COMPARATIVE DIAGNOSTIC PERFORMANCE OF SERUM PIIINP AND COLLAGEN TYPE IV AS NON-INVASIVE BIOMARKERS FOR LIVER FIBROSIS STAGING

Abstract

Background: Liver fibrosis is a progressive consequence of chronic liver diseases and may lead to cirrhosis and hepatocellular carcinoma. Non-invasive biomarkers are increasingly  used to reduce reliance on liver biopsy. Procollagen type III N-terminal propeptide (PIIINP) and collagen type IV are extracellular matrix components associated with fibrogenesis. To compare the diagnostic performance of serum PIIINP and collagen type IV in staging liver fibrosis. A prospective analytical study included 120 participants: chronic HBV (n=40), chronic HCV (n=40), and healthy controls (n=40). Serum PIIINP and collagen IV levels were  measured using ELISA. Fibrosis stage was assessed by transient elastography (FibroScan). Correlation analyses and ROC curve analyses were performed to evaluate diagnostic performance. Both biomarkers were significantly elevated in HBV and HCV groups compared with controls (p<0.01). PIIINP showed strong correlation with elastography (r=0.71, p<0.001), while collagen IV demonstrated slightly stronger correlation (r=0.74, p<0.001). ROC analysis revealed good discrimination for advanced fibrosis (≥F3), with AUC values of 0.87 for PIIINP and 0.90 for collagen IV. Combined biomarker analysis improved AUC to 0.93. Both PIIINP and collagen IV are valuable non-invasive markers of liver fibrosis. Collagen IV demonstrated marginally superior diagnostic performance, while combined assessment provided the highest accuracy.