Chronic Inflammation Flashcards
Define chronic inflam
Chronic response to injury with associated fibrosis
What cell types are principally involved in chronic inflam?
Macrophage, lymphocytes, eosinophils, fibroblasts/myofibroblasts, plasma cells
What is the role of a macrophage?
phagocytosis,
presentation of antigens to immune system,
synthesis of complement components + clotting factors + proteases,
control of other cells via cytokines
What is the role of a lymphocyte?
B type (plasma cells) produce Abs,
T type involved in control and cytotoxic functions
Outline the function of an eosinophil
allergic reactions, parasite infestations
Describe the role of a fibroblast/myofibroblast
make collagen
What is the role of a plasma cell?
Diff B cell – now prod Abs
What is a giant cell?
Multinucleate cells made by fusion of macrophages = can’t phagocytose so fuse to form giant cell
What are the different types of giant cell and when are they found?
Langhans giant cell – TB – horse shoe nucleus,
Foreign body giant cell – foreign material,
Touton giant cell – occurs in fat necrosis
How can knowing the giant cell type be useful?
Giant cell tyoe may be a help to diagnose
When does chronic inflam arise?
After or alongside acute inflam,
Chronic persistent infections,
Autoimmune conditions,
Prolonged exposure to toxic agents
Name the possible complications of chronic inflam
Tissue destruction, Excessive fibrosis/scaring, Impaired function, Atrophy, stim of immune response (macrophage-lymphocyte interactions)
Name some clinical examples in which chronic inflam occurs
Rheumatoid arthritis (many plasma cells),
Ulcerative colitis: superficial + Crohn’s disease: transmural (IBD),
Chronic cholecystitis (repeated obstruction by gallstones),
Chronic gastritis (many lymphocytes),
cirrhosis
What is chronic cholecystitis?
repeated obstruction by gallstones = repeated acute inflam = chronic inflam – fibrosis of gall bladder wall
Define fistula
Abnormal connection between 2 epithelium-lined organs
When does chronic inflam lead to an increase in function?
Thyrotoxicosis – graves’ disease = Abs to TSH receptor = prod too much thyroxin
Define granuloma
organized collection of macrophages = collection of epithelioid histiocytes (modified immobile macrophage), surrounded by lymphocytes
When does granulomatous inflam occur?
persistent, low grade antigenic stim by foreign material, infect (TB, fungi), unknown
What are the major causes of granulomatous inflam?
foreign material,
infections (tuberculosis, leprosy, syphilis, aspergillosis),
unknown causes (sarcoidosis, Crohn’s disease)
If granulomas are present what should be your first thought?
Is this TB?
How does a tuberculous granuloma appears microscopically?
Caseous necrosis centre, epithelioid histiocytes surrounded by lymphocytes, langhans giant cell
Discuss the presentation and microscoptic appearance of RA
pres = joint pain, worse in the morning
microscopic = presence of immune cells
Discuss ulcerative colitis
pres = abdo pain weight loss, diarrhoea sometimes bloody
Dx = IBS, crohns, bowel cancer, diverticulitis
microscopic = distorted crypt
macroscopic = inflam limited to mucosa/submucosa of colon/rectal
complications = Severe bleeding, perforated colon, severe dehydration, liver disease, osteoporosis
Discuss crohns
pres = abdo pain weight loss, diarrhoea sometimes bloody, mouth sores
Dx = IBS, UC, bowel cancer, diverticulitis
microscopic = granulomas, transmural
macroscopic = discontinuous distribution of any part of GI tract, cobblestone bowel, fistulas
complications = Inflammation, bowel obstruction, ulcers, anal fissure, malnutrition, colon cancer
