USE OF BLOOD COMPONENTS IN CLINICAL

PRACTICE – Part 1

By

Dr.Varughese George

INTRODUCTION• In the past whole blood was the only preparation administered to replace

RBCs, platelets and coagulation factors.

• Unnecessary administration of unwanted cells/ plasma constituents in addition to what patient required.

• Large volume of blood required to achieve satisfactory replacement of particular component.

• Techniques became available for separation of blood components in a closed system and patient could be administered specific replacement therapy.

• 1 unit of donor's blood can be utililized for preparation of different components and thus can benefit more than one patient.

BLOOD COMPONENTS

HISTORY:

• 1628 - Sir William Harvey described venous circulation.

• 1665 - First animal-to-animal (dog) blood transfusion performed at Oxford by Richard Lower

• 1667- First animal-to-human blood transfusion by Jean-Bapiste Denis .

• 1818- First human-to-human blood transfusion was performed by James Blundell.

BLOOD COMPONENTS

HISTORY:

• 1900- The ABO blood grouping system was classified by Landsteiner.

• 1907- The first pretransfusioncross-match was done by Ottenberg.

• 1940- The system of Rh typing was invented by Landsteiner and Wiener.

BLOOD COMPONENTS

FURTHER DEVELOPMENTS

• 1950 - Glycerol cryoprotectant for freezing RBCs

• 1950 - Carl Walter & W.P.Murphy introduced the plastic bag for blood collection.

• 1954 -= The blood product Cryoprecipitate was developed for people suffering from hemophilia.

• 1960 - A.Solomon and J.L.Fahey reported the 1st therapeutic plasmapheresis procedure.

• 1972 - Apheresis was used to extract one cellular component.

• 1979 - A new anticoagulant preservative, CPDA-1, which extends the shelf life of whole blood and RBCs to 35 was introduced.

• There were no Blood Banks in India before 1942 when first Blood Bank was established in Calcutta due to perceived threat by advancing Japanese forces.

• Thereafter Bombay, Lucknow, Pune and Lahore blood bank were established during world war II.

• Colonel CWG Bird and Colonel SDS Grewal of IMS in British Indian Army played pivotal role in development of Blood Bank programme and the production units in AFMC and rest of the country.

• Veteran transfusion man Professor PD Jolly pioneered development of Blood Banking Programme in whole of the country from inception.

• There have been major inventions in the component therapy in the 20th century

e.g. invention of anticoagulant and preservative solutions, refrigeration, plastic blood bag, etc.

• Transfusion medicine is a separate speciality by now and MD transfusion medicine courses have started at many premier institutions at JIPMER, AIIMS, AFMC, PGIMER Chandigarh, SGPGI Lucknow and many other centres.

REGULATIONS:

• Drugs & cosmetic act 1940 and Drugs &

cosmetic (amendment) rules 1999 – Human

blood is covered under the definition of drugs.

• These regulations give requirements,

processing & distribution of whole human

blood & blood components by the blood banks

and manufacture of blood products.

• Blood products are therapeutic substances

prepared from human blood which comprise:

Blood components: Plasma derivatives:

-RBC conc. -Albumin

-Platelet conc. -Coagulation factors

-Granulocytes -Immunoglobulins

-Fresh plasma

-Cryoprecipitates

• Advent of component therapy was in 1980 in U.K by use of factor VIII for Haemophilia which was prepared by fractionating human plasma.

• In UK and other western countries, whole blood is no longer used routinely for transfusion – it is processed in various components and only that are specifically needed by the patient are used.

• Donors are chosen to exclude anyone who may harm the recipient and anyone who may be harmed by donating blood.

• Acceptable limit - 450 – 500 ml upto 3 times a year.

Blood components

From whole blood Apheresis – only the

after collection. component to be used is

separated out &collected

& rest is returned to the donor.

• With development of closed system of PVC bags

with integral tubing, separation of components

could be achieved safely without risk of infection.

• Blood components can be prepared in any licensed

blood bank which has the required space,

specialized equipment, storage facility and trained

personnel.

