Diagnostic value of urinary biomarkers excretion in estimation of morphological lesions in patients with primary glomerulopathies

Abstract

To investigate the diagnostic value of biomarkers in assessing the severity of sclerotic and atrophic lesions in primary glomerulopathies. One hundred patients were included in the study, according to the results of kidney biopsy in 9 (9%) cases minimal change disease was diagnosed, in 28 (28%) focal segmental glomerulosclerosis, in 26 (26%) membranous nephropathy and in 37 (37%) IgA nephropathy. The clinical course of nephropathy was evaluated, standard laboratory tests were performed, and urinary excretions of cystatin C, 1-microglobulin, 2-microglobulin and NGAL were measured. The degree of glomerulosclerosis was assessed quantitatively, tubulointerstitial sclerosis and tubular atrophy semiquantitatively. According to the results of linear correlations and ROC-analysis, urinary excretion of cystatin C and 1-microglobulin had diagnostic value for early degree of tubulointerstitial sclerosis (cut-off value 319.9 and 10.94 mg/day, respectively). Urinary excretion of 2-microglobulin reflected the initial degree of tubalar atrophy (cut-off value of 0.224 mcg/day), as well as tubulointerstitial sclerosis of various degrees of severity (cut-off value 0.224 and 0.240 mkg/day). NGAL urinary excretion was the only marker of early degree of glomerulosclerosis with its excretion of more than 1445.4 ng/day and tubular atrophy, with a severity of 50% or more (cut-off value 4897.8 ng/day). A comprehensive assessment of sclerotic and atrophic lesions in the renal parenchyma, can be performed using a panel of traditional (GFR, proteinuria) and specific biomarkers (1-, 2-microglobulins, cystatin C, NGAL) to implement a comprehensive, personalized approach, as well as to assess the prognosis of nephropathy. In addition, the evaluation of the panel of different biomarkers can be used in those clinical situations where kidney biopsy can not be performed.