Abstracts for Publication Only A1-A326
The presence of donor specific HLA antibodies (DSA) in a patient is a contraindication for kidney-transplantation. Crossmatches (Xm) are performed with the potential donor to exclude the presence of such antibodies.
In 1997 and 1998 124 transplants were performed on 123 patients. According to the local transplant protocol all transplants were performed with a negative CDC-Xm. For 117 patients donor spleen cells were available that were crossmatched retrospectively by flow cytometry (FC). Immunosuppression was tacrolimus based, follow up was till 1/9/03. In the study group a total of 30 grafts failed of which 19 were transplantectomized, and 39 patients experienced at least one rejection episode.
T-cell FC-Xm showed 115 patients to be negative and two to have a positive Xm at the time of transplantation. Both transplants failed, one experienced hyperacute rejection and failed after three weeks, the other one failed after two years. T-cell DSA after transplantation were demonstrable in one patient before graft failure and in eight patients after graft failure.
Preliminary results of the B-cell FC-Xm indicate a high percentage of positive crossmatches at the time of transplantation, 9/98 (9%). Also B-cell DSA were detected after transplantation in 20/98 patients (20%). In two patients B-cell DSA were detected before graft failure and in 11 patients after graft failure. Seven patients with B-cell DSA still had a functioning graft.
In the present material 2/117 (2%) current T-cell crossmatches and 9/98 (9%) current B-cell crossmatches were positive. From 117 patients nine (8%) produced T-cell DSA at various times after transplantation, most of them after failure. B-cell DSA were also found in 20% of the patients, but with a less deleterious effect on graft outcome sofar.
Identification of HLA antigen specificity is currently under investigation.