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Abstract: SA-PO411

The Endothelial Glycocalyx Is Damaged in Acute ANCA-Associated Vasculitis and Is Improved After Treatment

Session Information

Category: Glomerular Diseases

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Liew, Hui, Eastern Health, Melbourne, Victoria, Australia
  • Roberts, Matthew A., Eastern Health, Melbourne, Victoria, Australia
  • McMahon, Lawrence P., Eastern Health, Melbourne, Victoria, Australia
Background

The endothelial glycocalyx (EG) lines and protects the luminal surface of the endothelium. Damage to this layer can be detected by increased serum levels of EG constituents as well as an increase in the perfused boundary region (PBR) of sublingual capillaries using the novel Glycocheck™ device. ANCA-associated vasculitis (AAV) is a widespread inflammatory process affecting blood vessels, causing endothelial dysfunction (ED). The effects of AAV on the EG are unknown.

Methods

We aimed to examine the effects of acute AAV and its treatment on the EG compared to healthy controls by collecting blood for EG markers (syndecan-1 and hyaluronan), markers of ED (vascular cell adhesion molecule: VCAM-1), urine for albumin:creatinine ratio (uACR), and performing a PBR measurement. Investigations for controls were performed once, whereas vasculitis patients were studied at the time of admission, after 2 weeks of plasma exchange (PEX) if indicated, and after 3 months of immunosuppressive therapy.

Results

Patients with acute AAV (n=8) and healthy controls (n=28) were recruited. Mean ages were 63 ± 13 years and 40 ± 13 years (p<0.001), respectively. AAV patients demonstrated EG damage at baseline compared to controls, with higher syndecan-1 and hyaluronan levels and a greater PBR. Three patients required dialysis, and one remained on dialysis at 3 months. After treatment, the median eGFR of AAV patients increased from 12 (3-40) mL/min at baseline to 19 (6-60) after plasma exchange (p=0.031, n=5), but not at 3 months. Median syndecan-1 levels decreased significantly from baseline to 3 months with a corresponding decrease in PBR values. However, no differences were detected in hyaluronan, VCAM-1 or uACR at any point.

Conclusion

Markers of EG damage were higher in the AAV patients at baseline compared to controls. The PBR and syndecan-1 levels of these patients improved at 3 months, reflecting an improvement in the EG layer due either to treatment or better renal function. The lack of change in hyaluronan and VCAM-1 levels warrants further investigation.

 ControlsPatients with acute AAV
BaselinePost PEX3 monthsPaired t-test Controls vs. BaselinePaired t-test Baseline vs. 3 months
PBR (µm)2.04 ± 0.312.39 ± 0.232.43 ± 0.312.09 ± 0.160.00140.045
Syndecan (ng/mL)26 (10-146)100 (58-205)76 (20-131)44 (27-99)<0.00010.034
Hyaluronan (ng/mL)32 ± 2592 (16-134)92 (24-175)95 (24-240)0.00020.562
VCAM-1 (ng/mL)613 (379-1189)1208 (27-1511)465 (16-1372)1091 (52-1597)0.590.844
uACR (mg/mmol)0.5 (0-2)121 ± 87431 ± 173303 ± 270<0.0010.625