Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 2026 2 2026 08 25 185 193 Mohammad Bayat Craniomaxillofacial Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Naghmeh Bahrami Craniomaxillofacial Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran. Mahta Malek Craniomaxillofacial Research Center, Tehran University of Medical Sciences, Tehran, Iran. Mahsa Sadat Seid Saleh Department of Biology, Faculty of Sciences, Islamic Azad University, Tehran, Iran. Somayeh Lookzadeh Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. Parvaneh Safarian Department of Biology, SR.C, Islamic Azad University, Tehran, Iran. Mohammad Varahram Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Mehdi Kazem Pour Dizaji Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Abdolreza Mohamadnia Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran; Tobacco Prevention and Control Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2026 02 07 2026 08 14 Introduction: Chronic obstructive pulmonary disease (COPD) is associated with persistent airway inflammation and an increased risk of adverse outcomes following coronavirus disease 2019 (COVID-19). While the lower airways have been the primary focus of most studies, the upper respiratory tract plays a critical role in SARS-CoV-2 entry and early symptom development. Inflammatory mediators, including interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and C-reactive protein (CRP), as well as the viral entry–related protease TMPRSS2, are involved in both COPD-associated inflammation and COVID-19 pathogenesis. This study investigated the expression of these markers in COVID-19 patients with underlying COPD.  Materials and Methods: In this case–control study, peripheral blood samples were collected from COVID-19 patients with a documented history of COPD and from age- and sex-matched healthy controls. Total RNA was extracted, reverse transcribed into cDNA, and relative mRNA expression levels of IL-6, MCP-1, CRP, and TMPRSS2 were quantified using real-time polymerase chain reaction. Statistical analyses were performed using parametric tests, with statistical significance defined as p < 0.05.  Results: Compared with healthy controls, COVID-19 patients with COPD demonstrated significantly higher mRNA expression levels of IL-6, MCP-1, and CRP (p < 0.05). TMPRSS2 expression was also elevated in the patient group, indicating a potential contribution to enhanced viral entry. Overall, the findings revealed a distinct inflammatory expression profile in patients with COPD during SARS-CoV-2 infection.  Conclusion: The increased expression of IL-6, MCP-1, CRP, and TMPRSS2 in COVID-19 patients with underlying COPD suggests a combined effect of chronic inflammation and viral entry mechanisms. These markers may be valuable as accessible blood-based indicators of disease severity, although further studies are needed.  Keywords: COVID-19; COPD; Gene expression; IL-6; MCP-1; TMPRSS2; C-reactive protein. https://jcr.tums.ac.ir/index.php/jcr/article/view/625 https://jcr.tums.ac.ir/index.php/jcr/article/download/625/497