Red blood cell distribution width to platelet ratio levels in assessment of histologic severity in patients with primary biliary cholangitis.

We aimed to investigate the relationship between the histologic severity and red blood cell distribution width to platelet ratio (RPR) in patients with primary biliary cholangitis (PBC). One hundred and seven consecutive patients with liver biopsy-proven and as yet treatment-naïve PBC were enrolled as the primary and validation cohort. The histologic stages were divided into early stage (Scheuer's stage 1 & 2) and late stage (Scheuer's stage 3 & 4). The overall patient demographics, clinical manifestations, hematological tests and biochemical profile were retrospectively collected from our database. Both groups were compared in terms of RPR, aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis index based on the 4 factors (FIB-4) and AST/ALT ratio (AAR). Of the 77 patients in the primary cohort, a total of 24 (31.2%) had early stage PBC, whereas 53 (68.8%) represented late stage. Patients with late stage PBC showed significantly higher red blood cell distribution width (15.5 vs. 14.1%, p = .016), RPR (0.15 vs. 0.09, p < .001), direct bilirubin (32.4 vs. 12.9 μmol/L, p = .041), FIB-4 (3.41 vs. 6.34, p = .001) and significantly lower platelet (132.8 vs. 185.8 × 10/L, p = .002). The area under the curve, cut-off value, sensitivity, specificity, positive predictive value, negative predictive value for determining late stage were 0.74, 0.14, 49.1%, 95.8%, 96.3% and 46.0%, respectively. Additionally, high RPR may also serve as a prognostic indicator for 18-month mortality. In conclusion, RPR can be used as a non-invasive and effective predictor of histologic severity in patients with PBC.