USE OF BLOOD COMPONENTS IN CLINICAL PRACTICE – Part 2

ByDr.Varughese George

Platelets :• Non-nucleated, smooth disc-shaped cellular

fragments that are produced by ‘budding off’ from megakaryocytes in the bone marrow.

• Measure 2-4 µms in diameter.• Have a circulatory lifespan of 8-14 days.• The normal adult count is 150-400 x 10 .⁹• 10-20% of the total platelet population lies

within the spleen.• Required for primary haemostasis.• Releases vasoconstrictors (e.g thromboxane

A2 & serotonin) are involved in the initiation of coagulation and are essential for retraction of the final clot.

Collection of Platelets• Platelets are collected in two ways :

Pooled platelets This is a two-step procedure 1 unit of platelet is produced from a unit of whole blood.4-6 of these units (from different donors) are pooled together in a single pack to be given to a

thrombocytopenic patient.

Apheresis platelets These have the advantage of being collected from a single donor to reduce the risk of disease

transmission.As blood cycles through apheresis machine, platelets are removed and all other blood

constituents are returned to the donor. The amount of platelets collected with this procedure represents the equivalent of 4-6 units

of random donor platelets.

Storage of Platelets• Platelets last for 3-5 days if stored on an agitator at 22 C at pH of ⁰

6.2-7.8.

• Each platelet bag has a volume of 250-350 ml.

• Should be inspected prior to infusion.

• Should be rejected/referred for further opinion if there is any unexpected appearance such as discolouration.

• Not cross-matched with the recipient, but wherever possible ABO specific platelets should be used.

Storage of Platelets• Risk of transmission of bacterial infections is higher with platelet

transfusions than red cells if stored for 3 days or more.

• Bacterial contamination may occur at the time of collection.

• The storage bags are made up of specific plastic, which allows gas exchange (for O2 & CO2 ) to occur across its walls at 22 C ⁰ preserves platelet function but promotes bacterial growth.

• The longer the platelets are kept prior to transfusion, the higher the risk of bacteremia.

Recommendations for platelet transfusion

• Appropriate use of platelet transfusion can reduce the volume of red cells transfused.• When a platelet transfusion is considered, the quality of endogenous platelets should

be taken into account as well as recipient’s platelet count• Platelet transfusion may be indicated despite an apparantly normal platelet count if

there’s known or suspected platelet dysfunction. • In stable patients, platelet count > 10 x 10 /L in absence of bleeding is satisfactory.⁹• In surgical if the platelet count > 100 x 10 /L or obstretic patients with normal platelet ⁹

count, platelet transfusion is rarely indicated and usually indicated if count < 50 x 10 /L in the presence of bleeding.⁹

• Invasive intervention in a patient with platelet count < 5 x 10 /L .⁹• Decision on platelet transfusion in patients with platelet counts between 50 & 100 x

10 /L should be based on platelet dysfunction, expected/ongoing bleeding or risk of ⁹bleeding.

• Prophylactic platelet transfusion is rarely indicated and ineffective in ITP/TTP.• Each adult therapeutic dose of platelets can raise the count by approx. 20 x 10 /L .⁹

PLATELET RICH PLASMA (PRP) & PLATELET RICH CONCENTRATE (PC)

PLATELET RICH PLASMA (PRP) &

PLATELET RICH CONCENTRATE (PC):• Can be prepared from -Random donor platelet (from 450ml whole

blood) 4 – 5 PRP units conc. in AS/ SAG-M (additive solution)

-Single donor platelets prepared by apheresis in cell separator.

-Random Donor Platelets – 450ml whole blood at RT (20-22 C) within ⁰

6-8hrs of collection.

• Thrombocytopenia: -Due to decreased platelet production – in this

endogenous / exogenous platelet survival is normal and platelet supportive therapy is useful:

-Leukaemia -Chemotherapy -BM transplantation -Marrow infiltrative diseases -Drug induced suppression -Radiation induced hypoplasia

Due to increased platelet destruction – endogenous/ exogenous platelet survival is shortened and benefit of platelet transfusion low:

Immune platelet destruction/ loss: -Idiopathic thrombocytopenic purpura (ITP) -Autoimmune thrombocytopenia -Drug induced thrombocytopenia (quinidine/ heparin) -Gram negative septicaemia.

