Kidney Injury Molecule-1 (KIM-1) in Blood Plasma of Patients with Clear-Cell Carcinoma

The concentration of kidney injury molecule-1 (KIM-1) was measured in blood plasma of 99 patients with clear-cell carcinoma and 14 patients with benign renal tumors using a Human Serum TIM-1/KIM-1/HAVCR Quantikine ELISA kit. The control group consisted of 15 healthy male and 14 healthy female subjects. KIM-1 levels in blood plasma of patients with cancer or benign renal tumors were significantly higher than in the control (p<0.00001 and p<0.01, respectively). In patients with benign tumors, this parameter was significantly lower than in patients with cancer (p<0.0001). KIM-1 level significantly increased with disease stage (p<0.0001), and even in stage I cancer, it was higher than in the control group (p<0.0001) or in patients with benign tumors (p<0.01). The best sensitivity/specificity ratio for stage I renal cancer detection (81 and 83% respectively) was achieved at cut-off level 77 pg/ml, the sensitivity of detection of for stages II-IV being 97%. Plasma level of KIM-1 increased with increasing the size and area of the primary tumor (T). This parameter was higher in patients with metastasis in regional lymph nodes irrespective of their number (N1 or N2) in comparison with patients without regional metastasis (N0). It is also higher in patients with distant metastasis (M+). In patients with grade III-IV cancer, KIM-1 level was 7-fold higher than in patients with grade I-II tumor (p<0.0001). Thus, KIM-1 can be regarded as a highly sensitive marker for early detection of clear-cell carcinoma.