Submission
| Title: | Bitter taste dysfunction and salivary gustin in long-COVID. |
| Presenter: | Harika Chowdary |
| Institution: | Indiana University School of Dentistry |
| Authors: | Parul Patel, Harika Choudhary, Naomi Riley, Shveta Jaishankar and Mythily Srinivasan. |
Abstract
| Background/Significance/Rationale: | Taste dysfunction was reported by nearly 40%-60% of coronavirus disease (COVID)-19 patients during the acute phase of the infection. While majority reported improvement and recovery over time, a subset of patients suffers from persistent taste dysfunction post-infection. Several studies estimate that 5-10% report taste dysfunction as persistent symptom of long-COVID syndrome. Gustation is an integrated event of multiple physiological processes occurring concurrently through activation of continuous renewing specialized taste cells. A balance between the cell generation and cell death maintains the homeostatic turnover. We hypothesized that a disruption of this homeostasis contributes to the taste dysfunction in long-COVID. Specifically, we postulated that an increase in taste cell exfoliation in long-COVID will be associated with reduced levels proteins associated with taste bud cell renewal including sonic hedgehog protein and gustin will be decreased. |
| Methods: | Individuals with long-COVID were recruited with the help of the Indiana CTSI Research Network (ResNet) services. The control included archived saliva samples catalogued prior to 2019. Objective assessment of taste perception was determined by the waterless empirical taste test. The SHH, gustin and inflammatory cytokines in unstimulated whole saliva were determined by ELISA. The expressions of epithelial and taste cell specific markers were assessed by immunoflurorescence. |
| Results/Findings: | Taste dysfunction was predominantly related to that of bitter taste. Salivary SHH and gustin were lower in long-COVID as compared to that in pre-COVID, although the difference was significant only with gustin. Interestingly, the decrease in gustin correlated with the lower bitter taste score. The salivary epithelial cell included cells positive for occludin, gustin and SHH as representative markers for taste bud cell. |
| Conclusions/Discussion: | The reduced salivary SHH and gustin suggest that the taste bud cell renewal is lowered and could constitute a potential mechanism of taste dysfunction in long-COVID. |
| Translational/Human Health Impact: | Salivary gustin could be a marker for taste dysfunction in long-COVID. |
