Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 50 9 2021 09 02 1882 1886 Ramin Hamidi Farahani Department of Infectious Diseases, School of Medicine, AJA University of Medical Sciences, Tehran, Iran Emran Esmaeilzadeh 1. Department of Basic Medical Sciences, School of Medicine, AJA University of Medical Sciences, Tehran, Iran 2. Fetal Health Research Center, Hope Generation Foundation, Tehran, Iran Amir Nezami Asl Department of Aerospace Medicine, School of Aerospace and Subaquatic Medicine, AJA University of Medical Sciences, Tehran, Iran Mohammad Foad Heidari Department of Laboratory Sciences, School of Aerospace and Subaquatic Medicine, AJA University of Medical Sciences, Tehran, Iran Ebrahim Hazrati Department of Critical Care Medicine, School of Allied Medical Sciences, AJA University of Medical Sciences, Tehran, Iran 2021 02 13 2021 03 06 Background: Human Leukocyte Antigen (HLA) system composed of a group of related proteins with important functions in the immune system. Several studies have reported that there is a significant association between specific HLA alleles and the susceptibility to different infectious diseases. This study aimed to detect the specific HLA alleles that cause higher susceptibility to COVID-19, we analyzed the HLA allele frequency distribution in Iranian patients with a severe form of COVID-19. Methods: Overall, 48 severe cases of COVID-19 that were hospitalized and required intensive care unit (ICU) admission between Oct and Dec 2020 were included in this study. Genomic DNA was extracted from the peripheral blood samples and HLA typing (Locus A, B, and DR) was performed for the patients. Results: After analyzing and comparing the results with a reference group of 500 Iranian individuals, a significant association was found for HLA-B*38, HLA-A*68, HLA-A*24, and HLA-DRB1*01. Conclusion: These results may be valuable for studying the potential association of specific HLA alleles with susceptibility to COVID-19 and mortality due to the disease. https://ijph.tums.ac.ir/index.php/ijph/article/view/23866 https://ijph.tums.ac.ir/index.php/ijph/article/download/23866/7355