en Infectious Diseases Infectious Diseases Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:13.7pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> This study aimed to evaluate the effect of pirfenidone on lung CT scan lesions in patients with severe COVID-19.</span><br> <span style="line-height:13.7pt"><b><i><span style="color:blue">Methods:</span></i></b> In this cross-sectional study, data were extracted from the electronic medical records of patients with severe COVID-19 who received one of the following treatments: pirfenidone alone (n= 40), prednisolone alone (n= 55), pirfenidone combined with methylprednisolone (n= 18), or supportive care only (n= 32). Chest CT images taken at baseline and two months post-treatment were assessed by a trained radiologist. p< 0.05 was considered statistically significant.</span><br> <span style="line-height:13.7pt"><b><i><span style="color:blue">Results:</span></i></b> The distribution of initial CT scan findings, Comparison of CT scan findings at admission and two months post-discharge, as well as the extent of pulmonary fibrosis and ground-glass opacity (GGO) grades across the groups, showed no statistically significant differences. However, significant differences were observed in CT scan findings and GGO grades between the four study groups at two months post-discharge. Moreover, in both the pirfenidone <span style="color:black">(p= 0.00) </span>and supportive care <span style="color:black">(p= 0.01) </span>groups, the extent of pulmonary fibrosis between admission and two months post-discharge showed statistically significant changes.</span><br> <span style="line-height:13.7pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> In summary, although antifibrotic agents such as pirfenidone may not lead to significant improvement in lung CT scan findings in patients with severe COVID-19, they may help slow the progression of pulmonary fibrosis following the acute phase of the disease.</span></span></span> Pirfenidone, pulmonary fibrosis, COVID-19, CT scan, prednisolone. 163 172 http://caspjim.com/browse.php?a_code=A-10-3670-1&slc_lang=en&sid=1 Sakineh Khatoon Gholamrezaei s8416358@gmail.com 100319475328460055838 0009-0003-7075-3630 No Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Mohammad Samet samet_mo@yahoo.com 100319475328460055839 100319475328460055839 No Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Amir Pasha Amelshahbaz pasha.shahbaz@gmail.com 100319475328460055840 100319475328460055840 No Department of Radiology, Afshar Hospital, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Nasim Namiranian namiranian.nasim@gmail.com 100319475328460055841 100319475328460055841 No Yazd Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Fatemeh al-Sadat Aghaei Meybodi Dr.meybodi@gmail.com 100319475328460055842 100319475328460055842 Yes Department of Internal Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran