MoD S3 - Chronic inflammation Flashcards
Define chronic inflammation
Chronic response to injury with associated fibrosis
List the four main cells involved in chronic inflammation and the role of each
Macrophage - phagocytosis, antigen presenting, stimulates angiogenesis, induce fibrosis, induce fever & acute phase response & cachexia
Lymphocytes‐ B type become plasma cells and produce antibodies, T type process antigens and are cytotoxic so kill cells
Eosinophils‐ attack large parasites, allergic reactions
Fibroblasts‐ produce connective tissue substances (collagen, elastin and glucosaminoglycans)
What are myofibroblasts?
Fibroblasts that have differentiated into cells capable of contraction
What are giant cells and when are they formed?
Macrophages fuse to form a single multinucleate cell
Frustrated phagocytosis
List the three types of giant cell, distribution of their nuclei and when each would be seen
Langhans‐ peripheral nuclei, tuberculosis
Foreign Body‐ nuclei arranged randomly, seen when hard to digest foreign body present
Touton‐ nuclei arranged in ring towards centre, form in lesions where high lipid content such as fat necrosis or xanthoma
What other cell type would touton giant cells contain?
Foam cells
How does chronic inflammation arise?
Take over or alongside acute inflammation
Without acute inflammation in chronic persistent infections or autoimmune conditions
How does fibrosis occur as an unwanted side effect or inflammation?
Cytokines stimulate fibroblasts to produce excess collagen
How does fibrosis lead to impaired organ function?
Fibrous tissue replaces normal parenchymal tissue thereby reducing organ function
List two other potential complications of chronic inflammation
Tissue destruction and atrophy
Define a granuloma
Body’s way of dealing with particles that are poorly soluble or hard to eliminate
What are epithelioid cells?
Macrophages that have been modified to look like epithelial cells as they are elongated, have eosinophilic cytoplasm and are tightly packed together
What are the two types of granuloma and when would each be seen?
Hypersensitivity/immune granuloma‐ develop around insoluble pathogenic particles that cause cell mediated immunity
Foreign Body granuloma‐ develop around material that is not antigenic
What would a hypersensitivity granuloma contain?
Macrophages, epithelioid cells, giant cells (Langhans), fibroblasts and lymphocytes
Undergo central necrosis
What would a foreign body granuloma contain?
Macrophages, epithelioid cells, giant cells (foreign body), some fibroblasts and few lymphocytes
