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
