24. MAP in early onset CD 140 patients: 2 – 16 yrs age Prospective samples no medication Optimised DNA extraction Controlled, MAP specific PCR Long term culture for MAP (Kirkwood; Inflamm. Bowel Dis.2009) Bull, (2009) 0% 8% 16% PBMC PCR 0% 32% UC 0% 15% Non-IBD 40% 39% CD Biopsy Culture Biopsy PCR
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30. MAP and HD5 HD5 expression is significantly reduced in the gut of CD patients. HD5 inhibits entry of MAP into human macrophage cell lines NOD2 mutation leads to HD5 depletion leads to MAP infection? Bull, (2009)
31. MAP Detection “ The association of MAP and Crohn’s disease, based on PCR or ELISA testing is well established” MAP +ve are 7 fold more likely in CD than Normals 10 – 40% presence of MAP in Non-STERILE and STERILE samples from Normals MAP is chronically and actively invading humans Bull, (2009)
32. MAP culture and VNC phenotype Viable Non-Culturable (lag) phase increases with repeated cycles of heat shock. Bull, (2009)
33. MAP culture and VNC phenotype MAP infection into human macrophages leads to Viable Non-Culturable (VNC) phenotype. Bull, (2009)
34. MAP culture and VNC phenotype MAP becomes Viable Non-Culturable (VNC) on intracellular entry Some Crohn’s Disease therapies are inhibitory to culture Immunotherapy (which aggravates MTB infection) does not promote MAP growth Negative MAP culture is NOT necessarily indicative of Negative MAP infection CD patients on some long term therapies may not be suitable for MAP culture studies Bull, (2009)
35. Summary MAP can and does Infect and persist in Crohn’s patients Respond to anti-MAP therapeutics in Crohn’s patients Exploit CD susceptibility gene defects to promote chronic persistence Generate a Th17 biased immune dysregulation that COULD lead to Crohn’s Disease Bull, (2009)
36. Verdict Viable chronic MAP infection is present in most patients with Crohn’s Disease MAP infection can cause the immune dysregulation that is the major predisposing factor to the development of Crohn’s Disease Bull, (2009)
