IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory condition with marked clinical heterogeneity [1]. Common manifestations include autoimmune pancreatitis and cholangitis, orbital inflammation, dacryoadenitis, sialadenitis, (peri)aortitis and retroperitoneal fibrosis [2]. Glucocorticoids (GC) have been considered the first line treatment and usually result in rapid improvement [3]. However, relapses are frequent during tapering [4], and GC-related toxicity is a major concern as multiple treatment courses are often required [5].
