Lung Diffusing Capacity for Nitric Oxide as a Marker of Fibrotic Changes in Idiopathic Interstitial Pneumonias

The diagnosis of idiopathic interstitial pneumonia (IIP) is based on computed tomography (CT) imaging, whereas lung function studies are used for staging and follow up. Lung diffusing capacity for carbon monoxide (DLCO) is generally reduced but weakly correlated with the severity of CT-determined fibrotic process. A possible explanation of this finding is that DLCO is relatively insensitive to changes in alveolar membrane diffusive conductance (DMCO). Lung diffusion capacity for nitric oxide (DLNO) was strongly correlated with CT-determined amount of fibrosis/honeycombing in both usual and non-specific interstitial pneumonias. Moreover. Both DLNO and DMCO were below the lower limit of normality even in patients with small amount of fibrosis. Measurement of DLNO may provide a more reliable assessment of fibrotic changes than DLCO because it better reflects DMCO.

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Key information

Conditions

Usual Interstitial Pneumonia Idiopathic Interstitial Pneumonias Idiopathic Pulmonary Fibrosis Lung Diseases Lung Diseases, Interstitial Nonspecific Interstitial Pneumonia Pulmonary Fibrosis Respiratory Tract Diseases

Sex eligibility

All sexes

Study type

Observational

About this study

Rationale: Lung diffusing capacity for carbon monoxide (DLCO) is decreased in both usual interstitial pneumonia-idiopathic pulmonary fibrosis (UIP-IPF) and nonspecific interstitial pneumonia (NSIP), but is weakly related to computed tomography (CT)-determined fibrotic changes.

Objectives: To determine whether measurement of lung diffusing capacity for nitric oxide (DLNO) better reflects fibrotic changes than DLCO.

Methods: DLNO and DLCO were measured simultaneously in 30 patients with UIP-IPF and 30 with NSIP. The amount of pulmonary fibrosis was estimated by volumetric analysis of visually bounded areas showing reticular opacities and honeycombing. Alveolar membrane conductance (DMCO) and pulmonary capillary volume (Vc) were calculated.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Chest computed tomography (CT) scan diagnosis of either usual interstitial pneumonia-idiopathic pulmonary fibrosis (UIP-IPF) or idiopathic nonspecific interstitial pneumonia (NSIP)

Exclusion criteria

Symptoms/signs or specific serum markers of an underlying autoimmune process
Previous environmental/occupational exposure to fibrogenic dusts
Use of fibrogenic medications

Treatment and study plan

Primary outcomes

Changes of lung diffusing capacity for nitric oxide (DLNO) in a group of 60 patients with fibrosing idiopathic interstitial pneumonias (IIPs)

Time frame: Within 1 month following idiopathic interstitial pneumonias diagnosis

Because DLNO is more sensitive to alveolar membrane diffusive conductance (DMCO) than standard lung diffusing capacity for carbon monoxide, DLNO changes may better reflect the extent of fibrotic process in IIPs

Sponsors and collaborators

Lead sponsor

IRCCS Azienda Ospedaliera Universitaria San Martino - IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy

Other

Registry information

Acronym: Dm&Vc

Important dates

Study start: 2013
Primary completion: 2015
Study completion: 2015
First posted: Nov 4, 2015
Registry last updated: Nov 4, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

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This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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