Serum and Urinary Levels of Tumor Necrosis Factor-Alpha in Renal Transplant Patients

Objectives: Allograft rejection is an important cause of early and long-term graft loss in kidney transplant recipients.Tumor necrosis factor-alpha promotes T-cell activation, the key reaction leading to allograft rejection. Here, we investigated whether serum and urinary tumor necrosis factor-alpha levels can predict allograft rejection. Materials and Methods: This study included 65 living related-donor renal transplant recipients with mean follow-up of 26 +/- 9 months. Serum and urinary tumor necrosis factor-alpha levels were measured at pretransplant and at posttransplant time points (days 1 and 7 and months 3 and 6); serum creatinine levels were also monitored during posttransplant follow-up. Standard enzyme-linked immunoabsorbent assay was used to detect tumor necrosis factor-alpha levels. Clinical variables were monitored. Results: Nine of 65 patients (13.8%) had biopsy-proven rejection during follow-up. Preoperative serum and urinary tumor necrosis factor-alpha levels were not significantly different when we compared patients with and without rejection. Serum tumor necrosis factor-alpha levels (in pg/mL) were significantly higher in the allograft rejection versus nonrejection group at day 7 (11.5 +/- 4.7 vs 15.4 +/- 5.8; P = .029) and month 1 (11.1 +/- 4.8 vs 17.8 +/- 10.9; P =.003). Urinary tumor necrosis factor-alpha levels (in pg/mL) were also elevated in the allograft rejection versus the nonrejection group at days 1 (10.2 +/- 2.5 vs 14.1 +/- 6.8; P= .002) and 7 (9.8 +/- 2.2 vs 14.5 +/- 2.7; P < .001) and at months 1 (8.0 +/- 1.7 vs 11.8 +/- 2.4; P < .001), 3 (7.7 +/- 1.6 vs 9.6 +/- 1.7; P = .002), and 6 (7.4 +/- 1.6 vs 8.9 +/- 0.9; P = .005). Conclusions: Our preliminary findings suggest that tumor necrosis factor-alpha has a role in diagnosing renal transplant rejection. Serum and urinary tumor necrosis factor-alpha levels may be a possible predictor for allograft rejection.