Extracellular Oxidative Stress Markers in COVID-19 Patients with Diabetes as Co-Morbidity.

COVID-19 patients have a higher risk of developing inflammatory responses associated with serious and even fatal respiratory diseases. The role of oxidative stress in exacerbating manifestations in COVID-19 pathogenesis is under-reported.This study aimed touseserum levels of superoxide dismutase (SOD3) and glutathione-S-transferase (GSTp1) by ELISA, zinc (ErbaChem5), ferritin and free iron (VitrosChemistry, Ortho Clinical Diagnosis, Raritan, NJ, USA) at the first encounter of randomly selected RT-PCR-positive COVID-19 patients, for assessing disease severity. The parameters which helped in identifying the severity, leading to poor prognosis, were neutrophil:lymphocyte higher than 4, high CRP, low SOD3 values and high GSTp1 values, and diabetes mellitus as a co-morbidity. Higher zinc levels correlated with high GSTp1 and low SOD3, indicating the protective effect of zinc on ROS. The increased high GSTp1 shows an anticipated protective biochemical response, to mitigate the low SOD3 values due to ROS consumption. Decreased SOD3 levels indicate a state of high oxidative stress at cellular levels, and an anticipated increase in GSTp1 levels points to the pathophysiological bases of increasing severity with age, sex, and co-morbidities, such asdiabetes. High levels of initial GSTp1 and zinc levels possibly offer protection to redox reactions at the cellular level in severe COVID-19 infection, preventing deterioration.

Effective community screening for asymptomatic and symptomatic COVID-19 with a fast and extremely low cost COVID-Anosmia Checker tool (preprint)

Background: Covid-19 curve can be flattened by adopting mass screening protocols with aggressive testing and isolating infected populations. The current approach largely depends on RT-PCR/rapid antigen tests that require expert personnel resulting in higher costs and reduced testing frequency. Loss of smell is reported as a major symptom of Covid-19, however, a precise olfactory testing tool to identify Covid-19 patient is still lacking. Methods: To quantitatively check for the loss of smell, we developed an odor strip, COVID-Anosmia checker, spotted with gradients of coffee and lemon grass oil. We validated its efficiency in healthy and COVID-19 positive subjects. A trial screening to identify SARS-CoV-2 infected persons was also carried out to check the sensitivity and specificity of our screening tool. Results: It was observed that COVID positive participants were hyposmic instead of being anosmic when they were subjected to smelling higher odor concentration. Our tool identified 97% of symptomatic and 94% of asymptomatic COVID-19 positive subjects after excluding most confounding factors like concurrent chronic sinusitis. Further, it was possible to reliably predict COVID-19 infection by calculating a loss of smell score with 100% specificity. We coupled this tool with a mobile application, which takes the input response from the user, and can readily categorize the user in the appropriate risk groups. Conclusion: Loss of smell can be used as a reliable marker for screening for Covid-19. Our tool can rapidly quantitate anosmia, hyposmia, parosmia, and can be used as a first-line screening tool to trace out Covid-19 infection effectively.