Abstract: SA-PO262
Analysis of Single Urinary Extracellular Vesicles from Subregions of the Nephron as a Diagnostic Tool in Early Diabetic Nephropathy
Session Information
- Diabetic Kidney Disease: Basic - 2
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Diabetic Kidney Disease
- 701 Diabetic Kidney Disease: Basic
Authors
- Greig, Morgan, UVA Health, Charlottesville, Virginia, United States
- Mallawaarachchi, Indika V., UVA Health, Charlottesville, Virginia, United States
- Ma, Jennie Z., UVA Health, Charlottesville, Virginia, United States
- Diamantidis, Clarissa Jonas, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
- Harding, Michael A., UVA Health, Charlottesville, Virginia, United States
- Yavuz, Hayrettin, UVA Health, Charlottesville, Virginia, United States
- Musante, Luca, University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Solga, Michael, UVA Health, Charlottesville, Virginia, United States
- Upson, Samantha G., UVA Health, Charlottesville, Virginia, United States
- Scialla, Julia J., UVA Health, Charlottesville, Virginia, United States
- Erdbruegger, Uta, UVA Health, Charlottesville, Virginia, United States
Background
Urinary extracellular vesicles (uEVs) have been identified as early and sensitive biomarkers in kidney disease, however, their association with diabetic kidney disease (DKD) progression and DKD clinical traits is not yet clear. Characterization of uEVs may allow investigation into the relationship between uEVs of glomerular and tubular origin and distinct pathophysiological and clinical DKD phenotypes.
Methods
We attained uEVs from 24-hour urine collections in 116 adults with diabetes mellitus enrolled in the Simultaneous Risk Factor Control Using Telehealth (STOP-DKD). To determine uEV count, size and cargo, single EV characterization was performed via spectral flow cytometry (SFC) as a high throughput tool and SP-IRIS (Exoview R100) for small sample volumes. We used markers for CD26/DPP4(PT S1)+, CD35/CR1(podocyte)+, CD10/MME/NEP(PT S1,S2,S3)+, and tetraspanin,CD9(EV marker)+ labeled uEVs. Linear regression was used to assess the cross-sectional association of SFC data, kidney function and degree of microalbuminuria (UACR). SP-IRIS analysis compared a cohort of 10 healthy to 10 early DKD patients.
Results
Participants were 63.65±9.20 years of age; 50.4% female. Baseline eGFR was 81±22 ml/min/1.73m^2 and median UACR was 20.26(IQR 8.38 to 92.97mg/g). Higher counts of uEVs detected by SFC carrying DPP4 and MME were significantly associated with higher eGFR after adjustment for sex, race, age, log UACR and total urine creatinine. No markers demonstrated significant association with log UACR, and size was not considered further. SP-IRIS analyzed DPP4 and MME subpopulations captured by the CD63 and CD9 probes for exploration of small sample sizes. DPP4/Total Ratio was significantly higher in healthy patients when captured by CD63(p=0.0176), and results show sample size can be microscaled.
Conclusion
These results suggest that subgroups of tubular derived uEVs detected by SFC are associated with an increase in eGFR in a cohort of early DKD. However, tubular markers are also decreased in DKD when compared to HC. Further exploration is necessary to fully understand if these tubular derived uEVs derive from healthy tubular cells or are expressed more during tubular stress in early DKD.
Funding
- Private Foundation Support