Crossmatch tests--an analysis of UNOS data from 1991-2000

Based on more than 20,000 cadaver donor transplants reported to UNOS between 1991-2000 with crossmatch results, the following observations were made: 1. One-hundred sixty-nine transplants performed despite a positive T-cell NIH crossmatch (usually with an historical serum sample) were reported to UNOS and had 5%, 6%, 7%, and 11% lower graft survival at one, 6, 12, and 24 months after transplantation compared with negative crossmatch transplants, respectively. 2. Transplants with a positive T-cell FCXM (n = 714) yielded 4%, 7%, and 9% lower graft survival at one, 6, and 12 months after transplantation compared with negative crossmatch transplants, respectively. 3. Transplants with a positive B-cell crossmatch using NIH, Wash, AHG or flow cytometry XM yielded statistically significantly lower (4-6%) graft survival rates compared with B-cell negative crossmatch transplants. 4. The differences in graft survival rates comparing recipients with a positive versus a negative T-cell crossmatch test (NIH, AHG, and FCXM) were significant in univariate analyses; however, only the NIH and FCXM showed a significant effect on graft survival after adjustment of other factors in a multivariate analysis. 5. Regrafted patients with a positive T- and B-cell FCXM experienced a higher incidence of primary nonfunction (12%) compared with those who had a negative T- and B-cell FCXM (1%; P < 0.001). Flow cytometric or ELISA screening of patient sera in addition to conventional cytotoxic crossmatch tests can provide additional information to aid in the final decision of renal transplantation.