Prognostic nutritional index as a predictor of ursodeoxycholic acid response in primary biliary cholangitis: a retrospective study.

BACKGROUND

Primary Biliary Cholangitis (PBC) is an autoimmune hepatic disorder characterized by the progressive destruction of intrahepatic bile ducts. Ursodeoxycholic acid (UDCA) remains the primary treatment modality; however, a subset of patients exhibits non-responsiveness to UDCA therapy. The objective of this study is to investigate the association between the Prognostic Nutritional Index (PNI) and UDCA treatment non-responsiveness in individuals diagnosed with PBC.

METHODS

This retrospective study encompassed PBC patients who received UDCA therapy (13-15 mg/kg) from June 1, 2014, to December 31, 2021. The criterion for UDCA non-response was defined as an alkaline phosphatase (ALP) level exceeding 1.67 times the upper limit of normal (ULN) after 12 months of UDCA therapy. Logistic regression analysis was utilized to examine the relationship between baseline PNI and response to UDCA. The stableness of the findings was assessed through both unadjusted and adjusted models.

RESULTS

The study included 241 patients with PBC (mean age 55.80 ± 11.694 years; 210 (87.1%) females). During the 12-month clinical follow-up, 83 patients exhibited non-responsiveness to UDCA, corresponding to a non-response rate of 34.44%. Univariate binary logistic regression analysis indicated that factors such as alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total bile acid, total cholesterol, neutrophils, and PNI were associated with UDCA non-responsiveness (p < 0.05). Multivariate regression analysis showed that lower baseline PNI was associated with UDCA non-response (odds ratio [OR]: 0.882, 95% confidence interval [CI]: 0.825-0.943, p < 0.001). PNI showed modest discriminatory ability for UDCA non-response, with an AUROC of 0.664 in the overall cohort and 0.676 in non-cirrhotic patients. Based on the Youden index, the optimal PNI cut-off value was 49.03.

CONCLUSIONS

Lower baseline PNI was associated with inadequate biochemical response to UDCA in patients with PBC and may serve as a supportive risk stratification marker. However, its modest discriminatory performance and retrospective design limit its standalone clinical application. Further prospective validation is needed.