To investigate the clinical features and prognosis of interstitial lung disease patients with positive anti-neutrophil cytoplasmic antibody.

The patients with interstitial lung disease who visited Peking Union Medical College Hospital from March 2006 to March 2016 were divided into three groups: interstitial lung disease with ANCA-positive(ANCA-ILD), connective tissue disease associated interstitial lung disease and interstitial pneumonia with autoimmune features (CTD-ILD/IPAF) and idiopathic interstitial pneumonia (IIP). The three groups were analyzed in terms of clinical manifestations, serology, lung function, imaging, survival and recurrence.

Two hundred and seventy four patients were enrolled and 38 (14%) were ANCA-positive of whom 16 were male and 22 were female. The age of 38 ANCA-positive patients was (59±10) years and the follow-up time was (52±31) months. Seven among the 38 ANCA-positive patients died and the death rate is 18.42%. The ANCA-positive patients with interstitial lung disease have higher onset age (ANCA-ILD:59±10,CTD-ILD/IPAF:52±10,IIP:53±11,H=19.29, P<0.001), lower hemoglobin (ANCA-ILD: 129±21, CTD-ILD/IPAF: 138±15, IIP: 140±19, H=8.17, P=0.017), higher erythrocyte sedimentation rate (ANCA-ILD:45±35, CTD-ILD/IPAF:26±24,IIP:19±22,H=19.73, P<0.001), lower lung function improvement rate after treatment (ANCA-ILD:31%,CTD-ILD/IPAF:59%,IIP: 39%,χ²=11.74,P=0.003), lower absorption rate of CT lesion (ANCA-ILD:61%,CTD-ILD/IPAF:82%,IIP:67%, χ²=9.23,P=0.010) and higher death rate(ANCA-ILD:18%,CTD-ILD/IPAF:6%,IIP:12%, χ²=7.16,P=0.028).

There are significant differences in clinical characteristics between ANCA-positive patients and other types of pulmonary interstitial disease. And both the treatment effect and the prognosis is poor for the ANCA-positive patients.

Antibodies, anti-neutrophil cytoplasmic; Lung disease,interstitial