Immuno-Patho of IBD Flashcards
IBD
Inflammatory Bowel Disease
Disorders of IBD
Ulcerative Colitis and Crohn’s Disease
Ulcerative Colitis
chronic inflammation and ulcers in innermost lining of colon and/or rectum
Crohn’s Disease
inflammation of lining of GI which often spreads deep and may occur in any part of the GI
How does the epithelial barrier of the GI tract change in patients with IBD?
increase in permeability caused by impaired formation of tight junctions
How are inflammatory responses induced in patients with IBD?
bacterial components cross the mucosal barrier and induce innate and adaptive immune responses
IBD develops as a result of…
persistent and inappropriate pertubation of the immune system and commensal bacteria resulting in dysbiosis and mucosal inflammation
Aberrant responses in UC
disruption of barrier function and changes in immunoregulation
Aberrant responses in CD
dysfunction of microbe sensing, changes in immunoregulation
Signs and Sxs of CD
abd pain, obstruction, fever
Lab test for CD
ASCA-positive, Anti-Saccharomyces Cerevisiae Abs
Signs and Sxs of UC
bloody diarrhea, urgency
Lab test for UC
pANCA-positive, perinuclear Anti-Neutrophil Cytoplasmic Abs
Causes of IBD
genetic susceptibility, luminal microbial antigens and adjuvants, immune response, environmental triggers
Environmental factors that trigger IBD
smoking, diet, drugs, geography, stress, microbes and enteric flora, permeability, appy
Functional roles of gut microbiota
protection, facilitation, provision of immunologic surveillance signals
Where does IBD develop?
areas of high bacterial concentration, terminal ileum and colon
Lymphocytes from IBD patients show reactivity against what antigens?
fecal antigens
Classification of bacteria found in proximal GI tract
aerobic and facultative anaerobic bacteria
Classification of bacteria found in distal GI tract
obligate anaerobic bacteria
Gut microbiome is primarily composed of what species
Firmicutes, bacteroidetes
Major Firmicutes Spp. in microbiota
Clostridium, Lactobacillus, Eubacterium
Major Bacteroidetes Spp. in microbiota
Bacteroides, Prevotella
Major bacteria present in UC
proteobacteria
Major bacteria present in CD
actinobacteria, firmicutes
How is the microbiota of babies born from IBD women different from those not?
lower bacterial diversity and altered bacterial comp
What factors control the microflora composition?
host genetics, maternal transfer, abx, infection, inflammation, age, diet, obesity
How does a high fiber diet impact microbiota?
increases levels of bacteroidetes, firmicutes and actinobacteria, decreases proteobacteria
How does a high protein diet impact microbiota?
increases bacteroidetes, firmicutes, and proteobacteria