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Transfusion Medicine - Comprehensive Notes

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1. Blood Safety and Principles of Clinical Transfusion Practice

Blood Safety

1. A nationally coordinated blood transfusion service - centralized, quality-managed, with a national blood policy.
2. Collection from voluntary, non-remunerated regular donors - family/replacement donors and paid donors carry higher risk of transfusion-transmissible infections (TTIs).
3. Testing of all donated blood - mandatory screening for HIV, HBV, HCV, syphilis, and malaria (in endemic regions). NAT (nucleic acid testing) reduces the window period significantly.
4. Rational use of blood - avoid unnecessary transfusion; use alternatives where possible.

• Pre-donation donor deferral (permanent and temporary)
• Blood component therapy (use only what the patient needs)
• Leucodepletion (reduces febrile reactions, CMV transmission, HLA alloimmunization)
• Pathogen reduction technologies (PRT) - Intercept, Mirasol, THERAFLEX
• Haemovigilance - systematic surveillance of adverse events

Principles of Clinical Transfusion Practice

1. Transfuse only when clinically indicated - no threshold-based automatic transfusion; use the patient's clinical state.
2. Restrictive strategy is generally preferred - haemoglobin threshold of 7-8 g/dL for stable patients; 8 g/dL for cardiac patients (supported by the TRICC and FOCUS trials).
3. Patient Blood Management (PBM) - a multidisciplinary, evidence-based approach to optimize the patient's own blood:
   • Preoperative anaemia correction (iron, EPO)
   • Intraoperative blood conservation (cell salvage, antifibrinolytics)
   • Tolerance of anaemia in the postoperative period
4. Informed consent - patient should be informed of risks and alternatives.
5. Correct identification - two-point identification of patient and blood unit (bedside check) is mandatory.
6. ABO/Rh compatibility - never transfuse ABO-incompatible blood.
7. Pre-transfusion testing - ABO/Rh typing, antibody screen, crossmatch.
8. Rate and monitoring - most transfusions given over 1.5-4 hours; monitor vitals at start, 15 minutes, and end.
9. One unit at a time - reassess need before each unit.
10. Acute transfusion reactions - stop transfusion immediately if suspected haemolytic, anaphylactic, or TRALI reaction.
11. Documentation - complete records of indication, component, volume, reaction.

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2. Platelet Concentrate Preparation, Recent Modifications, Principles of Transfusion, and Platelet Substitutes

Methods of Preparation

1. Platelet-Rich Plasma (PRP) method (Slichter method):
   • Whole blood centrifuged at LOW speed (soft spin) → PRP separated
   • PRP centrifuged at HIGH speed (hard spin) → Platelet pellet
   • Plasma removed; platelets resuspended in 50-70 mL residual plasma
   • Yield: ~5.5 × 10¹⁰ platelets per unit
2. Buffy Coat (BC) method (European method):
   • Whole blood centrifuged at HIGH speed → buffy coat layer isolated
   • Four to six buffy coats pooled and centrifuged at LOW speed
   • Platelets remain in suspension; leucocytes/RBCs pellet out
   • Advantages over PRP: Less leucocyte contamination, better pH maintenance, less platelet activation, longer shelf life
   • Standard in Europe; increasingly preferred globally

• Collected via automated apheresis (MCS+, Trima Accel, Amicus, Spectra Optia)
• One collection = 3-8 × 10¹¹ platelets (equivalent to 4-6 RDP units)
• Advantages: Reduced donor exposure, lower HLA alloimmunization risk, CMV-safer, suitable for refractory patients

