en پژوهشی اصيل Original Research <br> &nbsp;<span style="font-size:10pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" style="font-family:">Aims:</span></b><b> </b><span cambria="" style="font-family:">Although the preliminary studies have reported that some ABO system antigens may predispose individuals to COVID-19 infection, their findings are still under debate. The present study aimed to investigate the association of ABO blood group with the risk of COVID-19 infection, its hematology findings and mortality.</span></span></span></span><br> <span style="font-size:10pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><a name="_Hlk119928193"><b><span cambria="" style="font-family:">Instrument & </span></b></a><b><span cambria="" style="font-family:">Methods: </span></b><span cambria="" style="font-family:">This cross-sectional descriptive study was conducted in all patients referred to Shahid Jalil Hospital in Yasuj city, southwest Iran, due to the possibility of infection with COVID-19 from May to October 2021. Totally, 182 patients were recruited using the census method. Data were analyzed using Chi-Square, independent T, and one-way-ANOVA tests in SPSS 21 software.</span></span></span></span><br> <span style="font-size:10pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" style="font-family:">Findings:</span></b><span cambria="" style="font-family:"> The ESR, red cell distribution width (RDW), and mean corpuscular hemoglobin concentration (MCHC) were significantly different between the COVID-19 negative and positive groups</span><span cambria="" style="font-family:">.</span> <span cambria="" style="font-family:">There were no significant differences in ABO blood types between the COVID-19 positive and negative groups according to gender (p=0.148). There was no significant association between the ABO blood group phenotypes and the mean of demographic and laboratory information in the COVID-19 positive patients. </span></span></span></span><br> <span style="font-size:10pt"><span style="unicode-bidi:embed"><span new="" roman="" style="font-family:" times=""><b><span cambria="" style="font-family:">Conclusion:</span></b><span cambria="" style="font-family:"> There is no association between ABO blood groups and COVID-19 infection and its mortality.</span></span></span></span> ABO Blood Types,Cell-Typing,Back-Typing,COVID-19, 39 43 http://jccs.yums.ac.ir/browse.php?a_code=A-10-214-1&slc_lang=en&sid=1 P. Etemadfar 10031947532846004644 10031947532846004644 No Department of Pediatrics, Yasuj University of Medical Sciences, Yasuj, Iran F. Rad Fariba.rad89@gmail.com 10031947532846004645 10031947532846004645 Yes Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran SH. Rostami Yasuj Sh.rostami.lab70@gmail.com 10031947532846004646 10031947532846004646 No Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran Gh. Fakhari hemathology90@gmail.com 10031947532846004647 10031947532846004647 No Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran O.S. Esmaeili danaei.nazanin@gmail.com 10031947532846004648 10031947532846004648 No Blood Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine, Tehran, Iran H.R. Niazkar Hrn85@hotmail.com 10031947532846004649 10031947532846004649 No Student Research Committee, Gonabad University of Medical Sciences, Gonabad, Iran M.A. Ghatee Ghateea1980@gmail.com 10031947532846004650 10031947532846004650 No “Cellular and Molecular Research Center” and “Department of Microbiology, School of Medicine”, Yasuj University of Medical Sciences, Yasuj, Iran