CRP and respiratory system disorder: Previous studies have shown that the predictors of severe prognosis in patients with COVID-19 included age, sex, CRP, LDH, lymphocyte count, D-dimer, and comorbidity (including hypertension, diabetes, cardiovascular disease, respiratory disease) (Huang H. et al., 2020; Liang et al., 2020b; Wynants et al., 2020).