Week 5 Flashcards
Autoantibodies may react with all or most of:
- Screening cells
- Recipient red cells
- Donor red cells
- ‘Pan-agglutination’
Indication of an autoantibody
- Many cells reacting in antibody screen/panel
- Positive autocontrol
- Positive DAT
- Anomalous ABO reverse group reactions
Specificity of autoantibody less important than
determining if it is masking an ___________
alloantibody
• If so, is the alloantibody clinically significant?
Adsorption is used to detect and investigate underlying _________ Adsorbed serum may also be used to _______ compatible units after
________ identification
alloantibodies, crossmatch, alloantibody
What are the Two types of adsorption
1, Autoadsorption: No transfusion in the last 3 months
• Autoantibodies are removed using patient’s own RBCs - Patient red cells are pre-treated with ZZAP (DTT + enzyme)
2. Allogenic (Differential) adsorption
• If transfused in the last 3 months
• Uses other cells with the patient’s serum
Adsorption is performed at __°C for WAIHA or __°C for CHAD
37, 4
When is elution useful?
Elution is useful when you want to investigate the cause of positive DAT (eg. Antibody
specificity in AIHA, transfusion reactions, HDNB
How does the Elution method work?
disturbing the Ag-Ab bond, allowing removal of
the antibody from the red cell membrane
Is Preoperative Autologous Donation recommended?
Not recommended • Risks when donating • Increased risk of pre-op anaemia • Associated with worse outcomes • Increases likelihood of transfusion
Why are white blood cells (leukocytes) removed from blood?
May reduce the risk for febrile transfusion reactions, may help prevent alloimmunizaton to MHC (HLA) donor antigens, and help reduce the risk for cytomegalovirus (CMV) infection.
What is FFP used to treat?
Treat coagulopathy in bleeding or at risk patients
Replacement of clotting factors eg in surgery
Warfarin overdose (with Prothrombinex)
What is the difference between FFP and Cryoprecipitate?
FFP contains coagulation factors at the same concentration present in plasma. Cryoprecipitate is a highly concentrated source of fibrinogen.
Cryodepleted Plasma
Cryodepleted plasma is the supernatant plasma left after removal of cryoprecipitate from fresh frozen plasma
Red cells are stored at 2 – 6 oC and can be transported at 2 – 10°C what are they used to treat?
Treat symptomatic anaemia
Replacement of blood loss
What are Platelets used for?
Treat bleeding due to severe thrombocytopaenia
Prophylactic use in chronic thrombocytopaenia
or
Pre-surgery in thrombocytopaenic