This is a hospital-based retrospective cohort study and the Immunohematologic characteristics of COVID-19 patients will be investigated systematically. In this study, we will seek to understand the association between SARS-CoV-2 infection and blood groups and explore the Anti-A and Anti-B effects in COVID-19 patients with graded severity. We will analyze the transfusion requirement and the clinical recurrences of COVID-19 patients. The discrepancy of blood group phenotypes in COVID-19 patients with graded severity will be also analyzed on the molecular level. This retrospective cohort study was conducted using electronic health recording data in Tongji Hospital. The clinical characteristics for all eligible patients will be retrieved. The records will be verified to avoid possible bias. Data collection was carried out independently by two investigators and reviewed by two different investigators.
This is a hospital-based retrospective cohort study and the Immunohematologic characteristics of COVID-19 patients will be investigated systematically.