Morphofunctional, Gene, Inflammation Molecules and Oxidative Stress Analysis in Kidney Tissue of COVID-19 Patients

The involvement of the kidneys in patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the outset of the pandemic was associated with high mortality rates worldwide. This was in part due to the generation of an inflammatory process and exacerbated oxidative stress. The present study was initiated to investigate the relationship between morphofunctional changes and gene expression in the kidney tissue of deceased Mexican patients prior to the initiation of vaccination. The investigator designed a single-center, prospective, cohort study, to analyze and relate the morphofunctional changes and gene expression of inflammatory and oxidative stress molecules in the kidney tissue of men who died from severe COVID-19. A total of 40 percutaneous renal biopsies from deceased patients with severe acute respiratory syndrome coronavirus 2 infection were included in the study and divided into two a groups. One group was preserved in trizol to obtain RNA and total protein, while the remaining sample was fixed in formalin to be examined by staining with hematoxylin and eosin. The histopathological analysis was conducted by an experienced pathologist. The expression of molecules was evaluated by real-time polymerase chain reaction assay (nphs2, slc9a1, cx3cl1, havcr1, slc22a17, sod2, egf, timp2, hmox1, fabp1, and so forth). The following biomarkers were analyzed: interleukin-6, Arginase-1 (Arg-1), Dipeptidyl peptidase-4 (DPP-4), GSTT1, type I gamma-glutamyltransferase (GGT1), Occludin (OCL), CYP3A4, and Claudin-8 (CL-8). Additionally, Western blot analysis was conducted on claudin-5 (CL-5), occludin, HSP70, Nuclear factor erythroid 2-related factor-2 (NRF-2), superoxide dismutase-2 (SOD-2), nicotinamide adenine dinucleotide phosphate dehydrogenase 1 (NQO1), Gamma glutamylcysteine synthase (γ-GCL), and receptor for advanced glycation end products (RAGE). The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, with the subjects divided into two groups based on their eGFR: \>60 or \<60 ml/min/1.73 m². The statistical analysis was conducted using the Stata program and GraphPad software, version 10.2.3.