Flashcards in 17. Acute-phase reactants Deck (15):
Acute phase reactants- definition
Factors whose concentrations change significantly in response to inflammation
Acute phase reactants produced by (when, and induced by)
produced by liver in both acute and chronic inflammantory states
Notably induced by Il-6
Acute phase reactans - types and the way they change
Up regulated 1. CRP
5 Serum amyloid
C- reactive protein - function and clinical relevance
1. opsonin (enhances phagocytosis)
2. Fixes the complement
--> Measured clinically as a sign of ongoing inflammation
Ferritin - function
Binds and sequesters iron to inhibit microbial iron scavenging
Fibrinogen - function (as acute phsae reactant
1. coagulation factor
2. promotes endothelial repair
decreases iron absorption (by degradinf ferroportin) and decreases iron release (from macrophages ) --> anemia of chronic disease
serum amyloid prolonged elevation
conserves AA for postitive reactants
internalized by macrophages to sequester iron
• Where are acute-phase reactants produced, and which cytokines induce serum level changes?
Liver; IL-6, IL-1, interferon-γ & tumor necrosis factor-α
• A woman with severe lupus has chronic anemia. What is the function of the acute-phase reactant that is most likely responsible?
Hepcidin is upregulated and prevents release of ferritin-bound iron, resulting in anemia of chronic disease with inflammation
• A woman with rheumatoid arthritis has decreased serum albumin. What will measurements of her amino acid metabolism (hint: allocation) show?
Amino acids will be diverted to the production of positive reactants (serum amyloid A, C-reactive protein, ferritin, fibrinogen, hepcidin)
A biopsy of a man with rheumatoid arthritis shows extracellular fibril deposition. What acute-phase reactant is present in these fibrils?
Amyloid A (persistent elevation of serum amyloid A with chronic inflammation can lead to amyloidosis)