| IPF-positive autoimmunity | IPF-negative autoimmunity |
Age, median (range) | 60 (47-9) | 64 (39-84) |
Male gender, n (%) | 48 (66) | 66 (76) |
Smoking, current and former smokers, n (%) | 58 (79) | 59 (68) |
Familial – IPF, n (%) | 16 (22) | 16 (18) |
HRCT features consistent with UIP, n (%) | 26 (36) | 32 (37) |
Median follow up, months (range) | 32.19 (0.68-106.9) | 32.48 (0.42-114.3) |
AZA, CSS, NAC treatment, n (%) | 9 (12) | 15 (17) |