Clinical features of type 1 autoimmune pancreatitis: an analysis of 13 cases

Objective To investigate the clinical features of type 1 autoimmune pancreatitis ( AIP) , and to deepen the understanding of this disease, reduce false positive rate, and enhance people' s awareness of this disease. Methods A retrospective analysis was performed for the clinical data of 13 patients with type 1 AIP who were admitted to The First Hospital of Jilin University from January 2012 to December 2016, including general status, clinical manifestations, laboratory serological examination, imaging findings, histopathological findings, treatment, and prognosis. Results Of all 13 patients, there were 9 male and 4 female patients with a mean age of 60. 08 ± 9. 47 years. Major clinical manifestations included jaundice ( 69. 2%) , abdominal pain ( 61. 5%) , and weight loss ( 61. 5%) . The most common organ involved was bile duct ( 46. 2%) , and 30. 8% of the patients had sclerosing cholangitis. Of all patients, 23. 1% had diabetes. As for serological markers, 92. 30% patients had more than 2 times increase in Ig G4, and 7. 69% had 1-2 times increase in Ig G4; 53. 85% patients had an increase in CA19-9; 69. 23% patients had an increase in total bilirubin; more than two thirds of the patients had an increase in aminotransferases or gamma-glutamyl transpeptidase. As for imaging findings, 53. 8% patients had diffuse enlargement of the pancreas on CT, 46. 2% had focal enlargement of the pancreas, and 46. 2% patients had low-density cyst-like shadow in pancreatic lesions. Pathological examination showed fibrous connective tissue proliferation with infiltration of lymphocytes and plasma cells. All patients were given standard glucocorticoid therapy ( initial dose of prednisone: 30-40 mg/d) and the remission rate of glucocorticoid therapy was 100%. The follow-up time was 12 months, and one patient experienced multiple recurrences in the course of the disease. Conclusion Type 1 AIP is the local manifestation of Ig G4-associated disease in the pancreas, which often occurs in middle-aged and elderly men, and most patients are complicated by extrapancreatic lesions. Glucocorticoid therapy is effective and most patients have good prognosis. Recurrence often occurs in the case of no standard or long-term glucocorticoid therapy.