ABO Typing Discrepancies Jayme Heimonen MTASCPSBB Blood Bank
ABO Typing Discrepancies Jayme Heimonen MT(ASCP)SBB Blood Bank Technical Specialist Borgess Medical Center Kalamazoo, MI ASCLS-Michigan 2016 1
ABO Typing Discrepancies • Expected reactions are missing Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 0 0 0 Anti-A Anti-B Anti-D Co A 1 Cells B Cells 0 0 4+ 0 0 3+ 2
ABO Typing Discrepancies • Unexpected reactions are present. Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 0 2+ 4+ Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 2+ 0 4+ 3
ABO Typing Discrepancies • Reactions are weaker than expected. Anti-A Anti-B Anti-D Co A 1 Cells B Cells 1+ 0 4+ 0 0 4+ 4
ABO Typing Discrepancies First Steps; • Always repeat the testing in all tubes or microtubes, following your SOPs and the manufacturers product insert. • Repeat using washed cells (at least 3 times). • Observe tube testing reactions microscopically if possible. • Obtain the patient’s history including age, transfusion history and diagnosis. 5
ABO Typing Discrepancies Next steps: • Evaluate the reactions in the forward and reverse typing to determine which type is most convincing. • Remember: Forward type tests the antigens on the cells. Reverse type test the antibody in the plasma. • Determine what ABO group to crossmatch for the patient. 6
ABO Typing Discrepancies What can lead to forward type discrepancies? • Transfusions with other ABO types • Weak Subgroups • Mixed cell population (HSCT) • Certain disease states • Rouleaux 7
ABO Typing Discrepancies Example with Transfusions ***Expected reaction is missing Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 0*** 4+ 0 0 0 AB patient massively transfused with Group: A red blood cells. 8
ABO Typing Discrepancies Group: AB patient massively transfused with Group: A red blood cells. • Phone call to other hospital where transfusions were administered. Have they typed a pre-transfusion specimen? • Observe reactions microscopically(tube testing)-may see weak reactions with patient’s cells and anti-B. • Transfuse with Group: AB, A, B or O cells 9
ABO Typing Discrepancies Weak subgroups ***Expected reaction is missing Anti-A Anti-B Anti-D Co A 1 Cells B Cells 0*** 0 4+ 0 0 3+ Weak subgroup of A such as Am • Adsorption/elution. • Secretor testing. • Transfusion with Group: O red blood cells. 10
ABO Typing Discrepancies Mixed cell population ***Expected reaction is weaker Anti-A Anti-B Anti-D Co A 1 Cells B Cells 1+*** 0 4+ 0 0 3+ Group: O patient who received a Group: A HSCT in last 30 days. 11
ABO Typing Discrepancies Group: O patient who received a Group: A HSCT in last 30 days. • Call the Blood Bank of the transplant hospital for their transfusion guidelines. • Transfuse Group: O red blood cells until there is evidence marrow has engrafted. • Transfuse Group: A plasma product to be compatible with newly produced red blood cells. • Transfuse irradiated blood products. 12
ABO Typing Discrepancies Disease states such as acute myeloid leukemia and other cancers with chemotherapy. ***Expected reaction is weak Anti-A Anti-B Anti-D Co A 1 Cells B Cells 0 1+*** 4+ 0 3+ 0 • Previous typing history. • Enhance agglutination. • Adsorption/elution. 13
ABO Typing Discrepancies Disease states such as warm autoimmune hemolytic anemia ***unexpected reaction Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 2+*** 0 4+ • Spontaneous agglutination-cells coated with high concentration of warm autoantibodies. • Perform direct antiglobulin test. • Always give Group: O blood until discrepancy is resolved. 14
ABO Typing Discrepancies Disease states such as Cold Hemagglutinin disease Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 3+ 0 4+ • Incubate type at 37 o. C. • Wash cells in 37 o. C saline. • Prewarm reagents and serum/plasma. 15
ABO Typing Discrepancies Rouleaux Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 2+ 2+ 4+ Microscopically observe cells as a stacked coin retractile appearance: Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ R R 4+ • Saline replacement. 16
ABO Typing Discrepancies What can lead to reverse type discrepancies? • Weak or missing antibodies. • Extra antibodies. • Transfusion. • HSCT recipient. • Rouleaux. 17
ABO Typing Discrepancies Weak or missing antibodies ***Expected reaction missing Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 0 0 0*** Elderly patient with low anti-B titer • Incubate all tubes including autocontrol at room temperature for 30 min or 4 o. C. • Increase serum/plasma to cell ratio. • Increase incubation time. • Transfuse with Group: A red blood cells. 18
ABO Typing Discrepancies Weak or missing antibodies ***Expected reaction missing Anti-A Anti-B Anti-D Co A 1 Cells B Cells 0 4+ 4+ 0 0*** 0 Increased antibody concentration where antibody exhibits prozoning. • Perform isohemagglutinin titer. 19
ABO Typing Discrepancies Atypical antibodies ***Unexpected reaction present Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 0 2+*** 4+ Weak subgroup of A with anti-A 1 present. • Type patient’s cells with A 1 lectin. • Test patient’s serum/plasma with cells lacking A 1 antigen (such as A 2 cells). • Perform antibody identification for anti-A 1. • Transfuse Group: A cells lacking A 1 antigen or Group: O cells. 20
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ABO Typing Discrepancies Atypical antibodies ***Unexpected reaction present Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 0 2+*** 4+ Patient with alloantibody (anti-M, Anti-N, anti. P 1, anti-Lea or anti-Leb). • Perform antibody identification procedures. • Test patient with A 1 cell lacking antigen. 22
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ABO Typing Discrepancies Transfusion ***Unexpected reaction Anti-A Anti-B Anti-D Co A 1 Cells B Cells 4+ 4+ 4+ 0 0 3+*** Group AB patient transfused with Group O cryoprecipitate. 28
ABO Typing Discrepancies Hematopoietic stem cell recipient Anti-A Anti-B Anti-D Co A 1 Cells B Cells 0 1+ 4+ 0 0 1+ Group: A recipient transplanted with Group: B donor at day 56 • Contact the transplant hospital and get their guidelines for transfusion of packed red cells and plasma products. 29
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