Transfusion Medicine Quality Manual ABO Grouping Tube Method
1.0 Policy Statements 1.1 Each recipient blood sample for compatibility testing shall be tested for ABO group. 1.2 The results of the red cell and plasma test must agree. Current and previous results should be compared to identify any ABO discrepancy. 1.3 All blood group discrepancy shall be resolved and the resolution documented before issuing red cells. If transfusion is necessary before resolving the ABO discrepancy the recipient should receive group O red cells and AB plasma products. 1.4 Blood group testing for A, B and D antigens only is required for: 2.0 Linkages 1.4.1 Infants less than 4 months of age; and 1.4.2 Confirmation of the ABO group on donor units; Patient Identification and Specimen Labeling. Available at: http://www.health.gov.nl.ca/health/bloodservices/pdf/patient_id_and_specimen_la beling.pdf Determining Specimen Suitability. Available at: http://www.health.gov.nl.ca/health/bloodservices/pdf/determining_specimen_suit ability.pdf Patient History Check. Available at: http://www.health.gov.nl.ca/health/bloodservices/pdf/patient_history_check.pdf Preparation of Red Cell Suspensions. Available at: http://www.health.gov.nl.ca/health/bloodservices/pdf/preparation_of_red_cell_sus pensions.pdf Quality Control of Reagents and Antisera. Available at: http://www.health.gov.nl.ca/health/bloodservices/pdf/quality_control_of_reagents and_antisera_ver1.pdf Page 2 of 11
Resolving ABO & Rh Blood Group Discrepancies. Available at: http://www.health.gov.nl.ca/health/bloodservices/pdf/resolving_abo_rh_blood_gr oup_discrepancies.pdf 3.0 Scope 3.1 All Transfusion Medicine Laboratory Technologists who are responsible for testing and reporting transfusion medicine samples. 4.0 General Information 4.1 ABO blood groups are determined by phenotyping the recipient s red cells for the presence or absence of A and B antigens on red cells and by testing the recipient s plasma for the presence or absence of anti-a and anti-b. 4.2 ABO typing and ABO compatibility testing is the foundation of pretransfusion testing. 4.3 Transfusion of ABO incompatible blood can be associated with acute intravascular hemolysis, renal failure and death. 4.4 Routine tests to determine the ABO group consists of testing red cells with anti-a and anti-b (forward group) and testing the plasma with A 1 and B red cells (reverse group). 4.5 Hemolysis is interpreted as a positive result. 4.6 Pre-washing the red cells is not necessary, however, if a discrepancy is detected the cells should be washed and the tests repeated. 4.7 Washed red cells may reduce false positive results associated with rouleaux or autoantibodies. 4.8 Positive reactions in the forward group characteristically demonstrate a grade three (3) to grade four (4) agglutination. Reactions in the reverse grouping (serum and reagent red cells) are often weaker. 4.9 Reactions in the forward group that demonstrate less than grade 2 reactions should be further investigated. Page 3 of 11
4.10 The serum tests may be incubated at room temperature for 5 to 15 minutes to enhance weak reactions. 4.11 A mixed field reaction maybe detected if a recipient has been transfused with ABO compatible red cells other than that of their own ABO group. 4.12 False positive or negative results can be caused by variables such as: 4.12.1 Improper technique 4.12.2 Contaminated materials 4.12.3 Omission of reagents or anti-sera 4.12.4 Delays in testing 4.12.5 Inadequate incubation time and temperature 4.12.6 Inappropriate centrifugation 4.12.7 Inappropriate or prolonged storage of red cells. 4.13 If performing the ABO grouping by automation follow manufacturer s instructions for operation and resulting. 5.0 Process 5.1 Quality Control 5.1.1 All reagents shall be used and controlled according to the manufacturer s written instructions. 5.1.2 All anti-sera must be visually inspected for contamination such as discoloration, cloudiness, turbidity and/or particulate matter. 5.1.3 All reagent red cells must be visually inspected for hemolysis and/or discoloration. 5.1.4 The results of the visual inspection, reagent lot number, expiry date, date of the inspection and the individual performing the inspection must be documented. 5.1.5 The expiry date should be checked on each reagent used. Do not use reagents beyond expiry date. Page 4 of 11
