8Antibody Identification (cont’d) ExclusionsExclude based on negative reactions to cells having presumed homozygous expressions of antigenExclude with one negative cellExceptions
9Evaluation 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?
10Evaluation of Panel (cont’d) Tube, Gel, Solid PhaseAre 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?
11Cost-effective Methods Use of outdated reagent red cellsUse of diluted antisera for screeningUse of unlicensed antisera for screeningUse of outdated antiseraUse of proper controls for outdated or unlicensed antisera
12SummaryNo 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.
14Case 1 70 year old Caucasian female Admitted with cellulitis of right legTransfused 3 months agoThree units of blood ordered STATBlood type: O PositiveDAT: NegativeRh Phenotype: C+E-c+e+Antibody screen 4+ positive (all three screening cells) using automated solid phase testing
18Case 2 34 year old Caucasian female Admitted with abdominal pain and bleedingHemoglobulin: 8.9 g/dLHistory of transfusion (> 3 months ago)History of pregnancyBlood type: AB PositiveRh Phenotype: C-E+c+e-Hospital reports 2+ using Gel (SC-I)