Calcium concentration and artificial precipitates in human pancreatic juice

Increased activation of hereditary pancreatitis-associated human cationic trypsinogen mutants in presence of chymotrypsin C

Mutations in human cationic trypsinogen (PRSS1) cause autosomal dominant hereditary pancreatitis. Increased intrapancreatic autoactivation of trypsinogen mutants has been hypothesized to initiate the disease. Autoactivation of cationic trypsinogen is proteolytically regulated by chymotrypsin C (CTRC), which mitigates the development of trypsin activity by promoting degradation of both trypsinogen and trypsin. Paradoxically, CTRC also increases the rate of autoactivation by processing the trypsinogen activation peptide to a shorter form. The aim of this study was to investigate the effect of CTRC on the autoactivation of clinically relevant trypsinogen mutants. We found that in the presence of CTRC, trypsinogen mutants associated with classic hereditary pancreatitis (N29I, N29T, V39A, R122C, and R122H) autoactivated at increased rates and reached markedly higher active trypsin levels compared with wild-type cationic trypsinogen. The A16V mutant, known for its variable disease penetrance, exhibited a smaller increase in autoactivation. The mechanistic basis of increased activation was mutation-specific and involved resistance to degradation (N29I, N29T, V39A, R122C, and R122H) and/or increased N-terminal processing by CTRC (A16V and N29I). These observations indicate that hereditary pancreatitis is caused by CTRC-dependent dysregulation of cationic trypsinogen autoactivation, which results in elevated trypsin levels in the pancreas.

Pancreatitis after a primary and secondary excision of congenital choledochal cysts

PURPOSE

Pancreatitis has been reported long after total choledochal cyst excision. The aim of this study was to determine if the disease process of postoperative pancreatitis differs between a primary and secondary cyst excision in a long-term follow-up.

METHODS

Among 53 postoperative patients who underwent a total cyst excision and were followed up, 44 patients underwent a primary cyst excision (primary excision group), while 9 patients underwent a secondary cyst excision after a previous cyst-duodenostomy for internal drainage (secondary excision group). The long-term clinical course, including the pancreatographic findings after a total cyst excision, was compared.

RESULTS

In the primary excision group, six patients had mild pancreatitis. Endoscopic retrograde pancreatography demonstrated ductal dilatation that was limited to the common channel in two patients, concurrent with the ventral duct in three, and extended the duct of Santorini in three. Conservative treatments were carried out in three patients, and endoscopic irrigation in one patient with protein plugs in the ventral duct. A resection of the choledochal remnant in the pancreas was performed in two patients with choledochal remnant-associated pancreatitis. From the secondary excision group, 5 of the 9 patients had chronic pancreatitis. Endoscopic retrograde pancreatography showed entire pancreatic ductal dilatation. Two of these patients underwent duodenal papilloplasty at the same time as secondary surgery; however, the disease progressively worsened.

CONCLUSION

In patients undergoing a secondary total excision after internal drainage, it is difficult to half the ongoing aggravating process in pancreatitis.

Pancreatitis complicated with dilated choledochal remnant after congenital choledochal cyst excision

We describe here three cases of pancreatitis after congenital choledochal cyst excision. In these three cases, the choledochal remnant in the pancreas head was markedly dilated, probably because of an incomplete resection of the cyst at the primary operation, and an increase in intraluminal pressure of the pancreatic duct caused by a dynamic obstruction by a protein plug or a pancreatic calculus. Complete cyst excision, including the choledochal wall in the pancreas, is therefore strongly recommended.