Apheresis [ done ]
photopheresis
Utilizes leukapheresis to collect the buffy coat layer from WB used for the treatment of cutaneous T cell lymphoma - treated with 8- methoxypsoralen (8-MOP) - exposed to ultraviolet A (UVA) light then re-infused
why are hematopoietic stem cells commonly used prior to HPC collection?
increase # of circulating stem cells in PB
what is therapeutic plasma exchange?
removal and retention of the plasma, with return of all cellular components - removal of an offending agent in the plasma - replacing a normal factor or substance that may be missing/deficient in the patient's plasma effective tool to remove IgM antibodies
HPC apheresis definition
removal of HPCs - also referred to as PBSC (PB stem cells)
erythrocytapheresis definition
removal of RBCs
plasmapheresis def
removal of plasma
plateletpheresis definition
removal of platelets
leukapheresis definition
removal of white blood cells (WBCs) - in donors, granulocytes are collected - in patient, removal of granulocytes and lymphs
what is the therapeutic goal of RBC exchange (erythrocytapheresis)?
remove incompatible RBCs from patient's circulation
Erythrocytapheresis
removes a large number of RBCs from the patient and return the patient's plasma and platelets with compatible allogeneic donor RBCs - most commonly used to reduce complications of sickle cell disease (reduce hgb S to less than 30%)
separation of blood components is based on ?
specific gravity or weight of each constituent
leukapheresis is used for ?
treat patients with hyperleukocytosis
RBC donation
typically collected as a double unit - 2RBC, double red, or double RBC procedure - reduces donor exposure for recipient - both autologous and allogeneic - saline infused during to account or blood loss
what are the two common methods of centrifugation and compare
Intermittent Flow Centrifugation (IFC) - processed in batches (or cycles) - single- needle procedure with one venipuncture site - instrument: Haemonetics MCS plus Continuous flow centrifugation (CFC) - blood withdrawal, processing, and reinfusion performed simultaneously - two venipuncture sites - instruments: COBE spectra, Baxter/Fenwal Amicus
frequency of plasma (infrequent) donation
every 4 weeks, no more than 13 times/year
frequency of platelets, double or triple
every 7 days
The most common fluid replacement for TPE is __________________
5% human albumin
one WB platelet should increase the adult patient's platelet count to
5,000-10,000
platelets are leukoreduced; so they must contain less than __________ WBCs per unit
5.0 x 10^6 /µL
each unit of platelets from WB (RDPs) must contain at least _____ platelets
5.5 x 10^10
the concentration of most plasma substances is reduced by _________ after one standard plasmapheresis treatment
50-60%
If one RBC and one plasma/platelet product are collection, how long must the donor wait to donate another RBC product?
56 days
apheresis platelets provide the equivalent of __________ units of WB-derived donor platelets
6-8
the patients extracorporeal blood volume (ECV) should be ______% of the total blood volume (TBV) in order to minimize risk of hypovolemia
<15%
leukapheresis is defined as a WBC or blast count of
>100,000
What is the rationale for therapeutic apheresis (TA)?
A pathogenic substance exists in the blood that contributes to a disease process or its symptoms. Said substance can be more effectively removed by apheresis than by the body's own mechanisms
Apheresis definition
A procedure where whole blood is removed from the body and passed through an instrument that separates out one or more blood components. The remaining portion is returned to the individual - patient or blood donor
membrane filtration technology
Alternative method for plasma collection only - membrane separators are typically composed of bundles of hollow fibers or flat plate membranes with specific pore sizes - pores can be sized to prevent the passage of even small cellular elements Advantages - cell-free product - ability to selectively remove specific plasma proteins
what type of centrifugation requires two venipuncture sites?
Continuous flow (CFC)
what are the side effects of the RBC sedimenting agent, hydroxyethyl starch (HES)?
Headaches, peripheral adema
frequency of granulocyte donation
every 2 days
frequency of plasma (frequent) donation
every 2 days (no more than 2 times in 7 days)
what three effects may be impactful on the donor's body when donating for apheresis?
- anticoagulation - fluid shifts - cellular loss
variables for consideration
- centrifuge speed and diameter - dwell time of the blood in centrifuge - type of solutions added - cellular content or plasma volume of the patient/donor - leukoreduction occurs during apheresis process
what are most deaths from during therapeutic apheresis?
- circulatory overload (cardiac arrest or arrhythmia)
adverse effects of apheresis
- citrate toxicity - vascular access difficulties (catheter insertion) - vasovagal reactions (fainting) - hypovolemia - allergic reactions - hemolysis
what is the criteria for a granulocyte donation?