Essential equipments in a blood bank

Essential equipments are:

-A steady flow of voluntary blood donors

-Testing facility for transfusion transmitted infections

-Refrigerated blood bank centrifuge

-Integral multiple blood bags

-Plasma expressor

-Blood sealer/ aluminium rings

-Blood bank refrigerator

-Deep freezer

-Cryoprecipitate bath

-Platelet agitator

-Laminar flow cabinet for pooling

Use of blood products ensures added advantages:

• Maximised use of one unit of blood for a number of patients with

same unit.

• Shelf life of components is longer than whole blood.

• Better patient care with specific components without danger of

overloading/ side effects of other components.

• Cost effective blood bank system wherein cost of processing a unit of

blood is shared by a number of patients rather than one patient if given

as whole blood.

Production of blood components &

plasma derivatives

Production of blood components &

plasma derivatives• Whole blood is centrifuged to separate plasma from red cells.• Concentrated RBCs become too viscous to infuse safely and are depleted in

nutrients, glucose and adenine.• Following collection, red cells are resuspended & stored in a preservative solution

to keep them in good condition.•

• Most common solutions used are SAGM – contains sodium chloride, Adenine Glucose Mannitol.

Glucose provides energy source for the metabolic requirements of the cells Adenine helps maintain cellular levels of ATP Saline and Mannitol provides aqueous medium of appropriate osmolarity and pH.

Blood Component Screening

• Blood screening varies across the globe.In UK, all blood donations are tested for Hepatitis B (Surface antigen) Human Immunodeficiency Virus (HIV) HTLV (Human T Lymphocyte Virus) Hepatitis C (Ab & RNA) Syphilis (antibody)

• In case, donor has been exposed to infections through travel Malaria antibody. Trypanosoma Cruzi (Chagas disease) antibody. West Nile Virus RNA.

Some blood donations are tested for Cytomegalovirus (CMV) antibody to meet the needs of specific patient groups.

Blood Component Screening

Since October 1999, all blood components used in UK & Ireland have been leucodepleted ( removal of white blood cells by filtration) in an attempt to reduce the risk of transfusion transmitted infections & variant Creutzfeldt-Jakob disease (vCJD) – no test for reliable detection is available.

Each blood donation is also tested to establish ABO & Rh D group of donors’ red cells.

Plasma derivatives

• Plasma derivatives are partially purified preparations of human plasma proteins that are produced in a pharmaceutical process from large volumes of plasma.

• Thawing , addition of ethanol, exposure to varying temperature, pH & ionic strengths are combined with filtration, chromatography and centrifugation to separate the different groups of proteins.

•

• Purification and virus inactivation steps are also performed.

• Final products supplied as solutions or freeze dried powders.

• Pooling of huge number of donations potentially increases the risk of infective disease transmission.

Plasma derivatives

• Since 1999, UK has imported plasma for fraction from areas reporting low incidence of Bovine Spongiform Encephalopathy, which is associated with vCJD.

• The USA supplier only provides plasma from male donors to reduce the risk of Transfusion Related Acute Lung Injury (TRALI).

• Women are excluded as they may be a source of Antibodies that increase risk of TRALI, which are though to occur during pregnancy.

Blood Component Therapy

• Used to correct coagulopathy and thrombocytopenia once exsanguination has been stopped by physical means.

• The availability of near patient testing equipment such as thromboelastography(TEG) can provide useful information to help guide component therapy.

Blood Component Therapy

Whole blood:

• Accounts for most transfusions in many countries, rarely used in developed nations.

• Shelf life :

CPD - 21 days.

CPDA – 35 days.

AS-1, AS-3, AS-5 – 42 days

• 70ml of citrate preservative solution is added to 420ml of blood.

Blood Component Therapy

Whole blood:

• Whole blood/ RBC concentrate less than 12 – 24 hrs from time of collection are considered fresh, difficult to provide, as screening is rarely completed within that period.

• 80 -90 % platelets become non-functional.

• 30-40% labile factors V & VIII lost in 24 hrs at 4-6⁰C.

• Justified when no facilities for component separation, sometimes in newborn due to high fetal Hb.

