The relationship and diagnostic efficacy of N-terminal propeptide type III collagen in pathological changes associated with non-alcoholic steatohepatitis.

OBJECTIVE: This study delves into the role of N-terminal propeptide type III collagen (PIIINP) in the diagnosis and management of liver pathological changes associated with non-alcoholic steatohepatitis (NASH).

PATIENTS AND METHODS: We collected baseline information, pathological data, and serum PIIINP levels of 168 patients diagnosed with non-alcoholic fatty liver disease (NAFLD) via ultrasound imaging in our hospital. Based on the non-alcoholic fatty liver disease activity score (NAS), patients with different NAFLD patterns were divided into a Definite NASH group and a Not/borderline group. Differences in PIIINP levels and pathological features between the two groups were compared and analyzed. The diagnostic value of PIIINP for NASH was evaluated using the receiver operating characteristic (ROC) curve.

RESULTS: Patients with NASH exhibited significantly higher values of homeostatic model assessment for insulin resistance (HOMA-IR), fibrosis biomarker fibrosis-4 (FIB-4), aminotransferase-to-platelet ratio index (APRI), and serum PIIINP levels than those classified as Not/borderline. A marked increase in the serum concentrations of PIIINP was observed with the severity of fatty degeneration, lobular inflammation, and hepatocellular ballooning. The AUC of PIIINP for diagnosing definite NASH was 0.766 (95% CI: 0.694, 0.839), APRI was 0.634 (95% CI: 0.549, 0.718), and FIB-4 was 0.621 (95% CI: 0.534, 0.708). The AUC of PIIINP for diagnosing definite NASH was significantly higher than that of APRI and FIB-4 (all p<0.05). Utilizing the predetermined threshold values for diagnostic parameters, the PIIINP measure demonstrated a sensitivity of 71.6% and a specificity of 73.6% in diagnosing definitive NASH when its value exceeded 7.72 ng/dL. This yielded a Youden index of 0.45. Similarly, when the APRI measure exceeded 0.21, it exhibited a sensitivity of 60.5% and a specificity of 63.2%, resulting in a Youden index of 0.24. Moreover, when the FIB-4 index surpassed 0.26, it showed a sensitivity of 46.9% and a specificity of 79.3%, culminating in a Youden index of 0.26.

CONCLUSIONS: NASH patients in this study exhibited significantly elevated PIIINP serum levels, which were closely associated with hepatocyte pathological changes. PIIINP demonstrated superior competence in diagnosing NASH than APRI and FIB-4 and thus offers a viable alternative for the clinical diagnosis of NASH.