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28 Cards in this Set
- Front
- Back
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unexpected Ab
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i.e. anti Rh
formed only in response to exposure to a foreign Ag |
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primary immune response type of Abs
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IgM
10-14 days after exposure -don't cross placenta -5 day half life -bind C' and cause intravascular hemolysis |
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secondary immune response type of Abs
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IgG
-1-48 hours after exposure -cross placenta- can cross and cause hemolytic dz of newborn -21 day half life -may or may not bind C' and cause only extravascular hemolysis |
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anti-human globulin testing
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-reagent: polyspecific anti-human globulin (IgM, IgG, and/or C')
-attaches to human immunoglobins if they are coating RBCs to cause agglutination |
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Ab screen testing
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antihuman globulin used to detect Ab in pt's serum
-pt's serum added to reagent RBCs -if Abs present, the RBCs have the Ag -if Ab is IgG, very small, so adding antihum globulin will form a lattice and agglut will occur |
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direct antiglobulin test
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detect Ab coating pt's RBCs
-detect alloAbs or autoAbs -pt's RBCs with anithuman globulin reagent -if Abs present on pts RBCs, agglutination will occur |
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formation of ABH Ags on RBC membrane:
backbone |
H Ag: precursor carb chain/backbone for all blood groups (fucose to carb chain on RBC membrane)
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formation of ABH Ags on RBC membrane:
inherited enzymes: type A |
-A gene: N-acetylgalactoseaminyl transferase
adds: N-acetyl galactosamine |
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formation of ABH Ags on RBC membrane:
inherited enzymes: type B |
-B gene: galactosyl transferase
adds: galactose |
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formation of ABH Ags on RBC membrane:
inherited enzymes: type O |
no enzyme is formed and no further sugars are added to carb chain
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most common blood type to least
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OO
A B(asian and africa-american) least: AB |
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what does it mean to be Rh +
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possess RHD gene and express D Ag
+ 85% - 15% |
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RHCE gene
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encodes for C/c E/e Ags
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anti-D
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IgG Abs
-result from exposure to incompatible Ags from previous pregnancy or transfusion -80% of Rh- form anti-Ds |
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reverse testing
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agglut = not the blood type of mixed blood
mixing sample of pt blood with: type A blood (has anti-Bs) - if pt is type A they won't have agglut, if pt is type B, anti-Bs will cause agglut |
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forward testing
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agglut = blood type
mix pt's blood with anti-A serum: if type A the anti-As will cause agglut |
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blood components in whole blood (WB)
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each unit = packed RBCS, platelets, FFP or cryoprecipitate
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any component with a significant amount of RBCS must...
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ABO compatible
crossmatched to pts plasma |
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giving Whole blood provides
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oxygen carrying capacity, stable coAg factors, and blood volume expansion
-don't use in normocytic anemia -used in acute bleeding, exchange transfusion -1 WB unit = 400-500 mL -1 WB unit = 38-44% Hct -21 days after collection |
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RBC component
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-remove plasma
-must be < or = 80% Hct -42 days -restore or maintain o2 carrying capacity to meet tissue demands 1 unit= inc 1 g/dL [Hb] -filter, slowly, w/in 4 hours, nL saline |
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FFP
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-frozen within 8 hours of collection
-all coAg factors -frozen within 24 hours (used within 5 days) -nL coAg levels except for VIII -thawed plasma (use within 5 days -dec levels of VIII and V 1 mL plasma = 1 IU of CoAg factors |
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plasma effect
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1 unit = inc clotting factor by 2% (nL 30%)
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indications for plasma transfusions
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-active bleeding
-cong def of V, II, X, XIII -rev of warfarin -replacement when performing exchange for TTP |
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platelet products
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use within 5 days of collection
-pools of 4-6 units (50 mL each) -inc platelet count 5000-10000 uL |
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plateletpheresis or SDP effect
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separates blood components during collection and returns unneeded components to donor
unit = 200-400 mL inc platelet count by 30000-50000uL |
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platelet transfusion therapy indications
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-prophylaxis when <10000
-surgical pt if <50000 -dysfunctional platelets and evidence of bleeding |
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contraindications for platelet transfusion therapy
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TTP, HIT, ITP
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cryo contains
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no Abs/plasma
-fibrinogen (inc by 5 mg/dL) -factor VIII -vonwilibrand -factor XIII -fibronectin |
