Uromodulin Levels in Chronic Kidney Disease

Objectives: Uromodulin is a protein exclusively produced by Kidney in tubular cells lining thick ascending limb (TAL) of the loop of Henle. It has been linked to water electrolyte balance, protective role against urinary tract infections and renal stone formation. To analyse its trend in Chronic Kidney Disease (CKD), its levels were analysed in serum and urine of patients at different stages of CKD. Methods: CKD stage-1 and stage-2 (N=14), Stage-3 (N=24), Stage-4 (N=9), Stage-5 (N= 19) and controls (N=16) were recruited as per the National Kidney Foundation – Kidney Disease Outcome Quality Initiative guidelines. Uromodulin levels were analysed by enzyme linked immunsorbent assay (ELISA). Results: Uromodulin levels both in serum and urine decreased with decreasing kidney function. Bivariate analysis within CKD group showed significant (p=0.001) positive correlation of urinary Uromodulin (spearman correlation [rs]=0.664) and serum Uromodulin (rs=0.855) levels with eGFR and significant (p=0.001) negative correlation of urinary Uromodulin (rs= ̶ 0.872) and serum Uromodulin (rs= ̶ 0.859) with serum creatinine levels. Serum Uromodulin levels in addition showed significant (p=0.001) negative correlation with phosphorus (rs = ̶ 0.523) and corrected calcium phosphorus product (rs= ̶0.484). Conclusion: Serum and urine levels of Uromodulin decreased with increasing severity of CKD. Apart from its other protecting role, its reduction may accelerate pathophysiology associated with elevated calcium-phosphorus product in CKD.