Recent Modifications in Technique

1. Pathogen Reduction Technology (PRT):
   • Intercept Blood System (Cerus Corporation): Uses amotosalen (psoralen) + UVA light - cross-links nucleic acids of bacteria, viruses, and protozoa. Also inactivates leucocytes.
   • Mirasol (Terumo BCT): Riboflavin + UV light
   • THERAFLEX UV-Platelets: UVC light alone
   • Benefits: Reduces bacterial contamination risk (leading cause of platelet-associated sepsis), eliminates need for bacterial culture testing, prolongs shelf life potential
2. Extended shelf life (7 days): With bacterial detection or PRT, some countries allow storage up to 7 days vs standard 5 days.
3. Cold-stored platelets (4°C):
   • Traditionally discarded; recent evidence shows cold-stored platelets (in presence of TPO receptor agonists) have better haemostatic function in trauma and bleeding patients
   • Phase II trials show promise
4. Additive solutions (PAS - Platelet Additive Solutions):
   • PAS-III (Intersol), PAS-E, etc. - replace 65-80% plasma with synthetic additive
   • Reduces plasma-related transfusion reactions (TRALI, allergic reactions)
   • Allows plasma harvested for fractionation
5. Cryopreserved platelets (DMSO): For rare blood groups, military use; being re-evaluated.

Principles of Platelet Transfusion

• Therapeutic: Active bleeding with thrombocytopenia (<50,000/µL for surgery, <100,000 for CNS/ocular surgery)
• Prophylactic: Platelet count <10,000/µL in stable haematology patients; <20,000 in febrile/septic patients

• Adults: 1 unit RDP per 10 kg body weight or 1 apheresis unit
• Expected increment: 5,000-10,000/µL per RDP unit; 30,000-60,000 from one apheresis unit

• HLA-matched or crossmatch-compatible platelets for refractory patients
• Irradiation for immunocompromised patients (prevent TA-GvHD)
• CMV-negative or leucodepleted for CMV-negative recipients
• ABO-compatible preferred (ABO antigens on platelets)
• Rh(D) negative platelets preferred for Rh(D) negative females of childbearing potential

Platelet Substitutes

1. Lyophilized (freeze-dried) platelets (Stasix, Thrombosomes by Shire): Processed platelets that retain haemostatic function, room temperature storage, long shelf life. Used in military trauma.
2. Infusible Platelet Membranes (IPM): Sonicated and dried platelet membrane fragments that bind to fibrinogen and help plug wounds.
3. Plateletsome / Synthocyte: Liposomes coated with platelet surface glycoproteins (GPIb, GPIIb/IIIa) - synthetic platelet mimics.
4. Hemospheres: Albumin microspheres coated with fibrinogen - bind to activated platelets at bleeding site.
5. Thromboerythrocytes: RBCs surface-modified with platelet-like properties.
6. TP10 (Soluble Complement Receptor 1): Experimental - not yet platelet substitute per se but modifies platelet activation.

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3. Advances in Antibody Screening, Compatibility Testing, and Blood Grouping

Blood Grouping - Advances

1. Gel Column Agglutination Technology (CAT) / ID-System (Bio-Rad):
   • Blood mixed with reagents in microtube filled with Sephadex gel
   • Agglutinated cells trapped in gel; non-agglutinated cells pellet to bottom
   • Standardized, objective, less technically demanding, permanent record
   • Can perform ABO, Rh typing, antibody screen, DAT, elution, crossmatch
2. Solid Phase Red Cell Adherence (SPRCA):
   • Red cell antigens or antibodies immobilized on microplate wells
   • Agglutinated cells adhere to well surface (positive); non-agglutinated pellet
   • Automated, high-throughput, reproducible
3. Microplate/Microtiter technology: Adapts tube methods to 96-well format for high-volume testing.
4. Molecular Blood Grouping (Genotyping):
   • PCR-based (PCR-SSP, PCR-RFLP) or SNP microarrays
   • BeadChip (BioArray Solutions / Immucor): Tests >2,000 alleles across 40+ blood group systems in one assay
   • Progenika/Grifols ID CORE XT array
   • Applications:
     • Patients with recent transfusion (serological typing unreliable)
     • Sickle cell/thalassaemia patients needing extended phenotype matching
     • Weak/partial antigens (partial D, DEL phenotype)
     • Resolving discrepancies
     • Fetal genotyping from maternal plasma (non-invasive prenatal testing - NIPT) - prevents HDFN
5. Next-Generation Sequencing (NGS) in blood grouping: Comprehensive allele resolution; identifies novel alleles.

