Peter Malfertheiner Department of Gastroenterology, Hepatology and Infectious Diseases

1. Acute Pancreatitis Pathogenesis and clininical implications Peter Malfertheiner Department of Gastroenterology, Hepatology and Infectious Diseases Otto-von-Guericke-University Magdeburg

2. Acute Pancreatitis Two clinical categories - localized to the pancreas - rapid improvement - restitutio ad integrum Mild - local - cardiovascular - respiratory - renal - septic - metabolic - Defective healing Severe complications

3. Acute Pancreatitis Buechler MW, Uhl W, Malfertheiner P, Sarr MG. Diseases of the pancreas. Karger 2004. Mild form (edematous pancreatitis) 85% Severe form (necrotizing pancreatitis) 15% Sterile necrosis 60% Infected necrosis 40% Lethality < 1% Lethality 5% Lethality 10-20%

4. Acute Pancreatitis Pathophysiology • etiology • mechanisms of cell damage • translation of basic knowledge for prognostic assessment and drug development

5. Idiopathic Alcoholic Other Biliary Acute Pancreatitis Etiology • Autoimmune • Drug-induced • Iatrogenic • IBD-related • Infectious • Inherited • Metabolic • Neoplastic • Structural • Toxic • Traumatic • Vascular

6. Infectious disease and pathogens associated with acute pancreatitis Viral Mumps Viral hepatitis Coxsackie virus B Echovirus Cytomegalovirus (CMV) Varicella-zoster virus (VZV) Epstein-Barr virus (EBV) Human immunodeficiency virus (HIV) Herpes simples virus (HSV) Rabies Rubella virus Rotarius enteritis Bacterial Yersinia enterolcolica and Y.pseudotuberulosis Salmonella typhimurium and S. enteriditis Campylobacter jejuni Typhoid fever Tuberculosis Mycobacterium avium-intracellulare Leptosprosis Legionnaires´disease Connatal lues

7. Infectious disease and pathogens associated with acute pancreatitis Parasitis Ascaris lumbricoides Clonorchis senensis Fasciola hepatica Taenia saginata Giardia lamblia Echinococcus Pneumocystis carinii Toxoplasma gondii Fungal Candida Exophiala dermatitidis Cryptococcus neoformans Cryptosporidium Aspergillus

8. Classification of drugs published as causing acute pancreatitis Class I Alpha-methylopa 5-Aminosalicylate (ASA) Azathioprine Cimetidine Cytosine arabinoside Dexamethasone Ethinylestradiol/lynestrenol Furosemide Isoniazid 6-Mercaptopuride Metronidazole Norethindrone/mestranol Procainamide Pentamidine Stibogluconate Sulindac Sulfamenthazole Sulfamethoxazole Sulfasalazine Sulindac Tetracycline Trimethoprim/sulfamethoxazole Valproic acid

9. Latencies of drugs implicated in causing AP

10. Pathogenesis Etiologic factors Toxic factors (e.g. alcohol) 0bstructive factors (e.g. Gallstones) Intra-acinar triggering Intra-acinar triggering Intracellular enzyme activation Increases intraductal pressure with disruption of the duct barrier Interstitial enzyme activation Inflammation Enzyme activation Disruption of compartmentalization with colocalization ‚Autodigestion‘ Büchler,Uhl,Malfertheiner,Pancreatic diseases 2004l

11. Schematic representation of working hypothesis for the onset of acute pancreatitis Diet-induced Mouse Severe Secretagogue-induced Rat Mild Duct obstruction-induced Rat/rabbit Mild Duct obstruction-induced Opossum Severe Model Animal Severity Blockage of digestive enzyme secretion Redistribution of lysosomal hydrolases and colocalization with digestive enzyme zymogens Intra-acinar cell activation of digestive enzymes Acinar cell injury Pancreatitis

12. Acute Pancreatitis 3 phenotypic responses in early phase • changes in secretion • intracellular activation of proteases • induction of inflammatory responses

13. Pathophysiology (Acinar Cells) Lumen Triggering factor Physiologic enzyme synthesis and secretion 1= zymogen granules 2= hydrolsis Defense mechanisms against intracellular enzyme activation Intracellular injury resulting from enzyme activation (crinophagy)

