SFTPD and interstitial lung disease: After adjusting for these covariates, multivariate analysis using a Cox regression model also revealed that A/S-ILD, higher serum ALD and SP-D levels, and lower %FVC were independent risk factors for relapse in patients with anti-ARS-ILD (P=0.0007, 0.0004, 0.01, and 0.0005, respectively; Table 3).