Manufacture of blood products

Manufacture of blood products

Manufacture of blood products


No units made each year

§   1.9 million red cells

§   FFP / Cryo 400,000

§   Platelets 200,000

§   Granulocytes 1000


Specifications for blood products




Red cells



>240 x 109 in >90%

HCT >0.55

FVIII > 0.7u/mL


150-350 mL

250-300 mL

273 +/-17


<1 x 106

<5 x 106



5d at 22oC

35 d at 2-6oC

14d pre / post irradiation

2 years at -30oC


Thawed at 37oC

Time allowed at room temp

5d from donation

4 hours at 22oC


4 hours at 22oC

24 hours at 4 oC



1. Donor selection

§   Categories of blood donor voluntary v paid v replacement v directed v autologous

§   Guidelines made by UKBTS / NIBSC professional advisory committee (consult EU directives, department of health, minority interest groups eg Terrence Higgins Trust, Commission for racial equality, disability groups, scientific advisory groups)


§   Donor safety

§   Weight >50kg

§   Age > 17 / <66 for first time donation (no limit providing they have donated in the last 2 years)

§   Hb >12.5 F / >13.5 M

§   Pregnancy (until child 9 months old)

§   Medical conditions (Cardiovascular disease (hypertensives allowed providing no changes in medication, Epilepsy, Respiratory diease, renal / liver failure)

§   Awaiting medical investigations

§   Dangerous occupation (e.g. fighter pilot)

§   Frequency of donation limited to 1500mL /year due to risk of iron deficiency (minimum interval 12 weeks - median donations 1.4/yr)

§   Previous severe reaction (late faints)


§        Recipient safety (donor questionnaire reduces risk 40-fold)

§        Permanent exclusions

§        Chronic infections HIV / Hep B carrier / Hep C carrier / HTLV

§        Malignancy (except SCC / CIN) / autoimmune disease / disease of unknown aetiology (all of which could be viral)

§        vCJD risk

·        Previous blood transfusion

·        Transplant recipient

·        Growth hormone / fertility treatment

·        Neurosurgery pre 1992 (due to use of duramater patches)

§        Donor has high risk behaviour

·        MSM

·        Money for sex

·        IVDU

·        Sex with a partner from sub-saharaAfrica

§        Red cells defective (G6PD deficiency / spherocytosis) HbS trait alright providing no problems with leukodepletion filters

§        Temporary exclusions

§        Sex with someone high risk

§        HIV/Hep B/Hep C

§        Women who have had sex with bisexual men or a sex with a partner has ever been an IVDU or prostitute

§        Someone from sub-Saharan Africa (unless left as a child or pre 1977)

§        Piercing / Tattoos

§        Flexible endoscopy

§        Travel

§        Malaria-endemic country (6 months)

§        West Nile (USA  Canada May-Nov/ Chickungunya (28 days)

§        Drugs (e.g. Roacutane – teratogenic, aspirin alright but need to discard platelets)

§        Live vaccines (8wks) eg oral polio, typhoid, yellow fever, measles, rubella, small pox

§        Other aspects of donor care

§        Language barrier / ability to give informed consent

§        Requested to contact NBS if they develop infection within 14 days of donation

§        Disability alright providing able to transfer from wheelchair to bed in case of faint


Donor side effects

1.      Fainting (Late faint particularly dangerous – excluded)

2.      Bruising

3.      Neurological injury – tingling in fingers

4.      Phlebitis (treated with abx / analgesics)

5.      AV fistula (1:50,000)

6.      Iron deficiency (pre anaemic – reduced memory / lassitude)



2. Processing quality control

§        Quality control (to detect non-conforming products or services)

§        Checking / testing manufacturing procedures

§        Quality assurance (to prevent detect and correct variation and errors)

§        Management procedures / SOPs

§        Root cause analysis of errors / serious adverse events

§        Essential minimum requirements

§        Processes must be reliable and perform consistently

§        Contingency planning (eg blood packs come from 3 manufacturers in case one manufacture has quality control problems)

§        Inspection

§        Self inspection (CPA)

§        MHRA inspection to comply with EU directive



§        Quality control of all aspects of processing

§        WC in leukodepleted blood <106

§        Environmental monitoring for bacteria

§        Evaluation of product eg platelets if there are changes in the manufacturing process

§        In vitro (minor change eg altering a filter)

§        pH, lactate, ADP, Platelet activation studies, markers of apoptosis

§        In healthy volunteers

§        Radiolabel to measure platelet recovery and survival post transfusion

§        In patients (if major change eg changing shelf life as expensive)

§        Count increments

§        Assessment of bleeding score (large number)

§        Same true of red cells (HCT, Hb, haemolysis, K, pH, lactate, ATP, 2,3 DPG in vitro / radiolabelling / tissue oxygenation in patients (impossible!)) and FFP (PT/APTT/Coagulation factors/vWF activity/global assays (TEG) in vitro; clinical studies v difficult as would want to show correction of bleeding).


