Reduction in alkaline phosphatase is associated with longer survival in primary sclerosing cholangitis, independent of dominant stenosis

SummaryBackground Alkaline phosphatase (ALP) is an important serum marker in primary sclerosing cholangitis (PSC). Patients with obstruction of the large bile ducts due to dominant strictures (DS) are a special, clinically important phenotype. Aim To determine the impact of ALP reduction on liver transplantation-free survival in PSC patients with DS. Methods Prospective cohort study in 215 PSC patients. We performed subgroup analysis for patients without DS (no DS, n = 84), DS at first presentation (DS early, n = 72) and development of DS during the course of the study (DS late, n = 59). We evaluated two scores of ALP reduction. ALP reduction 1 was defined as ALP normalisation, 50% reduction compared with baseline values, or reduction below 1.5 times of upper limit of normal (ULN) within 6 months. ALP reduction 2 was defined as ALP reduction below 1.5 times of ULN within 12 months. Results Of the patients, 59.5% reached an ALP reduction 1 and 56.7% according to ALP reduction 2. Achievement of each score was associated with longer transplantation-free survival in all three groups (ALP reduction 1: no DS P = 0.001; DS early P