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Donor ABO Blood Grouping Discrepancies. Heather Hume Greg Denomme CBS HO Serology Laboratory Feb 20, 2009. GAL. GAL. GLNAC. GLNAC. GAL. GAL. GL. GL. GALNAC. GAL. GAL. GLNAC. GAL. GL. Group ‘O’ Antigen. Group ‘B’ Antigen. Group ‘A’ Antigen. C. A 1. A 2. B 1. G. O 1.
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Donor ABO Blood Grouping Discrepancies Heather Hume Greg Denomme CBS HO Serology Laboratory Feb 20, 2009
GAL GAL GLNAC GLNAC GAL GAL GL GL GALNAC GAL GAL GLNAC GAL GL Group ‘O’ Antigen Group ‘B’ Antigen Group ‘A’ Antigen
C A1 A2 B1 G O1 Common A, B,and O Alleles: exons 6 - 7 261 526703796/8031060 Exon 7 Exon 6
ABO Blood Grouping Discrepancies • Missing reactivity? • apparent absent antigen • apparent absent antibody • Additional reactivity? • apparent extra antigen • apparent extra antibody
ABO Blood Grouping Discrepancies Most Common Causes • Patients • decreased antibody levels • physiologic - newborns, elderly • immunodeficiency - congenital or acquired • auto- or alloantibodies • recent transfusion • HSCT • Donors • unusual blood group - genetic polymorphisms
Donor Testing Laboratory Results Case #1 PK7200 Data Log Results Prediluted Olympus reagents used DTL Manual Bench Results Immucor Gamma-clone reagents used
National Reference Laboratory Investigation Red Cell Testing Results NA=not applicable
National Reference Laboratory Investigation Plasma Testing Results
Comparability Study w=weak
Conclusion Case #1 • Anti-A1 lectin neg and anti-H lectin pos • Reverse grouping as a Group A individual • Autoantibody present at 4oC 60’ incubation • Comparability Study helped determine a possible Ax subgroup • All results confirms subgroup of A
A1 Ax B1 G O1 Ax: 646A, 681A [novel changes] 261 526646681703796/803
Donor Testing Laboratory Results Case #2 PK7200 Data Log Results Prediluted Olympus reagents used DTL Manual Bench Results Immucor Gamma-clone reagents used
National Reference Laboratory Investigation Red Cell Testing Results NA=not applicable
National Reference Laboratory Investigation Plasma Testing Results NA=not applicable
Comparability Study w=weak MF=mixed field
National Reference Laboratory Investigation Results of Eluate Testing Performed fixation/elution with Donor RBCs and Human anti-A
Conclusion Case #2 • Anti-A1 lectin neg and anti-H lectin pos • No reactivity with Anti-A and Anti-A,B reagents • No reactivity with A2 RBCs in the reverse grouping • Anti-Apresent in the plasma at 4oC • Comparability Study showed no A antigen prompting further investigation of Ael subgroup • Anti-A was fixated and a weak anti-A was eluted from donor RBCs
A1 Ael B1 G O1 Ael : 467T[novel], 646A[Ax], 681A[Ax} 261 467526646681703796/803
Donor Testing Laboratory Results Case #3 PK7200 Data Log Results Prediluted Olympus reagents used DTL Manual Bench Results Immucor Gamma-clone reagents used MF=mixed field
Red Cell Testing Results National Reference Laboratory Investigation w=weak NA=not applicable
National Reference Laboratory Investigation Plasma Testing Results 1 w=weak
National Reference Laboratory Investigation Plasma Testing Results 2 w=weak NA=not applicable
National Reference Laboratory Investigation Plasma Testing Results 3 w=weak NA=not applicable v w=very weak NT=not tested
Comparability Study w=weak MF=mixed field
Flow Cytometry Results Testing perfomed by Jill R. Storry, Ph.D., FIBMS of Blodcentralen Skane in the UK Flow cytometric analysis of the donor RBCs, shown in red, with anti-H (left) and anti-A (right)
Conclusion Case #3 • Donor reverses as a Group A individual as per the PK7200 results and MF reactions in the forward suggest Subgroup of A (slide 11) • DTL results also MF reaction in the forward grouping and reverse grouping reaction with Group O cells suggests interfering antibody present in the plasma possible cold agglutinin (slide 11) • Cold antibody present in plasma • Presence of anti-H and excludes anti-I and other antibodies to the major blood group antigens • The comparability study concludes that this donor has some A antigen expressed. • Flow Cytometry results confirm that donor is Ah with weak A antigen present on the RBCs
ABO(H) Antigens • Type 2 precursor chain: • fucosyltransferase 1 (FUT1) H substance • Type 1 precursor chain: • fucosyltransferase 2 (FUT2) H substance • H Substance: • N-acetylgalactosaminyltransferase: A • galactosyltransferase: B • Bombay phenotype • FUT1 deletion, FUT2 deletion (se/se) • Para-Bombay phenotype • FUT1 deletion, Secretor
Donor Testing Laboratory Results Case #4Unit returned to CBS - Labelled B pos, tested AB pos at hospital PK7200 Data Log Results Prediluted Olympus reagents used DTL Manual Bench Results Immucor Gamma-clone reagents used MF=mixed field
Red Cell Testing Results National Reference Laboratory Investigation v w=very weak w=weak NA=not applicable
National Reference Laboratory Investigation Plasma Testing Results
Conclusion Case #4 • Numerous donations and historically a Group B+ individual • Forwards and reverses as a Group B individual on this donation • Mixed field reactions seen with anti-A reagents • 1/100 Group B individuals reacts with a blend of 2 monoclonal anti-A, one clone is used for its rapid reactions with A1 and A2 RBCs and the second clone for its ability to react strongly with Ax RBCs • B(A) activity
B(A) activity • The wild-type B glycoslytransferase transfers very little A sugar onto H substance • not detectable using antibody probes! • Some B glycosyltransferases transfer more A sugar onto H substance. • B cells phenotype as B with some moAbs and weakA,B with other moAbs • The B glycosyltransferase was found to contain an 703G (235Gly), normally associated with the A1 • represented by the acronym BABB • Can make anti-A
A1 B1 B(A) G O1 B(A) : 703G[A1] 261 526703796/803
Donor Testing Laboratory Results Case #5 PK7200 Data Log Results Prediluted Olympus reagents used DTL Manual Bench Results Immucor Gamma-clone reagents used
A1 B1 G O1 O2 O2 : 526G[B], 802A[novel] 802 261 526703796/803 The (nondeletional) O2 allele produces an enzygme with weak glycosyltransferase A activity
Donor Testing Laboratory Results Case #6 PK7200 Data Log Results Prediluted Olympus reagents used DTL Manual Bench Results Immucor Gamma-clone reagents used
A1 B Bel G O1 Sudbury case (Bel ?): B + 641G[novel] 261 526 641 703796/803
References • Westhoff CM, Reid ME. ABO and related antigens and antibodies. In Blood Banking and Transfusion Medicine Basic Principles and Practice 2nd ed. Hillyer CD et al eds. Churchill Livingstone, Philadelphia, PA. 2007: 69-79. • ABO, Lewis and P groups and Ii antigens. In Mollison's Blood Transfusion in Clinical Medicine 11th ed. Klein HG, Anstee DJ eds. Blackwell Publishing Inc, Malden, MA. 2005:114-162. • Investigating ABO typing problems. In Judd's Methods in Immunohematology 3rd ed. Judd WJ, Johnson SJ, Storry JR eds. AABB Press, Bethesda, MA. 2008: 515-558