Non immune platelet destruction or loss: -Disseminated Intravascular coagulation (DIC) -Thrombotic thrombocytopenic puepura (TTP) -Hemolytic uremic syndrome

Platelet sequestration: -Hypersplenism -Hypothermia

Indications of platelet transfusion: -Platelet count < 5000/ul due to any conditions. -Platelet count – 5000 – 10000/ul – if increased risk of bleeding due to hematological malignancies, sepsis, BM aplasia/ transplant. -Platelet count – 10000 – 20000 /ul if bleeding present mucus membranes, surgical incisions, venipuncture site, scattered patechiae/ echymosis. -Chemotherapy - platelet count < 20,000/ul -DIC - if platelet count < 50,000/ul -Massive transfusion - if platelet count < 50,000/ul -In major surgery - if platelet count - <70,000/ul

• DOSAGES:One unit random donor platelets 5000 – 10,000/ulOne unit apheresis donor 30,000 – 60,000/ulMonitoring - Platelet count, BT, PT, Aptt, Fibrinogen.

-ABO incompatability – acceptable.-Rh negative females given compatible platelets

otherwise Rh Ig 20ug for each unit of platelets to be given.

• Contraindications: -Thrombotic thrombocytopenic purpura (TTP) -Heparin induced thrombocytopenia -Idiopathic thrombocytopenic purpura unless life threatening hemorrhage. -No prophylactic use <50,000/ul in surgery.

GRANULOCYTES:

• Indicated for life-threatening infections in neutropenic cancer patients who are unresponsive to antibiotics.

• Prepared by separating white cells from blood donated by volunteers whose leucocyte count has been increased by pre treatment with corticosteroids, or with chronic granulocyte leukemia.

• Blood donations must be cross-matched as they contain large numbers of RBCs.

• Should also be irradiated to remove lymphocytes.

• Collected either by apheresis or derived from whole blood and can be stored for 24 hrs at 20-24 °C.

GRANULOCYTES:

Indications: Septicaemia not responding to antibiotics Infections in patients of chemo / radiotherapy Gram –ve infections with neutrophil counts < 500/cumm Temporary bone marrow depression in 1-2 weeks

Products:Buffy coat –from 450ml blood 0.60x10 granulocytes,⁹ other leucocytes, RBC, platelets, 15-20ml plasma.Apheresis – Granulocytes (1x 1010), other leucocytes , RBC, Plasma 200 ml.

• Doses and administration: 1 unit prepared by apheresis (equivalent to 18-20

units of buffy coat ) daily.

• Contraindications: Infections responsive to antibiotics.

FRESH FROZEN PLASMA• Mainly used to provide replacement coagulation factors in cases of excessive

bleeding or to prevent bleeding in those patients with abnormal coagulation.• Contains all the coagulation factors and albumin.• Source of plasma cholinesterase.

Collection and Storage of FFP:• FFP is collected as supernatant after centrifugation of whole blood.• It Is frozen within 8 hrs and may be stored upto 1 year at -30 C, thus ⁰

minimizing the loss of Factor V and VIII .• Brittle and handled with care.• Thawed using a dry oven (10min) / microwave (2-3min) / water bath (20min).• Best used immediately / stored at 4 C & infused within 24 hrs.⁰

Recommendation for FFP transfusion

• Correction of excessive microvascular bleeding in presence of PT > 1.5 times normal & INR > 2.0 or aPTT > twice normal.

• Correction of excessive microvascular bleeding that is secondary to coagulation factor deficiency in patients transfused with more than one blood volume (approx 70 ml/kg) and when PTT or INR cannot be obtained in an appropriate amount of time.

• Urgent reversal of warfarin therapy when human prothrombin complex is unavailable.