3. Screening tests

Mandatory testing

HIV (1:6 million)

§   Anti-HIV and Ag (seroconverts 1 month)

§   NAT (window period 12d)

HCV (1:40 million)

§   Anti HCV and Ag (seroconverts at around 2 months)

§   NAT (window period 15-20d)

HVB (1:800,0000)

§   HBsAg

§   HBcAb (discretionary – if tattoos / piercing since first donation)

§   Due to commence NAT testing will reduce window period to 2-3 weeks from 3 months  / risk to 1:2 x106



§   TPPA

HTLV (1:1 million)

§   Anti-HTLV ELISA on NAT pools as high Ab titres persist in infected people


Positive results

§   False positives for most tests outnumber the true positives by a factor of 50:1 therefore need repeat testing at the reference laboratory.

§   Managed centrally with standard letters (sent out early in week, donor allowed to contact for advice)

§   Interviewed for HIV and referred (mechanism for dealing with non responders)


Discretionary testing



1.      Visitors – defer for 6 months and malaria Ab test or defer 12 months (no test needed)

2.      Residents (lived in malaria area for more than 6 months) must have malaria Ab test at first visit and after every donation when they have been to a malaria area

3.      Previous malaria – defer for 3 years and then treat as a resident


Hepatitis A - serology



§        Used in people at risk of HB from tattoo / piercing as there is a window period in people who are seroconverting when the HBsAg has disappeared prior to high levels of HBsAb developing in which they are infectious (HBcAb rises earlier than HBsAb)


T. Cruzi

§        Test on first visit if donor or donors mother born in S. America

§        Defer 6 months if primitive subsistence farming for >4 wks then test


West Nile virus

§        Seasonal (May to Nov) in US / Canada – defer 28 days – testing not practical as take 28d to come back



§        Most areas also have malaria - only MauritiusSeychelles, Reunion, Ravena Italy not – defer 28d


Emerging threats

Surveillance sources (HPA in UK; ECDC in Europe; CDC in US; WHO)

§   SARS

§   Dengue

§   CCHF


Hepatitis B interpretation







First to rise (before onset of jaundice)

Found in active and chronic carriers

Appears late and indicates immunity. 

Also detectable after vaccination


Present in acute hepatitis

If found in chronic ® persitence of infectivity

Anti-HBeAb in chronic infection indicates low infectivity (may develop HCC)

Lack of anti-HBeAb indicates high infectivity


Not seen in blood

Anti-HBc IgM appears earlier than HBsAb and is used cover the period where (HBsAG has disappeared prior to anti-HBs antibodies developing)

IgG indicates past exposure (differentiates from vaccination)


Chronic infection (5%)

a)   Low replication (HBsAG + anti-HBe / HBV DNA)

§        usually asymptomatic with normal LFTs

§        low infectivity

§        may develop HCC

b)   High replication - Chronic Active (HBsAG + HBeAG)

§        progressive liver injury

§        leads to fibrosis and cirrhosis / HCC


Bacterial contamination

1:350 platelets (skin organisms – S. Epi / Aureus / Serratia) kills 1:170,000

§        New rules coming in – test platelets at 5d and if negative can transfuse up to day 7

1:1500 blood (Y. Enterocolitica / Pseudomonas Putida or Fluorescens)

§        Around 3 cases per year clinically apparent – 25% mortality


Preventative measures

1.      Closed bag system

2.      Donor arm cleansing

3.      Divert pouch

4.      Storage at 4C for blood

5.      Short shelf life for platelets (5 days)

6.      Environmental monitoring (eg ensuring centrifuge clean)


4. Storage

§   Blood stored at 4C, reducing bacterial contamination

§   Carefully monitored cold chain

§   If cold storage fails likely to destroy products unless minor infringement on a very large scale in which testing might be used to confirm product still within specifications.


5. Pathogen inactivation

§        Methylene blue treatment of FFP

§        Plasma put into illumination bag with methylene blue

§        Then illuminated for 30 min disrupts DNA in the sample

§        Methylene blue then removed with a filter

§        Amotosalen

§        Similar system to methylene blue (involving illumination resulting in DNA crosslinking and killing of viruses, bacteria and leukocytes)

§        Concerns about removal at the end of inactivation


§        Solvent detergent

§        Can transmit parvovirus and hep A (non lipid coated viruses)

§        Reduced risks of TRALI / anaphylactic reactions as pooled product


6. Better blood transfusion

§   Ensuring that transfusions not given inappropriately

§   Previous wide variation in transfusion practice (up to of 20% transfusions given inappropriately)

§   Training of staff

§   MLSO training

§   Maximum blood scheduling


7. Surveillance / tracing

§        IT facilities to trace each product from the donor to patient

§        Allows forward and reverse analysis of cases

§        SHOT

§        Errors in transfusion (30% sampling; 40% collection and administration; 30% laboratory)

§        Archiving of samples for 3 years – 300mL for viral testing

§        Phone line for donors to call if unwell following a donation

§        Remove donations if diarrhoea….

