Abstract

Purpose: The objective of our study was to ascertain whether the SARS-CoV-2 virus exerts direct cytotoxic and genotoxic effects on human blood defence cells. 

Materials and Methods: An in vitro analysis was conducted to assess the cytotoxic and genotoxic effects of the virus using three established tests: the mitotic index (MI), micronucleus (MN), and comet assay (CA). These tests were applied to blood samples from 101 patients. The blood samples were simultaneously analyzed using the polymerase chain reaction (PCR) test. The study population included patients of all ages and genders who presented to the outpatient clinic with symptoms suggestive of a respiratory tract infection and fever. Results: The frequency of MN in the human lymphocytes of COVID-19-infected patients (1.06) was higher compared to COVID-19-negative patients (0.68). Similarly, in COVID-19-positive individuals, parameters such as tail length (3.67), tail moment (1.786), and tail intensity in the comet assay showed a significant increase compared to the negative control, indicating DNA damage. In the cytotoxicity assessment, the MI frequency of COVID-19-positive individuals (0.041) was significantly lower than that of negative controls (0.051). Gender did not influence the cyto/genotoxicity (except for tail length) in SARS-CoV-2-infected patients. Among age groups, the SARS-CoV-2 virus increased MI frequency and tail intensity only in middle-aged individuals (26–36 years). Conclusion: The SARS-CoV-2 virus has the potential to induce cytotoxic and genotoxic effects in the human lymphocytes of infected individuals. Keywords:. Comet assay, COVID-19, genotoxicity, micronucleus, mitotic index