• Correction of known coagulation factor deficiencies for which specific coagulation factors concentrates are unavailable.

• Heparin resistance (antithrombin III) deficiency in a patient requiring heparin.

FRESH FROZEN PLASMA• FRESH FROZEN PLASMA: Fresh frozen plasma (FFP) is that is separated from whole blood and is

frozen within 6-8hrs of collection. FFP contains plasma proteins & all coagulation factors, including labile factors

V andVIII, if stored at -30 C ⁰

• Indications for FFP: -Actively bleeding multiple coagulation defeciencies as in liver diseases. -Disseminated intravascular coagulation (DIC) -Coagulopathy in massive transfusion -Thrombotic thrombocytopenic purpura (TTP) -When specific disorder cannot be identified -Familial factor V deficiency if conc. Factor not available -Deficiency of factors II, VII, IX, X (vit.K deficiency or coumarin overdose)

if bleeding - Antithrombin III deficiency -Congenital / acquired coagulation factor deficiency -Use of FFP with RBC’s has largely replaced fresh blood.

• Dosage of FFP:• Should be given in doses calculated to achieve a minimum of 30% of plasma factor

concentration – achieved at 5-15ml/ kg body wt • 5-8 ml/kg is usually enough for urgent reversal of warfarin therapy.• The quantity of coagulation factors provided by 1 unit of FFP ~ those provided by

– 4-5 units of platelet concentrates.– 1 unit of single donor platelets.– 1 unit of fresh whole blood.

FFP is also treated with methylene blue to reduce the risk of viral infection especially in the case of vCJD transmission

Must be thawed at 30 – 37 C in water bath⁰ Must be used within 12hrs if stored at 2-4 C.⁰ Monitor by post transfusion aPTT, PT & Fibrinogen Must be ABO compatible but not group specific. Donor plasma should not contain

antibodies that might interact with A or B on recepient’s RBC’s.

Contraindications for the use of FFP: - Blood volume expander - Hypoproteinaemia - Source of immunoglobulins - When PT is < 18 seconds.

CURRENT STATUS – FFP IN CONFLICT/ DISASTER ZONES: Fresh frozen plasma in a frozen plasma prepared

from fresh plasma. FFP is provided on battle field at Combat Support Hospitals tp provide replacement of clotting factors in severly bleeding battle casualties. FFP that has been Thawed Plasma (TP) may be provided at the Forward Surgical Teams. However upto 40% units breaking during transhipment (on dry ice) and the logistics involving substantial weight, power and cube in theatre because of inherent need to maintain it in frozen state.

Freeze Dried Plasma (FDP) - benefits to war fighter.• Freeze Dried Plasma does not require shipment on

dry ice and is packaged in ruggedized containers. These factors substantially reduce breakages and waste of vital medical products during shipment to and across rugged terrain in battle field.

• It has been used later part of 2nd world war and subsequent conflicts and peace keeping missions.

• Many countries have their strategic production units including ours.

Freeze Dried Plasma (FDP)From Shelf

5 Minutes forreconstitution

To Infusion

- Recent American and French forces in Afghan war has shown seriously injured with massive hemorrhage in shock and coagulopathic state which require RBC and plasma in ratio 1:1. FFP requires thawing and badly fits emergency for overseas operations and poorly developed chain of evacuation to Regional Trauma Centres. Refinement of the product to render it more safe has been an ongoing process till date.

FDSP (Freeze Dried Secure Plasma):• Dilution and neutralisation of natural anti A and

anti B haeagglutinins. • Further securization process is quarantine in which

donor is retested after a period longer than window period of known viruses.

• This is compatible with all RBC and most ideal universal donor AB plasma.

• At ambient temperature fibrinogen and all other clotting factors are equal to FFP upto more than 2 yrs.

-Quarantine may be dispensed if technology for

pathogen inactivation exists. -LyPTM – autologous freeze dried plasma could

be prepared for each combatant and be included amongst his equipment.

-Pathogen inactivation – Ceras corporation in USA has developed INTERCEPT BLOOD SYSTEM technology to render blood products pathogen free.

