Relationship between diffusion capacity and small airway abnormality in COPDGene

Criner, Rachel N.; Hatt, Charles R.; Galbán, Craig J.; Kazerooni, Ella A.; Lynch, David A.; McCormack, Meredith C.; Casaburi, Richard; MacIntyre, Neil R.; Make, Barry J.; Martínez, Fernando J.; Labaki, Wassim W.; Curtis, Jeffrey L.; Han, Mei Lan K.

doi:10.1186/s12931-019-1237-1

Cited by 28 publications

(23 citation statements)

References 11 publications

(14 reference statements)

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“…Additional longitudinal CT analyses suggest that over time, voxels with PRM SAD among at-risk smokers progress to voxels with emphysema ( 46 ). Diffusion-capacity abnormalities correlate with PRM SAD in mild to moderate COPD ( 47 ), suggesting PRM SAD might detect airways transitioning to early emphysema, with resulting impaired gas exchange. Finally, in an analysis of the MESA, CanCOLD, and SPIROMICS cohort studies, the airway-to-lung ratio (dysanapsis; i.e., the geometric mean of airway-lumen diameters at standard anatomic locations divided by the cube root of lung volume) was associated with airflow-limitation severity, COPD prevalence, and COPD incidence, suggesting that lung development early in life conditions the risk of developing COPD and susceptibility to airborne noxious components ( 48 ).…”

Section: Imaging Biomarkers Of Disease Progressionmentioning

confidence: 99%

From GOLD 0 to Pre-COPD

Han

Agustí

Celli

et al. 2021

Am J Respir Crit Care Med

136

139

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Currently the diagnosis of chronic obstructive pulmonary disease (COPD) requires the demonstration of airflow limitation, defined as a post-bronchodilator FEV 1 /FVC <0.7, a measurement that remains methodologically robust and widely available. FEV 1 is one of the most powerful predictors of clinically relevant outcomes including symptoms, exacerbations and mortality. However, reliable data suggest that respiratory symptoms, in particular chronic bronchitis, airway abnormality and emphysema detected using modern imaging techniques such as computed tomography (CT), and certain physiologic measures including rapid decline in FEV 1 and DLCO are present among individuals who do not meet spirometric criteria for COPD. These abnormalities may help to identify individuals at increased risk for developing airflow limitation in the future. Here, we review the evidence that support the use of the term "pre-COPD" in individuals with symptoms (e.g., "Non-Obstructive Chronic Bronchitis" (NOCB)), physiologic (e.g., low DLCO) and/or imaging abnormalities (e.g. CT emphysema) but spirometry in the normal range, who are at risk of developing COPD defined by a reduced FEV 1 /FVC ratio. We acknowledge, however, that further research on early disease in young individuals will be critical to develop a clinically operable definition of "pre-COPD" that demonstrates good sensitivity and specificity.

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Section: Imaging Biomarkers Of Disease Progressionmentioning

confidence: 99%

From GOLD 0 to Pre-COPD

Han

Agustí

Celli

et al. 2021

Am J Respir Crit Care Med

136

139

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“…First, we compare our model against the data of Criner et al ( 2019 ). These authors analyzed data in 1,846 individuals with ≥10 pack-years smoking history and for whom forced expiratory volume in 1 s (FEV 1 ) and CT imaging data were available and obtained on the same day.…”

Section: Resultsmentioning

confidence: 99%

“…To analyze this with our model, we first interpolated the authors data to yield a continuous link between PRM fSAD and PRM Emph . Then, we performed several simulations, for varying values of PRM fSAD , imposing an alveolar overpressure of 250 Pascals (because this value leads with our model, using the reference geometry, to an expiration flow rate of 2.78 l/s, corresponding to the average FEV 1 of healthy subjects mentioned by Criner et al, 2019 ). For each simulation, we randomly selected a percentage PRM fSAD of the small airways ( D i,j < 2 mm) and reduced their lumen area by 99% (β = 0.99).…”

Section: Resultsmentioning

confidence: 99%

“…For the gas supply ratio, there is FIGURE 6 | (A) Link between FEV 1 (in % of its reference value in healthy subjects) and PRM SAD obtained with our model (black curve). The open diamonds represent the experimental data of Criner et al (2019). (B) Relation between inspiration flow rate and pressure drop in the bronchial tree, calculated with the model, for three situations: healthy lungs (black curve), lungs with PRM fSAD = 21% (orange curve), and lungs with PRM fSAD = 35% (purple curve).…”