Antibody Screening - Advances

1. Column agglutination with enzyme-treated cells or PEG (polyethylene glycol) enhances detection of weak antibodies.
2. Solid phase systems - high sensitivity.
3. LISS (Low Ionic Strength Saline) - reduces incubation time, enhances antigen-antibody binding.
4. PEG-IAT (Polyethylene Glycol Indirect Antiglobulin Test): Most sensitive method for detecting clinically significant alloantibodies.
5. Gel card with polyspecific AHG - detects IgG and complement simultaneously.

Compatibility Testing - Advances

1. Electronic Crossmatch (Computer Crossmatch): No physical mixing of patient and donor blood; computer algorithm confirms ABO/Rh compatibility using historical and current typing results. Requires: two ABO typings on different samples, negative antibody screen. Approved by AABB; saves time (blood available in 5 minutes vs 45+ minutes for serological crossmatch).
2. Type and Screen (T&S): Replace routine crossmatch for low-risk procedures. Blood held available; crossmatch done only if needed.
3. Immediate Spin Crossmatch (IS XM): Detects ABO incompatibility only; used when antibody screen is negative.
4. Full Serological Crossmatch (AHGXM): Required when antibody screen is positive or incompatible.
5. Automation:
   • Ortho Vision Max, Immucor Neo, Bio-Rad IH-500 - fully automated platforms integrating typing, screening, and crossmatch
   • Barcode-driven sample and unit tracking
   • Bidirectional LIS/LIMS interface
   • Reduced clerical errors, TAT
6. NAT in infectious disease screening: Transcription-mediated amplification (TMA) and real-time PCR have dramatically reduced the window period:
   • HIV: from 22 days to 9 days
   • HCV: from 70 days to 7 days
   • HBV: from 50 days to 38 days

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4. Autologous Stem Cell Transplantation (ASCT) in Haematological Malignancies

Definition

Source of Stem Cells

• Peripheral blood stem cells (PBSC): Most common; mobilized from bone marrow by:
  • G-CSF (filgrastim, lenograstim) ± plerixafor (CXCR4 antagonist)
  • Harvested by apheresis when CD34+ cells ≥10/µL (target: 2-5 × 10⁶ CD34+ cells/kg)
• Bone marrow harvest: Rarely used now for autologous transplants
• Cryopreservation: DMSO (10%) as cryoprotectant; stored in liquid nitrogen at -196°C

Conditioning Regimens

Indications

• Multiple myeloma (MM) - upfront consolidation after induction (VRd → ASCT)
• Relapsed/refractory Hodgkin lymphoma (after DHAP/ESHAP salvage)
• Relapsed/refractory diffuse large B-cell lymphoma (DLBCL)
• Relapsed follicular lymphoma

• Peripheral T-cell lymphoma
• Mantle cell lymphoma
• Relapsed AML (selected patients, CR2)
• Primary CNS lymphoma
• Systemic AL amyloidosis

Procedure Steps

1. Mobilization + Apheresis
2. Cryopreservation (DMSO + controlled-rate freezing)
3. Conditioning chemotherapy
4. Day 0: Stem cell infusion (thaw and infuse)
5. Engraftment monitoring: ANC ≥500/µL for 3 consecutive days (typically day +10-14)
6. Platelet engraftment: >20,000 independent of transfusion (day +12-18)

Outcomes

• Transplant-related mortality (TRM): <5% in experienced centres (lower than allogeneic)
• No graft-versus-host disease (GvHD) - major advantage
• No graft-vs-tumour (GvT) effect - major disadvantage (hence higher relapse rate)
• Myeloma: Median PFS ~3-4 years; improved with maintenance lenalidomide (CALGB 100104, IFM 2005-02 trials)

