Chronic Inflammation Flashcards
What is chronic inflammation?
prolonged inflammation with associated repair
Features of chronic inflammation
delayed variable duration variable appearance limits damage, initiate repair cause debilitating symptoms
when can chronic inflammation arise?
After acute (if resolution not possible) Alongside acute (persistent irritiation) De novo (by itself, eg. autoimmune conditions)
cells present in chronic inflammation
macrophage lymphocyte (B and T) plasma cells Eosinophils fibroblasts/myofibroblasts giant cells
macrophage name change
in blood - monocyte
in tissue - macrophage
macrophage appearance
large
lots of foamy cytoplasm
slipper shaped nucleus? (indented)
macrophage function
phagocytosis (remove pathogen/debris)
produce inflammatory mediators
antigen presentation
Lymphocyte appearance
small (similar little larger than RBC)
spherical nucleus
thin cytoplasm
T cell function
helper - assists other inflammatory cells
cytotoxic - destroy pathogens
B cell function
mature into plasma cells
produce antibodies
plasma cell appearance
eccentric nucleus (to one side) nucleus: clock face clumped chromatin (around outside) peri nuclear clearing (lighter patch around nucleus = golgi for antibodies)
plasma cell function
produce antibodies - its a mature B cell
Eosinophil appearance
bilobed nucleus
granular pink staining cytoplasm
tomato with sunglasses
eosinophil function
release mediators (granular cytoplasm) Hypersensitivity reactions (allergies and asthma) Parasitic (worm) infections
giant cells
fused macrophage
same cytoplasm, multinucleated
why do giant cells form?
when one macrophage cannot destroy pathogen alone
3 types of giant cells
foreign body
Langhan
Touton
foreign body giant cells
random nuclei distribution
surround foreign body
Langhans giant cell
usually tuberculosis
Nuclei is arranged around periphery
horse shoe nuclei pattern
Touton giant cell
Central organised nuclei
fat necrosis
What can cells in chronic inflammation indicate?
proportion of cells can indicate diagnosis
diagnosis for lots of plasma cells
Rheumatoid arthritis
Diagnosis for lots of lymphocytes
chronic gastritis
Diagnosis for lots of macrophages
Protozoal infection (Leishmaniasis)
effects of chronic inflammation
Fibrosis (collagen deposition)
Impaired function (rarely increased eg Graves)
Atrophy
Stimulation of immune response
Cholelithiasis
Repeated obstruction of bile duct from gall stones
Fibrosis (thickened and pale wall of gall bladder)
Repeated bouts of acute inflammation then becomes chronic
how does fibrosis appear H&E?
pale pin linear strands
Idiopathic inflammatory bowel disease effects and names
Crohns disease or Ulcerative colitis red and inflamed abdominal pain altered bowel motion weight loss rectal bleeding
Crohns disease features
Can affect all of GI
Discontinuous inflammation (skip lesions)
Inflammation affects full thickness (transmural) - can cause strictures (narrowing) or fistulae (connect to other tissues)
Granulomata
Less likely rectal bleeding
Ulcerative Colitis features
Only affects large bowel Continuous inflammation Only affects superficial bowel (mucosa and submucosa) No granulomata More likely rectal bleeding
Cirrhosis
End stage liver damage
Fibrosis (pale areas) with attempted regeneration (nodules)
causes of cirrhosis
alcohol
hepatitis
drugs/toxins
fatty liver disease
what is granulomatous inflammation?
Chronic inflammation with granuloma
what is a granuloma?
collection of epithelioid histiocytes
with surrounding lymphocytes
what is a epithelioid histiocyte?
Macrophages that looks like an epithelial cell
light pink and packed
types of granuloma
Foreign body
Immune mediated
Foreign body granuloma
destruction and removal of foreign material (surgical thread, implant, shrapnel)
few lymphocytes
Immune mediated granuloma
Destruction and removal of pathogens (bacteria/fungi)
Central necrosis can occur
can be idiopathic
MANY lymphocytes
Infections that often cause granuloma and why
Mycobacterium (mycobacterium tuberculosis, mycobacterium leprae)
Difficult destroy due to thick cell wall and mycolic acids (proteins on surface)
Specific features of mycobacterium granuloma
Epithelioid histiocytes
Central caseous necrosis
Many lymphocytes
Causes of granulomatous inflammation
Crohns (non caseating)
Sarcoidosis (non caseating) - lungs, skin and lymph
can cause nodules on skin, enlarged lymph nodes and breathlessness
