ABSTRACT
The novel coronavirus disease 2019 is an ongoing pandemic and a global health emergency. Since the main portal of entry for the virus is the nose, olfactory and taste dysfunction have gained attention as important symptoms in COVID-19. The primary objectives are to assess the prevalence of olfactory and taste dysfunction in patients affected with COVID-19. And to determine whether anosmia and ageusia are early predictors of COVID-19. A prospective study was conducted on 300 patients who were laboratory diagnosed cases of COVID-19 admitted in tertiary care centre and a covid care centre. A written informed consent was taken. All patients underwent olfactory and taste examination and the details were noted in a case-record proforma. The prevalence of olfactory dysfunction in COVID-19 patients was 21% and that of taste dysfunction was 26.6%. Majority of the affected individuals were males and mainly of the younger age group. These symptoms lasted for a duration of 7-9 days and 97% of the patients showed complete recovery. Acute sudden onset olfactory and taste dysfunction seems to be a useful indicator for early diagnosis of patients thus helping in early isolation, timely management of the illness and controlling the spread of the disease.
ABSTRACT
Immune cell dysregulation and lymphopenia characterize COVID-19 pathology in moderate to severe disease. While underlying inflammatory factors have been extensively studied, homeostatic and mucosal migratory signatures remain largely unexplored as causative factors. In this study, we evaluated the association of circulating IL-6, soluble mucosal addressin cell adhesion molecule (sMAdCAM), and IL-15 with cellular dysfunction characterizing mild and hypoxemic stages of COVID-19. A cohort of SARS-CoV-2 infected individuals (n = 130) at various stages of disease progression together with healthy controls (n = 16) were recruited from COVID Care Centres (CCCs) across Mumbai, India. Multiparametric flow cytometry was used to perform in-depth immune subset characterization and to measure plasma IL-6 levels. sMAdCAM, IL-15 levels were quantified using ELISA. Distinct depletion profiles, with relative sparing of CD8 effector memory and CD4+ regulatory T cells, were observed in hypoxemic disease within the lymphocyte compartment. An apparent increase in the frequency of intermediate monocytes characterized both mild as well as hypoxemic disease. IL-6 levels inversely correlated with those of sMAdCAM and both markers showed converse associations with observed lympho-depletion suggesting opposing roles in pathogenesis. Interestingly, IL-15, a key cytokine involved in lymphocyte activation and homeostasis, was detected in symptomatic individuals but not in healthy controls or asymptomatic cases. Further, plasma IL-15 levels negatively correlated with T, B, and NK count suggesting a compensatory production of this cytokine in response to the profound lymphopenia. Finally, higher levels of plasma IL-15 and IL-6, but not sMAdCAM, were associated with a longer duration of hospitalization.