5.1.6 A control consisting of 6-8% bovine serum albumin or a diluent control may be used with the recipient s red cell suspension. 5.1.7 The reactivity of blood grouping reagents shall be confirmed each day of use by control tests with known antigen positive and negative red cells. Positive control cells should be selected to represent weak expression of the specific antigen. 5.2 Procedure 5.2.1 Centrifuge specimen according to facility policy. 5.2.2 Determine specimen acceptability. 5.2.3 Perform a patient history check. 5.2.4 Ensure patient information on the sample corresponds with the patient information on the worksheet. 5.2.4.1 Forward group: 5.2.4.1.1 Place 1 drop of anti-a in a clean, labeled test tube; 5.2.4.1.2 Place 1 drop of anti-b in a separate, clean, labeled tube; 5.2.4.1.3 Add 1 drop of a two (2)% to five (5)% patient cell suspension to each tube; 5.2.4.1.4 Mix the contents of the tubes gently; 5.2.4.1.5 Centrifuge for the calibrated spin time; 5.2.4.1.6 Gently resuspend the cell buttons, and examine them for agglutination; and 5.2.4.1.7 Read, interpret, and record the test results. 5.2.4.2 Reverse group 5.2.4.2.1 Add 2 or 3 drops each of serum or plasma to two clean, labeled test tubes; 5.2.4.2.2 Add 1 drop of A1 reagent red cells to the tube labeled A1; 5.2.4.2.3 Add 1 drop of B reagent red cells to the tube labeled B; 5.2.4.2.4 Gently mix the contents of the tubes; then centrifuge for the calibrated spin time; Page 5 of 11
5.2.4.2.5 Examine the serum overlying the red cell buttons for evidence of hemolysis. Gently resuspend the cell buttons, and examine them for agglutination; 5.2.4.2.6 Examine the serum overlying the red cell buttons for evidence of hemolysis. Gently resuspend the cell buttons, and examine them for agglutination; and 5.2.4.2.7 Read, interpret, and record test results. 5.3 Guidelines (NA) 5.4 Materials 5.4.1 Reagents 5.4.1.1 Anti-A anti-sera 5.4.1.2 Anti-B anti-sera 5.4.1.3 A 1 reagent red cells 5.4.1.4 B reagent red cells 5.4.1.5 Isotonic saline 5.4.2 Supplies 5.4.2.1 Test tubes (10x75mm) 5.4.2.2 Transfer pipettes 5.4.2.3 Test tube rack 5.4.3 Equipment 5.4.3.1 Serological centrifuge 5.4.4 Specimen 5.4.4.1 Blood sample collected in EDTA anticoagulant; or 5.4.4.2 Red cells from clotted samples (SST tubes with gel separator should not be used); or 5.4.4.3 Venous or capillary blood sample from neonates. Cord blood must not be used for pre-transfusion testing. Page 6 of 11
6.0 Acronyms EDTA SST Ethylenediamine tetracetic acid (anticoagulant) Serum-separating tubes 7.0 Definitions rouleaux compatibility testing ABO discrepancy mixed field The stacking up of red blood cells caused by extra or abnormal proteins in the blood that decrease the normal distance red cells maintain between each other. Testing to determine if the donor's blood is compatible with the blood of an intended recipient. The result of red cell tests disagree with that of the serum tests. The presence of two populations of red cells. 8.0 Records Management 8.1 The recipient transfusion data file in the Transfusion Medicine Laboratory shall be retained indefinitely. 8.2 All transfusion records in the recipient s medical chart shall be retained in accordance with health care facility policy. 8.3 Quality control of blood components, blood products, reagents and equipment shall be retained for 5 years. 8.4 Date and time of specimen collection and phlebotomist s identification shall be retained for 1 year. 8.5 Request form for serologic tests shall be retained for one month or as per facility policy. Page 7 of 11
8.6 Documentation of staff training and competency must be kept for a minimum of ten years. 9.0 Key Words Forward blood group, reverse blood group, ABO group Page 8 of 11
10.0 Supporting Documents 10.1 Process Flow/Algorithm Determine specimen suitability NL2010.012 Is specimen suitable? Yes Centrifuge specimen No Collect new specimen Label Test Tubes A/A, A/B, A1, B Add plasma to tubes labeled A1 and B Add RBC suspension to tubes labeled A/A and A/B Mix contents of tubes Centrifuge tubes Check specimen suitability after centrifugation Is specimen suitable? Yes No Collect new specimen Prepare RBC suspension NL2012-033 Add appropriate antisera to labeled tubes A/A, A/B Remove tubes from centrfuge Verify recipient s identification on tubes, specimens and worksheet match Re-suspend cell button Perform patient history check NL2010.013 Read macroscopically Check name on specimen matches worksheet Add A1 and B cells to labeled tubes A1 and B Grade and record Interpret results and compare to previous reports ABO Discrepancy Yes Resolve Discrepancy before reporting No Report Results Page 9 of 11
10.2 Tables/Charts Interpreting ABO Test Results Forward Grouping (Cells) Reverse Grouping (Plasma) Interpretation Anti-A Anti- B A 1 cells B cells ABO Group Neg Neg Pos Pos O Pos Neg Neg Pos A Neg Pos Pos Neg B Pos Pos Neg Neg AB Page 10 of 11
References Cooling L. ABO, H, and Lewis blood groups and structurally related antigens. In: Fung M, Grossman BJ, Hillyer CD, Westhoff CM, eds. Technical manual. 18th edition. Bethesda, MD: AABB, 2014:291-315. Immucor Gamma. (2012) Blood Grouping Reagent: Package Insert. Immucor Gamma. (2012) Reagent Red Cells; Package Insert. American Association of Blood Banks, (2011). Standards for Blood Banks and Transfusion Services, (27 th ed.). Bethesda, MD: Author. Canadian Standards Association, (2010). CAN/CSA-Z902-10, Blood and Blood Components. Mississauga, ON: Author. Canadian Society for Transfusion Medicine, (2011). Standards for Hospital Transfusion Services, Version 3.0. Ottawa, ON: Author. Page 11 of 11