§        Can give IVIg to protect against Hep A / B (EBV)


Donor Apheresis

Can perform apheresis for plasma, platelets, red cells, granulocytes, lymphocytes or stem cells)


1. Platelets

§        Currently around 80% of platelets (target 100%)

§        Advantages

§        Reduced donor exposure

§        Ability to provide HLA / HPA matched products

§        Provision of ‘neonatal’ platelets

§        Disadvantages

§        Cost

§        Recruitment and retention more difficult (monthly donations / greater time commitment)

§        Percentage meeting specification not normally as high as pooled platelets

§        Loss of blood if haemolysis in the circuit or malfunction of apheresis machine

§        Donation

§        Tend to be large male donors (allows collection of more platelets) / females if negative for HLA / granulocyte antibodies

§        Able to make commitment to monthly donations each lasting up to 2h (max 15 /year due to iron deficiency – 100ml lost each time to the machine)

§        Good antecubital fossa viens

§        High platelet count

§        HLA matching

§        Only require class I matching

§        Homozygous donors useful (as can match a variety of patients)

§        Must irradiate to avoid GvHD

§        HPA matching

§        Panel of HPA 1a 5b negative platelet donors



2. Red cells

Double dose red cells

§        Advantages

§        Reduced donor exposure

§        Known motivated donors who have been tested several times therefore increasing safety

§        Helps to maintain stocks of rarer blood groups (eg O neg and very rare blood groups)

§        Standardised product in terms of red cell volume

§        Average donation frequency 1.3 x per year therefore could double the amount of blood donated at a single yearly visit.

§        The apharesis machine will filter and add SAG-M therefore saving processing costs

§        Disadvantages

§        More expensive overall (especially equipment costs)

§        Donors for DRC need to weigh >70kg and have an Hb >14

§        Increased donor commitment and length of donation (but now down to 35 mins)

1+1 (single dose red cells and single dose platelets)

§   Not used much as need 3 visits /year and only obtain 3 pools of platelets cf up to 15 pools platelets if pure platelet donor

§   Quality of red cells also lower than standard red cells Hb 50g v 56g

§   Group O donor wanted for blood / Group A donors for platelets


3. Plasmapheresis

§   Done in many countries to allow production of albumin . factor VIII, anti-D etc.

§   All plasma imported in the UK due to the risk of CJD


Indications for CMV

§        CMV seronegative patients

§        Potential candidates for stem cell or imminent solid organ transplant

§        Within 6 months of autograft

§        Allograft if donor negative

§        HIV

§        IUT

§        Neonates and infants up to 1 year

§        Pregnant women


Irradiated blood products

Cellular blood components (red cells / plts) to prevent TaGVHD

§        HLA disparity

§        Natural killer/ T-lymphocyte mediated

§        90% mortality

§        Target organs

§        Skin

§        Thymus

§        GI tract

§        Spleen/ liver/ bone marrow

§        Onset is 1-2 weeks after transfusion

§        Diagnosis

§        Skin biopsy

§        Confirmation of persistence of donor lymphocytes in recipient done by analysis for RFPs

§        Irradiation

§        At least 25Gy – prevents cells from multiplying (doesn’t change function – NB for granulocyte infusions)



§        Allo

§        Donors

§        Within 7-14 days of harvest

§        Recipient

§        Conditioning to 6 months post or immunosupression stopped (lymphocytes >1)

§        Auto

§        Within 7-14 days of harvest to 3 months post (6 months if TBI)

§        Hodgkin’s disease

§        Purine analogue (fludaribine/cladaribine) and campath

§        Granulocyte/ buffy coat

§        HLA-matched blood components

§        Donations from family members

§        IUT

§        Transfusions for babies that received IUT (up to 1 year)

§        Exchange transfusion in neonate

§        Congenital immunodeficiency (includes Di George)

§        Except mucocutaneous candidiasis


Red cell shelf life reduced to 14d following irradiation (no change in platelet shelf life)


Regulation of blood transfusion


WHO – ethical principles


EU directives (2002/98/EC and 2004/33/EC) have been transposed into UK law through the Blood Safety and Quality Regulations 2005

§        Monitored by the MHRA

§        Cover the following areas:

1.      Quality management

2.      Traceability (vein to vein – kept for 30 years)

3.      Haemovigilance

4.      Processing – only done in blood establishment

5.      Education and training


Better blood transfusion (NHS circulars)


§   Hospital transfusion committee

§   Participation in SHOT

§   Encourage cell salvage


§   Hospital transfusion team


§   Avoid unnecessary transfusion in obstetric practice / and minimise HDN

§   Improved public involvement


NHS litigation authority

Has criteria which if attained will reduce the trusts insurance premiums


Clinical pathology accreditation

§        Peer review audit every 3 years with an interim inspection

§        Not compulsory but would be difficult to function without accreditation (needed for private work, research etc.)

§        Look at staffing, procurement, maintainance, clinical interface and results reporting



National patient safety agency

§        SPN 14 Training and competency assessment of everyone involved in transfusion