Acute phase proteins Flashcards
What does raised CRP suggest? Why?
It is an opsonin on microbes and marker of inflammation.
What does raised mannan-binding lectin suggest? Why?
Produced in the liver in response to infection. Raised because involved in mannan-binding lectin pathway of complement activation.
Why may clotting factors be raised?
Coagulation traps invading microbes in blood clots. Hence, they are acute-phase proteins.
Why is ferritin an acute-phase protein?
Microbes take up iron as part of their life cycle. Ferritin binds and stores iron intracellular to prevent this.
Why is hepcidin an acute-phase protein?
Stimulates the internalisation of ferroportin, preventing release of iron bound by ferritin within the intestinal enterocytes and macrophages. As such, less is available for microbes.
How and why is albumin an acute phase protein?
It is a negative acute-phase protein (decreases during inflammation). This is to save amino acids for producing positive acute-phase proteins more readily.
Why is ESR a less-reliable indicator of inflammation? (x2)
Its levels are largely dependent on elevation of fibrinogen (an acute-phase protein). In other words, it is a secondary marker of inflammation, as inflammation is not the primary mechanism for its rise. In addition, unlike CRP with a half-life of 6 hours, ESR has a half-life of one week. As such, it lasts in the blood longer, even after inflammation.
