Assessment of Genotoxic Biomarker in Tongue and Buccal Mucosal Epithelial Cells of COVID-19 Patients: An Observational Study

Abstract

Introduction: Angiotensin-converting enzyme 2 (ACE2) is the main host cell receptor for coronavirus disease 2019 (COVID-19) and is highly expressed in the tongue and buccal mucosa. Therefore, the present study was conducted to investigate genotoxic changes in epithelial cells of the buccal and tongue mucosa following COVID-19 infection. Materials and methods: This study included 40 patients aged 25-40 years, divided into two groups: Group 1 (control group) included 20 healthy individuals with no prior history of COVID-19 infection subdivided into Group 1a (buccal mucosa), and Group 1b (tongue mucosa); Group 2 (case group) included 20 patients with a history of mild to moderate COVID-19 infection subdivided into Group 2a (buccal mucosa) and Group 2b (tongue mucosa). Genotoxic biomarkers, such as the number of micronuclei, pyknosis, karyolysis, and karyorrhexis, were assessed in epithelial cells from the buccal mucosa and the ventral surface of the tongue. Analysis of variance was used for intragroup comparisons, followed by post-hoc analysis using Tukey’s test. Results: The mean age of the patients was 27.4±6.52 years. Statistically significant differences were observed between cases and controls in the number of micronuclei, pyknosis, karyolysis, and karyorrhexis in the epithelial cells of the buccal and tongue mucosa (p = 0.05). Conclusion: SARS-CoV-2 has pronounced genotoxic effects on the epithelium of the ventral surface of the tongue in comparison to the buccal mucosa Therefore, patients with COVID-19 should be monitored regularly to develop future carcinomas, particularly those with habits of smoking, alcohol consumption, and tobacco usage.

A brief history of the Feulgen reaction

“…These examples show that the Feulgen reaction represents a valid tool in various biological applications, ranging from animal to plant cell biology, even in the 2020s—a hundred years after its first description. Remarkably, the Feulgen reaction even found relevance during the COVID-19 pandemic, when it was used to investigate nuclei of mucosa samples collected from patients with COVID-19 (Sadik et al 2023 ).…”