• SINGLE DONOR & CRYOPRECIPITATE – POOR PLASMA:

- Plasma prepared from one unit of whole blood before days of expiration is single donor plasma. Cryoprecipitate poor plasma is byproduct of cryoprecipitate preparation.

- Both lack the labile coagulation factors V and VIII but contain factors II, VII, IX & X.

Indications: -Deficiency of stable clotting factors (e.g warfarin drugs) -Burns

CRYOPRECIPITATE• If FFP is thawed to refrigerator temperature (4° C), cryoprecipitate is

formed which is rich in high molecular proteins – Factor VIII, von Willebrand Factor and fibrinogen.

• Viral infection risk is as for whole blood. • Administered through blood filters.

Collection and Storage:• Cryoprecipitate is prepared in volumes of 20-40 ml in the UK and Ireland.• 1 unit of whole blood provides 15 ml of Cryoprecipitate.• 1 pack contains at least 150-300 mg of fibrinogen and 70 IU of Factor VIII.• Usually issued by the hospital blood bank in 10 prepared units (300ml

volumes).• May be pooled in 1 bag.

Cryoprecipitate

Recommendations of Cryoprecipitate transfusionTransfusion of cryoprecipitate is rarely indicated if fibrinogen

concentration > 150mg/dl.Indicated when fibrinogen concentration is less than 100mg/dl in

the presence of excessive microvascular bleeding.Indicated to correct excessive microvascular bleeding in

massively transfused patients when fibrinogen concentration cannot be measured in a timely fashion.

Indicated for patient with von Willebrand disease and congenital fibrinogen deficiency.

CRYOPRECIPITATE: Cryoprecipitated proteins derived from FFP which contains

factor VIII, von-Willebrand factor, factor XIII and fibrinogen.

Indications: -Hemophilia A -von-Willebrand disease -Congenital/ acquired fibrinogen deficiency -Acquired factor VIII deficiency (e.g DIC, massive transfusion) -Factor XIII deficiency -Source of fibrin glue as topical hemostatic agent in surgical

proceduresAdministration - of factor VIII conc, 500 IU/vial, available as

pharmaceutical products is choice for most hemophilias.

-Cryopreservation and lympholisation of platelets and platelet substitutes are all being studied as remedies for the short span of platelet components.

- FFP and cryosupernatant are being used in Therapeutic Plasma Exchange (TPE). This removes much of von-Willebrand factor. Its multimers leaving vWF enzyme to degrade existing multimers.

- Blood substitutes have been advanced as remedies for some of the complications with component transfusion.

- Gamma radiated RBC’s are used to prevent GVHD in severely immunocompromised, lymphoma, BM/ SC transplants & Intrauterine transfusions.

TRANSFUSION SUPPORT FOR STEM CELL/BONE MARROW TRANSPORT PATIENTS

• Peripheral Blood Stem Cell/Bone marrow transplant in hematological malignancies, solid tumors and genetic disorders.

• Allogenic /autologous.• Irradiated blood products reduce Graft V/S Host

Disease.• Prevent alloimmunization – leucodepletion.• CMV Antibodies in India approximately 98% and hence

difficult to find seronegative donors and hence CMV prophylaxis only by leucodepletion.

Uses of plasma derivatives

Human Albumin Solution / Plasma protein fraction

• It is also prepared by the fractionation of pooled plasma ( where all cellular and coagulation factors are removed).

• Available either in 5% or 20% (salt poor albumin) solution.• Both contain 140-150 mmmol/ sodium (the latter contains less sodium

per gram of albumin).• Heat treated to kill viruses.• Shelf life of 2 years and stored at room temperature.

Uses :• It is given to restore or maintain blood volume in the patients who has

hypovolemia without acute blood loss.• In emergency treatment of shock due to trauma, hemorrhage,surgery

or infection.• Also given in hypoproteinaemic conditions particularly when edema is

present.

