Serum levels of CXCR3 ligands predict T cell-mediated acute rejection after kidney transplantation

The early diagnosis of acute rejection is crucial for graft survival after kidney transplantation. The interferon- (IFN)-CXCR3-chemokine-dependent inflammatory loop plays a pivotal role in the recruitment of T lymphocytes during acute rejection. Previously published studies have typically focused on the CXCR3 receptor rather than on its ligands. In the present study, we used Luminex assays to detect the levels of CXCR3 ligands, monokine induced by IFN (MIG), IFN-induced protein 10 (IP-10) and IFN-induced T-cell chemoattractant (I-TAC), in the serum of renal allograft recipients. According to a renal biopsy performed one month after kidney transplantation, 32 recipients were diagnosed with T cell-mediated acute rejection and 38 patients were evaluated as stable. Serum was collected after the diagnosis of acute rejection or one month after transplantation. The concentrations of MIG (median, 4,271 pg/ml), IP-10 (median, 686.7 pg/ml) and I-TAC (median, 44.32 pg/ml) in the serum during an acute rejection episode were significantly higher compared with those of the stable patients (MIG, P=0.0002; IP-10, P=0.0001; I-TAC, P=0.0103; vs. the stable function group, P<0.05). Based on the receiver-operating characteristic (ROC) curve, the joint detection of MIG, IP-10 and I-TAC in the serum using Luminex analysis may constitute a non-invasive and efficient method for the early prediction of T cell-mediated acute rejection following kidney transplantation.