sunovion, personal fees and non-financial support from Teva, other support from two XAR, personal fees from University of Birmingham Alabama, personal fees from UpToDate, non-financial support from Veracyte, personal fees from Vindico, personal fees and non-financial support from WebMD/MedScape, non-financial support and other support from Zambon, non-financial support from ProTerrix Bio, and personal fees from IQVIA, Raziel, Abvie and Verona. TJD has received grant support from Bristol Myers Squibb, consulting fees from Boehringer Ingelheim and L.E.K. consulting, and has been part of a clinical trial funded by Genentech. The remaining authors have reported no conflicts of interest., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

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.