Andrea A. Zachary*, Jeffrey T. Sholander, Julie A. Houp, Mary S. Leffell
Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
Received 8 April 2009
Accepted 9 June 2009
Available online 12 June 2009
Virtual crossmatches have been performed for more than 40 years under the guise of unacceptable antigens. Today, solid-phase assays provide the opportunity for more accurate identification and more precise mea- surement of the strength of donor-specific antibodies. The process of performing a virtual crossmatch begins with establishing a correlation between the antibody testing assay and the results of actual crossmatches. We provide here data indicating that the identity and strength of DSA defined with solid-phase phenotype panels correlates significantly with the outcome of both cytotoxic (CDC; r 0.83) and flow cytometric (r 0.85) crossmatches. Based on the threshold established from these correlations, we were able to correctly predict the results of CDC and flow cytometric crossmatches in 92.8 and 92.4% of cases, respectively. The correlations with single antigen panels were substantially lower (82.6 – 47.9%) and may be caused by a variety of factors, including variability in the amount and condition of different antigens and extremely high sensitivity, which may make the test less robust. We demonstrate that adding additional information to the solid-phase results can increase the frequency of correct crossmatch prediction. We also present data demonstrating an addi- tional use of the virtual crossmatch in posttransplant monitoring.
© 2009 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.