Serum uromodulin as an early biomarker of tubular atrophy and interstitial fibrosis in patients with glomerulopathies

Abstract

To assess the significance of the serum uromodulin (Tamm-Horsfall protein - THP) concentration (Sumo) as an early biomarker of tubular atrophy (TA) and interstitial renal fibrosis (IF) in patients with glomerulopathies. 84 patients with glomerulopathy and 11 practically healthy persons (control) were examined. Uromodulin concentrations in serum and urine (Uumo) were measured, renal excretion of this protein and the estimated glomerular filtration rate (eGFR) were established. A semi-quantitative assessment of nephrobioptates was performed. Sumo decreases with a minimum expression of tubular atrophy (TA) or interstitial fibrosis (IF), when the values of eGFR still remain normal. Variations of such excretory parameters of THP as Uumo, daily excretion, and ratio: urinary uromodulin / urinary creatinine, did not manifest a similar trend. Sumo is promising as an early biomarker of fibrotic and atrophic renal damage. The parameters of renal excretion of THP do not seem to have this property. The reason for the delay in the decline of Uumo in the progression of CKD as compared to the decrease in Sumo seems to be the need to maintain a sufficient Uumo to counteract urinary tract infection and stone formation.