IgG4-Related Sclerosing Disease Incorporating Sclerosing Pancreatitis, Cholangitis, Sialadenitis and Retroperitoneal Fibrosis with Lymphadenopathy

Background and Aims: Autoimmune pancreatitis is usually associated with elevated serum IgG4 concentrations, and sometimes with sclerosing cholangitis and Sjogren's syndrome. This study aimed to elucidate the proposed entity of IgG4-related sclerosing disease. Methods: Subjects were patients with autoimmune pancreatitis (n = 26), sclerosing sialadenitis (n = 5), chronic alcoholic pancreatitis (n = 20), sialolithiasis (n = 34), Sjogren's syndrome (n = 50), and primary sclerosing cholangitis (n = 3). Sections of various organs and tissues of these patients were examined immunohistochemically using antibodies to CD4-T, CD8-T, and CD20B cell subsets and IgG4, and serum IgG4 concentrations were measured.Results: Patients with autoimmune pancreatitis were associated with sclerosing cholangitis (n = 23), sclerosing sialadenitis (n = 2), retroperitoneal fibrosis (n = 2), and abdominal (n = 5) and cervical (n = 4) lymphadenopathy. They demonstrated infiltrations of more abundant IgG4-positive plasma cells in the pancreas, peripancreatic retroperitoneal tissues, extrahepatic bile duct, gallbladder, stomach, minor salivary gland, and abdominal lymph nodes compared with those of other diseases (p < 0.01). Such infiltrations were also observed in the minor salivary gland and submandibular gland of patients with sclerosing sialadenitis (p < 0.01). Serum IgG4 concentrations were significantly elevated in patients with autoimmune pancreatitis and sclerosing sialadenitis (p < 0.01).Conclusion: We propose a new clinicopathological entity of IgG4-related sclerosing disease incorporating sclerosing pancreatitis, cholangitis, sialadenitis and retroperitoneal fibrosis with lymphadenopathy.