Clinical features and diagnosis of autoimmune hepatitis-primary biliary cirrhosis overlap syndrome

Objective To analyze the clinical features and laboratory test results of patients with autoimmune hepatitis ( AIH) - primary biliary cirrhosis ( PBC) overlap syndrome, as well as their correct diagnosis rate and time to diagnosis. Methods Fifty- three patients who were diagnosed by liver biopsy as having AIH- PBC overlap syndrome from January 2009 to June 2013 were selected as subjects; 53 AIH patients and 53 PBC patients were selected as control groups. Their clinical manifestations, laboratory test results, and diagnosis on admission were retrospectively analyzed. Comparison of normally distributed quantitative data between groups was made by one- way analysis of variance, and multiple comparisons were made by SNK- q test; comparison of qualitative data between groups was made using R × C contingency table, and multiple comparisons were made by Scheffe's confidence interval test. Results The 53 patients with AIH- PBC overlap syndrome had a serum alanine aminotransferase level of 173. 65 ± 52. 08 U / L, a serum total bilirubin level of 38. 07 ± 6. 82 μmol / L, a serum alkaline phosphatase ( ALP) level of 293. 81 ± 28. 89 U / L, and a serum gamma- glutamyl transpeptidase level of 57. 57 ± 78. 84 U / L. ALP showed significant difference between the patients with AIH- PBC overlap syndrome and control groups. The serum level of immunoglobulin M in overlap syndrome patients was 3. 33 ± 2. 12 g / L, which was significantly different from those of two control groups. Of the 53 overlap syndrome patients, 27 were positive for anti- mitochondrial antibody- M2, and the positive rate was significantly different from those of two control groups. Without liver biopsy, the correct diagnosis rate was the lowest ( 52. 83%) , and it took the longest time ( 8 ± 7. 7 d) to confirm the diagnosis on admission. Conclusion The clinical manifestations of patients with AIH- PBC overlap syndrome are more similar to those of PBC patients, but their biochemical test results are more similar to those of AIH patients. AIH- PBC overlap syndrome has the clinical features of both AIH and PBC.