Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 6 2025 12 13 1049 1058 Zeynab Rahni Department of Molecular Virology, Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran Seyed Reza Mohebbi Department of Medical Virology, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran Seyed Masoud Hosseini Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran Shahrzad Shoraka Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran Kambiz Nabati Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran Mahsa Saeedi Niasar Foodborne and Waterborne Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran Shabnam Shahrokh Department of Medical Virology, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran Amir Sadeghi Department of Medical Virology, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Reza Zali Department of Medical Virology, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2024 08 24 2025 10 09 Background and Objectives: Coronavirus disease 2019 (COVID-19), due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has expanded rapidly to all over the world. Interleukin-17 is one of the inflammatory cytokines which is highly expressed in the blood of individuals with COVID-19. Our aim in the present survey was to assess the mRNA expression levels of cytokine IL-17A, IL-17F and TNF-α in the blood of COVID-19 patients compared with healthy control individuals. Materials and Methods: A total of 69 patients including 32 mild patients, 20 severe and 17 asymptomatic patients in comparison with 25 healthy controls were evaluated. To measure the expression profile of IL-17A and IL-17F in whole blood, quantitative PCR was used. Results: Asymptomatic, mild, and severe SARS-CoV-2 infections were found to have significantly higher levels of IL-17A and IL-17F mRNAs than the healthy group (fold change IL-17A: 3.778; p= 0.002, 4.003; p= 0.001, 2.608; p= 0.0001 respectively, fold change IL-17F: 2.967; p= 0.003, 3.819; p= 0.001, 2.617; p= 0.0012 respectively). TNF-α mRNA expression was also measured, which shows an approximately similar increase compared to IL-17 (fold change: 2.726; p= 0.002, 2.383; P= 0.001, 2.631; p= 0.001, respectively). Conclusion: SARS-CoV-2 infection severity was associated with blood levels of IL-17A and IL-17F mRNA. https://ijm.tums.ac.ir/index.php/ijm/article/view/5009 https://ijm.tums.ac.ir/index.php/ijm/article/download/5009/1853