Tehran University of Medical Sciences Case Reports in Clinical Practice 2538-2683 7 1 2022 06 14 9 12 EN Mahsa Rekabi Pediatric Respiratory Disease Research Center, National Research Institute of Tuberculosis and Lung, Tehran, Iran. Farhad Seif Department of Immunology and Allergy, Academic Center for Education, Culture, and Research, Tehran, Iran.AND Neuroscience Research Center, Iran University of Medical Sciences, Tehran, Iran. Farzad Nouri Pediatric Respiratory Disease Research Center, National Research Institute of Tuberculosis and Lung, Tehran, Iran. Alireza Mahdaviani Pediatric Respiratory Disease Research Center, National Research Institute of Tuberculosis and Lung, Tehran, Iran. Ali Akbar Velayati velayati @ theaasm . org 2021 03 01 2021 04 10 Chronic Granulomatous Disease (CGD) is a rare inherited primary immune deficiency disorder with defective respiratory burst activity in phagocytes, resulting in recurrent pyogenic infections. In this study, we described two CGD patients who had done bone marrow transplantation (BMT). As Bone marrow transplantation (BMT) is the definitive treatment of the disease, we evaluated the function of their lungs before and after BMT. In both patients, the BMT was from their siblings. In case 1, the patient’s pulmonary function (PFT) before BMT was: FEV1: 34, FVC: 40, FEV1 / FVC: 72%, and after BMT was: FEV1: 66, FVC: 40 by 49, FEV1 / FVC: 64%. In case 2, the patient’s PFT before BMT was: FEV1: 22, FVC: 36, FEV1 / FVC: 41%, and after BMT was: FEV1: 47, FVC: 33, FEV1/FVC: 43%. BMT significantly improved their Pulmonary Problems and Preclinical (PFT). In addition, after BMT, both patients’ well-tolerated clinical signs and the infection rate, and the number of hospitalizations in both patients decreased. https://crcp.tums.ac.ir/index.php/crcp/article/view/488