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ABO Incompatible Blood Transfusion

Dr. Gwen Clarke

Case study

· A 54 year- old woman was undergoing a routine, elective cholecystectomy for cholelithiasis at a small rural hospital. · The hospital blood bank "stock" included 2 units of group O positive blood.

· The blood bank fridge had two units of group B positive red cells and two units of group A positive red cells · These had been crossmatched by a reference lab and were tagged and allocated for specific hospital inpatients.

· Two additional units of group O positive blood were also on hand for a planned elective transfusion in a chronic transfusion recipient · The patient had a type and screen ordered and sent out prior to surgery. The reference lab reported that she was group O Rh positive.

· Intraoperatively there were complications, including liver laceration, and the patient had ongoing massive blood loss. · The two units of group O Rh positive stock were transfused along with the two units of group O positive blood on hand for another patient.

· The physician performing the anaesthetic urgently needed more blood. · The blood supplier was distant from the hospital and the earliest time at which additional blood could reach the hospital was 2 ­ 4 hours hence.

· The anaesthetist asked for the units of group A and group B blood because of the risk of exsanguinating hemorrhage.

Acute Hemolytic Transfusion Reaction

­ ­ ­ ­ ­ ­ Anxiety Fever Chills Flushing Nausea Low Back Pain ­ ­ ­ ­ ­ ­ Dyspnea Chest Pain Pain at infusion site Hypotension Bleeding Oliguria/Anuria

ABO Blood Group Primer

· Chromosome 9 · A and B genes encode acetyl transferase enzymes which add oligosaccharides to precursor glycoproteins the cell membrane on membrane · O gene - no enzyme

ABO Antibodies

· IgM · "Naturally occurring" · Present in all immunocomptent individuals after 4 ­ 6 months of age · Group A anti B · Group B anti A · Group O anti A anti B and anti A,B · Group AB no antibody

Acute Hemolytic Reaction

Group A donor red cells Group B recipient

Coagulation activation cytokine release neuroendocrine response The cells lyse

Anti A coats the cells and fixes complem ent

Acute Hemolytic Reactions

· 1/33,000 ­ 1/70 000 Units transfused · Most, but not all, reflect unintentional ABO incompatible transfusion

TTISS Reports 2002/2003

· 1 629 684 units of blood components transfused by participating sites (50% rbc)

­ 14 cases of ABO incompatibility reported

· 9 RBC · 3 Platelets · 2 plasma

­ 6 resulted in AHTR ­ 3 were life threatening (no fatalities)

Mortality with AHTR

· Fatal outcome

­ 1/1 000 000 units transfused

· The severity of the reaction depends on the volume of incompatible blood transfused

· Review of case Reports

­ ­ ­ ­ No deaths if < 500mL incompatible blood 25% mortality when 500 ­ 1000 mL transfused 44% mortality when > 1000mL transfused As little as 30 mL has been fatal

What is all the fuss about...

· The rate of mislabeled and miscollected samples is 1000 ­ 10 000 times more frequent than the risk of viral infection due to blood transfusion · The risk of erroneous administration of blood may be as high as 1 per 12 000 units.

Studies...

· International, multi-center trial

­ 1 in every 165 samples or 6.1 per 1000 mislabeled in some way (1.2 ­ 17/1000) ­ 1 in 1986 samples (0.5 per 1000) had wrong blood in the tube (0.3 ­ 0.9 per 1000)

Dzik, Murphy, Andreu et al. An international study of the performance of sample collection from patients. Vox Sang (2003)85;40-47

More Studies ...

· 1/19000 rbc units administered over an 8 year period were erroneously administered (256 transfusion services)

­ 56% resulted from a single error outside the Transfusion service ­ most frequently administration of properly labeled blood to the wrong patient ­ 13% were phlebotomy labeling errors (wrong blood in tube)

­ 29% were isolated blood bank errors including issuing the wrong unit or testing errors ­ both technical and clerical ­ 2 or more errors occurred in 15% of reported events

· Issue of wrong, tagged unit by blood bank with failure of detection at bedside check

Linden, Wagner, Voytovich, Sheehan; Transfusion errors in New York State: an analysis of 10 years' experience. Transfusion 2000;40:1207

Beware of contributory factors

· Similar names leading to misidentification · Sequential patient identifiers without full names ­ as in unidentified trauma patients · Telephone orders · Rush situations · Simultaneous handling of specimens from multiple patients

What about rejection for mislabeled samples...

· Specimens labeled incorrectly were 40 times more likely than correctly labeled samples to have a blood typing discrepancy when historical or subsequent patient data were consulted

Lamadue,Boyd,Ness. Adherence to a strict specimen labeling policy decreases the incidence or erroneous blood grouping of blood bank specimens. Transfusion 1997;37:1169

Local error and rejection rates in Capital Health Region

· Frequency of sample rejection for failure of compliance with labeling:

­ 1/23 (612/14267)

· Of 14 267 samples collected, 8571 were on patients with prior historical blood grouping information on record

­ 2 had ABO groups which varied from prior record (WBIT) ­ Following correction for silent error estimated WBIT of 1/2678

Transfusion reaction investigation

· Clerical Check · DAT · Repeat crossmatch/Type and Screen with pre and post samples

· · · · Bilirubin, LDH, Haptoglobin Coagulation Studies Plasma Hemoglobin Urine hemoglobin and hemosiderin

Is it ever OK?

