In sensitivity analysis, positivity for anti-GP2 IgA was associated with poor outcome in the subgroup of patients with adult onset PSC (PLog-rank = 0.034) and concomitant IBD (PLog-rank < 0.001), but not in the subgroup of patients with pediatric onset PSC (PLog-rank = 0.098) and no concomitant IBD (PLog-rank = 0.666). Here, CD79A is linked to pancreatic serous cystadenoma.