Pathogenesis of IBD

Question 1

They are both _____ diseases and there is no single locus but susceptibility loci have been located on chromosomes 16 (IBD-1), 12, 6, 14, 5 , 19, 1, 16 (IBD-8) and 3

Answer 1

They are both polygenic diseases and there is no single locus but susceptibility loci have been located on chromosomes 16 (IBD-1), 12, 6, 14, 5 , 19, 1, 16 (IBD-8) and 3

Question 2

what specific gene has been associated with IBD?

Answer 2

NOD2/CARD15 gene on chromosome 16 g12

Question 3

Homozygotes have __ -___ fold increased risk of disease

Answer 3

Homozygotes have 20-40 fold increased risk of disease

Question 4

what does the NOD2 gene do?

Answer 4

encodes protein involved in bacterial recognition and hence contributes to normal mucosal defences

Question 5

There is altered bacterial flora in colons with UC and CD

• In UC there is an increase in ______ bacteria
• In CD there is an increase in ______ bacteria

Answer 5

There is altered bacterial flora in colons with UC and CD
In UC there is an increase in aerobic bacteria
In CD there is an increase in anaerobic bacteria

Question 6

Depending on the cytokines in the environment when a macrophage or dendritic cell presents the antigen to the T cells, the T cell will mature to different types

in ____ ____ IL-12 cytokines present so we get Th1 mediated disease

in ___ ____ Mixed Th1/Th2 mediated disease/NKTcells

Answer 6

1. crohn’s disease

2. ulcerative colitis

Question 7

immune response:
The pro-inflammatory cytokines released by the activated T cells stimulate ______s to release TNF alpha, IL1and IL6 in large quantities.

______s are also stimulated by plasmacytoid dendritic cells via NK cells which themselves also secrete inflammatory cytokines
These mechanisms all result in the migration of _______ from the lumen to the tissue to release chemokines.

Answer 7

he pro-inflammatory cytokines released by the activated T cells stimulate macrophages to release TNF alpha, IL1and IL6 in large quantities.
Macrophages are also stimulated by plasmacytoid dendritic cells via NK cells which themselves also secrete inflammatory cytokines
These mechanisms all result in the migration of leukocytes from the lumen to the tissue to release chemokines.

Question 8

Infectious agents (viral, mycobacterial) cause a similar pathology to ____ ____

Answer 8

crohn’s disease

Question 9

which IBD does smoking aggravate?

Answer 9

crohn’s but not UC