Abstract: Objective To examine serum levels of red blood cell distribution width (RDW), albumin (Alb) and prothrombin time (PT) in primary biliary cholangitis(PBC) patients , and to analyze their association with disease severity. Methods Between March 2017 and September 2021, our hospital recorded 91 PBC patients and 60 healthy subjects. The PBC patients were categorized into non-cirrhotic(47 cases), compensated cirrhotic(29 cases), and decompensated cirrhotic(15 cases) groups, reflecting disease severity. Serum Alb levels were measured using an AU5800 automatic biochemical analyzer, PT was assessed with a STAGO automatic coagulation analyzer; and RDW was determined using a BC-5390 blood cell analyzer. The diagnostic efficacy of serum RDW, Alb, and PT levels for primary biliary cholangitis and cirrhosis was evaluated using the receiver operating characteristic curve (ROC). Results In the observational cohort, serum RDW and PT levels were significantly elevated at 49.6±7.5% and 14.4±3.4 seconds, respectively, compared to 39.8±2.9%and 12.4±0.7 seconds in the control group. Conversely, Alb levels were markedly recuced in the observation group (37.1±7.0 g/L) relative to the control group (46.5 ± 2.5 g/L) (P<0.05). In the non-cirrhosis cohort, serum RDW, Alb, and PT levels were recorded at 46.5±4.1%、40.3±4.9 g/L、and 12.7±0.9 seconds, respectively. The compensated cirrhosis group presented serum RDW, Alb, and PT levels of 48.8±7.5%、38.6±4.8 g/L、and 13.4±1.3 seconds, respectively. In the decompensated cirrhosis group, these levels were significantly higher for RDW(57.4±7.9%) and PT(19.8±3.8 seconds) , and lower for Alb(28.0±6.5 g/L), when compared to both the compensated cirrhosis nd non-cirrhosis groups(P<0.05).The Area Under the Curve(AUC) for the combined diagnostic utility of serum RDW, Alb, and PT levels in distinguishing primary biliary cholangitis and cirrhosis was 0.973, significantly surpassing the AUCs for RDW(0.927), Alb(0.894), and PT(0.707) when used individually. This combined diagnostic approcah achieved a sensitivity, specificity, and accuracy of 92.7%, 93.3%, and 93.0%, respectively, denonstrating superior efficacy. Conclusion In patients with PBC and cirrhosis, serum levels of RDW and PT exhibits significant increase, whereas Alb levels significantly decline. As the disease advances, the combined assessment of RDW, Alb, and PT demonstrates substantial diagnostic efficacy for identifying PBC and cirrhosis, offering valuable insights for the clinical appraisal of disease severity.

Key words: Primary biliary cholangitis, red blood cell distribution width, Albumin, Prothrombin time, diagnosis