Transfusion Biology And Therapy Flashcards
The production of antibodies directed against antigenic determinants of another individual
Alloimmunization
First and most important blood group antigen system in transfusion medicine
ABO blood group system
Universal recipient blood type, with regards to RBC transfusion
Type AB
Universal donor blood type
Type O
Presence of this antigen confers Rh “positivity”
D antigen
Most common cause of incompatibility during pretransfusion screening
Antibodies to Lewis system
Used for the collection of multiple units of platelets from a single donor
Apharesis
How much hemoglobin and hematocrit increase to be expected in BT of 1 unit pRBC?
Increase by 10g/L hemoglobin and 3% hematocrit
Ideal blood component for patients who have sustained acute hemorrhage of >/= 25% total blood volume loss
Whole blood
An apharesis procedure done to patients with hemoglobinopathies by which sickled RBCs are replaced by donor RBCs
RBC Exchange
In normovolemic patients without cardiac disease, what is the cutoff hemoglobin content that can maintain adequate oxygenation?
70 g/L
Platelet count Threshold for prophylactic platelet transfusion, without invasive procedure
10,000 /uL
*50,000 /uL for invasive procedures
Signs of increased platelet consumption
Splenomegaly
Fever
DIC
Lowers risk of alloimmunization for those requiring multiple transfusions
Use leukocyte-reduced components
Blood component containing stable coag factors and plasma proteins: fibrinogen, antithrombin, albumin, protein C & S; used in warfarin reversal and TTP treatment
Freah frozen plasma (FFP)
Blood component with fibrinogen, factor VIII, vWF; ideal for supplying fibrinogen to volume-sensitive patient
Cryoprecipitate
2 types of transfusion reactions
1) immune-mediated: due to preformed donor/recipient antibody
2) nonimmune: due to chemical property of blood component
Test that detects the presence of antibodies (or complement) on the surface of erythrocytes
Direct Coombs (antiglobulin) test
Test that detects antibodies in the serum that may bind to donor erthrocytes
Indirect Coombs (antiglobulin) test
Most frequent reaction associated with transfusion of cellular blood components; characterized by chills and rigors and >1 deg Celsius rise in temp
Febrile nonhemolytic transfusion reaction
Severe allergic reaction presenting after few mL of BT; may present with DOB, couging, nausea/vomiting, hypotension, bronchospasm, shock
Anaphylactic reaction
Frequent complication of allogenic stem cell transplantation in which lymphocytes from the donor attack and cannot be eliminated by an immunodeficient host
Graft-versus-host disease
*Can be prevented by irradiation of cellular components before BT to patients at risk
BT reaction presenting with hypoxia and bilateral interstitial infiltrates during or within 6 hr; results from transfusion of donor plasma with high titer anti-HLA class II antibodies that bind to recipient leukocytes
Transfusion-Related Acute Lung Injury (TRALI)
Treatment for TRALI
Supportive; patients recover without sequelae
The only pretransfusion selection test to prevent RBC alloimmunization
Cross-matching (for RBC antigen)
How many units of RBC before Signs/symptoms of iron overload appear?
100 units RBC
