Urinary CXCL9 and CXCL10 Levels and Acute Renal Graft Rejection.

Background: Monitoring of chemokines, CXCL9 and CXCL10, in serum may present a non-invasive detection method for rejection.

Objective: To investigate the relationship between urinary levels of CXCL9 and CXCL10 and graft function following renal transplantation.

Methods: 75 living-related donor renal transplant recipients were studied. Urinary levels of chemokines were collected pre-operatively, on post-operative 1^st day, 7^th day, 1^st month, 3^rd month, and at the time of rejection. Chemokines levels were assayed using and enzyme-linked immunosorbent assay.

Results: Clinical variables were monitored. 10 (15%) patients had biopsy-proven rejection during the follow-up period. The urinary CXCL9 level in those with rejection was significantly higher than that in those with non-rejection group at the 1^st day (p<0.001), 7^th day (p<0.001), and at the time of rejection (p=0.002). The urinary CXCL10 level was also significantly higher in those with rejection compared with non-rejection group at 1^st day (p<0.001), 7^th day (p<0.001), and at the time of rejection (p=0.001). Serum creatinine level was strongly correlated with the urinary CXCL9 and CXCL10 levels at the time of rejection (r=0.615, p=0.002; and r=0.519, p=0.022, respectively). Among those with T cell-mediated rejections the mean urinary CXCL10 level increased to as high as 258.12 ng/mL.

Conclusion: Urinary CXCL9 and CXCL10 levels might have a predictive value for T cell-mediated rejection in early post-transplantation period. Measurement of urinary CXCL9 and CXCL10 levels could provide an additional tool for the diagnosis of rejection.