Using SFTPC and computed tomographic volumetric imaging to diagnose and predict outcomes in usual interstitial pneumonia-type idiopathic pulmonary fibrosis

This study aimed to unravel the possible diagnostic ability and prognostic efficacy of SFTPC and volume computed tomography in usual interstitial pneumonia-type idiopathic pulmonary fibrosis (UIP-IPF). The surfactant protein C‌ (SFTPC) genes related to pulmonary fibrosis were screened using the DISCO database. The expression level of SFTPC mRNA in the patients’ serum was detected, and the CALIPER vessel-related structure (VRS) scoring was performed using CT detection. SFTPC mRNA and CALIPER VRS underwent Receiver Operating Characteristic (ROC) curve analysis individually, followed by an integrated diagnostic ROC evaluation combining both modalities. Survival prognostication involved Kaplan-Meier analysis stratified by SFTPC mRNA or CALIPER VRS categories, with multivariable Cox proportional hazards regression modeling to determine the predictive ability for the death of patients. SFTPC demonstrated the most significant transcriptomic expression in myofibroblasts. SFTPC was elevated in UIP-IPF patients than in connective tissue disease-associated usual interstitial pneumonia (CTD-UIP) controls (p < 0.001), with an AUC of 0.7912 for diagnostic prediction. And the CALIPER VRS scoring system showed discriminative capacity (AUC, 0.7912). Their multimodal integration significantly enhanced prognostic accuracy (combined AUC, 0.8284). Survival analysis revealed stratification patterns: SFTPC mRNA high-expression vs. low-expression groups (log-rank p = 0.006) and CALIPER VRS high-risk vs. low-risk cohorts (log-rank p = 0.012) exhibited comparable mortality disparities. Cox regression confirmed SFTPC’s prognostic value (HR, 2.096; p = 0.021), with CALIPER VRS demonstrating a stronger mortality association (HR, 2.847; p = 0.017). These findings showed that the expression level of SFTPC and the CALIPER VRS was capable of independently or in combination diagnosing UIP-IPF and, as factors to participate in prognosis.