Serum Cystatin C and Neutrophil Gelatinase- Associated Lipocalin as Biomarkers of Glomerular and Tubular Kidney Damage in Patients with Chronic Glomerulonephritis and Saved Renal Function

Aim: to analyze the histological kidney features in patients with CGN and arterial hypertension (AH) and without it, to assess the relationship between serum CysC and NGAL and histological signs of glomerular and tubular kidney lesion in patients with CGN with saved renal function. Methods: eighty one patients with CGN were enrolled in the study. Blood samples for biomarkers were collected. The diagnosis of "chronic glomerulonephritis" was defined by the clinical, laboratory data and renal biopsies. Patients were divided into 2 clinical groups: patients with AH and without AH. We used data of renal biopsies to analyze the signs of kidney glomerular apparatus and tubulo-interstitial tissue lesion in patients with CGN. Levels of serum CysC and NGAL were measured by ELISA kits. 148 Oleg Kraydaschenko et al. Results: according to the results of renal microscopy 88% patients had mesangial proliferative glomerulonephritis, 7% – membranous nephropathy, 5% – membranous proliferative glomerulonephritis. Patients with CGN and AH have more severe histological glomerular and tubular lesion parameters than patients with CGN without AH. On the basis of rank correlation analysis we proved that serum cysC directly correlates with all indicators of glomerular apparatus kidney lesion in patients with CGN, strong direct relationship was found between the level of serum cysC and glomerulosclerosis (r = 0.85, p < 0.05). Level of serum NGAL directly correlates with indicators of tubulo-interstitial kidney tissue lesion in patients with CGN, strong direct relationship was found between the level of serum NGAL and interstitial fibrosis (r = 0.65, p < 0.05). Conclusion: glomerulosclerosis has determined of the serum cysC level with the efficiency of 96.55%. Diagnostics of interstitial fibrosis by determining of the serum NGAL level is a highly sensitive and specific method, with the efficiency of 95.3%.