This prospective study enrolled 160 individuals with confirmed COVID-19 infection using PCR. They were recruited from Al-Zahraa Hospital, Faculty of Medicine (Girls), Al-Azhar University, Cairo, Egypt, which was specifically designated for the isolation of SARS-CoV-2 positive patients. According to the Egyptian ministry of health and population's (MOHP) recommendations, patients were divided into 80 mild-moderate COVID-19 patients and 80 severe COVID-19 patients. Cases classified as mild-moderate fulfilled the following criteria: fever and respiratory symptoms, CORAD 1-5, and oxygen saturation (SpO2 92 percent), while severe cases met the following criteria: fever and respiratory symptoms, CORAD 4-5, and oxygen saturation (SpO2 92 percent). All participants or their corresponding companions signed a free informed consent form. The study was approved by the research ethics committee of Al-Azhar University's Faculty of Medicine (Girls), Cairo, Egypt, with approval number (202106884), and adhered to the Helsinki Declaration's precepts. Pregnancy, COVID-19 patients with morbid obesity, cancer, or autoimmune disease, and those who took immunomodulators or initiated the COVID-19 treatment programme were excluded. Additionally, patients having a history of recurrent COVID-19 infection were excluded from the study.
This study aimed to investigate the change in serum level of copeptin, a neuroendocrine biomarker, in differentiation between mild-moderate and severe COVID-19 cases on admission time and to find its diagnostic potential.