Recent Advances in ASCT

1. Tandem ASCT: Two consecutive autologous transplants (myeloma, germ cell); EMA-19 trial showed benefit in high-risk myeloma.
2. Maintenance therapy post-ASCT: Lenalidomide maintenance becomes standard of care in myeloma.
3. CAR-T vs ASCT: TRANSFORM and ZUMA-7 trials showed CD19 CAR-T superior to ASCT in relapsed/refractory LBCL.
4. Auto-allo sequential transplant: ASCT followed by reduced-intensity allogeneic - for high-risk patients.
5. Minimal Residual Disease (MRD) monitoring: Next-generation flow cytometry and NGS post-ASCT guide therapy decisions.
6. Improved supportive care: Posaconazole prophylaxis, letermovir (CMV), G-CSF, and PEG-filgrastim for engraftment.

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5. Problems in Paediatric Blood Transfusion

Key Problems

• Neonatal blood volume: 80-100 mL/kg; premature: 95-105 mL/kg
• Dose: 10-15 mL/kg of pRBCs (raises Hb by ~2-3 g/dL)
• Small volumes (paediatric aliquots) must be prepared from adult units
• Volume overload risk with standard adult units

• Maternal IgG anti-HPA-1a (most common) crosses placenta → fetal platelet destruction
• Presents with intracranial haemorrhage, purpura
• Treatment: HPA-1a-negative washed maternal platelets or HPA-1a-negative random donor platelets + IVIG

• ABO (mild), Rh (severe), Kell (severe - suppresses erythropoiesis)
• Intrauterine transfusion (IUT): O-negative, CMV-neg, irradiated, washed, Kell-negative blood at 75-85% haematocrit
• Exchange transfusion: double-volume exchange (2 × 85 mL/kg) for severe neonatal jaundice

• Immunocompromised neonates/children cannot eliminate donor lymphocytes
• Fatal in >90% - unique rash, diarrhoea, pancytopenia
• Prevention: Irradiation of all cellular components (25 Gy) for:
  • Premature neonates (<1200g)
  • Intrauterine transfusion recipients
  • Congenital immunodeficiency
  • Directed donor transfusions
  • HLA-matched/crossmatch platelets

• Neonates (<1200g) and immunocompromised children are at risk
• Prevention: CMV-seronegative blood or leucodepleted blood (equivalent efficacy)

• Large volume/rapid transfusions → hypocalcaemia (citrate toxicity), hyperkalaemia (stored blood leaks K+), acidosis, hypothermia
• Warm blood (blood warmers) for exchange transfusions and large volumes

• HCT >65% → partial exchange transfusion with normal saline or albumin

• Chronic transfusion program for primary stroke prevention (TCD velocity >200 cm/s)
• Simple vs exchange transfusion
• Iron chelation needed with chronic transfusion (deferasirox)

• 10-15 mL/kg per transfusion
• Single donor apheresis preferred to minimize donor exposure
• Leuco-depleted, irradiated for immunocompromised

• Fresh blood (storage <7 days) preferred in neonates for better RBC function and lower K+ load
• Irradiation mandatory for the indications listed above
• Leucodepletion universal in most developed countries' paediatric programmes

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6. Synthetic Blood Products

A. Oxygen Therapeutics (Blood Substitutes / HBOCs / PFCs)

• Vasoconstriction due to NO scavenging
• Oxidative toxicity
• Short half-life (8-24 hours)
• Cardiovascular adverse events (increased MI, stroke in PolyHeme trial)
• Regulatory hurdles

• Perfluorocarbons dissolve O2 physically (not chemically like Hb)
• Oxygen delivery is proportional to FiO2
• Products: Fluosol-DA (first approved, withdrawn), Oxygent (Alliance Pharmaceutical - Phase III failed), Perftoran (Russia - approved), Oxycyte (Synthetic Blood International)
• Problem: Require high FiO2 (>60%) to be effective; short intravascular half-life; complement activation; currently no product approved globally

• Produced via E. coli or yeast expression systems
• Di-alpha Hb (crosslinked), Optro (Baxter) - discontinued
• Hemoglobin-based liposomes (artificial red cells) - research phase

