As shown in Table 4, univariable logistic regression analysis revealed that sex, old age, leucocytosis, neutrophilia, lymphocytopenia, thrombocytopenia, CD3, CD4 and CD8 T-cells, alanine aminotransferase, aspartate aminotransferase, total bilirubin, blood urea nitrogen, creatinine, lactate dehydrogenase, creatine kinase, myoglobin, Hs-TnI, C-reactive protein, prothrombin time, activated partial thromboplastin time, and procalcitonin were associated with in-hospital death in severe patients with COVID-19. Here, CD4 is linked to COVID-19.