BAL bronchoalveolar lavage CT computed tomography CTD connective tissue disease DAD diffuse alveolar damage DAH diffuse alveolar haemorrhage DLCO diffusing capacity of the lung for carbon monoxide FEV 1 forced expiratory volume in 1 s FVC forced vital capacity HLA human leukocyte antigen HRCT high-resolution computed tomography Ig immunoglobulin IIP idiopathic interstitial pneumonia IL interleukin ILD interstitial lung disease IPAF interstitial pneumonia with autoimmune features IPF idiopathic pulmonary fibrosis IPS idiopathic pneumonia syndrome LIP lymphocytic interstitial pneumonia MALT mucosa-associated lymphoid tissue NSIP nonspecific interstitial pneumonia OP organising pneumonia PAH pulmonary arterial hypertension PFT pulmonary function test PH pulmonary hypertension RA rheumatoid arthritis SLE systemic lupus erythematosus SSc systemic sclerosis UIP usual interstitial pneumonia List of abbreviations