Plasma Cascades Flashcards Preview

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Flashcards in Plasma Cascades Deck (10):
1

Hageman factor (factor XII) initiates a cascade to produce what?

1) Bradykinin

2) Complement (C3a, C5a)

3) Clotting factors (thrombin, plasmin, fibrin)

2


Sensor for Classical, Lectin, Alternative Pathways


Classical: C1q

Lectin: MB-Lectin or Ficolin

Alternative: C3(H2O)

3


C3 convertase for Classical, Lectin, Alternative Pathways


Classical: C4b2a

Lectin: C4b2a

Alternative: C3(H2O)Bb or C3bBb

4

C5a (anaphylotoxin)


Chemotaxis for leukocytes

Edema (Increase vascular permeability)

Release histamine from mast cells

5


C3a (anaphylotoxin)


Edema (Increased vascular permeability)

Release histamine from mast cells

6


What are the three results of complement?


1) Recruit inflammatory cells (using C5a, and indireclty...C3a)

2) Opsonize (using C3b on surface)

3) Membrane attack complex

Note: complement good for encapsulated bacteria (ie Neisseria)

7


Protease Inhibitor


Inhibits effects of inflammatory proteases outside areas of inflammation

Alpha1 protease inhibitor (Alpha1-antitrypsin): inhibits elastase in the lung (smoking inhibits Alpha1-antitrypsin so you get too much breakdown of elastin = emphysema)

C1 inhibitor: inhibits plasma kallikrein and C1s (deficiency causes inflammation = hereditary angioedema)

However, alpha2-macroglobulin deficiency doesn't cause anything bad to happen

8


DAF


Displaces Bb from C3b (alternative pathway)

Displaces C2a from C4b (classical and lectin pathways)

9


CD59 (protectin)

Prevents formation of membrane attack complex

10


C-reactive protein


Measured in clinic, if high means inflammation

Initiates binding of complement

(Specifically binds C-polysaccharide of S. pneumoniae)