The relevance of donor T cell-directed immunoglobulin G in historic sera in the age of flow cytometry

Background. Renal transplant recipients with a positive historic cross-match due to donor T cell-directed IgG antibodies are considered to have decreased graft survival, even if their current serum is negative prior to transplantation, With the use of flow cytometric cross-match for testing current sera, false-negative results could be eliminated and the outcome of transplantation in this group of patients could be improved, assuming that immunological memory is effectively controlled with immunosupression. Methods. We reviewed our records to identify those patients who underwent cadaveric renal transplant, with a historic IgG positive cytotoxic T cell crossmatch and a current negative flow cytometric T cell cross-match. Results. Eighteen patients underwent cadaveric renal transplant in the face of a historic IgG positive T cell cross-match and a current negative flow cytometric T cell cross-match. In 14 patients treated with cyclosporine-based immunosuppression the 1-, 2-, and 3-year cumulative graft survival. rates were 57, 50, and 43%, respectively, Ten of the 14 patients (71%) ultimately lost their grafts. Conclusions, Even with negative flow cytometric crossmatch in current serum, a positive historic conventional cross-match suggests a high risk of graft failure.