Urinary extracellular vesicles as a monitoring tool for renal damage in patients not meeting criteria for chronic kidney disease

Abstract

Abstract Background Current definition of chronic kidney disease (CKD) identifies only advanced stages, but effective management demands early detection. Urinary albumin‐to‐creatinine ratio (ACR) 30 mg/g is a cut‐off point for CKD clinical diagnosis. Patients with lower values (normoalbuminuria) and eGFR > 60 mL/min/1.73 m2 are considered at no increased cardiorenal risk. However, higher incidence of renal function decline and cardiovascular events have been shown within the normoalbuminuria range. Novel subclinical indicators may help to identify higher‐risk patients. Urinary extracellular vesicles (uEVs) are sentinels of renal function non‐invasively. Here we aimed to approach the early assessment of cardiorenal risk by investigating the protein cargo of uEVs. Methods Hypertensive patients were classified in control group (C) with ACR 6200 uEVs proteins identified, 43 define a panel significantly altered in HN patients without variation in urine, mostly annotated in the tubule (39 out of 43). The tubular transporter long‐chain fatty acid transport protein 2 (SLC27A2) and the apical membrane protein amnionless (AMN) confirmed their alteration in HN patients evidencing impaired tubular reabsorption. SLC27A2 showed tubular expression and significantly reduced levels in patients with diagnostic criteria for CKD. Conclusions Alterations in the EV‐mediated molecular profile are evident before pathological ACR levels are reached. Direct quantitation of SLC27A2 and AMN in uEVs helps identifying normoalbuminuric subjects with higher cardiorenal risk in early monitoring of CKD.

Keywords

• albuminuria
• AMN
• cardiovascular risk
• chronic kidney disease
• ExoView
• extracellular vesicles