Identification of Dialysis Patients with Panel-reactive Memory T Cells Before Kidney Transplantation Using an Allogeneic Cell Bank

Donor-reactive cellular sensitization does not routinely suggest humoral sensitization and vice versa, but both predict poor kidney transplant outcome. Irrespective of donor reactivity, panel-reactive antibody (PRA) screening identifies patients who are at enhanced risk. Therefore, it was hypothesized that panel-reactive memory T cell reactivity (PRT) might be an additional risk assessment factor of dialysis patients who are on the transplant waiting list. IFN-gamma-enzyme-linked immunosorbent spot memory T cell frequencies were determined in 10 healthy volunteers and 41 hemodialysis patients using for stimulation an allogeneic cell bank (ACB) from 17 healthy individuals who represented the most frequent white HLA antigens. Positive responses to ACB were analogous to PRA defined as percentage of positive assays of the ACB sets. Hemodialysis patients expressed higher PRT levels compared with healthy volunteers. Five of 10 PRT++ patients were PRA negative, and only four of 10 PRA++ patients exhibited PRT reactivity, suggesting independence of humoral and cellular sensitization. Pretransplantation PRT testing of recipients might improve individual risk assessment to make individualized therapy decisions.