1. Helicobacter pylori infection and its consequences

2. We pathologists knew squat about gastritis before H pylori was discovered.

3. H pylori infects the whole stomach, but it induces a chronic gastritis that is most intense in the antal mucosa

4. Classic H pylori gastritis: the great blue biopsy

5. Plasmacytosis (superficial) in the lamina propria

6. Induced lymphoid follicles at the base of the mucosa

7. Activity with PMNs in the necks

8. In most cases, the bacteria can be found in the H and E stained section, on the surface epithelium, often over the intecellular junctions and beneath the surface mucus coat. They appear as tiny thin rods often with a bend in the center, like a set of wings.

9. Bugs on the surface of the epithelium

10. Often they hide in the detached mucus

11. Not all H pylori gastritis is the same. There may be population differences population differences individual differences individual differences minimal disease with tons of bugs minimal disease with tons of bugs intense disease with few bugs intense disease with few bugs variable eosinophils variable eosinophils variable activity variable activity

12. H pylori identification when they are difficult to find on H&E; other stains have been used. Silver Diff-quick

13. H pylori identification when they are difficult to find on H&E Immunostain, our current method

14. Active H pylori antral gastritis

15. H pylori Gastritis Untreated l Plasmacytosis l Activity l Bugs l Lymphoid hyperplasia Treated l Bugs disappear l Activity stops l Plasmacytosis recedes l Lymphoid follicles atrophy H pylori killer

16. killer

17. Biopsies that look like treated H pylori gastritis are common

18. Superficial Plasmacytosis

19. No activity. No bugs on the surface.

20. Usually, this inactive chronic gastritis has no H pylori

21. These days, a few biopsies of inactive chronic gastritis have bugs on immunostain, often deep in the pits and even in the glands and not on the surface. Thid may result from chronic PPI use In the pits In the glands

22. Otherwise, this common inactive chronic gastritis without H pylori has no name and no literature. But we keep seeing it.

23. Chronic inactive gastritis, with no bugs: WHY? Biopsy missed bugs Biopsy missed bugs different cause different cause proton pump inhibitors proton pump inhibitors antibiotics antibiotics

24. Approach to patients with heartburn and dyspepsia First, acid suppression, commonly Proton Pump Inhibitors (PPIs) If no response, then upper endoscopy and potential biopsies

25. Protein pump inhibitor effects Parietal cell acid secretion Hypergastrinemia  Parietal cell hypertrophy: snouts  ?Parietal cell hyperplasia  ?Polyps containing fundic glands  ECL cell stimulation in humans unclear antral pH

26. Protein pump inhibitor effects Parietal cell acid secretion antral pH Treats antral H pylori: Bugs migrate proximally or deeply  activity disappears  Plasmacytosis recedes  lymphoid follicles atrophy

27. H pylori Causes: peptic ulcers ( mechanism unknown), a clinical disease peptic ulcers ( mechanism unknown), a clinical disease chronic active gastritis, mostly antral, not a clinical disease chronic active gastritis, mostly antral, not a clinical disease

28. Complications of H pylori infection Peptic ulcers, mainly in the duodenum Adenocarcinoma, secondary to dysplasias that develop in atrophic gastritis (see atrophic gastritis module for definitions and diagnostic criteria) B cell lymphomas, both low and high grade, probably developing in the induced lymphoid follicles at the base of the mucosa

29. There is a second bacterium that causes an active chronic gastritis, similar to, but less intense than, H pylori gastritis.

30. Helicobacter heilmannii

31. Helicobacter heilmannii is really rare around here. The bugs: 7-10 microns 7-10 microns Urease + Urease + Dog and cat transmitted Dog and cat transmitted The disease: 39 cases in 15,180 antral bxs 39 cases in 15,180 antral bxs (Heilmann & Borchard, Gut 32:137, 1991 (Heilmann & Borchard, Gut 32:137, 1991 Antrum 100%; body 20% Antrum 100%; body 20% Chronic active -it is, less than H pylori Chronic active -it is, less than H pylori

32. H heilmannii comes from household pets, so don’t share eating utensiles with your cats and dogs unless you eat first.