Liver transplant-free survival according to alkaline phosphatase and GLOBE score in patients with primary biliary cholangitis treated with ursodeoxycholic acid

Background: After 1 year of ursodeoxycholic acid (UDCA), patients with primary biliary cholangitis (PBC) may have a normal GLOBE score despite high alkaline phosphatase (ALP) levels. Aim: To assess the association between ALP and liver transplantation (LT)-free survival according to the GLOBE score. Methods: Among patients with a normal or elevated GLOBE score in the Global PBC cohort, the association between ALP after 1 year of UDCA and the risk of LT/death was assessed. The LT-free survival was compared with that of a matched general population. Results: After 1 year of UDCA, ALP was associated with the risk of LT/death (aHR 1.31, 95% CI 1.003–1.72, p = 0.048) among 2729 patients with a normal GLOBE score. The 10-year LT-free survival among these patients with an ALP >2.0 × ULN was 94.0% (95% CI 90.1–97.9) for those <50 years, and 82.6% (95% CI 76.5–88.7) for those ≥50 years, which was significantly lower (p = 0.040) and similar (p = 0.736) to that of the matched population, respectively. The 10-year LT-free survival in patients ≥50 years with normal GLOBE score and normal ALP (90.8%, 95% CI 87.7–93.9) was significantly higher (p = 0.022) than the matched population. Among 1045 patients with an elevated GLOBE score, ALP was associated with LT/death only in those <50 years (aHR 1.38, 95% CI 1.06–1.81, p = 0.016). Conclusion: The LT-free survival of patients with PBC with a normal GLOBE score is optimal in case of normal ALP levels, also in relation to the general population. Despite their generally favourable prognosis, an elevated ALP level may still indicate a need for add-on therapy.