Apheresis Flashcards
Erythrocytapheresis:
Erythrocytapheresis: Red Blood Cell Exchange. Replacement fluid of choice: RBC or RBC LR; if for polycythemia vera: colloid solution.
Leukocytapheresis:
Leukocytapheresis: Selective removal of white blood cells in disease states or for transfusion [stem cells, donor lymphocyte infusion (DLI), or granulocytes.] Replacement fluid: none or colloid/crystalloid. May need a sedimenting agent such as hydroxyethyl starch.
Thrombocytapheresis:
Thrombocytapheresis: Removal of platelets for Thrombocytosis. Replacement fluid: none or colloid/crystalloid.
Plasma Exchange (TPE):
Plasma Exchange (TPE): Removal of plasma. Replacement fluid: plasma, colloid or colloid/crystalloid; depends on the disease state.
Filtration Selective Removal:
Filtration Selective Removal: Plasma is separated from whole blood using a filter with a selective pore size. Used for plasma exchange, collection, or as a preliminary step to further process plasma on an immunoadsorption column. Replacement fluid: plasma, colloid or patient’s treated plasma
Immunoadsorption:
Immunoadsorption: passing the separated plasma over a column with an active component such as Staph Protein A to remove immunoglobulins. Replacement fluid: patient’s treated plasma
Extracorporeal photopheresis:
Extracorporeal photopheresis: removal of WBCs after patient treatment with photoactive psoralen, followed by treatment of WBCs with Ultraviolet A light, and reinifusion of the treated WBCs to produce an immunomodulative effect.
LDL Apheresis:
LDL Apheresis: removal of low-density lipoproteins using, various filtration or adsorption techniques.
TA Indication Catagories I-IV
- Therapeutic apheresis (TA) is standard and acceptable.
- TA is generally acceptable but not usually the primary treatment
- Possible benefit but insufficient evidence or supporting clinical trial.
- Controlled clinical trials have shown no benefit.
Frequent Plasma Donor:
A person donating more than every 4 weeks.
Must be at least two days between procedures.
No more than two procedures in 7 days.
Annual physical, total protein, protein electrophoresis and Ig levels are required.
Infrequent Plasma Donor:
Person who donates no more than one plasma donation in 4 weeks.
Donation Frequency for platelets (and granulocyte) donors
At least 48 hours between two procedures
No more than 2 procedures in 7 days
No more than 24 procedures per year
Platelet Count for donors
Platelet count
No count needed for first time donors or if interval is 8 weeks or more
Needed if more frequent than every 8 weeks
Post count from previous donation can be used
Pre-procedure >150,000
Previous donation in 4 weeks but post donation count less than 150,000
Leukocyte Reduction for blood components must reduce WBCs to:
< 5 x 10^6
Leukocyte Reduction for platelets must reduce WBCs to:
<8.3 x 10^6
Platelet by Apheresis QC requirements
3.10^11 platelets in 90%
pH >6.2 in 90%
If leukoreduced <5 x 10^6 in 95%
Which of the following statements regarding plateletpheresis donation is true?
a. Donors cannot donate more than 24 times per year
b. Donors cannot donate more frequently than every 56 days unless approval of the medical director is obtained
c. Donors must have a minimum platelet count of 150,000/ul to be eligible to donate without approval of the medical director
d. Donors must have abstained from ingested aspirin-containing products for at least 24 hours prior to donation in order to be eligible.
Correct: Donors cannot donate more than 24 times per year
Plateletspheresis donors cannot donate more than 24 times in a year.
Plateletspheresis donors do not have to wait 56 days in between donations.
The choice regarding the platelet count is not a true statement ALL of the time. The AABB standards does mandate that a sample is collected BEFORE the donation to determine the platelet count, but the platelet count is not required to qualify a first time donor. The testing for platelet count may occur at any time before, during or after the donation.
The choice that states that donors who ingest aspirin containing compounds must wait 24 hours is not true. They must wait a minimum of 48 hours before donating. In addition, donors who ingest clopidogrel and piroxicam must wait a minimum of 14 days before donating plateletspheresis.
The shelf life of a granulocyte component collected via apheresis is:
a. 24 hours
b. 48 hours
c. 3 days
d. 5 days
Correct: 24 hours
Granulocytes have a 24 hour outdate because of the fragility of the component. In addition, granulocyte transfusion is often a last-ditch kind of treatment when conventional antibiotic therapy is not successful.
The short outdate means that components are emergency released without the viral marker testing being complete. Typically the ABO, Rh and Antibody screen are done prior to release.
