Urinary Nephrin as an Early Biomarker of Hypertensive Nephropathy

Hypertensive nephropathy (HN) is characterized by kidney damage due to chronic high blood pressure. Podocytes play a crucial role in the pathogenesis of HN, thus, nephrin could be important in the early diagnosis of HN. The aim of the study was to investigate the association of urinary nephrin (u-nephrin) levels with clinical and laboratory characteristics in patients with HN and to test diagnostic relevance of u-nephrin as an early biomarker of HN. In this cross-sectional study, 114 subjects were recruited, 84 patients with chronic hypertension (CH) and 30 healthy controls. All patients with CH were classified according to the urinary microalbumin/creatinine ratio (UM/CR) and according to the chronic kidney disease (CKD) stage. Urine samples were collected to estimate the u-nephrin level by ELISA and to determine UM/CR. Blood samples were used for biochemical analyses. We found elevated u-nephrin in 78.3% of normoalbuminuric subjects with CH. The levels of u-nephrin increased gradually with the stage of CKD. ROC curve plotted for u-nephrin showed 89.7% sensitivity and 88.8% specificity, while UM/CR showed a sensitivity of 44.8% and specificity of 86.1% to detect HN in the early stage. It is concluded that u-nephrin can be useful as an early biomarker of HN.