Currently, PJP diagnosis guidelines recommend a comprehensive analysis of host factors, microbiological evidence, chest CT findings, polymerase chain reaction(PCR), and detection of CD4+T cells, lactate dehydrogenase(LDH), and 1,3-β-d-glucan (BDG) in serum for HIV-positive patients with PJP, categorized by severity [6]. This evidence concerns the gene CD4 and pneumocystosis.