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
What is irradiated blood?
Irradiated blood is blood that has been treated with radiation (by x-rays or other forms of radioactivity) to prevent Transfusion- Associated Graft-versus-Host Disease (TA-GvHD)
What is cytomegalovirus and who uses CMV neg blood?
Cytomegalovirus infection is a common herpesvirus infection.
people who are immunocompromised, such as people with HIV or AIDS, should be given CMV negative blood when needed.
What are Immunoglobulins (blood product wise)?
Normal immunoglobulins are solutions of human plasma proteins with broad spectrums of antibody activity. They treat patients with a range immune conditions.
What are specific immunoglobulins?
Specific immunoglobulins have high levels of specific antibodies and are used to treat or prevent specific conditions. ie: CMV, Hep B Tetnus, Anti-D
What is Albumin product therapy?
Albumin is the dominant protein in blood that helps to maintain the balance of fluid and carries important chemical around the body. It’s produced from pooled and fractionated human plasma. Used is patients with low albumin levels - cardiothoracic surgery or burns victims.
Explain clotting factors therapy.
Used to prevent or treat bleeding from specific deficiencies . Products have a single or combo of clotting factors
Should or Must
Lab ______ have clearly written policies on selection of red cells for transfusion
• Routine situations
• Emergency situations
must,
Should or Must
• Red cells________ be same ABO and Rh(D) group as recipient
• Group O red cells _____ be selected when patient’s ABO group cannot be determined
• Rh(D) negative cells _______ be selected when patient’s Rh(D) group cannot be determined
• Females of childbearing potential ______ receive red cells also matched for K
should, must, must, should
Should or Must
• When a clinically significant antibody has been identified (or a history of such an antibody exists), red cells ______ be negative for corresponding antigen
• Crossmatch compatible by IAT
• Antigen typing of donor units _________ be confirmed by the laboratory
should, should
When selecting FFP and Cryoprecipitate for transfusion is pretransfusion compatibility testing required?
No but ABO group should be confirmed
When FFP and Cryoprecipitate are selected Plasma products should be same ABO group as patient
If that is not possible -
ABO compatible products may be given
• Rh(D) groups are not relevant
Platelet concentrates should be of same ABO group as recipient. If unavailable, decision needs to be made on using what order of preference
• Order of preference is usually:
- ABO/Rh(D) antigen compatible (plasma incompatible)
- ABO/Rh(D) antigen incompatible (plasma compatible)
Patients expected to require long term transfusion
support • Eg. Sickle-cell disease, thalassemia, haematology-oncology patients
• Should have _______
an extended red cell phenotype performed prior to initial transfusion • E.g. Rh, K, Kidd, Duffy, Ss
Recipients of allogeneic haemopoietic stem cell grafts should receive what kind of blood products?
All cellular products must be irradiated
• Prevent graft versus host disease
• Also CMV negative where indicated
