In univariate analysis (Table 3), age (hazard ratio [HR] 1.051, p = 0.033), current smoker (HR 6.689, p = 0.018), %FVC (HR 0.962, p = 0.011), serum Krebs von den Lungen-6 (KL-6; HR 1.001, p = 0.009), serum surfactant protein D (SP-D; HR 1.007, p = 0.048), NSIP + OP pattern on HRCT (vs. NSIP pattern; HR 0.111, p = 0.037), high extent of lung fibrosis on HRCT (HR 5.705, p = 0.015), comorbid other CTDs (HR 0.167, p = 0.029), and neuropsychiatric lesions (HR 5.762, p = 0.027) were significant prognostic factors. Here, SFTPD is linked to pulmonary fibrosis.