On the Horizon...

· Stealth Cells · Immune tolerance Induction?

­ Experience from ABO Incompatible organ transplants

Platelet Transfusion

· Indications · Dose · Apheresis vs Random Donor Pool vs Buffy Coat · Blood Group · Other variables

Platelets: Indications for transfusion

· Bleeding ­ therapeutic transfusions

· Thrombocytopenia · Platelet dysfunction

· Risk of Bleeding ­ prophylactic transfusions

­ Surgical bleeding unlikely to occur with counts > 50 X 109/L ­ spontaneous bleeding rarely occurs if platelet counts >20 X 109/L ­ Some studies suggest that thresholds as low as 5 X 109/L may be appropriate in some patients

Platelet Dose

· 5 units Random Donor Platelets · 1 Buffy Coat Pool · 1 Apheresis Platelet Unit

Platelet Production

PRP Method

Step 1: Whole blood centrifuged at low speed (soft spin) to produce two layers ­ Red Cell and PRP Step 2: PRP extracted from top of pack, passing through leukoreduction (LR) filter

Plasma (PRP)

Red cells

PRP Method cont.

· Step 3: PRP centrifuged at high speed to concentrate the platelets · Step 4: Platelet poor plasma (PPP) extracted from top

PRP Method cont.

Step 5: Red cell preparation · Additive solution (AS-3) is added to the Red Cells to prime the filter. · RCs passed through LR filter into storage bag

Buffy Coat Method

Step 1: Whole Blood is collected into a top and bottom pack and is Buffy Coat Layer centrifuged (hard spin) Red Cell Concentrate to produce platelet poor plasma, red blood cells and a buffy coat

Platelet Poor Plasma

Red Cell Additive (SAG-M)

Buffy Coat Method cont.

Step 2: After centrifugation, the Whole Blood is loaded into the Compomat G4 (component separator)

Buffy Coat Method cont.

Step 3: Extraction

Plasma

Buffy Coat

Red blood cell

Buffy Coat Method cont.

Step 4 cont: Pooling (Train Method)

Plasma Buffy Coats sterile docked together Platelet storage bag sterile docked to the Buff Coat "train"

Buffy Coat Method cont.

Step 5: Pooled Buffy Coat is then centrifuged at low speed (soft spin)

Buffy Coat Method cont

Step 6: Leukofiltration & Extraction of Platelet Concentrate · Buffy Coat Pool is loaded into Compomat G4 · Supernatant (PRP) pressed through LR filter into storage bag

Buffy Coat Method cont.

· Pooled Platelet Concentrate, LR is Similar in physical size & dosage to an apheresis platelet concentrate

Apheresis Platelet

Collection

www.americanredcrossblood.org/ images/platelet

Platelet Antigens

· ABO

­ Antigens present but weakly expressed on platelets ­ Platelet count increments slightly but not significantly reduced with ABO mismatched platelets ­ ABO antibodies in plasma may produce clinically significant hemolysis

Platelet Antigens

· HPA · HLA · These become important considerations in refractory patients

ABO and Platelets

· ABO preference: ­ ABO specific ­ ABO compatible(plasma product) ­ ABO incompatible ­ Chronic shortages often mean that ABO incompatible platelets are given to adults

ABO Compatibility Table Platelet and Plasma Products

Patient (Recipient) ABO Group O A B AB Donor (Unit) ABO Group O, A, B, AB A or AB B or AB AB

Platelet Incompatible Platelets

· ABO antigens intrinsic to platelet membrane and adsorbed ABO antigens

­ Occasional donors may have strong antigen expression ­ Studies of post transfusion increments in most recipient/donor combinations suggest 20% lower increments for ABO incompatible units

Plasma Incompatible Platelets

· No effect on post transfusion increments · May result in positive DAT +/- hemolysis · Particular caution with multiple incompatible units, pediatric recipients, and group O Buffy Coat pools of platelets

Group O Pools

· What to do?

­ Plasma reduce the units by centrigugation

· Need sterile connection to satellite bag to express plasma · "rest" pretransfusion · Slight reduction in increments expected

­ Titres of isohemagglutinins in group O pools/plasma

· 1/200 dilution of suspending plasma tested at RT, IS phase vs A and B cells · Non reactive units OK to transfuse · No gold standard titration technique

Platelet Component Selection

· · · · · · ABO Rh Irradiation CMV Status Plasma Volume Reduction Pool vs Apheresis

Cryoprecipitate

· Plasma Compatibility preferred · Not critical because of small volume of plasma per unit · AB Cryo reserved for neonates

Plasma and ABO

· Plasma (antibody) Compatibility with Donor RBC · Current valid blood group required but no crossmatch with recipient · CBS does antibody screen to rule out significant non ABO antibodies

ABO Compatibility Table Plasma Products

Patient (Recipient) ABO Group O A B AB Donor (Unit) ABO Group O, A, B, AB A or AB B or AB AB

ABO Incompatible Plasma and Positive DAT

Positive DAT

· A positive DAT in a patient who has had platelet or cryoprecipitate transfusions may reflect anti A or anti B · Remember to set up A and B cells with your screen if you are going to investigate with an eluate

Summary ­ ABO Incompatible Transfusion

· · · · Red Cells ­ Never Plasma ­ Never Platelets ­ Sometimes Cryo - Often

Questions?

Information

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