Published online Jun 7, 2013. doi: 10.3748/wjg.v19.i21.3332
Revised: February 18, 2013
Accepted: March 6, 2013
Published online: June 7, 2013
Processing time: 172 Days and 15.2 Hours
AIM: To describe protease serine 1 (PRSS1) gene mutations in patients with autoimmune pancreatitis (AIP) and the clinical features of AIP.
METHODS: Fourteen patients with AIP, 56 with other chronic pancreatitis, 254 with pancreatic cancer and 120 normal controls were studied. The mutations and polymorphisms of four genes involved with pancreatitis or pancreatic cancer, PRSS1, SPINK1, CFTR and MEN1, were sequenced. The pathogenic mechanism of AIP was investigated by comparing the wild-type expression system with the p.81Leu→Met mutant expression system.
RESULTS: Two novel mutations (p.81Leu→Met and p.91Ala→Ala) were found in PRSS1 gene from four patients with AIP. PRSS1_p.81Leu→Met mutation led to a trypsin display reduction (76.2%) combined with phenyl agarose (Ca2+ induced failure). Moreover, the ratio of trypsin/amylase in patients with AIP was higher than in the patients with pancreatic cancer and other pancreatitis. A large number of lymphocytes and plasma cells were found in the bile ducts accompanied by hyperplasia of myofibroblasts.
CONCLUSION: Autoimmune pancreatitis may be related to PRSS1 gene mutations.
Core tip: Novel mutations (p.81Leu→Met and p.91Ala→Ala) were found in protease serine 1 gene from the patients with autoimmune pancreatitis. Trypsinogen abnormal activation resulted in multiple organ injuries. And this offers direct evidence in support of the trypsinogen gene mutation and abnormal immune system.