Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 20 1 2021 02 11 46 66 Tooba Ghazanfari Immunoregulation Research Center, Shahed University, Tehran, Iran AND Simorgh Clinical Laboratory, Tehran, Iran Mohammad Reza Salehi Department of Infectious Diseases, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Saeed Namaki Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Jalil Arabkheradmand Ahya Neuroscience Research Center, Tehran, Iran Abdolrahman Rostamian Department of Rheumatology, Valiasr Hospital, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Maryam Rajabnia Chenary Simorgh Clinical Laboratory, Tehran, Iran Sara Ghaffarpour Immunoregulation Research Center, Shahed University, Tehran, Iran Sussan Kaboudanian Ardestani Department of Immunology, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran Maryam Edalatifard Thoracic Research Center, Tehran University of Medical Sciences, Tehran, Iran Mohammad Mehdi Naghizadeh Immunoregulation Research Center, Shahed University, Tehran, Iran AND Non-communicable diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran Saeed Mohammadi Hematology-Oncology and Stem Cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran Maryam Mahloujirad Simorgh Clinical Laboratory, Tehran, Iran Alireza Izadi Department of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Hossein Ghanaati Advanced Diagnostic and Interventional Radiology Research Center (ADIR), Tehran University of Medical Sciences, Tehran, Iran Mohammad Taghi Beigmohammadi Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Mohammad Vodjgani Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Bentolhoda Mohammad Shirazi Immunoregulation Research Center, Shahed University, Tehran, Iran Ensie Sadat Mirsharif Immunoregulation Research Center, Shahed University, Tehran, Iran Alireza Abdollahi Department of Pathology, School of Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Mostafa Mohammadi Department of Anesthesiology and Intensive Care, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Hamid Emadi Kouchak Department of Infectious Diseases, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Seyed Ali Dehghan Manshadi Department of Infectious Diseases, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Mohammad Saber Zamani Immunoregulation Research Center, Shahed University, Tehran, Iran Maedeh Mahmoodi Aliabadi Department of Laboratory, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Davoud Jamali Department of Immunology, Shahed University, Tehran, Iran Nasim Khajavirad Department of Internal Medicine, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran Ali Mohammad Mohseni Majd Immunoregulation Research Center, Shahed University, Tehran, Iran Zahra Nasiri Immunoregulation Research Center, Shahed University, Tehran, Iran Soghrat Faghihzadeh Department of Biostatistics and Social Medicine, Zanjan University of Medical Sciences, Zanjan, Iran 2020 11 29 2021 02 02 The severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) spread rapidly all over the world in late 2019 and caused critical illness and death in some infected patients. This study aimed at examining several laboratory factors, especially inflammatory and immunological mediators, to identify severity and mortality associated biomarkers. Ninety-three hospitalized patients with confirmed coronavirus disease 2019 (COVID-19) were classified based on disease severity. The levels of biochemical, hematological, immunological, and inflammatory mediators were assessed, and their association with severity and mortality were evaluated. Hospitalized patients were mostly men (77.4%) with an average (standard deviation) age of 59.14 (14.81) years. The mortality rate was significantly higher in critical patients (85.7%). Increased serum levels of blood sugar, urea, creatinine, uric acid, phosphorus, total bilirubin, serum glutamic-oxaloacetic transaminase, serum glutamic-oxaloacetic transaminase, lactic dehydrogenase, C-reactive protein, ferritin, and procalcitonin were significantly prevalent (p=0.002, p<0.001, p<0.001, p=0.014, p=0.047, p=0.003, p<0.001, p<0.001, p<0.001, p<0.001, P<0.001, and p<0.001, respectively) in COVID-19 patients. Decreased red blood cell, hemoglobin, and hematocrit were significantly prevalent among COVID-19 patients than healthy control subjects (p<0.001 for all). Troponin-I, interleukin-6, neutrophil/lymphocyte ratio (NLR), procalcitonin, and D-dimer showed a significant association with the mortality of patients with specificity and sensitivity more than 60%. Age, sex, underlying diseases, blood oxygen pressure, complete blood count along with C-reactive protein, lactic dehydrogenase, procalcitonin, D-dimer, and interleukin-6 evaluation help to predict the severity and required management for COVID-19 patients. Further investigations are highly recommended in a larger cohort study for validation of the present findings. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3054