What is the purpose of performing Therapuetic Plasma Exchange (TPE) procedures?
a. removal of the plasma containing the pathologic substance, and infusion of replacement fluid.
b. collection of a 1 liter plasma component for transfusion.
c. Reducing the patient’s total blood volume
d. Replacement of vital plasma proteins in an immunocompromised patient.
Correct: removal of the plasma containing the pathologic substance, and infusion of replacement fluid.
Note:
Plasmapheresis refers to a procedure in which the plasma is separated from the blood either by centrifugation or membrane filtration. Once separated the plasma can be manipulated in a variety of ways. Plasma exchange refers to discarding the plasma totally and substituting a replacement fluid.
TPE is used in the treatment of various autoimmune diseases, conditions that cause the body to recognize a part of itself as foreign and generate proteins (called autoantibodies) that attack part of the body. These proteins are found in the plasma component of blood.
The question is asking about therapeutic plasma exchange. The word “exchange” should tell you that we need to remove something harmful and replace it, or exchange it, with a neutral fluid.
If we needed to reduce the patient’s blood volume, we might do therapeutic phlebotomy but we would NOT do an exchange.
Which granulocyte component below reflects the minimum standard for acceptability? (/uL)
a. 3.0 X 10^11
b. 5.5 X. 10^10
c. 1.0 X 10^10
d. 5.0 X 10^6
Correct: 1.0 X 1010
The question is asking which unit reflects the minimum standard, so you should select the component that has a count at the minimum requirement of 1.0 X 1010.
This may seem picky, but these QC numbers are critical for you to know for the SBB exam as well as for your career as an SBB. There may be times when a number is given to you and you will be the person who has to make the determination of whether or not the component is acceptable.
What is the purpose of administering Hydroxyethyl Starch (HES) prior to a granulocyte donation?
a. To protect the donor’s RBCs from hemolyzing
b. To hemolyze the RBCs in order to separate and collect the granulocytes
c. To improve the yield of granulocytes by enhancing RBC aggregation and sedimentation
d. To increase the amount of circulating granulocytes by mobilizing them from the marginal pool
Correct: to improve the yield of granulocytes by enhancing RBC aggregation and sedimentation
Hydroxyethyl starch is sometimes given to WBC pheresis donors to promote the harvest of WBCs with minimal RBC contamination.
HES is used as a physical means to promote cell separation and is NOT stimulating more granulocytes to be produced by the donor.
Granulocyte Stimulating Colony Factor (GSCF) can also be administered to donors prior to donation and THAT solution will increase the release of granulocytes so that the total number of circulating granulocytes is increased, and in turn, may enhance the collection during donation.
Corticosteroids are also agents that cause more granulocytes to be released from the periphery.
Plasma removed from patients undergoing therapeutic plasma exchange may be ______?
a. Used for transfusion as FFP if the donor qualifications and component preparation standards are met.
b. Sold for further manufacturing
c. Reinfused to the patient
d. Discarded
Correct: discarded
TPE and plasmapheresis are not the same but similar. See below for differences. The key word is therapeutic plasma exchange. The plasma is beging removed following plasmapheresis.
The plasma removed as part of TPE is considered part of the treatment process, and as such may not be transfused or sold. Remember that the patient undergoing TPE is receiving a treatment and as such is not being assessed in any way for donor suitability.
Note:
Plasmapheresis refers to a procedure in which the plasma is separated from the blood either by centrifugation or membrane filtration. Once separated the plasma can be manipulated in a variety of ways. Plasma exchange refers to discarding the plasma totally and substituting a replacement fluid.
During the process of apheresis, using centrifugation to separate blood components, which component is locate the farthest from the axis of rotation?
a. Plasma
b. Platelets
c. Lymphocytes
d. Red Cells
e. Granulocytes
Centrifugall force separates the various components of blood according to their specific gravity (density). The densest components collected the farthest from the axis of rotation, while the least dense layer collects the closest. The order of the layers of separation from the axis of rotation outward is plasma, platelets,lymphocytes, granulocytes and red cells. Red cells and granulocytes have an overlap in densities resulting in poor separation. This is why granulocyte products contain large numbers of red cells. Greater separation can be achieved by the addition of hydroxyethl starch. This aggregates the red cells, resulting in their having a greater density than the granulocytes.
Which blood component is removed during a leukapheresis procedure?
a. Red Cells.
b. Buffy coat.
c. Platelet rich plasma.
d. Plasma.
Specific plasma protein.
During a leukapheresis procedure, the buff coat is removed from the patient’s blood. The buffy coat is also removed during an extracorporeal photopheresis procedure; however, this buffy coat is reinfused to the patient after treatment with a psoralen compound and UVA light.