Transfusion and Blood Donation

Flashcards covering key vocabulary and concepts related to blood transfusion, blood donation, and related processes, as taught in the lecture notes.

Learning outcomes

Regulatory bodies involved in the transfusion process, blood donation, safety aspects, cost implications, and methods to monitor blood stocks.

Blood supply chain

Donation center -> blood center -> hospital blood bank -> patient, with vein to vein traceability required.

Multiple regulatory bodies for Blood safety

Blood Safety Quality Regulations 2005, BSH guidelines, NICE guidelines, Guidelines for the Blood Transfusion Services in the UK, UK Transfusion Laboratory Collaborative, Safety of blood, tissues and organs, Serious Hazards of Transfusion, Joint United Kingdom Blood Transfusion and Tissue Transplantation Services Professional Advisory Committee, Health and Care Professions Council, General medical council, UKAS ISO15189, Medicines and Healthcare products Regulatory Agency

Blood tracking

Electronic tracking and vein to vein audits of blood components, tracing cold chain adherence, recording temperatures, real-time updates of unit fate, full electronic traceability, reduces human interaction, records kept for 30 years.

Blood donation in the UK

All blood components are sourced from donations made by voluntary unpaid donors in the UK.

Two purposes of donor selection

Protect the donor from harm and protect the recipient from any ill effects of transfusion.

Donor requirements

Fit and healthy, weigh between 50kg and 158kg, aged between 17 and 66 (or 70 if you have given blood before), over 70s that have given a full blood donation in the last two years.

Clinical donor restrictions

minimum pre-donation Hb concentration is 125 g/L for female donors and 135 g/L for males; Donors asked to donate ~470ml of whole blood

Donor criteria reason

Underlying illness may be more important than the drug itself. Teratogen?,ACE inhibitors?; Don’t want to be borderline anaemic before surgery – may bleed and require transfusion; Cancer caused by blood borne virus?; Antibodies in the blood that may cause an issue?; Could affect glucose control; Possibility of infection; High risk sexual activity; Drug use; Recent Tattoo/Piercing

Transfusion Transmitted Infections

chronic and persistent infection.Present as healthy individuals and still pose a risk of transmitting infectious agents

In the UK, all donations are screened for:

HBV, HCV, HEV, HIV1 and HIV2, HTLV 1 and HTLV 2, Treponema palladium (Syphilis)

Optional testing for blood donations:

Malaria, West Nile Virus, Cytomegalovirus (CMV), Trypanosoma cruzi (Chagas disease)

variant Creutzfeldt–Jakob Disease

Caused by same agent as Bovine Spongioform Encephalopathy (BSE) in cattle or ‘mad cow disease’. Disease causing agent is a PRION

Leucodepletion

Introduced to minimise transmission of vCJD via the blood supply and removes (99.9% of) white cells from all blood products

NHS Blood & Transplant (NHSBT)

Provides blood components and tissues for transplantation: Blood components; Stem cell transplants; Solid organ tissues & Tissue bank

Whole blood processing separates into

Red Blood Cells (RBCs); Platelets; Plasma products (Fresh Frozen Plasma (FFP) & Cryoprecipitate (Cryo))

Blood components

RBCs - ↑Hb & Bleeding; Platelets - Bleeding & ↓ platelet count; FFP - Clotting proteins, Albumin & Bleeding; Cryoprecipitate - Clotting proteins & Severe bleeding

Red cells

~300ml RC per unit, Leucodepleted SAGM, Tx within 4 hours, Increase the Hb by ~10g/L

Platelets

Store: 20-24ºC, agitated Shelf life: 5-7 days; Major bleeding: <50 x10⁹/L; Minor procedures: <20 x10⁹/L

Fresh Frozen Plasma (FFP)

Store: <-25ºC Shelf life: Frozen: 36 months Thawed: 4ºC – 24hrs RT: 4hrs; Dose:15ml/kg body weight &male donors only (TRALI)

Cryoprecipitate (Cryo)

Rich in FVIII, vWF, Fibrinogen, FXIII & Fibronectin;1x ATD = ↑ Fibrinogen by ~1g/L