14. Physiologic regulated apical exocytosis and pathologic basolateral exocytosis in pancreatitis SNARE proteins mediate exocytosis Gaisano and Gorelick, Gastroenterology 2009;136:2040-2044

15. Zymogen activation during acute pancreatitis Proposed compartments Possible role of Inflammatory cells and zymogen activation • Lysosomes/endosomes • Autophagic vacuoles • Secretory granules release factor(s) that stimulate zymogen activation in the acinar cell activate or degrade zymogens secreted basolaterally Gaisano and Gorelick., Gastroenterology 2009;136:2040-2044

16. Acute Pancreatitis Pathophysiology EARLY EVENTS • Trypsinogen autoactivation • Cleavage of trypsinogen to trypsin by cathepsin B • Intracellular pancreatic trypsin inhibitor decreased • loss of compartimentalisation of zymogens and lysosomal enzymes • Trypsinogen activation by calcium

17. Acinar lumen Cathepsin B activation Disruption in CA2+ signaling/ Trypsinogen autoactivation/ Inappropriate trypsinogen activation Zymogen activation Organelle rupture Cellular injury Cell death

18. Acute Pancreatitis Cell death • necrosis • apoptosis • autophagy

19. Cell death pathways Cell Stress Initiator caspases Lyosomes ER Mitochondria Calcium Effector caspases PARP Cathepsin B Cytochrome c  ATP Effector caspases Trypsin Effector caspases PI3-kinase NF-B IAPs Necrosis Apoptosis

20. Acute Pancreatitis Pathophysiology The form of acinar cell death itself an important determinant of the severity of acute pancreatitis Bhatia M,Am J Physiol 2004 Induction of apoptosis reduces severity of experimental pancreatitis

21. Caspase-dependent and caspase-independent routes to cell death Maiuri et al, Molecular Cell Biology 2007;8:741-752

22. Autophagic process María I. Vaccaro, Pancreatology 2008;8:425-429

23. Autophagy, autodigestion and cell death are early cellular events in acute pancreatitis Acute pancreatitis Early cellular events Autophagy Autodigestion Cell death Necrosis Programmed cell death Cell survival María I. Vaccaro, Pancreatology 2008;8:425-429

24. Acute necrotizing pancreatitis Usually occurs within96h Ranson Apache 2 CRP>150

25. Pancreatic Necrosis h after onset of pain <24 46 70 24-<48 97 48-<72 72-<96 100 0 20 40 60 80 100% Development of pancreatic necrosis. After 96 h, all patients with necrotizing pancreatitis exhibit signs of necrosis (CRP, CT).

26. week 1 2 3 4 Pathophysiology of severe acute pancreatitis The two-phase-model Initial phase late phase SIRS Inflammation cascade Sepsis Infection of necrosis

27. Systemic Complications

28. Routes of Infection 1 = Hematatogenous; 2 = reflux of enteric content from the duodenum; 3 = reflux of bacteriobilia; 4 = lymphogenous (translocation); 5 = direct transperitoneal spread

29. Acute Pancreatitis: Pathophysiology Alcohol other agents gallstones Pancreatic cell-damage PMN-and Macrophages-Activation release activated enzymes endothelial damage PAF TNFa; IL1, 6, 8 PMN-Elastase, PLA2, O-Radicals CRP Tissue damage circulatory effects Activation of proteolytic cascade MOF

30. Acute Pancreatitis Pathophysiology • etiology • mechanisms of cell damage • translation from basic mechanisms to prognostic assessment and drug development

31. Acute Pancreatitis Biochemical markers • CRP • Serum Amyloid A • Procalcitonin • Interleukin1;6 • Trypsinogen activation peptide (TAP) • PMN elastase • Hematocrit

32. Acute Pancreatitis Pathophysiology- Conclusion • Unravelling the basic mechanisms in the early phase and during disease progression will help to develop approaches to block the damaging responses • Towards autophagy and apoptosis to prevent the more deleterious necrotic cell death (with recruitment of inflammatory cells) (?)

33. Acute Pancreatitis: Pathophysiology Alcohol other agents gallstones Pancreatic cell-damage PMN-and Macrophages-Activation release activated enzymes endothelial damage PAF TNFa; IL1, 6, 8 PMN-Elastase, PLA2, O-Radicals CRP Tissue damage circulatory effects Activation of proteolytic cascade MOF