IFNA17 and COVID-19: Using a Cochran–Mantel–Haenszel test with multiple imputation of missing baseline predictors, when patients possess either anti‐CD209 or anti‐CD209L IgM or anti‐IFNα autoantibodies, the presence of anti‐ACE2 IgM was the one significantly associated with COVID‐19 severity [OR (95% CI): 4.14 (1.37, 12.5)].