Primary Biliary Cholangitis at a Young Age : Clinical Characteristics and Prognosis

BACKGROUND Previous studies suggest that patients diagnosed with PBC at a young age differ from those diagnosed in middle age, regarding clinical features, response to therapy and prognosis. The aim of this study was to quantify these potential differences related to age in a large, international population. METHODS The Global PBC Study Group’s cohort was used. Patients <33.5 yrs of age at PBC diagnosis were classified as early onset PBC (youngest 5% of the cohort). The young group was sex and center matched 1:2 to PBC patients of average age at diagnosis. For a subgroup of these patients, additional data were collected on symptoms and comorbidities. RESULTS 233 young patients and 466 patients of average age at diagnosis were included for analyses. Additional data was collected for 95 early onset PBC patients and 190 matches (92% female), originating from the Netherlands, Canada and Italy. Their median FU was 8.4yrs (IQR 4.7-13.6). Median age at diagnosis in this young group was 30.3 yrs (27.132.3), and 54.1 (52.2-55.8) among their controls. UDCA treatment was given to 85% of young patients and 92% of controls. In the young group, 1 liver-related death and 10 liver transplantations (LTs) occurred. Among matches, 17 died (n=7 liver related) and 6 underwent LTs. Young PBC patients were more often symptomatic at diagnosis (76%) than their matches (45%) (p<0.001). Fatigue and pruritus were present in 62% and 52% of young patients, as opposed to 34% and 25% of matches (both p<0.001). In young patients, transplant-free survival of those with fatigue and/or pruritus was worse than when asymptomatic (p=0.19); after 10 years, no death’s or LTs were noted in the asymptomatic young patients, against 9 endpoints in the symptomatic young group. Baseline bilirubin and ALP were comparable between groups (p=0.16, p=0.24). However, of UDCA-treated patients with lab available, 55% of young patients responded to UDCA therapy (Paris I criteria), as opposed to 74% of matches (p=0.01). In the overall group (N=699), transplant-free survival was comparable for young patients and matches (p=0.071) with a 10-year survival of 89% in the young group vs 81% in the older patients. Survival free of liver-related death or LT was also comparable (p=0.250). CONCLUSION Patients with PBC at a young age more often have PBC-related symptoms at diagnosis and are less likely to biochemically respond to UDCA. Their survival free of liver-related death and LT is comparable to their older counterparts. Given their young age at diagnosis, the prognosis of young patients with PBC is markedly worse than that of middle-aged patients.