Abstract Presentations from the AABB Annual Meeting Orlando, FL, October 22–25, 2016

Abstract

Background/Case Studies: Platelet crossmatching using Capture-P#sup#VR#/sup# (Immucor, Norcross, GA) solid phase system for detection of IgG antibodies to platelets is used to perform the platelet crossmatching. The Capture-P#sup#VR#/sup# instructions for Use (IFU) lists the source of platelet used for crossmatching as platelet rich plasma (PRP) derived from whole blood collected in EDTA, ACD, CPD or CPDA-1 or samples obtained directly from the platelet bag. Platelet suspended in InterSol Platelet Additive Solution 3 (PAS3) (Fenwal, Inc. Lake Zurich, IL) is not listed as a platelet source for Capture-P#sup#VR#/sup# testing. Study Design/Methods: Parallel Capture-P#sup#VR#/sup# testing for detection of antibodies to platelets with known refractory patient specimens using EDTA derived PRP and PAS3 aliquots as a platelet source was performed to determine if PAS3 is an acceptable source of platelets to detect IgG antibodies to platelets using Capture-P#sup#VR#/sup# testing methodology. The PAS3 test results were compared to the EDTA derived PRP results. Results/Findings: Platelet crossmatching using Capture-P#sup#VR#/sup# solid phase system for detection of IgG antibodies to platelets was performed on 59 platelet donors. Both the donor's PRP derived from whole blood collected in EDTA and PAS3 samples were tested in parallel with 29 known reactive patient specimens to give 266 parallel test occasions. Results consistent with the EDTA derived PRP results were considered the true positive and true negative results. PAS3 positive or negative interpretation result different than the EDTA derived PRP result were considered a false positive and false negative. The accuracy of the crossmatch when using PAS3 samples to correctly identify incompatible and compatible platelets was 98.9%. The sensitivity of the crossmatch when using PAS3 samples to correctly identify incompatible platelets was 99.5%. The specificity of the crossmatch when using PAS3 sam-ples to correctly identify compatible platelets was 97.4%. Conclusion: Patients who receive multiple platelet transfusions are at risk of developing antibodies to the HLA and/or HPA platelet antigens. Platelet crossmatching using Capture-P#sup#VR#/sup# solid phase system for detection of IgG antibodies is an effective method for detecting antibodies to both the HLA and HPA platelet antigens. Our study demonstrated that a platelet aliquot obtained from AMICUS-leukoreduced apheresis platelets using PAS3 storage solution was an acceptable platelet source in Capture-P solid phase system for detection of IgG antibodies. As the transfusion medicine field is continually developing new platelet products for the reduction of transfusion associate reactions/ diseases such as pathogen inactivated platelets, the acceptability of the newly developed platelet products for use in platelet crossmatching will be required.