Are MUC5B and TERT mutations genetic risk factors for pulmonary fibrosis in individuals with severe COVID-19?

Introduction: The genetic risk factors for Coronavirus disease-2019 (COVID-19)-associated pulmonary fibrosis (CAPF) are not clearly defined. Mutations in the genes encoding telomerase reverse transcriptase (TERT) and mucin 5B (MUC5B) are well-known genetic risk factors for pulmonary fibrosis. In this study, we aimed to show whether the most common proven mutations of pulmonary fibrosis affect the development of CAPF.Materials and Methods: Forty-eight patients who were matched for age, gen-der, COVID-19 disease severity, and respiratory support type and needed high flow nasal cannula, non-invasive mechanical ventilator, or invasive mechanical ventilator due to COVID-19 were followed up prospectively. Eighteen patients were excluded from the follow-up due to known structural lung disease, col-lagen tissue disease, and occupational exposure to fibrosis. The patients were called for follow-up three months after discharge, and CT was performed. Those with fibrosis (n= 15) in the third-month follow-up CT were included in the CAPF group, and those with complete resolution (n= 15) were included in the control group. Blood samples were taken for genetic analysis.Results: TERT gene study revealed that six (40%) of the fibrosis group was normal, while five were heterozygous (33.3%). MUC5B polymorphism was not detected in 10 (66.7%) of the fibrosis group.Conclusion: Individuals with TERT mutations may be at a higher risk for CAPF. Further studies are needed to clarify the genetic risk factors for CAPF.