The involvement of the kidneys in patients infected with the severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2) at the outset of the pandemic was associated withhigh mortality rates worldwide. This was in part due to the generation of an inflammatoryprocess and exacerbated oxidative stress. The present study was initiated to investigatethe relationship between morphofunctional changes and gene expression in the kidneytissue of deceased Mexican patients prior to the initiation of vaccination.The investigator designed a single-center, prospective, cohort study, to analyze andrelate the morphofunctional changes and gene expression of inflammatory and oxidativestress molecules in the kidney tissue of men who died from severe COVID-19. A total of 40percutaneous renal biopsies from deceased patients with severe acute respiratory syndromecoronavirus 2 infection were included in the study and divided into two a groups. Onegroup was preserved in trizol to obtain RNA and total protein, while the remaining samplewas fixed in formalin to be examined by staining with hematoxylin and eosin. Thehistopathological analysis was conducted by an experienced pathologist. The expression ofmolecules was evaluated by real-time polymerase chain reaction assay (nphs2, slc9a1,cx3cl1, havcr1, slc22a17, sod2, egf, timp2, hmox1, fabp1, and so forth). The followingbiomarkers were analyzed: interleukin-6, Arginase-1 (Arg-1), Dipeptidyl peptidase-4(DPP-4), GSTT1, type I gamma-glutamyltransferase (GGT1), Occludin (OCL), CYP3A4, andClaudin-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), superoxidedismutase-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 ChronicKidney Disease Epidemiology Collaboration (CKD-EPI) equation, with the subjects dividedinto two groups based on their eGFR: >60 or