Anti-neutrophil Cytoplasmic Antibody in Interstitial Lung Disease.
Anti-neutrophil Cytoplasmic Antibody in Interstitial Lung Disease.
The purpose of this study is to investigate the clinical features and long-term outcome of
 anti-neutrophil cytoplasmic antibody (ANCA)-positive interstitial lung disease (ILD) and
 assess the difference between microscopic polyangiitis (MPA) associated ILD and isolated
 ANCA-positive idiopathic interstitial pneumonia.
ILD patients with serum ANCA-positivity were enrolled in this study.

 1. Baseline data collection:

 1. Demographics information (age, gender)

 2. Clinical course

 3. Clinical symptoms and signs (cough, dyspnea, fever, fatigue, crackling, clubbing
 fingers, mechanics hand)

 4. Laboratory findings (blood and urine routine, liver and renal function tests,
 erythrocyte sedimentation rate, C reactive protein)

 5. Serologic tests (ANA , Rheumatoid factor , Anti-cyclic citrullinated peptide (CCP),
 Anti-dsDNA, Anti-Ro (SS-A), Anti-La (SS-B), Anti-Smith, Anti-Scl-70, Anti-Jo-1)

 6. Systemic manifestation if diagnosed as systemic vasculitis

 7. Pulmonary function tests (ventilation and diffusion capacity test)

 8. Chest high-resolution computed tomography (HRCT)

 2. Treatment: treatment will be given according to the experience of each pulmonologist.

 3. Follow-up:

 1. Patients were followed up at least once a year and basic laboratory tests,
 serologic autoantibodies, pulmonary function test and chest HRCT were evaluated
 routinely

 2. Follow-up end point was April 2019.

 4. Outcome
Inclusion Criteria:

 -  Males and females

 -  Aged from 18 to 85 years with informed consent

 -  Have a diagnosis of ILD based on clinical symptoms and radiologic features, with or
 without histopathologic results

 -  Have available ANCA testing results during the first visit and follow-up period

 Exclusion Criteria:

 -  Connective tissue disease associated ILD

 -  ILD induced by drug, environment, or occupational exposure

 -  Hypersensitivity pneumonitis and sarcoidosis