Background: It has been reported that donor-reactive T-cell responses may decrease during the first year after HLA-mismatched organ transplantation. We wondered whether donor-reactive T-cell responses directed to minor histocompatibility antigens (mHAgs) or other non-HLA antigens also decrease after HLA-identical living-related (LR) kidney transplantation. Methods: We studied donor-reactive T-cell responses by IFN-γ and granzyme B (GrB) Elispot assays in 15 HLA-identical LR kidney transplant recipients before, six months and one yr after transplantation. Third-party reactivity was used as control. Patient and donor peripheral blood mononuclear cells were typed for 11 known mHAgs. Results: During the study period, 60% and 36% of the patients demonstrated donor-reactive IFN-γ and GrB producing cells (pc), respectively. The number of donor-reactive IFN-γ and GrB pc was significantly lower than the number of third-party reactive IFN-γ and GrB pc. After transplantation, donor-reactivity and third-party reactivity were comparable to pre-transplant values. No relation was found in mHAg mismatches between donor and recipient and donor-reactive T-cell response. Conclusions: Donor-reactivity could be detected before and after HLA-identical LR kidney transplantation, but was not related with the number of mHAg mismatches, and did not decrease after transplantation.

Elispot, Kidney transplantation, Minor histocompatibility antigens, Non-HLA antigens, T-cell reactivity,
Clinical Transplantation
Erasmus MC: University Medical Center Rotterdam

Gerrits, J.H, van de Wetering, J, Drabbels, J.J, IJzermans, J.N.M, Claas, F.H.J, Weimar, W, & van Besouw, N.M. (2009). Non-HLA T-cell reactivity during the first year after HLA-identical living-related kidney transplantation. Clinical Transplantation, 23(5), 740–747. doi:10.1111/j.1399-0012.2009.01014.x