PREDICTIVE VALUES OF KIM-1 AND NGAL TISSUE EXPRESSIONS IN PATIENTS WITH IMMUNGLOBULIN A NEPHROPATHIES

Background: Kidney Injury Molecule-1 (KIM-1) and Neutrophil Gelatinase-Associated Lipocalin (NGAL) have important roles in both immunity and cell proliferation. It was previously reported that these markers were potential predictors of adverse renal outcomes in several renal diseases. We aimed to investigate the association of tissue expressions of KIM-1 and NGAL with histopathologic and clinical features in immunoglobulin A nephropathy (IgAN). Methods: Thirty-three patients (57.9%) with biopsy-proven IgAN and 24 patients (42.1%) who had nonspecific histological alterations in renal biopsy specimens were immunohistochemically examined for tissue expressions of KIM-1 and NGAL. Results: Forty (70.2%) cases were male and 17 (29.8%) were female. The mean age was found to be 39.2 +/- 16.5 years. Hematuria, proteinuria and tubular atrophy /interstitial fibrosis were detected in 30 (52.6%), 13(22.8%) and 15 (26.3%) cases, respectively. Tubular KIM-1 expression was significantly higher in patients with IgAN than in normal controls (P<0.001). Hematuria (p=0.002), global sclerosis (p=0.014) and segmental sclerosis (p=0.005) were associated with the presence of KIM-1 expressions in IgAN. More severe tubular atrophy/interstitial fibrosis was found to be associated with the presence of greater number of NGAL-positive interstitial inflammatory cells (p=0.011). The number of neutrophils infiltrating the glomeruli were more numerous in patients with high serum cholesterol levels (p=0.028). Conclusion: Initial data suggest that KIM-1 expression may be related to the disease severity in IgAN. However, further studies on larger populations are required to validate our reports and to evaluate the potential utility of KIM-1 and NGAL tissue staining in the prediction of progression of IgA nephropathy.

Automated summary

The study found that KIM-1 expression is higher in patients with IgAN compared to normal controls, and the number of NGAL-positive interstitial inflammatory cells is associated with the severity of tubular atrophy/interstitial fibrosis. Higher levels of serum cholesterol are correlated with increased neutrophil infiltration in the glomeruli.