Uses of plasma derivatives

ImmunoglobulinsProteins secreted by plasma cells. Involved in immunological defence systems.Administrated to human and are obtained from Pooled Human Plasma1. Human Normal Immunoglobulins• Used as long term replacement for missing/poorly functioning immunoglobulins, in proteins with

antibody deficiency disorders and also, in short, high dose courses, as immunomodulatory agents in a range of autoimmune or inflammatory diseases.

• May be given I/M for the prophylaxis of certain infections e.g measles, hepatitis, rubella in pregnant women. Some forms are given I/V as replacement therapy in immunodeficiency and in various immune related disorders.

2. Hyperimmune Immunoglobulins• Obtained from donors with high titres of specific antibodies and are used for passive immunization

against particular infections or to avoid potentially harmful immune reactions.• Given I/M and are available against hepatitis B, tetanus,rabies, Rhesus D Antigen and herpes viruses.

They are screened for hepatitis and HIV infection.

Uses of plasma derivatives

Immunoglobulins Immunomodulatory therapy with high dose Intravenous

immunoglobulin (IVIG)• IVIG is sourced from a plasma pool of 1000-10,000 donors and

provides polyclonal immunoglobulins to a wide variety of pathogens.

• Mechanism of action includes blocking of IgG binding Fc receptors on macrophages, antiinflammatory effects and effects on T and B lymphocytes.

• The product is expensive and scarcely available.

Uses of plasma derivatives

Immunoglobulins

Conditions where IVIg may benefit include : Primary immunodeficiency Guillain Barre Syndrome. Chronic Inflammatory Degenerating Polyneuropathy, Myasthenia Gravis. Polymyositis SLE Kawasaki’s Disease Neonatal Sepsis and Toxic Shock Pemphigus Rheumatologic Autoimmune disorders

Uses of plasma derivativesHemolytic disease of the newborn (HDN) and Anti RhD Immunoglobulin (anti-D)

• Rh D Antibodies are acquired during pregnancy/ tranfusion of Rh +ve cells to Rh -ve recipient.

• Use of anti RhD immunoglobulins has considerably reduced it.

• Anti-D Immunoglobulins is prepared from plasma of donors who have high levels of anti D following RhD +ve cells during pregnancy or intentional immunization.

• Anti D products contain specific levels of anti D & can be given I/M or I/V destroys Rh +ve cells to prevent maternal Rh Antibodies. It is given as

– Rh –ve woman are expose d to Rh +ve cells entering maternal circulation. e.g following trauma.

– Prophylaxis for Rh –ve mothers at 28 weeks and 32 weeks respectively and in case of fetomaternal hemmorhage.

– Higher dose if increase RBC from fetus is more.

– Recurrent APH – further doses six weekly intervals.

Uses of plasma derivativesCoagulation factor concentrates

Could be tranfused individually to treat specific factor deficiency. These include –

• Recombinant Factor VIII and Factor IX Most severe haemophiliacs receive it by

recombinant gene engineering technology in countries like UK and the West.

Risk of viral infections is less.

• Factor VIII and Factor IX concentrate Concentrates produced by fractionation of large

pools of plasma. Current licensed products are all treated to

inactivate viral infections and are not reported to transmit hepatitis or HIV.

Plasma/Cryoprecipitates are used to treat haemophiliacs in many parts of the world due to unavailability/high cost of plasma derivatives.

Commercially produced factor concentrates such as "Advate", a recombinant Factor VIII, come as a white powder in a vial which must be mixed with sterile water prior to intravenous injection.

Uses of plasma derivativesCoagulation factor concentrates

• Factor II, VII,IX,X concentrates [Prothrombin complex concentrates (PCC)]

Main indication for this is Warfarin overdose where there is life-threatening bleeding.

Used in patients with hemorrhage, particularly when there is contraindiction to the use of FFP, but it has not been tested in clinical trials in this situation.

Doesn’t contain Factor V or VIII.

Uses of plasma derivatives

Coagulation factor concentrates

• Recombinant Factor VII a (NovoSeven®)

• Originally developed for use in haemophiliac patients with inhibitors to factor VIII / IX of clotting cascade.

