APOE e4 Genotype Predicts Severe COVID-19 in the UK Biobank Community Cohort

The novel respiratory disease COVID-19 produces varying symptoms, with fever, cough, and shortness of breath being common. In older adults, it has been found that preexisting dementia is a major risk factor for COVID-19 severity in the UK Biobank (UKB). In another UK study of 16,749 patients hospitalized for COVID-19, dementia was among the common comorbidities and was associated with higher mortality. Additionally, impaired consciousness, including delirium, is common in severe cases. The ApoE e4 genotype is associated with both dementia and delirium, with the e4e4 (homozygous) genotype associated with a 14-fold increase in risk of Alzheimer's disease compared to the common e3e3 genotype, in populations with European ancestries. The need to test associations between ApoE e4 alleles and COVID-19 severity, using the UKB data, is also emphasized.