Identification of genetic host susceptibility in COVID-19 patients

epidemiological study - The COVID-19 epidemic situation needs little introduction and represent a global world-wide emergency. Disease behavior is variable, with the majority of patients experiencing only mild symptoms or no symptoms at all. Some patients develop severe pulmonary affection, with aggressive and extensive inflammatory destruction of lung parenchyma and associated systemic inflammatory response syndrome (SIRS) and superinfections, driving large fractions of the COVID-19 related mortality. What exactly drives this development of severe lung disease remains unknown, but old age, smoking, obesity, diabetes and other co-morbidities increase the risk. Variation in virus genetics and patient immunology are also likely involved. As to the latter, we hypothesize that host genetics may play a role in determining development of severe lung disease in COVID-19 infection. We here aim to address the following research questions: (1) Are there genetic signatures suggesting which biological mechanisms are involved that may suggest relevant therapeutic approaches? (2) Can we predict those at risk (or those with very low risk)? (3) Are specific human leukocyte antigen (HLA) alleles/haplotypes associated with COVID19 disease? (4) Are blood groups of relevance in (a) the infection process and (b) in disease severity? Until today, no well-powered genetic analysis has been performed. To this end, we have collected 5,000 blood samples from some of the most strongest affected regions in Europe, including a significant fraction of severe COVID19 patients from intensive care units.