[Clinical analysis of diffusive interstitial lung diseases with positive anti-neutrophil cytoplasmic antibody]

To explore the features of pulmonary interstitial pathological changes in diffuse interstitial lung disease (DILD) patients with positive anti-neutrophil cytoplasmic antibody (ANCA), and the similarities as well as differences between ANCA positive patients with non-primary vasculitis and primary systematic vasculitis.

Clinical data of 122 patients with DILD having ANCA examined from October 1995 to September 2008, were reviewed. Among the ANCA positive patients with non-primary vasculitis (Group A), those with primary systematic vasculitis (Group B), and the ANCA negative patients (Group C), the results of syndromes, signs, radiological manifestations, pulmonary function tests, bronchoscope examinations, bronchoalveolar lavage fluid (BALF) cytology and other laboratory examinations were compared.

In the 122 DILD patients with ANCA results, 36 patients' ANCA (29.51%) were positive. The numbers of patients in Groups A, B, and C were 7, 29, and 86. Total lung capacity (TLC) decreased less and pleural pathological changes were more seen in Groups A and B than in Group C. Oliguria, haematuria, proteinuria, anaemia, and renal inadequacy in Group A, which were similar in Group C, appeared less than in Group B. Results of bronchoscope examination, BALF cytology, anti-nuclear antibody (ANA), and etc. were not significantly different among the three groups.

In DILD patients, pulmonary interstitial changes of those with positive ANCA accompany with more pleural pathological changes and TLC decreased less than those with negative ANCA. In patients with positive ANCA, non-primary vasculitis had some similar clinical manifestations as primary systematic vasculitis, however, anaemia and renal damages were less seen in the non-primary vasculitis patients.