Introduction: Early prognostic markers that identify high-risk patients could lead to increased surveillance, personalized immunosuppression, and improved long-term outcomes.
The aim of this prospective study was to assess whether urine levels of CCL2 and CXCL10 can be valuable, non-invasive source of information about ongoing immune inflammation, tubular injury, progression of fibrosis and other damage features in the kidney allograft.
Materials and Methods: In this prospective study 40 patients who underwent a protocolar biopsy within 1 year post kidney transplant were included. The levels of chemokines CCL2 and CXCL10 with reference to creatinine in urine were assayed in all patients.  Based on biopsy results research group (N=25) with diagnosis of BKV nephropathy, IFTA II-III, peritubular capillaritisis, C4d or rejection was selected. Patients with normal biopsy results were included as control group (N=15). CCL2 and CXCL10 levels were evaluated in individual groups.
Chi-square test or Fisher exact test were used for categorical variables and 2-sample t-test for continuous variables. Correlations were determined using Spearman and Pearson rank correlation coefficients. P values less than 0.05 were considered significant.
Results: Median urinary CCL2-to-creatinine (Cr) ratio [ng/mmol] was significantly elevated in research group compared to control group (21.76 ± 18.57 vs 8.99 ±5.12, p=0.003). There was no statistical difference between groups regarding CXCL10/Cr ratio (7.96 ± 9.08 vs 5.58 ±5.7 p=0.32).  Patients with BKV nephropathy (N=3) had much higher level of CCL2 [ng/l] than control group but the difference did not reach statistical significance (429.69 ± 166.49 vs 78.04 ±53.61, p=0.06).
Discussion: Urinary CCL2/Cr corresponds with ongoing damaging processes. The significance of CCL2 in BKV nephropathy should be further evaluated.
Conclusion: Urinary CCL2/Cr may be used as a non-ivasive tool useful for monitoring graft condition and predicting recipients with high risk of transplant kidney loss.