Which of the following represents the initiating event common to nearly all forms of acute pancreatitis, regardless of etiology?

• A Direct activation of pancreatic lipase by bacterial phospholipase
• B Retrograde reflux of duodenal contents activating enterokinase in the duct
• C Premature intracellular activation of trypsinogen to trypsin within acinar cells ✓
• D Complement-mediated necrosis of islet beta cells releasing proteases

Explanation

All etiologies of acute pancreatitis converge on inappropriate intrapancreatic activation of trypsinogen into trypsin inside acinar cells. Trypsin then activates other proenzymes, producing autodigestion, fat necrosis by lipase, and vessel damage by elastase. Normally trypsin is kept inactive by synthesis as a zymogen, sequestration, SPINK1 inhibition, and calcium regulation; failure of these defenses underlies alcohol, gallstone, and PRSS1 mutation related attacks. Lipase and other enzymes act downstream of trypsin.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.