We observed that patients who developed coinfection tended to have a significantly lower number of CD4+ T cells (121.19 VS 207.83cells/μL, P=0.001) and CD8+ T cells (79 VS 158cells/μL, P=0.006) and a higher proportion of CD4+CD8+ double-positive T (DPT) cells (3.66% VS 1.91%, P=0.011) on the day of hospital admission. This evidence concerns the gene CD4 and coinfection.