Abstract P3164: Podocalyxin, A Renal Podocyte Specific Protein Expression In Urine Exosome Acts As A Marker For Podocyte Injury During Sars-cov-2 Infection

Abstract

COVID-19 attributed to SARS-CoV2 infection has been associated with cardiovascular disease and diabetes. COVID-19 has been associated with endothelial cell dysfunction (ECD), which is manifested by entities such as microvascular thrombosis. ECD is quite common in type 2 diabetes mellitus (T2DM) where the renal podocyte dysfunction is often an early manifestation of microvascular complication. We explored whether presence of hyperglycemia predisposes to increased SARS-CoV2 infection and whether SARS-CoV2 infection puts an individual at a higher risk of developing cardio-metabolic complications such as kidney disease (DKD), with podocyte damage. We evaluated albuminuria and podocyte protein in urine derived exosomes in urine exosomes from SARS-CoV2 patients at 10 days, 6 months and 12 months post SARS-CoV2 infection. Methods: Blood and Urine samples from SARS-CoV2 patients post-acute phase of infection were procured. Peripheral blood mononuclear cells (PBMNCs) and urine exosomes were isolated and podocyte protein marker Podocalyxin (PODXL) was identified by western blot analysis. Results: Podocyte specific proteins were examined in urine exosomal fraction such as Podocalyxin and Nephrin (normalized to CD9 exosomal protein band intensities) levels increased significantly compared to urine samples from type-2 diabetes subjects with documented evidence of nephropathy. Podocalyxin levels were significantly high at 12month time point (p=0.001; n=9) and Nephrin levels were noted to be high at 10week (p=0.01; n=8), 6months (p=0.04; n=14 ) and 12Months (p=0.001; n=6) time points. Podocalyxin and Nephrin obtained from urine exosome samples collected from non diabetic subjects who never had COVID-19, showed little or barely detectable corresponding western blot bands. Interestingly, there was no significant differences noted on urine albumin: creatinine (UAR) ratios between the two groups, indicating that urine exosomal protein estimation may be an ideal biomarker to monitor podocyte damage in early phases of CKD. Conclusion: A persistent high levels of podocyte specific proteins was noted in urinary exosomes even at 12 months post acute Covid which may be secondary to long-standing podocyte inflammation leading to long term renal damage.