7 - Chronic Inflammation Flashcards
Acute inflammation signs
Fast onset
Neutrophil presence
Mild, self-limiting tissue injury
Prominent signs
Chronic inflammation signs
Slow onset: days
Subtle signs
Macrophages + lymphocytes
Severe progressive
Primary chronic causes - infection
TB, Leprosy, some viruses
Primary chronic causes - endogenous materials
Necrotic adipose tissue, uric acid crystals
Primary chronic causes - exogenous materials
External origin
Asbestos fibres, sutures, implanted prostheses
Primary chronic causes - autoimmune
RA
SLE
Pernicious anaemia
Primary chronic causes - primary granulomatous
Crohn’s
Sarcoidosis = granulomas collecting in organs
Primary chronic causes -
infection endogenous exogenous autoimmune primary granulomatous
Chronic inflammation - morphological features
Infiltration with mononuclear cells (macro, lympho, plasma)
tissue destruction
healing by fibrosis
Chronic inflammation - macroscopically
Dependent on the actual disease
Chronic abscess cavity or granulomatous or fibrosis
Chronic inflammation - microscopically
cellular infiltrate of lymphocytes, plasma cells and macrophages
exudation if fluid is not prominent
production of new fibrous tissue from granulation tissue
Mast cells produce what
Histamine
Wound healing involves
Granulation tissue
Angiogenesis
Fibroblasts deposit collagen
Inflammatory cells
Granulation tissue is
New connective tissue and blood vessels that form on the surface of a wound during healing
Fibrosis is
Formation of excess fibrous connective during repair of damaged tissue
Scarring
Called fibroma if arises from one cell line
Macrophage induced laying down of connective tissue inc. collagen
What is a granuloma?
Aggregate (nodule) of epithelioid histiocytes and other cells; lymphocytes and histiocytic giant cells
Granulomatous diseases inc.
TB & leprosy
What is a histiocytic cell?
Can form where material is indigestible to macrophages e.g. tubercle bacilli which have cell walls resistant to macrophages
How do histiocytic cells form?
They’re multinucleate giant cells which develop when 2+ macrophages try to engulf same particle.
Do all granulomas have giant cells?
No, solitary giant cells in the absence of epithelioid histiocytes is not a granuloma
Granulomatous disease
Bacterial - TB, leprosy Parasitic - schistosomiasis Fungal - cryptococcus Synthetic materials - silicosis Unknown - sarcoidosis, crohn's
Histology of granuloma types
Langhans giant cell
Caseous necrosis
Epithelioid macrophages
