Immunogenetic Characterization of COVID-19 Disease (IC-COVID-19)

The SARS-CoV-2 pandemic will remain a world-wide threat for the next year. It is unknown why some people get severely ill while others have mild or even asymptomatic infections. With this epidemiological study we want to investigate immunogenetic parameters which may determine the clinical course of COVID-19. We plan for a cohort study with approximately 10,000 patients to test two hypotheses: 1) Patients who present at a testing site with SARS-CoV-2 show a specific repertoire of Human Leukocyte Antigen (HLA)- and Killer Immunoglobulin-like Receptor (KIR)-genes. 2) Patients with severe COVID-19 courses have a different immunogenetic HLA- and KIR-gene repertoire compared to patients with mild or moderate symptoms. The hypotheses will be tested in a case-control study and a cross sectional study. We will use leftover material of the diagnostic pharyngeal swab for HLA- and KIR-genotyping. In the cross-sectional study the genotype distribution will be compared among patients with different disease courses. For the case-control study we will use genotype information available on more than 7 million stem cell donors registed with DKMS. If high risk ratios can be revealed for certain genotypes, this information will help identifying high risk individuals among patients and health care workers by a simple non-invasive genetic test. High risk individuals may benefit from more stringent isolation or pre-emptive measures while low risk individuals, who more often have asymptomatic infections, should strictly wear protective masks in order not to spread the virus.