Clinical significance of UbA52 level in the urine of patients with type 2 diabetes mellitus and diabetic kidney disease

Abstract

BackgroundUbiquitin-52 amino acid fusion protein (UbA52) is an important factor in the pathogenesis of diabetic kidney disease (DKD) and has been suggested a potential marker in the disease. However, whether upregulation of UbA52 marks early kidney injury in T2DM mellitus (T2DM) patients remains unclear. In this study, we examine the diagnostic value of UbA52 as a biomarker in predicting early diabetic kidney disease (DKD) in T2DM patients. MethodsWe used two-step ELISA to test UbA52 level in urine of 3 defined patient groups. Samples from T2DM patients without albuminuria or diabetic retinopathy (DM-WNP; n=30), T2DM patients with albuminuria and diabetic retinopathy, excluding other renal diseases clinically (DM-NP; n=30) and healthy controls (n=30) were analyzed. Spearman's correlation analysis and multiple linear regression model were used to analyze the correlation of urinary UbA52 level with laboratory results regarding kidney function. Receiver operating characteristic curve (ROC) was used to evaluate the diagnostic value of UbA52 in predicting T2DM and early DKD. ResultsUrinary UbA52 level in DM-NP group was 1.75 times and 2.71 times higher than in DN-WNP (p=0.004) and normal control group (p<0.001), respectively. The level of urinary UbA52 correlated significantly with serum creatinine (r=0.468, p<0.001), GFR (r=−0.300, p=0.004) and proteinuria (r=0.484, p<0.001). Multiple linear regression analysis showed that proteinuria level was independently associated with urinary UbA52 level (β=0.833, p<0.001). The area under the ROC of urinary UbA52 in diagnosing T2DM and DKD was 0.751 and 0.755, respectively. ConclusionThe level of urinary UbA52 increased significantly in T2DM patients with DKD. The level of proteinuria is independently associated with urinary UbA52 level. Urinary UbA52 could serve as an early marker in the diagnosis of DKD.ClinicalTrials.gov Identifier: NCT02204280.