Blood Component Therapy

Indications :

• Acute, active blood loss with hypovolemia.

• Exchange transfusion.

Contraindications :

Risk of volume overload :

Chronic anemia.

Incipent cardiac failure.

Red Cell Components

The objective of red cell components transfusion is to improve oxygen delivery to the tissues.

Packed Red Cells (PRBC) –

• Produced by removing 150-200ml of citrated plasma from a unit and whole blood. • 1 unit of PRBC has hematocrit between 60-70%.

Storage : Storing RBCs just above freezing temperature allows survival upto 42 days. There is gradual loss of 2,3 Diphosphoglycerate (2,3 DPG), leading to increased Hb affinity for

O2.

Left shift of O2 dissociation curve and reduced O2 delivery to the tissues. Gradual loss of cell membrane integrity as cells begin to age. Potassium leaks out of cells into suspension fluid and there is gradual buildup of lactate. Some cells may eventually die and become haemolysed.

• Giving packed red cells – faster way to increase the O2 delivery capacity of the blood• 1 unit of packed red cells will roughly increase patient’s hematocrit by 3% and Hb by 1 g/dl.

Blood components

Packed Red Blood Cells (PRBC):

-Symptomatic anaemia.

-Decreased BM production – Leukaemia, Aplastic anaemia.

-Decreased RBC survival conditions – Hemolytic anemia, Thalassemia.

-In bleeding patients – surgical bleeding, traumatic bleeding.

-Suggested levels of Hb warranting transfusion

– 6g/dl in absence of disease

– 8-10g/dl with disease

• Each count of RBC from 450 ml of whole

blood is expected to raise Hb level 1g/dl in a

70kg body wt individual, more quick with

RBC than whole blood.

Reasons Indications & Replacement fluid

Anaemia -Anaemia associated with incipient/

established cardiac failure.

-Hb value < 6g/dl

-Patients approaching delivery & has Hb

<7g/dl

-In hereditary hemolytic anemia & β

thalassemia major, guidelines are more

liberal.

Reasons Indications & Replacement fluid

Surgery -Patient needs urgent operation and has Hb

<10g/dl

-Anticipated blood loss > 1000ml

Other acute blood loss <20% -None

20-30% - Crystalloids/ colloids

30-40% - RBC & crystalloids

>40% - Whole blood / PRBC & Crystalloids

Broad indications for PRBC transfusion:

Advantages of transfusion of red cells:

-Reduce risk of circulatory overload due to less

volume of anticoagulant and plasma.

-Lessen severity and incidence of allergic reactions

-ABO antibodies are reduced, Red cells non ABO

identical to patients group can be given if

compatible.

-Removed plasma can be used for preparing FFP, &

Cryoprecipitate (factor VIII & V)

Contraindications of red cell transfusion:

- Well compensated anaemic patients such as chronic

renal failure.

-Nutritional anemia responsive to treatment, unless

signs of decompensation.

-To correct protein and coagulation factor deficiency.

-To prevent infection , promote wound healing,

general well being, etc.

Red cell aliquots

• For neonates

• 10-25 ml units

• 5ml/kg will raise Hb by approx. 1 gm/dl

Red Cell Components

Microaggregate - free blood

• Used to prevent reactions to leucocytes and platelet antigens.

• Specially designed machines are used to wash RBC.

• Washed RBC are then suspended in sterile saline.

• Washed RBC usually have hematocrit of 70-80% and a volume of about 180ml.

• Saline washing removes 98% of plasma & reduces concentration of leucocytes, platelets and cellular debris.

• Washing may be carried out at anytime during the shelf-life of a unit of blood.

• As washing is in an open system, the resultant RBC can be stored for 24 hrs at 1-6 °C.

Irradiated RBCs

• Gamma radiation is used to destroy the lymphocytes in a unit of packed RBCs that are responsible for transfusion related Graft V/S Host Disease.

• Used in severely immunocompromised patients.

lymphoma patients.

stem cell and marrow transplants.

unborn children undergoing intrauterine infusion.

Leucocyte depleted Red cells

• Has 99.9% of white cells removed by freezing or microfiltration.

