Diagnostic utility of plasma and urine KIM-1 levels in clear cell renal cell carcinoma: an observational prospective study
摘要
Kidney injury molecule-1 (KIM-1) is a transmembrane glycoprotein expressed in injured proximal tubules and renal cell carcinoma (RCC). This study evaluated urinary (uKIM-1) and plasma (pKIM-1) concentrations in patients with clear cell RCC (ccRCC) as potential diagnostic and prognostic biomarkers.
MethodsA prospective observational study included 73 patients undergoing nephrectomy for renal tumors and 34 healthy volunteers. KIM-1 levels were measured using ELISA and analyzed in relation to tumor size, TNM stage, WHO/ISUP grade, and histopathological features. Diagnostic performance was assessed using ROC curves. Correlations were evaluated using Spearman coefficients.
ResultsBoth uKIM-1 and pKIM-1 levels were significantly higher in ccRCC patients compared to those with non-ccRCC tumors and healthy individuals (p < 0.001). pKIM-1 > 75 pg/ml demonstrated high diagnostic performance for ccRCC (AUC = 0.93, sensitivity = 90.4%, specificity = 94.1%). uKIM-1 > 1.15 ng/mg uCr showed lower performance (AUC = 0.78, sensitivity = 69%, specificity = 73.5%). Biomarker levels correlated positively with tumor size (R = 0.66), TNM stage (R = 0.61), and histological grade (R = 0.58). Both markers were elevated in tumors with necrosis and perirenal fat invasion.
ConclusionKIM-1 is a promising non-invasive biomarker for ccRCC. Plasma KIM-1 > 75 pg/ml distinguishes ccRCC from healthy individuals with high sensitivity and specificity, while also correlating with tumor aggressiveness. Its measurement may support diagnosis, risk stratification, and follow-up in ccRCC patients.