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

Study Status: Completed
Recruit Status: Completed
Study Type: Observational

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

Brief Summary: 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.

Detailed Summary:

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.


Sponsor: IRCCS Azienda Ospedaliera Universitaria San Martino - IST Istituto Nazionale per la Ricerca sul Canc

Current Primary Outcome: 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


Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: IRCCS Azienda Ospedaliera Universitaria San Martino - IST Istituto Nazionale per la Ricerca sul Canc

Dates:
Date Received: October 29, 2015
Date Started: February 2013
Date Completion:
Last Updated: November 2, 2015
Last Verified: November 2015