Pretransplant Donor-Specific Interferon-γ ELISPOT Assay Predicts Acute Rejection Episodes in Renal Transplant Recipients

Interferon (IFN)-γ enzyme-linked immunosorbent spot (ELISPOT) assay is a powerful tool for measuring the frequency of alloantigen-specific T cells, reflecting cellular immunity. We correlated the pretransplant frequencies of donor-specific and third-party-specific IFN-γ ELISPOT tests, with the posttransplant outcomes of 45 recipients of living donor renal transplantations. The mean frequency of pretransplant donor-specific ELISPOT was significantly greater among patients with acute rejection episodes (ARE) than those without ARE (18.0 [12 to 50] versus 8.8 [5 to 30.4]) spots per 200,000 peripheral blood lymphocytes (PBLs; P = .024). A cutoff level of 12 spots per 200,000 PBLs on the donor-specific ELISPOT identified an ARE-positive patient with a sensitivity of 81.8% and a specificity of 64.7%. The recipients with pretransplant donor-specific ELISPOT + showed higher serum creatinine levels and lower glomerular filtration rate (GFR) at 6 posttransplant months (P < .05). Although the pretransplant third-party-specific ELISPOT results correlated with the donor-specific ELISPOT results (r = .783; P < .001), there was no significant difference in the third-party ELISPOT results between the ARE-positive and ARE-negative recipients. In conclusion, an analysis of pretransplant donor-specific IFN-γ ELISPOT may identify the posttransplant risk of developing ARE and displaying decreased GFR at 6 months.