Transfusion medicine

Blood bank testing


Editorial Board Member: Mrigender Singh Virk, M.D.
Deputy Editor-in-Chief: Patricia Tsang, M.D., M.B.A.
Raisa Balbuena-Merle, M.D., M.H.S.

Last author update: 17 May 2023
Last staff update: 17 May 2023

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PubMed Search: Transfusion medicine automation

Raisa Balbuena-Merle, M.D., M.H.S.
Page views in 2022: 876
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Cite this page: Balbuena-Merle R. Automation. website. Accessed June 9th, 2023.
Definition / general
  • Use of automatic operational equipment in the manufacturing or processing of whole blood or pretransfusion testing
  • Semiautomated systems allow for partial manual labor with automated interpretation
Essential features
  • Blood bank automation is an alternate method to manual tube testing and blood processing in transfusion medicine
  • Promotes standardization of interpretation, increased transfusion safety, specimen batching and efficiency in turn around times
  • 3 methodologies currently exist for automated pretransfusion testing and 1 for whole blood separation
  • Implementation requires appropriate equipment verification
  • Automated blood bank system
  • Automated pretransfusion compatibility testing
  • Automated blood processing system (ABPS)
  • Solid phase red cell adherence assay (SRCA)
  • Column agglutination test (CAT)
  • Erythrocyte magnetized technique (EMT)
Application of automation in transfusion medicine
  • Blood component collection and processing
    • Separation into plasma, red blood cell (RBC) and platelet components by apheresis
    • Leukoreduction to prevent transmission of cytomegalovirus (CMV)
    • Separation and processing of whole blood unit collections
  • RBC washing for IgA deficient patients (Transfusion 2015;55:2415)
  • Platelet agitation
  • ABO typing, antibody screening, ABO titers, selected cell panels and compatibility testing in pretransfusion (immunohematology) testing
  • Product safety and detection of growth of microorganisms in platelets through culture: BacT / ALERT (Transfus Med 2002;12:303)
  • Supply of uncrossmatched or crossmatched blood via remote allocation in blood storage machines located away from the blood bank (Transfusion 2018;58:372)
  • Possible use in manufacture of blood components (Transfusion 2021;61:568)
  • Electronic crossmatch in patients with negative antibody screens
Automated and semiautomated methodologies
  • Automated blood processing system (ABPS)
    • Method: separates whole blood units into components through centrifugation and expression of components into individual product bags
    • Degree of automation: full automation of manual whole blood separation steps
    • Application: processing of whole blood collections
    • Limitation: higher levels of platelets in plasma units (Transfus Med Hemother 2021;48:290)
  • Solid phase red cell adherence assay (SRCA)
    • Methods
      • Standard: serum added for antigen antibody reaction in microplates containing solid medium with reagent RBCs showing a visible tight or effaced button as a negative or positive reaction, respectively
      • Degree of automation: semiautomated and fully automated platforms
      • Application: pretransfusion testing
      • Limitation: does not detect IgM (method requires incubation at 37 °C), limiting application to the identification of non-ABO antibodies
      • Additional features: capacity for platelet serology
  • Column agglutination test (CAT)
    • Method: microtubes with gel or microbead matrix containing antisera or antihuman globulin
      • Serum mixed with reagent RBC, agglutination of cells in the gel or microbead matrix constitutes test positivity
      • Open system
    • Degree of automation: semiautomated and fully automated platforms
      • Application: pretransfusion testing
      • Limitation: very sensitive; increased false positives due to lack of wash step
      • Additional features: modified CAT, dilution factor based on degree of agglutination
  • Erythrocyte magnetized technique (EMT)
    • Method: serum added to magnetized RBC inside a microplate that agglutinates after a magnetic force is applied
    • Degree of automation: fully automated platforms
    • Limitation: does not detect IgM
    • Additional features: eliminates the need for centrifugation and washing steps
  • These methodologies have superior sensitivity to conventional tube testing (Asian J Transfus Sci 2012;6:140)
  • Pretransfusion testing commonly uses agglutination (hemagglutination) as the standard to measure a possible reaction
    • Agglutination techniques can be modified for various purposes of detection (e.g., latex agglutination, sample mixed with latex particles coated with an antigen or antibody)
  • Increased sensitivity is achieved with low ionic strength saline or bromelin methyl cellulose resulting in increased potential for false positives
  • Does not allow for unrestricted modifications of testing like dithiothreitol (DTT) treatment and proteolytic enzymes; laboratories with high complexity patients must retain tube agglutination methods to allow for modified testing protocols for specified situations
Pros and cons of automation
Existing platforms of automated equipment
  • All platforms perform antibody screening, ABO group testing, crossmatching and direct antiglobulin test (DAT)
  • Blood processing
    • Reveos by Terumo Blood and Cell Technologies (Tokyo, Japan)
      • ABPS
      • 2 separation procedures
        • RBC, plasma and residual leukocytes
        • RBC, plasma, interim platelet units and residual leukocyte units
      • Self contained
      • System management for workflow management and reporting
  • Pretransfusion testing
    • IH-1000 and IH-500 by Bio-Rad (USA)
      • CAT
      • Continuous reagents and sample loading
      • Additional features: extended phenotyping
    • Qwalys 3 by DIAGAST (France)
      • EMT
      • Continuous reagents and sample loading
      • Additional features: weak D testing and extended phenotyping
      • Studies have shown higher IgM titration levels when compared to tube and CAT methods (Vox Sang 2020;115:233)
    • Galileo and NEO by IMMUCOR (USA)
      • SRCA
      • Continuous reagents and sample loading
      • Additional features: weak D, Rh phenotyping, ABO titers and platelet antibody screening and crossmatch
    • Wadiana and Erytra by Grifols (Singapore)
      • CAT
      • Batch testing for Wadiana and continuous loading or batch testing for Erytra
      • Additional features: enzyme assays, weak D (Erytra) and extended phenotyping
    • Autovue Innova and ORTHO VISION by Ortho Clinical Diagnostics (USA)
      • CAT
      • Continuous reagents and sample loading
      • Additional features: indirect antiglobulin test and RH / Kell / Duffy phenotyping, selected cell panels, serial dilutions for titers (ORTHO VISION)
    • PK7300 / 400 by Beckman Coulter (USA)
      • SRCA
        • Rh and Kell phenotyping
      • Fully automated, batch testing of large volume samples (300/hour)
    • TANGO by Bio-Rad (USA)
      • 2 testing options
        • Erytype S: SRCA; precoated microplates with dried antisera
          • Rh and Kell phenotyping, Cord blood ABO and Rh
        • Solid screen II: SRCA with protein A coated microwells
          • Antibody screen and identification, DAT, weak D, crossmatch
      • Fully automated, batch testing
Electronic crossmatching
  • Computer based crossmatch using recipient blood bank history to match with stored units
    • Software matches compatible stored units at the blood bank based on recipient historical blood bank data (ABO / Rh and antibody testing)
  • Substitutes for immediate spin compatibility testing (recipient's plasma / donor RBCs)
  • Benefits
    • Accurate assignment of compatible units and verification of historical data
    • Faster release of units
    • Automated verification of unit's compatibility through barcodes
    • Promotes better use of storage by prioritizing units closer to expiration
  • Limitations
    • Accuracy depends on extensive validation with the laboratory information system (LIS)
    • Typically not used for recipients with history of or newly formed clinically significant antibodies
  • Modified or additional restrictions are placed per institution (e.g., exclusion of recipients of ABO incompatible hematopoietic stem cells) (Vox Sang 2013;104:350)
Board review style question #1
    As a blood bank director, you are appointed to oversee the implementation of a new automated system for pretransfusion testing. Which of the following is a requirement before implementation for all equipment used in collection, processing, testing or storage of blood components?

