Immunopathogenic Mechanisms of IBD Flashcards
What is a chronic relapsing idiopathic inflammation of the GI tract?
IBD
IBD is a term used to describe what two disorders that involve chronic inflammation of the gastrointestinal tract?
1) Ulcerative colitis
2) Crohn’s disease
Ulcerative colitis is characterized by chronic inflammation and?
Ulcers in the innermost lining of the colon and/or rectum
Crohn’s disease is characterized by inflammation of?
Where may it occur?
However, in 40% of patients with CD, what is spared from inflammation in contrast to its universal
involvement in UC?
1) The lining of GI
2) Any part of GI
3) The rectum
Patients with IBD have been shown to have increased permeability of?
This is caused by impaired formation of?
1) Epithelial barrier
2) Tight junctions
What has been invoked to explain an increased incidence of IBD?
Hygiene hypothesis
What does the increased intestinal barrier seen in IBD cause?
Commensal bacteria to cross mucosal barrier and induce both innate and adaptive immunity
Disruption of the barrier function is seen with what form of IBD?
Dysfunction of microbe sensing is seen with what form of IBD?
Changes in immune regulation of innate and adaptive immune response is seen with what form of IBD?
1) UC
2) CD
3) Both
Abdominal pain, obstruction, and fever are signs and symptoms of what IBD condition?
Bloody diarrhea urgency are signs and symptoms of what IBD condition?
1) CD
2) UC
Pseudopolyps, toxic megacolon, and mucosal/submucosal inflammation describes the pathology of what IBD condition?
Abscesses, fistulas, stictures, granulomas, and transmural inflammation describes the pathology of what IBD condition?
1) UC
2) CD
Which form of IBD shows string sign on barium x-ray and cobblestone appearance on endoscopy?
Which shows lead-pipe colon?
1) CD
2) UC
A patient with CD will be positive for what Ab?
A patient with UC will be positive for what Ab?
1) ASCA
2) pANCA
A patient that is positive for ASCA and negative for pANCA test have what condition?
CD
With IBD, the low concordance rate in identical twins (~50% for CD, and ~10% for UC) suggests the importance of?
Environmental factors
IBD develops in areas of?
High bacterial concentration such as terminal ileum and colon
What class of drugs have beneficial effects on IBD?
Antibiotics and probiotics
Circulating Abs against what antigens are detected in IBD?
What cells show reactivity against these Ags?
1) Fecal bacterial Ags
2) Lymphocytes
What component of gut microbiome dominants in UC?
What component dominants in CD?
1) Proteobacteria
2) Firmicutes and Actinobacteria
How do infants born from IBD women present in terms of their intestinal microbiota?
Low bacterial diversity and altered bacterial composition
In terms of diet, what is important for maintenance of normal microflora?
Fiber intake
If there is disruption in microflora composition, what takes place?
Dysbiosis which leads to immune dysregulation and inflammation of lamina propria (IBD)