Chapter 18 - APHERESIS

When should the replacement fluid in therapeutic apheresis be plasma?

Only in specific disease entities such as thrombotic thrombocytopenic purpura (TTP)

Membrane separators are typically composed of what?

bundles of hollow fibers or flat plate membranes with specific pore sizes

In fluid shifts, what changes occur secondary to removal of blood into extracorporeal circuit?

changes in intravascular volume

What are the height and weight requirements for collecting red blood cells by apheresis?

female donors must weight at least 130 lb and have a minimum height of 5 feet 1 inch; male donors should weight at least 150 lb and measure 5 feet 3 inches

When can be collected?

for transfusion to replace certain clotting factors or to undergo further manufacturing for pharmaceuticals such as clotting factor concentrates, albumin, immunoglobulins, or vaccines

For donor purposes of plasmapheresis, collection is divided into what 2 categories?

frequent and infrequent plasmapheresis

How do you prevent GVHD in granulocyte collection?

granulocyte components should be irradiated prior to transfusion

Cellulose acetate removes what?

granulocytes

In fluid shift, hypovolemia can elevate what?

heart rate

What are some factors removed by therapeutic plasmapheresis?

immune complexes, alloantibodies, autoantibodies, immunoglobulins causing hyperviscosity, protein-bound toxins or drugs, lipoproteins, and phytanic acid

What are the 2 common methods of centrifugation?

intermittent flow centrifugation (IFC) and continuous flow centrifugation (CFC)

What is the therapeutic goal of Erythrocytapheresis (Red Cell Exchange)?

removal of incompatible RBCs from patient's circulation

Granulocytes are occasionally used to treat what?

sepsis in neonates or adults

Erythrocytapheresis (Red Cell Exchange) is most commonly performed to reduce complications of what?

sickle cell disease

In anticoagulation, in some individuals, the decrease in ionized calcium levels can result in what?

symptomatic transient hypocalcemia

In anticoagulation, the binding of calcium ions by citrate inhibits what?

the calcium-dependent coagulation cascade

Apheresis impacts what?

the manipulation of the removed blood and subsequent reinfusion of portions of the blood back to the donor's body

In continuous flow centrifugation (CFC), blood is pumped from where?

the phlebotomy site

In fluid shifts, what may cause hypovolemia?

the total volume of components collected during apheresis may be more than a simple whole blood donation

What is the most common therapeutic apheresis procedure performed?

therapeutic plasma exchange (TPE)

Photopheresis utilizes leukapheresis to do what?

to collect the buffy coat layer from whole blood

Hematopoietic growth factors in Hematopoietic Progenitor Cells (HPCs) are commonly used prior to the collection procedure in order to do what?

to increase the number of circulating stem cells in the peripheral circulation

What is the goal for donor and patient apheresis?

to intentionally remove a specific cellular component

In therapeutic plasmapheresis, why are replacement necessary?

to maintain appropriate intravascular volume and oncotic pressure

What is the purpose of therapeutic plasma exchange (TPE)

to remove the agent in the plasma, such as an antibody, toxin, or abnormal protein, that is causing the clinical symptoms

Apheresis has procedures to track what are required?

to track annual cell losses

Individuals who donate a single apheresis platelet unit may give up to how many?

up to 24 times per year, but not more frequently than once every 2 days in a 7 day period

Is the extracorporeal volume is usually greater with IFC or CFC?

IFC than CFC

Staphylococcal protein A has an affinity for what classes?

IgG classes 1, 2, and 4 and for IgG immune complexes

Infrequent plasma donors may donate how often?

every 4 weeks but no more than 13 times per year

Individuals who donate double or triple apheresis platelet units may donate how often?

every 7 days

What is therapeutic plasma exchange (TPE)?

removal and retention of the plasma, with return of all cellular components

The concentration of most plasma substances is reduced by _______ after one standard plasmapheresis treatment, with the rate of return to steady state concentrations varying among analytes.

50% to 60%

In intermittent flow centrifugation (IFC), how many cycles does it take to collect a therapeutic dose?

6-8

When did developments in apheresis begin?

60 years ago when Dr. Edwin J. Cohn devised a method for purification of albumin from pooled human plasma

In therapeutic apheresis, the patient's extracorporeal blood volume (ECV) should be ________ of the total blood volume (TBV) in order to minimize the risk of hypovolemia

<15%

The rationale of therapeutic apheresis (TA) is based on what?

A pathologenic substance exists in the blood that contributes to a disease process or its symptoms and The substance can be more effectively removed by apheresis than by the body's own mechanisms.

What are the adverse Effects of Apheresis?

Citrate toxicity, Vascular access difficulties, Vasovagal reactions, Hypovolemia, Allergic reactions, Hemolysis

Therapeutic apheresis (TA) includes what 2 procedures?

Cytapheresis procedures and Plasmapheresis procedures

What are the requirements for collecting red blood cells by apheresis?

Donor hematocrit must be at least 40% and the hemoglobin level must be determined by a quantitative method

Individuals who donate granulocytes may donate how often?

every 2 days

What is apheresis?

