Clinical features of anti-gp210-positive, AMA-negative patients with abnormal liver function

BACKGROUND AND AIMS: Anti-gp210 and antimitochondrial antibody (AMA) are important serological markers in primary biliary cholangitis (PBC). This study aimed to characterize the clinical features of anti-gp210-positive, AMA-negative patients with abnormal liver function and to explore factors associated with a final diagnosis of PBC in this retrospective cohort. METHODS: We retrospectively identified 93 anti-gp210-positive, AMA-negative patients. Clinical, biochemical, serological, pathological, and follow-up data were reviewed. Because the non-PBC group comprised multiple etiologies with different clinical and pathophysiological characteristics, comparisons between the PBC and non-PBC groups were considered exploratory and were interpreted with caution. RESULTS: Forty-eight patients were classified as PBC and 45 as non-PBC after clinical evaluation. Compared with the non-PBC group, patients with PBC had higher alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) levels, a higher anticentromere antibody (ACA) positivity rate, and higher anti-gp210 titers, whereas total bilirubin (TBIL) and aspartate aminotransferase (AST) levels were lower. During follow-up, anti-gp210 became negative in 1 of 23 followed PBC patients and in 6 of 20 followed non-PBC patients. Given the small follow-up subgroup, this observation is descriptive and should be interpreted cautiously. CONCLUSION: Anti-gp210 positivity in AMA-negative patients supports consideration of PBC, but anti-gp210 positivity may also be detected in a subset of non-PBC liver diseases. In this retrospective cohort, higher anti-gp210 titers and a more cholestatic biochemical profile were more frequently observed in patients ultimately classified as PBC. These findings should be interpreted in light of the heterogeneity of the non-PBC group and the exploratory nature of the analyses.