Emerging evidence suggests that acute kidney injury (AKI) secondary to COVID-19 (COV-AKI) might result from direct infection of renal tubule epithelial cells (RTEC). A variety of epithelial cells express the ACE2 receptor which contains the receptor-binding domain (RBD) used by SARS-CoV-1 and SARS-CoV-2 to enter the cells. While direct infection of RTEC has not yet been proven data from multiple laboratories show virus in the kidney. It is this direct viral involvement of the RTEC that this proposal seeks to address.
One relatively simple approach would be to perturb the ability of the RBD to bind to its cellular (hACE2) receptor. Changes in pH may cause each amino acid residue, in the RBD, to assume a slightly different 'microscopic' conformation-dependent pKa value. Urine pH is normally 5.5- 6.5 (not too dissimilar to alveolar fluid-6.4-6.86) and can be easily and safely manipulated. In fact, urine alkalinization protocols have been used for decades to reduce renal toxicity from various compounds (especially chemotherapy) and are recommended by US and European toxicology societies. Here, the strategy will be deployed not for ion trapping but to inhibit the virus from infecting RTEC. Alkalinizing the urine using IV sodium-bicarbonate solution to pH of 7.5 or more can be easily and safely achieved.
While severe AKI does not appear to be a major part of the SARS-CoV-2 syndrome for most patients, when severe AKI does occur, mortality is very high and preventing early AKI may reduce AKI severity as the disease progresses.