• Works by activating coagulation and platelet adhesion but only if time factor is exposed.

• It has a local effect with no action on systemic coagulation factors.

• Its use in major secondary hemorrhage is unlicensed due to risk of thrombotic complications.

• These drugs are extremely expensive.

• Other indictaions are still being established.

Apheresis

• Process of removal of whole blood from the donor /patient separating it into various components followed by retention of desired or unwanted components while the remaining consitituents are reinfused back into the donor/patient.

The following terms are used according to the material retained :-

Plateletpheresis – where platelets are retained.Plasmapheresis – when plasma is retained.Leukopheresis – when white cells are retained.

Indications for ApheresisA. Collection of components from healthy donors• Plateletpheresis.• Plasmapheresis.• Leukapheresis.• Erythrocytaphersis.• Neocytapheresis.• Peripheral blood stem cells.

B. Removal of pathological components from plasma• Therapeutic plasma exchange.• Therapeutic leukapheresis.• Therapeutic thrombocytapheris.• Therapeutic red cell, exchange.

Techniques used in Apheresis

Manual Method• Performed using refrigerated centrifuges and specialized plastic bags.• Blood collected in the primary bag is centrifuged to separate the desired

component which is retained in the satellite bag and the remainder is reinfused through the same vein back to the donor.

Advantages:• Simple and less expensive method.

Disadvantages:• The amount of component prepared per procedure is less than that collected from

cell separators.• The risk of returning red cells to the wrong patient if stringent donor identification

is not done.

Techniques used in Apheresis

Cell separatorsApheresis machines using centrifugal force and differing

densities of various blood components is used for separation of desired components.

Types a) Intermittent flow centrifugation (IFC) e.g. - Hemonetics V-50, S-30, MCSb) Continuous flow centrifugation (CFC) - Fenwal CS 3000,

e.g. - Fenwal CS 3000 plus, Amicus, COBE Spectra.

Donor Selection for Apheresis Procedure.

Plateletpheresis donors• Donors should be healthy individuals meeting the standard

criteria for normal blood donation.• Donor must have a minimum platelet count of 1.5 x x 10 5/μL.• The interval between two procedures should be at least 48 hrs

and the amount of red cell loss should not exceed 25ml/week.• The donor should not have taken salicylates and antiplatelet

drugs for the last 72 hrs.• The validity of mandatory tested infectious disease markers is

taken upto 3 days, if a repeat procedure is done in that timeframe.

Donor Selection for Apheresis Procedure

Plasmapheresis donorsSerial plasmapheresis donors (donating at interval of less than 48 hrs) should:• preferably be < 50 yrs of age & have had given blood previously one or two

occasions.• Occasional plasmapheresis donors (no more than once in 4 weeks) are

accepted on the same criteria as mentioned for whole blood donation.• Total blood count & total serum proteins should be within normal range.• The maximum amount of plasma which an individual can donate in 1 sitting

should not exceed 500 ml if the weight is between 50-65 kg & no more than 900 ml if the weight is more than 65 kg.

• Adequate replacement fluids should be given to donor if >500 ml of plasma is drawn.

• If the red cells are not reinfused back to the donor, the donor should be deferred for 12 wks.

Apheresis

Leucapheresis• Defined as removal of white cells with the return of red cells, plasma

and platelets to the donors.• The granulocyte concentrate must contain minimum of 1.0 x 10 10/μL

granulocytes in at least 75% of the units tested.• The product should be transfused as soon as possible after collection.• The maximum shelf life is 24 hrs.• The granulocyte collection yield by apheresis procedure (cell

separator) can be increased by Increasing the granulocyte count of the donor by giving steroids or haematopoietic growth

factors. By improving the separation with addition of red cell aggregating agents, e.g hydroxyethyl

starch (HES).

Apheresis

NeocytaphersisIn patients requiring repeated transfusions e.g Thalassemia

major, the administration of relative young cells.Neocytes would improve the management of such patients by

decreasing the frequency of transfusion & rate of iron loading. The neocytes for transfusion purposes are prepared by the use of automated cell separator on the principle that young, larger and less dense red cells are expressed earlier than old cells.

