This is a mechanism module, not a specific disease. Disorder entries reference individual nodes via conforms_to (e.g., "pancreatitis_acinar_autodigestion#Premature Intra-Acinar Trypsinogen Activation"). The module defines the expected pathophysiology structure; conforming nodes in disorder files should include the corresponding cell types, biological processes, and causal edges, specialized to their etiology. Key etiology-specific substitutions for the trigger node: biliary pancreatitis uses gallstone-mediated duct obstruction and bile reflux; alcoholic pancreatitis uses alcohol and its metabolites; hereditary pancreatitis substitutes a PRSS1 trypsinogen gain-of-function variant or a SPINK1 (trypsin-inhibitor) / CFTR loss-of-function variant. The pancreatic acinar cell (CL:0002064) is the conserved cell type across the upstream nodes.
Premature Intra-Acinar Trypsinogen Activation
trigger
The initiating lesion of pancreatitis is the premature, inappropriate conversion of trypsinogen to active trypsin within the pancreatic acinar cell, rather than in the intestinal lumen where activation normally occurs. Across etiologies this reflects an imbalance between trypsinogen activation and the protective trypsin-inhibitor and degradation systems: gain of trypsin activity (PRSS1 hereditary mutations) or loss of inhibition (SPINK1 deficiency), or hyperstimulation and duct obstruction in biliary and alcoholic disease. The active trypsin then activates the broader cascade of digestive proenzymes.
Downstream
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Calcium Overload and Impaired Autophagy
Calcium Overload and Impaired Autophagy
amplifier
Sustained, pathological cytosolic calcium elevation and defective autophagy amplify the initial acinar insult. Prolonged global Ca2+ overload (driven by bile, alcohol metabolites, and other causes) promotes trypsin activation, vacuolization, and mitochondrial dysfunction, while autophagic flux is impaired because autophagosome-lysosome fusion fails, leading to accumulation of dysfunctional organelles. Together these processes drive the cell toward death and amplify the proenzyme cascade.
Downstream
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Acinar Cell Autodigestion and Necrosis
Acinar Cell Autodigestion and Necrosis
central effector
Unregulated intracellular activation of trypsin and the wider proenzyme cascade, together with calcium overload and failed autophagy, leads to proteolytic autodigestion of the acinar cell and the gland. Acinar cells undergo necrosis and stress-driven death, releasing damage-associated molecular patterns (DAMPs) and active enzymes into the parenchyma. This is the central effector step that converts intracellular enzyme activation into tissue destruction.
Downstream
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Local and Systemic Inflammatory Response
Local and Systemic Inflammatory Response
effector
DAMPs and reactive oxygen species released by dying acinar cells activate the innate immune system through pattern-recognition receptors, recruiting neutrophils, macrophages, and other immune cells that release cytokines and chemokines. This drives local pancreatic inflammation and, when amplified, a systemic inflammatory response that determines disease severity.
Pancreatitis
consequence
The convergent clinical syndrome of pancreatitis: acute inflammatory episodes of the exocrine pancreas that, on recurrence or persistence, progress to chronic fibro-inflammatory disease with progressive loss of the exocrine and endocrine compartments through atrophy and fibrotic replacement. Functional consequences include recurrent abdominal pain, maldigestion (exocrine insufficiency), and diabetes mellitus (endocrine insufficiency).