Abstract: Objective The aim of this study was to investigate clinical implications of peripheral blood leukocyte differentiation antigen 34 (CD34) positive mononuclear cell and interleukin-3 (IL-3) level changes in patients with autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and AIH-PBC overlap syndrome (AIH-PBC OS). Methods 40 patients with AIH, 35 patients with PBC and 25 patients with AIH-PBC OS were admitted to our hospital between June 2019 and December 2022, and they received prednisolone, ursodeoxycholic acid (UDCA) or combination of them therapy for 12 months. Percentage of peripheral blood CD34⁺ cells was detected by FCM, serum IL-3 level was measured by ELISA, and serum anti-gp210 antibody, anti-SP100 antibody, anti-mitochondrial M2 antibody (AMA-M2), anti-liver and kidney microsomal type I antibody (LKM-I) were detected by Western blot. Results At presentation, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in patients with AIH were (136.8±9.8)U/l and (116.3±28.1)U/l, while by end of 12 month treatment, they returned to (36.8±4.8)U/l and (46.3±8.1)U/l, respectively (P<0.05); serum total bilirubin (TBIL), alkaline phosphatase (ALP) and glutamyl transferase (GGT) levels in patients with PBC were (51.4±5.7)μmol/l, (321.1±30.0)U/l and (471.5±58.8)U/l, and they decreased to (31.2±4.6)μmol/l, (224.8±29.0)U/l and (271.7±48.9)U/l, respectively by end of 12-month treatment (P<0.05); serum TBIL, ALT, AST, ALP and GGT levels in patients with AIH-PBC OS were (28.3±5.7)μmol/l, (90.6±12.3)U/l, (89.6±11.9)U/l, (252.3±23.6)U/l and (323.6±46.3)U/l, and they all decreased to (20.4±4.6)μmol/l, (50.7±11.4)U/l, (39.4±10.1)U/l, (157.6±21.4)U/l and (228.8±41.8)U/l, respectively by end of 12-month treatment (P<0.05); percentages of peripheral blood CD34⁺ cells in patients with AIH, PBC and AIH-PBC OS were (8.8±2.1)%, (10.2±2.4)% and (12.6±3.2)%, and they decreased to (4.7±1.2)%, (5.1±1.3)% and (5.0±1.2)%(all P<0.05), and serum IL-3 levels were (46.3±7.8)pg/ml, (50.7±8.4)pg/ml and (58.2±9.7)pg/ml, and they all decreased to (32.7±5.4)pg/ml, (33.5±5.6)pg/ml and (30.9±5.2)pg/ml, respectively, by end of 12-month treatment (P<0.05). Conclusion Serum CD34 and IL-3 levels in patients with AIH, PBC and AIH-PBC OS increase, which might be surveillance parameters for assessment of the entity.

Key words: Autoimmune hepatitis, Primary biliary cirrhosis, Leukocyte differentiation antigen 34, Interleukin-3