B. Plasma Substitutes (Colloids and Crystalloids)

• Crystalloids: Normal saline, Ringer's lactate - not oxygen carriers but volume expanders
• Colloids: Albumin (human), hydroxyethyl starch (HES - now restricted due to renal injury), gelatin, dextran

C. Recombinant Coagulation Factors

• rFVIIa (NovoSeven): For haemophilia A/B with inhibitors, Glanzmann thrombasthenia; off-label in massive trauma haemorrhage
• Recombinant FVIII, FIX: Standard therapy in haemophilia A and B
• Recombinant fibrinogen concentrate (FCH): Under investigation for trauma and PPH
• 4-Factor Prothrombin Complex Concentrate (4F-PCC): For VKA reversal

D. Synthetic Platelets

E. Fibrin Sealants / Haemostatic Agents

• Tisseel, EVICEL: Human fibrinogen + thrombin - topical haemostasis in surgery
• Recothrom, Thrombin-JMI: Topical thrombin

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7. Automation in Blood Bank

Pre-Analytical Automation

• Automated sample sorting and labeling (barcode scanners, track systems)
• Automated sample receiving and centrifugation
• Pneumatic tube systems for urgent samples

Testing Automation

• ABO/Rh typing (forward and reverse)
• Extended antigen phenotyping (Kell, Duffy, Kidd, MNS)
• Antibody screen and identification
• DAT/IAT
• Crossmatch (serological and electronic)
• Elution studies
• Reflex testing algorithms
• LIS connectivity (bidirectional interface)
• Result interpretation with flag/alert system
• Traceability and audit trail

• Automated whole blood processing lines: Compomat G5 (Fresenius), Reveos (Terumo BCT)
• Process 4-6 units simultaneously; separate into RBC, plasma, buffy coat in closed system
• Platelet pools prepared from buffy coats in automated poolers
• Leucofiltration integrated into processing line

• Spectra Optia, Amicus, Trima Accel, MCS+ - automated apheresis for platelets, plasma, red cells, granulocytes, PBSC, therapeutic procedures

Post-Analytical / Inventory Automation

• Real-time inventory management
• Electronic crossmatch
• Expiry alerts
• Irradiator tracking
• Blood unit traceability from vein to vein
• Interface with hospital HIS/LIS

• Refrigerator monitoring (continuous temperature logging with alarms)
• RFID-tagged blood units for tracking
• Automated blood dispensing units (SmartFridge, Haemonetics BloodTrack)

• Reduced clerical/transcription errors (leading cause of ABO-incompatible transfusions)
• Faster turnaround time
• Standardized results (eliminates reader variability)
• Higher throughput
• Better documentation and traceability
• Frees technologist time for complex problem-solving

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8. Safe Blood Transfusion

The "10 Rights" Framework

Pre-transfusion Safety

1. Donor selection: Medical history questionnaire, deferral criteria (travel, behaviour, medications, recent illness)
2. Donation testing: HIV 1/2 (ELISA + NAT), HBsAg + anti-HBc + HBV-NAT, HCV (ELISA + NAT), syphilis (TPHA/RPR), malaria (in endemic areas)
3. ABO/Rh typing: Forward and reverse grouping; mandatory
4. Antibody screening: Detect unexpected alloantibodies
5. Crossmatch: ABO compatibility and detection of patient antibodies against donor cells
6. Correct labeling of blood component

At Bedside

• Dual identification of patient (name + date of birth + hospital number)
• Label check against patient wristband
• Visual inspection of bag (leaks, discolouration, clumps)
• Sign and date the compatibility form
• Use blood administration set with 170-200 µm filter

Monitoring During Transfusion

• Baseline vitals (BP, pulse, temp, SpO2) before starting
• Re-check at 15 minutes (most reactions occur here)
• Monitor at completion and 1 hour post
• Each unit to be transfused within 4 hours of leaving blood bank fridge

Adverse Reactions and Management

Haemovigilance

• Systematic monitoring of adverse events related to transfusion
• SHOT (UK), SAGM (France), FDA-MERS (USA), national programmes
• Data feeds back to improve safety practices and policy

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9. Umbilical Cord Blood Stem Cell Banking and Transplantation

What is Cord Blood?

