IBD IBD Pathophysiology 2 β Questions and Answers
Question 1: Which immune cell type is primarily responsible for the IL-17 driven response seen in IBD?
- Th1 cells
- Th2 cells
- Th17 cells (Correct answer)
- Treg cells
Correct answer: Th17 cells
Th17 cells produce IL-17 and contribute to the mucosal inflammatory cascade, particularly in Crohn's disease pathogenesis.
Question 2: What is the role of regulatory T cells (Tregs) in IBD pathogenesis?
- They amplify the inflammatory response
- They suppress excessive mucosal immune activation (Correct answer)
- They produce TNF-Ξ± directly
- They destroy intestinal goblet cells
Correct answer: They suppress excessive mucosal immune activation
Tregs normally suppress excessive immune activation in the gut mucosa; their dysfunction or deficiency contributes to the uncontrolled inflammation seen in IBD.
Question 3: Which barrier function is disrupted in IBD, leading to increased intestinal permeability?
- Mucus layer and tight junctions (Correct answer)
- Peyer's patches only
- Muscularis mucosae
- Mesenteric lymph nodes
Correct answer: Mucus layer and tight junctions
Disruption of the mucus layer and tight junction proteins (e.g., claudins, occludin) increases intestinal permeability, allowing luminal antigens to trigger inflammation.
Question 4: In UC, the histological finding of 'crypt abscesses' involves accumulation of which cells within crypts?
- Lymphocytes
- Eosinophils
- Neutrophils (Correct answer)
- Plasma cells
Correct answer: Neutrophils
Crypt abscesses in UC are characterized by neutrophil accumulation within the crypts of LieberkΓΌhn, reflecting acute active inflammation.
Question 5: The mesenteric 'fat wrapping' (creeping fat) is a gross pathological feature of which IBD condition?
- Ulcerative colitis
- Microscopic colitis
- Crohn's disease (Correct answer)
- Diversion colitis
Correct answer: Crohn's disease
Creeping fat β mesenteric adipose tissue wrapping around the bowel β is a macroscopic hallmark of transmural Crohn's disease inflammation.
Question 6: Which environmental factor has been most consistently shown to be protective against ulcerative colitis?
- High-fiber diet
- Cigarette smoking (Correct answer)
- Urban residence
- Appendectomy in childhood
Correct answer: Cigarette smoking
Paradoxically, cigarette smoking is protective against UC, with ex-smokers at higher risk of developing UC than current smokers.
IBD IBD Pathophysiology 2
Which immune cell type is primarily responsible for the IL-17 driven response seen in IBD?