Conducting Airways in Lung Fibrosis (VACFI)

Diffuse Interstitial Pneumonias are a heterogeneous group of chronic respiratory diseases. Idiopathic Pulmonary Fibrosis, one of such diseases, is characterized by lesions of the conducting airways including extension of bronchioles towards the distal lung, or bronchiolization of the distal lung. Such lesions are traditionally referred to as "traction bronchiectasis" although no evidence supports a cause-and-effect relationship between alveolar fibrosis and airway lesions. Another feature of IPF is chronic, invalidating dry cough. Our hypothesis is that IPF is characterized by early increases in the volume of conducting airways, that such changes correlate with cough, and that airway changes are in direct relation with airway fibrosis. The primary aim of this study is to demonstrate increased anatomical dead space (VD), a surrogate for conducting airway volume, in patients with moderate (or early) IPF, in comparison with subjects without any respiratory disease ("non-DIP controls"). The secondary aims are : To show that VD is increased in patients with IPF in comparison with patients with other DIPs ("DIP controls"), to show that in patients with IPF increased VD does not correlate with indices of alveolar fibrosis, and to show associations between increased VD and cough and other respiratory symptoms in patients with IPF.

IPF :

Inclusion criteria

• Age 18-85 years
• IPF diagnosed according to ATS/ERS/JRS/ALAT criteria
• Patient gave informed consent

NON INCLUSION CRITERIA

• Presence of respiratory comorbidities : Asthma, COPD, bronchiectasis, emphysema, tuberculosis sequelae, prior lung surgery
• Obstructive ventilatory disorder
• Counterindication to pulmonary function testing
• Women : Pregnancy or milking
• Lack of health insurance

Controls :

Inclusion criteria

• Volunteers aged 18-85 years, free of any respiratory disease
• Volunteer gave informed consent

Secondary EXCLUSION CRITERIA Abnormal PFT : Total lung capacity or FEV1/VC ratio < Lower Limit of Normal

Non-IPF ILD :

Inclusion criteria

• Age 18-85 years
• Radiological interstitial pneumonia, on 2 tests performed >3 months apart
• PINS histology OR sarcoidosis histology OR clinical diagnosis of drug-induced lung disease OR diagnosis of auto-immune disease
• Patient gave informed consent

NON INCLUSION CRITERIA

• Presence of respiratory comorbidities : Asthma, COPD, bronchiectasis, emphysema, tuberculosis sequelae, prior lung surgery
• Obstructive ventilatory disorder
• Counterindication to pulmonary function testing
• Women : Pregnancy or milking
• Lack of health insurance

Uncharacterized ILD :

Inclusion criteria

• Age 18-85 years
• Radiological interstitial pneumonia, on 2 tests performed >3 months apart
• Patient gave informed consent

NON INCLUSION CRITERIA

• Presence of respiratory comorbidities : Asthma, COPD, bronchiectasis, emphysema, tuberculosis sequelae, prior lung surgery
• Obstructive ventilatory disorder
• Counterindication to pulmonary function testing
• Women : Pregnancy or milking
• Lack of health insurance

Secondary EXCLUSION CRITERIA Final diagnosis other than either IPF or non-IPF interstitial pneumonia.