IBD Flashcards
Describe coeliac disease
Allergic response + autoimmune disease
Abdominal pain, diarrhoea
What are the histological features of coeliac disease?
Loss of villi
Increase in renewing epithelial cells
Severe inflammation
Describe immune recognition of coeliac disease
Gluten seen as foreign antigen
CD4+ T cells produced by α-gliadin
Converts glutamine to glutamic acid
What is human leukocyte antigen region?
Encodes many genes involved in autoimmunity
What are the inflammatory bowel diseases (IBDs)?
Crohn’s disease
Ulcerative colitis
Describe CD
Inflammatory lesions = transmural = involve all layers of intestine
Chronic + episodic
Obstruction + fistulation
What are the anatomical features of mucosal immune system?
Intimate interactions between mucosal + lymphoid
Compartments of lymphoid tissue - tonsils
Specialised antigen uptake mechanisms
What are the effector mechanisms of mucosal immune system?
Memory T cells
Effector/regulatory cells
Secretory IgA ABs
Distinctive microbiota
Why is microbiota important?
Influences development of mucosal tissue + immune system
What is the organisation of mucosal immune system?
Immune cells scattered throughout intestinal mucosa
2nd lymphoid tissues close to circulation
Describe how CD works
Bacterial antigens penetrate gut epithelium
Defective innate immune response + impaired clearance
Prolonged adaptive immune response
Granuloma formation
Damage mucosa
Describe UC
Genes implicate epithelial dysfunction
What helps UC?
Smoking
Describe gout
Inflammatory arthritis
Caused by hyperuricemia (excess uric acid)
Most prevalent in men
Diet is risk factor
Where is gout most common?
Influences by age + gender
What is primary gout?
Genetic factors involve genes involved in uric acid production + excretion
What is secondary gout?
Iatrogenic factors, eg. medications, inhibit uric acid excretion
Describe pathogenesis of gout
UA engulfed by phagocytic cells BUT not phagocytosed effectively
= crystals pierce cells
= release of lysosomal enzymes
= release macrophage contents
Describe type 1 diabetes
Autoimmune disease
Mediated by cytotoxic T cells
Describe type 2 diabetes
Metabolic disorder
Increased blood glucose levels = abnormalities in insulin secretion
Describe what happens with T2DM disease
Excessive levels of glucose stress islets
= release of cytokines + chemokines
= immune cells recruited
= local tissue inflammation
= released cytokines + chemokines enter circulation + promote inflammation