Banking

• After delivery (vaginal or caesarean), cord is clamped and cut
• Blood drained by gravity or syringe from the umbilical vein into a sterile collection bag with anticoagulant (CPD or ACD)
• Average yield: 75-150 mL; minimum acceptable: 40 mL, minimum cell count: 5 × 10⁸ total nucleated cells (TNC)
• Entire process in 5-10 minutes, does not affect mother or baby

• Volume reduction (remove excess RBCs and plasma) using hydroxyethyl starch (HES) or automated systems (Biosafe Sepax, ThermoGenesis AutoXpress)
• DMSO (10%) added as cryoprotectant
• Controlled-rate freezing to -196°C in liquid nitrogen
• Sample stored; segment retained for testing (infectious disease, HLA typing, cell count)

1. Public cord blood banks: Donation for allogeneic use; HLA-typed and listed in international registries (BMDW, WMDA); examples: CBCCI (India), NMDP (USA), Anthony Nolan (UK)
2. Private cord blood banks: Family banking; stored for autologous or directed family use; controversial (AAP, ACOG discourage routine private banking due to low probability of self-use and cost)
3. Hybrid banks: Collection for public use with option to retrieve for private use (tested in Europe)

• Minimum TNC: 5 × 10⁸; CD34+ cells: >10⁶
• Viability post-thaw: >85%
• Sterility, infectious disease negative, HLA-typed (at minimum HLA-A, -B by low-resolution; -DRB1 by high-resolution)

Transplantation

• No risk to donor
• Immediately available (off-the-shelf)
• Ethnically diverse donors available
• Greater HLA mismatch tolerance (up to 2/6 mismatch acceptable vs 0/6 for BM)
• Lower GvHD incidence (naïve T cells, less alloreactivity)
• Lower risk of CMV and EBV transmission

• Limited cell dose - engraftment is slower (ANC recovery: day +26 vs +18 for BM)
• Primary graft failure rate higher (~10-15%)
• Delayed immune reconstitution → higher infection risk
• Cannot collect more cells from donor if graft fails

• Haematological malignancies (ALL, AML, CML, MDS, lymphoma) - when no matched sibling or unrelated donor
• Non-malignant: aplastic anaemia, haemoglobinopathies (sickle cell, thalassaemia), immunodeficiencies, metabolic storage diseases (Hurler syndrome)

Recent Advances in Cord Blood Transplantation

1. Double cord blood transplantation (dCBT): Two UCB units infused together (one ultimately dominates); allows transplantation in larger adults; higher relapse-free survival in some studies.
2. Ex vivo expansion of cord blood HSCs:
   • MGTA-456 (Magenta Therapeutics): 1-integrin antibody + nicotinamide adenine dinucleotide expansion → 20-fold expansion; Phase I/II trials show accelerated engraftment
   • StemRegenin-1 (SR1, AhR antagonist): 50-fold expansion in CD34+ cells; Phase I (PBSC-1 trial) showed rapid engraftment
   • Delta1-Notch ligand expansion (NiCord): Phase II data showed median neutrophil engraftment day 11 vs 25 controls
3. Cord blood-derived regulatory T cells (Tregs): For GvHD prevention and immune tolerance research.
4. iPSC derivation from cord blood: Less invasive, high-quality source for induced pluripotent stem cells.
5. MSCs (Mesenchymal Stem Cells) from Wharton's Jelly: For GvHD treatment, cartilage repair, neurological disease - Phase II trials ongoing.
6. Cord blood as source for gene therapy: Easier to transduce HSCs from cord blood; used in sickle cell gene therapy trials (LentiGlobin/betibeglogene).