  1. Acceptable performance on external proficiency testing
  2. Calibration
  3. Equipment verification
  4. Inspection from accreditation agencies (e.g., CAP)
Board review style answer #1
C. Equipment verification is required before implementation. Answer A is incorrect because performance on proficiency testing is a way of monitoring specific tests or measurements of individual laboratories and comparing it with other laboratories. Answer B is incorrect, as the calibration of an instrument is a process for verification of the accuracy of results after implementation. Answer D is incorrect because inspections by accreditation agencies (e.g., CAP) aim to assess the compliance of a laboratory with the agency requirements.

Comment Here

Reference: Automation
Board review style question #2
    Which of the following patients is the best candidate for an RBC transfusion using electronic crossmatching?

  1. 18 year old man with sickle cell disease and multiple RBC transfusions presenting with increased lactate dehydrogenase (LDH), haptoglobin of < 10 mg/dL and hemoglobin of 5.4 g/dL
  2. 35 year old woman with history of systemic lupus erythematosus (SLE) and history of warm autoantibody and mild thrombocytopenia of 100 K/cmm
  3. 45 year old woman with laboratories showing a mean corpuscular volume (MCV) of 84.3 fL, hemoglobin of 7 g/dL, serum iron of 12 microg/dL (normal: 40 - 160 microg/dL), who had a positive antibody panel, showing a nonspecific antibody 5 years ago; current direct antiglobulin test (DAT) and antibody screen is negative
  4. 87 year old man with anemia (Hgb 6.9 g/dL) and newly diagnosed multiple myeloma, no history of transfusions and a negative antibody screen
Board review style answer #2
D. 87 year old man with anemia (Hgb 6.9 g/dL) and newly diagnosed multiple myeloma, no history of transfusions and a negative antibody screen. This answer is correct because the patient has no prior history of transfusions as well as a negative type and screen. Answer A is incorrect, as the patient's laboratory findings are consistent with hemolytic anemia likely attributed to a hemolytic transfusion reaction due to the presence of ≥ 1 alloantibodies suggested by the history of multiple transfusions. The patient's alloantibody(ies) must be identified in order to provide antigen negative full crossmatch compatible RBCs. Answer B is incorrect because a warm autoantibody causes a positive antibody screen and panagglutinin in the cell panel. Other special testing techniques (e.g., adsorption studies) are needed to rule out any alloantibodies in order to use electronic crossmatch. Answer C is incorrect since electronic crossmatching should not be used on patients with positive antibody screens without a certain alloantibody specificity.

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Reference: Automation
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