"taking away" whole blood is removed from the body and passed through an apparatus that separates out one or more particular blood constituent

In intermittent flow centrifugation (IFC), how many venipuncture are necessary?

1 or can be done using a double venipuncture with 1 needle for removal and for reinfusion

How much plasma volume can be exchanged per procedure in therapeutic plasma exchange (TPE)?

1-1.5 of plasma volume

How long must the donor be deferred for following a double-unit red cell apheresis?

16 weeks

Method used to collect granulocytes must result in a minimum number of ________ granulocytes in 75% of the apheresis units tested

1x10^10

In continuous flow centrifugation (CFC), how many venipuncture sites are necessary?

2

Modern apheresis instruments utilize what?

a computerized control panel, allowing the operator to select the desired component to be collected or removed

Plasmapheresis allows what?

a larger volume of plasma to be collected from a donor, such that each apheresis unit ("jumbo" plasma) contains a volume equal of at least two whole blood derived plasma units

Therapeutic plasma exchange (TPE) is also used to replace what?

a normal factor or substance that may be missing or deficient in the patient's plasma

Immunoadsorption refers to a method in which what happens?

a specific ligand is bound to an insoluble matrix in a column or filter

What is the most dramatic impact of apheresis instrumentation?

ability to collect (in one donation)

In therapeutic apheresis, what access is mandatory?

adequate vascular access

In therapeutic apheresis, patient must have what?

adequate veins at two sites capable of accommodating a 16- to 18-gauge needle

In intermittent flow centrifugation (IFC), blood is pumped from the body and mixed with what?

anticoagulant

What are the indications for therapeutic apheresis for category 2?

apheresis is generally accepted in a supportive role or as second line therapy

What are the indications for therapeutic apheresis for category 1?

apheresis is standard and acceptable, either as primary therapy or as a first line therapy

What are the indications for therapeutic apheresis for category 4?

apheresis lacks effectiveness or be harmful and should be discouraged in the disorders

What are the indications for therapeutic apheresis for category 3?

apheresis not clearly indicated based on insufficient evidence, conflicting results, or inability to document a favorable risk-to-benfit ratio

How are red blood cells typically collected?

as a double unit (termed 2RBC or double RBC procedure)

Donor preapheresis platelet counts must be how much?

at least 150,000/uL

Apheresis is performed using what technology?

automated

In intermittent flow centrifugation (IFC), blood is processed in what?

batches or cycles

Charcoal removes what?

bile acids

Frequent plasma donors may donate how often?

every 2 days but no more than 2 times in 7 days

Rare fatalities during therapeutic apheresis procedures have been reported. Most are caused by what?

circulatory (cardiac arrest or arrhythmia) or respiratory complications (acute pulmonary edema or adult respiratory distress syndrome)

In anticoagulation, what is added to whole blood as it is removed from the body and anticoagulates the blood before it enters the apheresis machine?

citrate

What are the advantages of membrane filtration over centrifugation?

collection of cell free product and ability to selectively remove specific plasma proteins by the varying pore size

Plasmapheresis is the collection of what?

collection of plasma by apheresis

What are donors stimulated with prior to collection?

corticosteroids or a granulocyte colony stimulating factor (GCSF)

What is the replacement fluid in therapeutic apheresis?

crystalloid (e.g. saline) or colloid (e.g. albumin), or a combination of these

Donor and patient apheresis would be expected to do what?

decrease circulating levels of specific cells

In apheresis, what do the on-board optical sensors do?

detects specific plasma-cell or cell-cll interfaces and diver the specific component to a collection bag

In fluid shift, the donor may experience hypotension due to what?

due to the depletion of intravascular volume if fluid is not infused during the apheresis procedure

Apheresis has effects of what 3 things?

effects of anticoagulation, fluid shifts, and cellular loss

Polymyxin B removes what?

endotoxin

In anticoagulation, PTH causes what 3 things when released?

mobilization of calcium from bone, increased intestinal reabsorption of calcium and increase reabsorption of calcium by kidneys

When can apheresis be performed?

on a donor to collect a specific blood component (blood apheresis) and on a patient to remove a particular blood component for therapeutic purposes (therapeutic apheresis)

In anticoagulation, what hormone is released in response to the decreased ionized calcium levels?

parathyroid hormone (PTH)

Leukapheresis is used to treat who?

patients with hyperleukocytosis (defined as a WBC or circulating blast count of >100,000/µL)

What can you harvest on an apheresis instrument?

plasma, platelets, WBCs, RBCs

What can be removed, or collected, using apheresis technology?

plateletpheresis for platelets, erythrocytapheresis for red blood cells, or leukapheresis for leukocytes

What are present in granulocyte collection?

plts and rbcs

What is plasmapheresis?

process of removing plasma

What is used during a granulocyte collection?

red cell sedimenting agent hydroxyethyl starch (HES)

What is therapeutic apheresis?

used to describe the removal of pathogenic substances from the circulation and is accomplished with an automated cell separation device

In fluid shift, hypovolemia can cause what?

vasovagal reaction

In continuous flow centrifugation (CFC), is the processes of blood withdrawal, processing, and reinfusion are performed simultaneously

yes

Granulocytes provide a higher ________ than whole blood?

yield product