Section: Delivery Of a Gas Species To The Acinimentioning

confidence: 99%

See 1 more Smart Citation

Modeling of the Transport and Exchange of a Gas Species in Lungs With an Asymmetric Branching Pattern. Application to Nitric Oxide

et al. 2020

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Over the years, various studies have been dedicated to the mathematical modeling of gas transport and exchange in the lungs. Indeed, the access to the distal region of the lungs with direct measurements is limited and, therefore, models are valuable tools to interpret clinical data and to give more insights into the phenomena taking place in the deepest part of the lungs. In this work, a new computational model of the transport and exchange of a gas species in the human lungs is proposed. It includes (i) a method to generate a lung geometry characterized by an asymmetric branching pattern, based on the values of several parameters that have to be given by the model user, and a method to possibly alter this geometry to mimic lung diseases, (ii) the calculation of the gas flow distribution in this geometry during inspiration or expiration (taking into account the increased resistance to the flow in airways where the flow is non-established), (iii) the evaluation of the exchange fluxes of the gaseous species of interest between the tissues composing the lungs and the lumen, and (iv) the computation of the concentration profile of the exchanged species in the lumen of the tracheobronchial tree. Even if the model is developed in a general framework, a particular attention is given to nitric oxide, as it is not only a gas species of clinical interest, but also a gas species that is both produced in the walls of the airways and consumed within the alveolar region of the lungs. First, the model is presented. Then, several features of the model, applied to lung geometry, gas flow and NO exchange and transport, are discussed, compared to existing works and notably used to give new insights into experimental data available in the literature, regarding diseases, such as asthma, cystic fibrosis, and chronic obstructive pulmonary disease.

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“…Single breath carbon monoxide diffusing capacity of the lung (DLCO) impairments in COPD have been previously associated with emphysema and are often seen in individuals with more advanced disease. A recent study showed CT defined small airway abnormality was associated with lower DLCO in GOLD 0 smoker individuls (24). In another study, from a cohort of 1570 smokers normal spirometry/normal DLCO group assessed over 45 ± 20 months, 3% developed GOLD-defined COPD.…”

Section: The Diffusing Capacity Of the Lungs For Carbon Monoxide (Dlco)mentioning

confidence: 90%

The methods other than spirometry in the early diagnosis of COPD

Şerifoğlu¹,

Ulubay²

2019

Tuberk Toraks

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The methods other than spirometry in the early diagnosis of COPD Chronic obstructive pulmonary disease (COPD) is a major cause of mortality and morbidity around the world. The diagnosis od COPD is based on the presence of clinical symptoms and the fact that the ratio of post-bronhodilator forced expiratory volume in 1 second to forced expiratory vital capacity(FEV 1 / FVC) is less than 0.70. Persistent limitation of airflow which is a characteristics of COPD is reproducible and most common lung function test that is why it is usually measured by spirometry. The small airway diseases and the parenchymal destruction play a role in the pathogenesis of COPD at different rates over time resulting in chronic airflow limitation. These pathologies are not always together at the same time and the contribution of those to the development of COPD differ from one individual to another. The pathophysiological involvement of small airways in COPD has been confirmed. When the obstruction of the small airways occur either by mucus, smooth muscle hypertrophy, inflammatory infiltration or air wall thickening; then the consequence is the increased resistance and ventilation impairment. The parenchymal destruction can be estimated via scanning and at the initial assessment of a COPD patient, it gives information about the concomitant pulmonary diseases and/or differential diagnosis. There is an increasing interest on symptomatic individuals whose whose COPD diagnosis has not been confirmed yet with spirometry but diagnosis is based on alternative methods and approaches. Although these methods nowadays are commonly used for the clinical research, they will offer an opportunity to the clinician to find out the COPD patients at an early stage. Herein we will discuss the available methods other than spirometry in the early diagnosis of COPD before the overt disease is confirmed.

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Relationship between diffusion capacity and small airway abnormality in COPDGene

Cited by 28 publications

References 11 publications

From GOLD 0 to Pre-COPD

From GOLD 0 to Pre-COPD

Modeling of the Transport and Exchange of a Gas Species in Lungs With an Asymmetric Branching Pattern. Application to Nitric Oxide

The methods other than spirometry in the early diagnosis of COPD

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