- infection for 24-48 hours that is unresponsive to treatment - myeloid hypoplasia of bone marrow - chance for bone marrow recovery
what are the clinical considerations for TPE (therapeutic plasma exchange)?
- overproduction of specific monoclonal antibodies or polyclonal antibodies
combined IFC and CFC
- single platform - draw/reinfusion (IFC) - centrifuge (CFC) - allowed for concurrent collection of blood components and leukkoreduction - instrument: Caridian BCT Trima, Baxter/Fenwal Alyx
what patient population benefits from granulocyte donations?
1. Neutropenic neonates with sepsis 2. Patients who underwent aggressive chemo (neutropenic)
what are the 4 indication categories for TA?
1. apheresis is standard and acceptable in primary therapy (first-line) or with other therapies 2. generally accepted in a support role or second-line treatment 3. decision making should be individualized 4. clinical applications should be based on approved research protocol
granulocyte apheresis must have a minimum therapeutic dose of _______ per day
1.0 x 10^10
Per AABB standards, the extracorporeal blood volume should not exceed ______ mL/kg of body weight
10.5 mL
what is the maximum L for plasmapheresis?
12L or 14.4L for donors over 175lbs
frequency of double RBC donation
16 weeks (112 days)
Each apheresis of plasma is the volume equivalent of at least ______ whole blood derived plasma units
2
one plateletpheresis should increase the adult patient's platelet count to
20,000-60,000
Platelet donors have an acute fall of _________ for cellular loss
20-29% - greater in female donors - considerations: mobilization of platelets from the spleen
a pool of 4-6 RDP units will contain roughly _______ platelets
3 x 10^11
plateletpheresis component is prepared from one donor and must contain a minimum of ______ platelets
3 x 10^11
What is the HCT requirement for double RBC donation (RBC apheresis)?
40% - quantitative method used to determine hgb and hct levels (no copper sulfate method)
how long is an aspirin deferral for plateletpheresis?
48 hours
frequency of donation for single platelets
every 2 days (not more than 2 times in 7 days, no more than 24 times per 12- month period)
Effects of anticoagulants
acid citrate dextrose is the primarily used anticoag - binds to calcium ions to inhibit Ca-dependent coag cascade - metabolized by liver, kidney, and muscles - previously bound calcium ions are released back into blood stream donor management - chills (provide blanket) - possibly give oral calcium tablet
vascular access
adequate vascular access is mandatory - peripheral veins, central veins, or a combination of both the patient must have adequate veins at TWO sites capable of accommodating a 16-18 gauge needle
Effects of fluid shifts
changes in intravascular volume occurs secondary to removal of blood - without infusing donor with additional fluid, donor may experience hypotension and an increased heart rate - hypovolemic reactions involve the sympathetic nervous system (not commonly encountered due to extracorporeal restriction of 10.5 mL/kg) - vasovagal reactions involve the parasympathetic nervous system (decreased heart rate)
who is most at risk for hypovolemic (volume depletion) considerations?
children and elderly individuals
Cytapheresis procedures vs plasmapheresis procedures
cytapheresis - selectively removes RBCs, WBCs, and/or PLTs plasmapheresis - removes plasma when a pathological substance is found in circulation
granulocyte donors see a drop in HCT of _____ and PLTs by ____%
drop in HCT of 3% drop in PLT of 22%
methodology of apheresis
modern apheresis instruments utilize a computerized control panel, allowing the operator to select the desired component to be collected or removed onboard optical sensors - detect specific plasma-cell or cell-cell interferences - divert component to specific bag disposable equipment - sterile single tubing sets, bags, and collection chambers duration - 45-120 minutes - HPCs can take longer Goals - determine instrument selection (donor or therapeutic apheresis)
leukapheresis - patient population - reduces WBC by how much?
most commonly in patients with AML and ALL - reduces WBC by 30-60%
immunoadsorption
refers to a method in which a specific ligand is bound to an insoluble matrix in a column or filter - selective removal of the pathogenic substance - reinfusion of patient's own plasma and cellular components
charcoal
used in selective adsorption - removal of bile acids
polymyxin B
used in selective adsorption - removal of endotoxin
cellulose acetate
used in selective adsorption - removal of granulocytes
staphylococcal protein A
used in selective adsorption- cell wall component of S. aureus - affinity for IgG classes 1, 2, and 4 and for IgG immune complexes
Therapeutic plateletpheresis
used to treat thrombocythemia with related symptoms - risk of thrombotic or hemorrhagic complications (platelet count exceeds 1,000,000/µL) reduces platelet count by 30-60%
what is the PLT count minimum for plateletpheresis?
≥150,000/µL
