IFNG and COVID-19: Old age (≧ 50 years) and positivity for anti-IFN-γ autoAbs could also significantly predict the severity of COVID-19 (odds ratio, 3.07, 95% CI 1.32-7.16, p <0.05; 6.84, 95% CI 1.53-30.64, p <0.05; respectively).