title: Multiple gene mutations in patients with type 2 autoimmune pancreatitis and its clinical features.
abstract: BACKGROUND
  It is now clear that there are two histological types (type 1 and type 2) of autoimmune pancreatitis (AI P). The histological substance of type 1 AI P is known as lymphoplasmacytic sclerosing pancreatitis (LPSP) or traditional AIP, and type 2 AIP is characterized by distinct histology called idiopathic duct centric pancreatitis (IDCP). Serum IgG4 increase is considered as a marker for type 1 AI P. Far less is known about type 2 and it lacks predicting markers, so it easily leads to missed diagnosis and misdiagnosis.
  
  
  OBJECTIVE
  The aim of this study was to describe multi-gene mutations in patients with type 2 AI P and its clinical features.
  
  
  METHODS
  Three unrelated patients with type 2 AI P, 10 cases with type 1 AIP, 15 cases with other chronic pancreatitis and 120 healthy individuals were studied. The mutations and polymorphisms of 6 genes involved in chronic pancreatitis or pancreatic cancer - PRSS1, SPINK1, CFTR, MEN1, PKHD1, and mitochondrial DNA - were sequenced. Information of clinical data was collected by personal interview using a structured questionnaire.
  
  
  RESULTS
  Novel mutations were found in the genes encoding for MEN1 (p.546 Ala > The) and PKHD1 (c. 233586 A > G and c. 316713 C > T) from patients with type 2 AIP. What is more, the serum TCR (T cell receptor) level is relatively higher in patients with type 2 AIP than in patients with type 1 AIP and other chronic pancreatitis or normal controls. Weight loss was the major manifestation and no patients had extrapancreatic involvement in type 2 AIP.
  
  
  CONCLUSIONS
  Type 2 AIP may occur with multi-gene mutations. For screening purposes, it is more reasonable to evaluate TCR levels in serum.
authors.affiliation: Department of Radiation Oncology, Fujian Medical University, Fuzhou, PR China ; These authors contributed equally to this manuscript.
authors.forename: Feng
authors.initials: F
authors.lastname: Dong
authors.affiliation: Department of Laboratory Medicine, Medical Technology and Engineering College, Fujian Medical University, Fuzhou, PR China ; These authors contributed equally to this manuscript.
authors.forename: Qing-Quan
authors.initials: QQ
authors.lastname: Chen
authors.affiliation: Department of Gastroenteropathy, Fujian Medical University, Fuzhou, PR China.
authors.forename: Ze-Hao
authors.initials: ZH
authors.lastname: Zhuang
authors.affiliation: Department of Surgery, Fujian Medical University, Fuzhou, PR China.
authors.forename: Qing-Liang
authors.initials: QL
authors.lastname: He
authors.affiliation: Department of Laboratory Medicine, the First Affiliated Hospital, Fujian Medical University, Fuzhou, PR China.
authors.forename: Feng-Qing
authors.initials: FQ
authors.lastname: Wang
authors.affiliation: Department of Laboratory Medicine, the First Affiliated Hospital, Fujian Medical University, Fuzhou, PR China.
authors.forename: Qi-Cai
authors.initials: QC
authors.lastname: Liu
authors.affiliation: Department of Cell Biology and Genetics, Fujian Medical University, Fuzhou, PR China.
authors.forename: He-Kun
authors.initials: HK
authors.lastname: Liu
authors.affiliation: Department of Laboratory Medicine, Medical Technology and Engineering College, Fujian Medical University, Fuzhou, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
keywords: autoimmune pancreatitis; gene mutations; serum TCR; type 2