IL33 and immunoglobulin G4-related sclerosing disease: Clinical relevance regarding these findings comes from the fact that serum IFN-α and IL-33 concentrations are markedly higher in patients with type 1 AIP and IgG4-RD than in patients with chronic alcoholic pancreatitis and healthy controls and that pDCs producing IFN-α and IL-33 are localized in the pancreas of patients with these disorders (9, 16, 17).