The requirement for a prospective crossmatch limits some organ allocation to local areas. The delay necessitated by the crossmatch restricts the distance across which offers can be made without unduly increasing the ischemia time. A collaborative study involving 14 transplant centers was undertaken by the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) Histocompatibility Committee to evaluate the accuracy with which the detection of unacceptable human leukocyte antigen (HLA) antigens by most advanced solid phase immunoassays can predict crossmatch results. In addition, using actual patients’ unacceptable HLA antigens, the number of compatible donors that would have been available from the OPTN deceased kidney donors during 2002 to 2004 were investigated.
Panel reactive antibodies were performed by conventional or solid phase assays, and crossmatches were performed by cytotoxicity or flow cytometry. Analyses were stratified for T and B cell and by method of identifying unacceptable HLA antigens and crossmatch techniques.
Combination of solid phase immunoassays and flow cytometry crossmatches resulted in a higher prediction rates of positive T cell (86.1%–93.5%) and B-cell crossmatches (91%–97.8%). Prediction of negative crossmatches based on different combination of panel reactive antibodies and crossmatch techniques varied from 14.3% to 57.1%. Furthermore, numerous potential compatible donors were identified for each patient, regardless of their ethnicity, in the OPTN database, when predicted incompatible ones were excluded.
The above results showed that with the advent of solid phase immunoassays, HLA antibodies can now be accurately detected resulting in prediction of crossmatch outcome. This should facilitate organ allocation and prevents shipment of organs to distant incompatible recipients.
1 OPTN/UNOS Histocompatibility Committee, Richmond, VA.
2 Texas Medical Specialty, Inc. Dallas, TX.
3 Research Dept/UNOS, Richmond, VA.
4 Puget Sound Blood Center, Seattle, WA.
5 John Hopkins Medical Center, Baltimore, MD.
6 Hartford Transplant Center, Hartford, CT.
7 DCI Laboratory, Nashville, TN.
8 University of Utah School of Medicine, Salt Lake City, UT.
9 Oregon Health Sciences Center, Portland, OR.
10 University of Pennsylvania, School of Medicine, Philadelphia, PA.
11 Medical College of Virginia, Richmond, VA.
12 Inland Northwest Blood Center, Spokane, WA.
13 University of Minnesota, Fairview-University Medical Center, Minneapolis, MN.
14 ECU School of Medicine, Greenville, NC.
15 MeritCare Transplant Services, Fargo, ND.
16 Tulane University School of Medicine, New Orleans, LA.
17 The Methodist Hospital/Weill-Cornell Medical College, Houston, TX.
This work was supported wholly or in part by HRSA contract 234-2005-370011C.
The content is the responsibility of the authors alone and does not necessarily reflect the views or policies of the Department of HHS, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.
18 Address correspondence to: Afzal Nikaein, Ph.D., Texas Medical Specialty, 7777 Forest Lane, Building C, Suite 768, Dallas, TX 75230.
Received 24 June 2008. Revision requested 9 July 2008.
Accepted 26 September 2008.