23 - Inflammation and Healing III - Chronic Inflammation Flashcards
Ways that chronic inflammation can arise 1) 2) a) b) c)
1) Can follow acute inflammation 2) Possible insidious onset from: a) Some infections b) Autoimmune diseases c) Repeated/prolonged exposure to potentially toxic agents (EG: asbestos)
Examples of disease processes that involve chronic inflammation 1) 2) 3) 4)
1) Tuberculosis 2) Atherosclerosis 3) Viral hepatitis 4) Fibrosing lung diseases
Macrophage appearance in histological stain
Single nucleus Nucleus is on one side of cell.
Different appearances of macrophages 1) 2) 3)
1) If phagocytose fat, become ‘foamy cells’ 2) If phagocytose carbon, have dark pigment in cytoplasm (but not much inflammation) 3) If phagocytose blood, produce heamosiderin
Disease where foamy cells are common
Atherosclerosis
Key cells in diagnosing granulomatous inflammation
Epithelioid macrophages, giant cells
Giant cells
Multinucleate macrophages. Very large
Histological appearance of lymphocytes
Large nucleus, narrow ring of cytoplasm surrounding it
Histological appearance of plasma cells 1) 2) 3) 4) 5)
1) Large nucleus on one side of cell. 2) Cell is ovular. 3) Pale area beside nucleus (paranuclear hof) 4) ‘Clockface chromatin’ 5) Purplish cytoplasm, as there is so much RNA in cytoplasm
Paranuclear hof
In a plasma cell an area of slightly paler cytoplsm beside nucleus. Where Golgi apparatus is. Stains less intensely than surrounding cytoplasm
Clockface chromatin
In a plasma cell. Chromatin is distributed around edge of plasma cell
Eosinophil histological appearance
Bilobar nucleus
Germinal centre histological appearance
Circles of slightly lighter material.
Primary follicale
B cells haven’t been exposed to cognate antigen. In lymph nodes, GALT
Secondary follicle
Activated B cells differentiating into plasma cells and memory cells
Difference between granulomatous inflammation and a granuloma
A granuloma is an area of granulomatous inflammation with a clearly delineated boundary of fibrous tissue.
Types of granulomatous inflammation
Immune and foreign body
What does granulomatous inflammation develop in response to?
Certain persistent or non-degradable antigens
Types of infections that area more likely to lead to granulomatous inflammation
Intracellular bacteria. Never viral.
Histological appearance of necrosis
Very eosinophilic
How can chronic rheumatic valve disease occur?
Strep infects airways, gets to heart. Fibrotic thickening of chordae tendinae occurs.
Examples of disease in which granulomatous inflammation occurs 1) 2) 3) 4)
1) Infection (syphilis, TB, leprosy, fungal, parasitic) 2) Unknown aetiology (Crone’s, sarcoidosis) 3) Lymphomas 4) Deposition of irritants (sutures, uric acid crystals, keratin)
Type of hypersensitivity that is granulomatous inflammation
Type IV hypersensitivity
How does granulomatous inflammation start?
Macrophages detect antigen, release: IFNg - Macrophage activation IL-2 - Th1 activation
Local effects of TNFa 1) a, b 2)
1) Inflammation a) Vascular effects - increased leukocyte adhesion molecules, IL-1, chemokine production, increased procoagulant, decreased anticoagulant activity) b) Leukocyte effects - Activation, production of cytokines 2) Repair - Fibroblast proliferation, collagen production
Acute phase proteins produced by hepatocytes 1) 2) 3) 4) 5)
1) C-reactive protein (CRP) 2) Fibrinogen 3) Serum amyloid A protein 4) Complement factors 5) Hepcidin
Erythrocyte sedimentation rate
Increased fibrinogen content leads to increased erythrocyte sedimentation. Test is placing RBCs in tube, see how quickly they sediment
Effect of prolonged serum amyloid A protein
Secondary amyloidosis. Deposits of amyloid in organs can damage them (EGL kidneys)
Effect of chronically elevated hepcidin
Reduces available iron for haemoglobin production. This can result in chronic anaemia
Effects of excessive IL-1, IL-6 and TNFa levels
Systemic endothelial dilation, shock
Cell type pointed to by arrow
Macrophages
What does this picture show?
GRanulomatous inflammation, with giant cell around hair.
Which cell type does this pictvure show?
Lymphocytes
Cell types displayed in this picture
Plasma cells (black)
Eosinophils (orange)
What are displayed in this picture?
Germinal centres