• This only reduces but doesn’t eliminate the risk of CMV, EBV, HTLV infections and febrile reactions.

• Since 1999, all blood components in the UK and Ireland have leucodepleted red cells in an attempt to decrease potential risk from transfusion transmitted vCJD.

Leucocyte reduced blood components/ RBC’s:

• Approximate residual leucocytes in cellular

blood components in one unit.

-Fresh whole blood 10⁹

-Red blood cell concentrate 10⁸ - 10⁹

-Buffy coat depleted red cells 10⁸

-Red cells leucocyte reduced by <10⁷

filtration

-Washed red cell concentrate 10⁷

-Deglycerolized red cells 10⁶ - 10⁷

-Platelet concentrate ≤10⁷

Leucocytes in blood components can cause:

-Non-hemolytic febrile transfusion reaction(NHFTR)

-Human leucocyte antigen (HLA) alloimmunization

-Transfusion of leucotropic viruses – CMV, EBV, HTLV-1

-Transfusion related Graft versus Host disease (GVH)

-Transfusion related Acute lung injury (TRALI)

-Transfusion related immunosuppression.

• Febrile Non Hemolytic Transfusion Reaction (FNHTR):

FNHTR – “rise of body temperature >1⁰C above 37⁰C”

-Antibodies against WBC in patients plasma endotoxins

-Leucocyte cytokines- product storage as in non leucocytereduced platelets in warmer climates.

-Antipyretics can be used prior & during transfusion.

-Difficulty in detecting antibodies in vitro.

-Patients with two or more FNHTR should receive leucocyte reduced blood components – pre-storage reduced leucocytes for reduced cytokines , Red cell component – fresh / washed.

-For platelets - residual plasma removed.

-Reducing leucocytes to less than < 5 x 10⁸ in one unit

of RBC prevents most of Non-hemolytic febrile

transfusion reactions.

-To prevent CMV transmission or alloimmunisation to

HLA antigen, leucocyte content is reduced to

< 5 x 10⁶ in a unit of RBC.

-Donor lymphocytes reacting against host antigen may

cause GVHD.

-Leucoagglutination in recepient may lead to

Transfusion Related Acute Lung Injury (TRALI) &

pulmonary edema.

• Leucocyte reduced Red Blood Cells:

Methods of preparation:

-Centrifuging and removing of buffy coat

-Filtration

-Washing RBC’s with saline

-Freezing and thawing of RBC’s

Can be done at:

-Prestorage – on collection

-After storage – before issue Disintegrated leucocytes & cytokines

may cause FNHTR & HLA alloimmunisation

-Bed side filtration

Indications for use:

• Multitransfused patients like thalassemia & other haemoglobinopathies

• Aplastic anemia

• Immunosuppressed

• Immunodeficient

• Multiparous women

• Prevention of FNHTR

• Prevention/ delay of primary alloimmunisation to HLA antigen

• Prevention of CMV transmission in at risk individual.

Indications under investigations:

• Prevention of platelet refractoriness due to

alloimmunisation

• Prevention of recurrent FNHTR to platelets

• Prevention of reactivation of latent CMV or HIV

infection.

Washed red cells :

-Washing of red cells removes 70 – 95% of leucocytes

and there is concomitant 15 – 20ml of RBC’s but

effective in removal of plasma proteins and

microaggregates.

Indications:

-Patients having recurrent attacks of FNHTR and

urticarial reactions.

-Patients who have developed antibodies to plasma

proteins

-IgA deficient patients who has developed anti IgA

(IgA deficiency prevalent in 1 in 700 persons)

FROZEN RED CELLS:

-Frozen red cells in high glycerol can be preserved at

-65⁰C before thawing for 10 years & -120⁰C in low

glycerol for 3 years and both can be used after

thawing for 24 hrs if stored at 2-4⁰C

IRRADIATED RED CELLS:

Gamma radiated to destroy T-Lymphocytes to prevent

GVHD in severely immunocompromised, Stem cells

/Bone marrow transplant Lymphoma & intrauterine

transfusions.