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10. Recent Advances in Transfusion Medicine

1. Pathogen Reduction Technologies (PRT)

• Amotosalen-UVA (Intercept) for platelets and plasma; riboflavin-UV (Mirasol) for platelets and whole blood
• Extended to red blood cells: Amustaline (S-303) + glutathione system - approved in Europe for RBCs
• Eliminates known and emerging pathogens including Zika, Dengue, Chikungunya, T. cruzi

2. Whole Blood Resuscitation (Damage Control)

• Return to low-titer group O whole blood (LTOWB) for trauma/military settings
• PROMMT, THOR studies show whole blood equivalent to balanced blood component therapy (1:1:1 FFP:PLT:RBC)
• Logistically simpler, reduces cold ischaemia, contains all components

3. Patient Blood Management (PBM)

• WHO-endorsed global initiative (2010)
• Three pillars: optimize erythropoiesis, minimize blood loss, optimize physiological tolerance of anaemia
• Pre-operative IV iron sucrose/carboxymaltose corrects anaemia without transfusion
• Tranexamic acid (TXA) - CRASH-2 trial: reduces mortality in trauma; now standard in PPH, elective surgery

4. CAR-T Cell Therapy and Blood Banking

• Leukapheresis to collect T cells; transduced with chimeric antigen receptor
• Blood bank manages apheresis, cryopreservation, chain of identity
• FDA-approved: Kymriah (tisagenlecleucel), Yescarta (axicabtagene), Breyanzi, Abecma

5. Genomics in Transfusion Medicine

• High-resolution molecular blood grouping (BeadChip, SNP arrays, NGS)
• Predict RBC phenotype for complex patients
• Identify high-frequency antigen-negative donors from genomic databases (rare donor registries)

6. Artificial Intelligence in Blood Banking

• AI algorithms predict blood demand, optimize inventory, reduce wastage
• Machine learning for antibody identification panels (ABO algorithm - Grifols)
• AI-assisted quality control and haemovigilance analysis

7. Extended Red Cell Matching for Haemoglobinopathies

• Sickle cell and thalassaemia patients: extended phenotype matching (Rh, Kell, Kidd, Duffy, MNS) reduces alloimmunization
• Genotype-matched transfusion programmes improving outcomes

8. Convalescent Plasma (CP)

• COVID-19 experience: Emergency use authorization 2020-2021; RECOVERY, CONCOR-1 trials showed limited benefit in severe disease
• Lessons learned for future emerging infectious diseases
• CP remains useful in humoral immunodeficiencies (anti-spike titres)

9. Cell Therapy and Advanced Therapy Medicinal Products (ATMPs)

• Gene therapy for haemophilia A (SPK-8011, BMN-270/valoctocogene) and B (Hemgenix - etranacogene)
• Gene-corrected HSCs for sickle cell (betibeglogene/Casgevy CRISPR-based) - FDA-approved 2023

10. 3D Bioprinting and In Vitro Red Cell Production

• Cultured red blood cells (cRBCs) from HSCs or iPSCs
• First-in-human trial (RESTORE, Bristol 2022): lab-grown RBCs transfused safely; longer lifespan than stored RBCs
• Scalability and cost remain major barriers

11. Cold Stored Platelets

• Revisited for trauma/haemostasis-targeted use
• Better haemostatic function; shorter lifespan but acceptable for acute bleeding
• Phase II trials (CLIP, SPRINT) ongoing

12. Microbiome and Transfusion

• Gut microbiome influences RBC alloimmunization (ABO-related cross-reactive antigens)
• Research into microbiome modulation to prevent alloimmunization

13. Nanotechnology

• Haemoglobin-encapsulated liposomes (artificial RBCs)
• Platelet-mimetic nanoparticles (PLGA + fibrinogen - "SynthoPlateTM")
• Drug delivery using RBC-membrane-coated nanoparticles

14. ISBT 128 and Traceability

• International standard for labeling blood products
• Barcode and RFID-based vein-to-vein tracking eliminates identification errors
• Integrates with electronic health records globally

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