Plasma N‐terminal propeptide of type III procollagen accurately predicts liver fibrosis severity in children with non‐alcoholic fatty liver disease.

Background & Aims: We examined the diagnostic performance of plasma N‐terminal propeptide of type III procollagen (PIIINP) levels, aspartate aminotransferase to platelet ratio index (APRI) and Fibrosis‐4 (FIB‐4) score for predicting non‐alcoholic steatohepatitis (NASH) and liver fibrosis stage in children/adolescents with non‐alcoholic fatty liver disease (NAFLD). Methods: We enrolled 204 children/adolescents with biopsy‐proven NAFLD at the "Bambino Gesù" Children's Hospital. We measured plasma PIIINP levels using a commercially available enzyme‐linked immunosorbent assay kit and calculated APRI and FIB‐4 scores using standard methods. Results: Children with NASH had higher plasma PIIINP levels, APRI and FIB‐4 scores compared with those without NASH (all P < .001). However, PIIINP levels had much better diagnostic performance and accuracy than APRI and FIB‐4 scores for predicting liver fibrosis stage. PIIINP levels correlated with the total NAFLD activity score (NAS) and its constituent components (P < .0001). The risk of either NASH or F ≥ 2 fibrosis progressively increased with increasing PIIINP levels (P < .0001), independent of age, gender, adiposity measures, insulin resistance, NAS score and the patatin‐like phospholipase domain‐containing protein‐3 rs738409 polymorphism. For every 3.6 ng/mL increase in PIIINP levels, the likelihood of having F ≥ 2 fibrosis increased by ~14‐fold (adjusted‐odds ratio 14.1, 95% CI 5.50‐35.8, P < .0001) after adjustment for the aforementioned risk factors. The area under the receiver operating characteristics curve was 0.921 (95% CI 0.87‐0.97) for F ≥ 2 fibrosis, and 0.993 (95% CI 0.98‐1.0) for F3 fibrosis respectively. Conclusions: Unlike APRI and FIB‐4 scores, plasma PIIINP levels are a promising, non‐invasive biomarker for diagnosing liver fibrosis stage in children/adolescents with biopsy‐proven NAFLD. [ABSTRACT FROM AUTHOR]