To B or not to B, that is the question

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To B or not to B, that is the question

• A case study presented by your
• GCP Reference Lab

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Clinical History

• 30 year old female
• African American origin
• Diagnosis Uterine myeloma
• Reason for admission Hysterectomy
• No previous transfusions or pregnancy history

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Hospital Blood Bank

• Forward grouping
• AB, Reverse grouping A
• Rh Positive
• A/S Negative
• H H 9gms/29
• Sent to ARC Reference Lab for ABO discrepancy
  resolution

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ARC Reference Lab
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Additional testing

• Red Cell Typings performed with
• 2nd lot of antisera similar results
• 3rd lot of antisera similar results
• Warm washed (x10) cells similar results
• Cold Screen negative
• Lectin Studies - negative

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DO YOU WANT TO TAKE A GUESS?
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Acquired B Phenotype

• Red cells agglutinate strongly with anti-A and
  weakly with anti-B
• Serum contains strong anti-B
• Autocontrol negative, pts own anti-B non
  reactive with acquired B cells
• Found most often in group A1
• May or may not be polyagglutinable
• Acquired B phenotype rarely seen since the advent
  of monoclonal antisera (lower pH)

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Acquired B phenotype

• Arises when microbial deacetylating enzymes
• modify the A antigen by altering the A-
• determining sugar (N-acetylgalactosamine) so
• that it resembles B-determining galactose.

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Clone ES 4

• Monoclonal anti-B prepared from clone ES 4 is
• particularly efficient at detecting red cells
  that
• acquire a B antigen. When this situation was
• recognized, adjustment of pH to 6.0 became
• necessary.

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Confirmation of the acquired B structure

• Diagnosis may be helpful (colonic bacteria)
• Negative autocontrol
• Test multiple lots of monoclonal anti-B
• Test with human source of anti-B adjusted to pH
  6.0
• or pH gt 8.5 (non-reactive)
• If secretor, only A, not B substance in saliva

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Patients cells tested with acidified monoclonal
anti-B
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Patients red cells tested with anti-B from human
source

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What next?

• Serologic testing indicates the presence of an
  acquired B phenotype.
• How do we prove this?
• Patients sample sent to PJ for DNA Molecular
  Testing

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DNA Molecular testing

• PCR RFLP testing for nucleotide positions of ABO
  genes
• Cloning and sequencing of A B transferase genes
• Testing indicated presence of A2 allele, B
  allele, A1 allele and revealed a NEW cis-AB
  allele
• ABO genotype cis-AB/A102
• Predicted phenotype A1Bweak

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Comments DNA Lab

• This new cis-AB would be predicted to have a
  similar amino acid profile to a cis-AB reported
  previously (Transfusion 401276-77,2000), but
  gene sequence differs. Family studies are needed
  to confirm the cis-AB phenotype.

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Issitt says

• In most individuals with an AB cis gene, the B
  antigen produced is abnormal enough that an allo
  anti-B is present in individuals serum
• Issitt PD, Anstee DJ. Applied blood group
  serology, 4th Ed. Durham Montgomery Scientific,
  1998

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Conclusion

• Old World (serology)
• Acquired B
• Brave New World (Molecular)
• cis-ABnew/A102
  

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2006 Customer Survey

• What did you tell us?

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Customer Survey Results
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Categories showing Improvement

• Overall performance and Customer Service compared
  to FY05
• Ordering (on all shifts) time required to
  process orders
• Problem resolution
• Communication about delayed/incomplete deliveries
• Billing issues
• Customer Service Team
• Interaction responsiveness
• Reference Lab
• Courtesy Timeliness of Reference Lab report

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Categories requiring Improvement

• Availability
• RBCs, specifically type O
• Apheresis in general mid week availability
• Value Added Services
• Education programs (quality, selection,
  frequency)

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Upcoming Educational Events

• IRL Teleconferences April 6, 2007, April 12,
  2007, May 4, 2007, June 1, 2007
• Resident Fellows Seminar April 18, 2007
• MAABB April 19 20, 2007 (Williamsburg, VA)
• AABB Teleconferences April 25, 2007, May 1,
  2007, June 20, 2007, July 11, 2007
• Medical Advisory Meeting April 25, 2007
• That Renowned Week of festivities we all know
  love is coming up..

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Wahoo!!!!!!!!!!!!

• Lab Week

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Thank you for coming, drive careful,
dont forget to go to work today ?