Clinical value of the sTim‑3 level in chronic kidney disease

Chronic kidney disease (CKD) is a global disease that is harder to treat at a later stage. Therefore, early diagnosis and monitoring of CKD are crucial. T cell immunoglobulin and mucin domain molecule 3 (Tim-3) is a negative regulator of the T cell responses and it is involved in the immunomodulation of kidney disease. To date, only a small number of reports regarding serum soluble Tim-3 (sTim-3) in CKD are available. In the present study, the serum levels of sTim-3 in patients with CKD at different stages and the levels of sTim-3 in the early diagnosis and monitoring of CKD were analyzed. A highly sensitive time-resolved fluorescence immunoassay was performed to quantify sTim-3 levels in 318 patients with CKD and 114 healthy individuals. The serum levels of sTim-3 in patients with CKD (33.47±20.77 ng/ml) were significantly higher than those in the healthy individuals group (8.32±3.23 ng/ml; P<0.0001). As CKD progressed from stage G1 to G5, the serum sTim-3 level gradually increased (P<0.0001). A cut-off value of 13.63 ng/ml for the sTim-3 concentration was effective in diagnosing patients with CKD (area under the receiver operating characteristic curve, 0.9176; sensitivity, 79.87%; specificity, 96.49%). At this critical value, the positive detection rate of CKD in the early stages (G1 + G2), G3, G4 and G5 was 55.70, 77.78, 84.44 and 92.86%, respectively. In conclusion, the serum sTim-3 levels in patients with CKD were significantly higher than those in the healthy individuals group. As CKD progressed from G1 to G5, the serum sTim-3 concentration gradually increased, facilitating the monitoring of the progression of CKD. In addition, serum sTim-3 had an auxiliary effect that was useful in the early diagnosis of CKD. The positive detection rate of CKD in the early stages was 55.70%, which can assist other clinically common kidney disease indicators.