Evaluation of Integrated SARS-CoV-2 Genome Presence in PBMC, Oropharyngeal, and Nasopharyngeal Samples of COVID-19 Patients

Background: Persistent detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in individuals who have recovered from coronavirus disease 2019 (COVID-19) remains an unexplained phenomenon warranting further study. Recent research suggests that this RNA could be the result of transcription from an integrated SARS-CoV-2 genome. Objectives: This study aimed to investigate the presence of the DNA form of the SARS-CoV-2 genome in oropharyngeal, nasopharyngeal, and peripheral blood mononuclear cell (PBMC) samples from COVID-19 patients with prolonged viral detection. Methods: We examined the presence of the reverse-transcribed viral genome in samples from eighty COVID-19 patients, including 40 outpatients (group 1), 40 hospitalized patients (group 2), and 40 healthy individuals (group 3), using a TaqMan® based real-time RT-PCR assay. Results: The mean ages of groups 1, 2, and 3 were 36.1 ± 11.0, 61.6 ± 18.4, and 39.0 ± 8.7, respectively. The molecular tests did not detect viral DNA forms, which may be produced during the SARS-CoV-2 life cycle, in the examined samples. Conclusions: Although no evidence of integrated viral DNA was found in this study, further research is essential to confirm these findings and explore the underlying mechanisms of prolonged SARS-CoV-2 RNA presence in recovered COVID-19 patients.