Neocytes obtained in such a manner show improved survival but are expensive and take approx. 3-4 hrs of donor time.

ApheresisErythrocytapheresis / 2 RBC collection procedure• For collection of negative RBC units, e.g. O negative.

Advantages :• Standardized RBC mass collection is possible.• Metered anti-coagulant obviates mixing during collection, thus reducing clot

formation.• Reduces the risk of hypovolemia to the donor.• On line separation of RBC and plasma is possible• Anti-coagulant to Whole Blood ratio is 1:16, thus decreases citrate toxicity.• Use of smaller gauge needle is possible.

Deferreal period • After 2 RBC procedure, the donor is deferred for 16 wks.

ApheresisAdverse EffectsCitrate toxicity may occur in the form of numbness & tingling

sensation around the mouth if the amount of citrate infused exceeds the body’s ability to metabolize it.

The above problem is solved by • decreasing the rate of infusion of anticoagulant or • by giving exogenous calcium to the donor.

Other adverse effects similar to that of normal blood transfusion.

Apheresis

Therapeutic Apheresis / Therapeutic Plasma Exchange/PlasmapherisisIf 500 ml of plasma is removed without any replacement fluid, the term

plasmapharesis is used.e.g to prepare anti- Rh immunoglobulin, donors are hyperimmunized to

Rh antigen. If more than the above amount is removed, the lost plasma proteins is replaced by crystalloid and colloidal solution.

Replacement fluids for plasma exchange.Exchange volumes vary between 1-1.5 times the plasma volume of the

patient.

ReplacementReplacement Advantages Disadvantages

Crystalloid •Low cost.•No risk of disease transmission

•No coagulation factors•No immunoglobulins•Hypo-oncotic

Albumin •No risk of disease transmission.•Iso-oncotic

•No coagulation factors•No immunoglobulins•Costly

Plasma Protein Fractions Less expensive than albumin. Induction of some hypotensive action.

Fresh Frozen Plasma Maintains normal levels of coagulation factors.Immunoglobulin and plasma protein.

Disease transmission if not tested properly.Citrate overload.

Current Research and Trials• Donor lymphocyte infusion is a new use for lymphocyte fraction obtained from apheresis.

• Red cell substitutes are coming up and several sources of haemoglobin based enhanced oxygen carriers are currently in Phase III Clinical trials in South Africa. These include Bovine Hemoglobin based oxygen carriers (HbOC) and Perfluorocarbon based red cell substitutes.

• Intravenous Immunoglobulins (IVIg) has been used over 10 years.

• Immunotherapeutic approach to cancer therapy using dendritic cell vaccine is in phase II clinical trials.

• Cryopreservation and lyophilization of platelets and platelet substitutes - microspheres and IPMO including infusible platelet membranes are all being studied as remedies for the short life span of platelet components.

• FFP and Cryosupernatant (Cryoprecipitate reduced plasma) are being used in Therapeutic Plasma Exchange (TPE). This removes much of vWF, its multimers leaving vWF enzyme to degrade exisiting multimers.

• Blood substitutes have been advanced as remedies for some of the complications with component transfusions.

• Gamma radiated RBCs are used to prevent GVHD in the severely immunocompromised , lymphoma,bone marrow/stem cell transplants and intrauterine transfusions.

TO SUMMARISE • Whole blood is a precious resource from which blood components and

plasma derivatives are obtained.• Blood components include red cell concentrates, plasma concentrates,

fresh plasma & cryprecipitates. Plasma derivatives include albumin, coagulation factors and immunoglobulins.

• The collection and storage of blood components and plasma derivatives has many phases that are specific to type. These are in place to ensure that the blood product is safe, effective and economical.

• Transfusion of blood components and plasma derivatives is not without risk in the immediate and long term perspective.

• Transfusion decisions require careful consideration of sound pathophysiologic principles and comprehensive assesment of patients risk factors in the immediate and the foreseeable.