Controlled storage & transport

Correct conditions (temperatures) to ensure cells remain viable, safe and clinically effective; Red cells must be stored at 4 - 6°C

Supply and demand

Sufficient supply of donations is essential to the maintenance of healthy stock levels. 4-6% of the eligible adult population donate blood

Blood Stocks Management Scheme (BSMS)

Aims to calculate how much blood is in the supply chain at any one time

Learning outcomes for Transfusion Scientist

Understand the antigens/antibodies involved in the ABO system & RhD; Understand the inheritance of the ABO and RhD antigens; Understand ABO & RhD testing in the laboratory & identify ABO blood group test results & Understand the implications of ABO incompatibility

ANTIGEN

A substance capable of stimulating production in an individual lacking that substance and have specific antigen-binding sites

ANTIBODY

Immunoglobulin produced in response to the introduction of a foreign antigen, stimulated by the immunogenic part of the antigen. Made by Memory B cells (lymphocytes)

Understanding Transfusion

Antibodies are created in response to ‘foreign’ antigens & help the immune system distinguish ‘self’ from ‘non-self’

RC antigens may be:

Carbohydrate attached to lipid; Carbohydrate attached to protein and Protein

ABO blood group system

Structural/ protective & A, B

Rh blood group system

Structural, transport & D, C, c, E, e

ABO inheritance

Inherit 2 alleles from a possible 3, The A & B alleles are DOMINANT, The O allele is recessive & The A & B alleles are CO-DOMINANT

Anti-A & Anti-B antibodies:

IgM, Naturally occurring (≥4 months) & Capable of causing intravascular haemolysis

Group O:

No naturally occurring antibodies & Considered universal donor

RhD antigen

Most immunogenic out of all systems (except ABO), Exposure to <1ml Rh+ RBCs can stimulate antibody production in a Rh- individual & Typically causes delayed (rather than acute) transfusion reactions

RhD antigen characterizations

Anti-D produced is a polyclonal mix of anti-Ds to each epitope!; RhD antibodies are IgG class NOT naturally occurring

Transfusion request form:

Strict labelling criteria, Clinician signature, Clear & unambiguous & Clinical details essential & Uniquely barcoded

ABO testing

Patient's blood is separated into RED CELLS and PLASMA by centrifugation, Red cells (expressing antigen) are mixed with a commercial serum containing known antibody

Column agglutination

Ready assembled test system

Sample arrival

Sample receipt in lab à Sample integrity & labelling checks à Checking patient history à Booking in requested tests à Sample preparation & analyser loading

Normal blood grouping reactions

Your turn! Understanding normal blood grouping reactions given a chart

What's so bad about an antibody meeting their antigen anyway?!

RBC Agglutination, Phagocytosis & Complement Antibody mediated RBC destruction

Intravascular Haemolysis: Blood results:

FBC, Morphology & Biochemistry

RBCs - What happens if… ?

Think about the naturally occurring antibodies present in the patient’s plasma!

Platelets - What happens if… we give the wrong blood group?

Plt RhD status is less significant regarding plasma products

Plasma products - What happens if…

Think about the antibodies present in the plasma product AND the antigens present on patient’s RCs!

Learning outcomes from understanding inappropriate use of specific blood components

Understand the antigens/antibodies involved in the ABO system & RhD Understand the inheritance of the ABO and RhD antigens Understand ABO & RhD testing in the laboratory & identify ABO blood group test results Understand the implications of ABO incompatibility

Acceptable reason to use RCs blood product

Relieve symptoms of anaemia

Acceptable reason to use FFP blood product

Rebalance haemostasis (Bleeding)

In case of emergency…

Considered Universal Donor*

Issue problems

Remember….. NEVER EVER WASTE BLOOD PRODUCTS!!!

Reported cases

Near Miss Events

Do something amazing…

Give blood!!, Sign up to the donor registry & tell your friends and family about your decision, Sign up to the British Bone Marrow registry & Sign up to the Anthony Nolan Bone Marrow registry