“It’s Just a Panel … It’s not Rocket Science” Shannon Long, MT(ASCP)SBB Lead Reference Technologist LifeShare Blood Centers

Methods - Tube Advantages Disadvantages Flexible Subjective grading Available equipment Relatively inexpensive Multiple phases of reactivity Use different additive solutions Disadvantages Subjective grading Increased hands-on tech time Washing problems

Methods - Gel Advantages Disadvantages Sensitivity Smaller sample size Less hands-on tech time Stable reactions Automation Disadvantages Special incubators Special centrifuges Special pipette and tips

Tips For Gel Users Screening cells positive  panel negative Screening cells positive  crossmatch negative Auto control

Methods - Solid Phase Advantages Disadvantages Smaller sample size than tube Stable reactions Pos and Neg control Automation Disadvantages Sensitive pipetting Questionable interpretation Special equipment Pos and Neg control

Tips For Solid Phase Users Screening cells positive  panel negative Screening cells positive  crossmatch negative Auto control

Antibody Identification Patient History Age? Sex? Race? Diagnosis? Medications? Transfusion history? Pregnancy history?

Antibody Identification (cont’d) Exclusions Exclude based on negative reactions to cells having presumed homozygous expressions of antigen Exclude with one negative cell Exceptions

Evaluation of Panel Tube Testing In what phase(s) and at what strength(s) did the positive reactions occur? Do all of the positive cells react at the same phase, or do any react at different or multiple phases? Does the serum reactivity match any of the remaining specificities?

Evaluation of Panel (cont’d) Tube, Gel, Solid Phase Are all commonly encountered RBC antibodies ruled out? Is the autologous control positive or negative? Is there sufficient evidence to prove the suspected antibody? Is the patient lacking the antigen corresponding to the antibody?

Cost-effective Methods Use of outdated reagent red cells Use of diluted antisera for screening Use of unlicensed antisera for screening Use of outdated antisera Use of proper controls for outdated or unlicensed antisera

Summary No matter what test method you use in your Blood Bank, the approach to antibody identification should always be the same. No test method is perfect, so use the one that works best for your facility.

Case Studies

Case 1 70 year old Caucasian female Admitted with cellulitis of right leg Transfused 3 months ago Three units of blood ordered STAT Blood type: O Positive DAT: Negative Rh Phenotype: C+E-c+e+ Antibody screen 4+ positive (all three screening cells) using automated solid phase testing

Case 1 – Initial Panel Results   D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s RT 37 AHG 1 + 1+ 2+ 2 1+w 3 3+ 4 5 6 w 7 8 9 10 11 A/C

Case 1 – Selected Cells D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s   D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s RT 37 AHG 1 + 1+ 2 3 1+s 4 5

Case 1 – Additional Selected Cells   D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s RT 37 AHG 1 + 2 3 1+s 4 2+

Case 2 34 year old Caucasian female Admitted with abdominal pain and bleeding Hemoglobulin: 8.9 g/dL History of transfusion (> 3 months ago) History of pregnancy Blood type: AB Positive Rh Phenotype: C-E+c+e- Hospital reports 2+ using Gel (SC-I)

Case 2 – Initial Panel Results   D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s RT 37 AHG PEG 1 + 1+ 1+s 2 3 4 mi+ 5 6 w 7 8 9 1+w 10 11 A/C

Case 2 – Selected Cells D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s   D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s PEG 1 + 2 3 w 4 1+ 5 mi+ 6 PT  NT

Case 2 – Ficin Treated Panel   D C c E e K Fya Fyb Jka Jkb Lea Leb P1 M N S s IS 37 AHG 1 + 2+ 2+s 1+ 2 3 4 mi+ 5 1+s 6 w 7 8 9 10 11 A/C