目的 探讨艾滋病(AIDS)合并肺 孢子菌肺炎(PCP)患者的细胞免疫功能与 CT影像特点。方法 回顾性分析53例AIDS 合并PCP患者临床资料，根据临床分期分 为早中期组(n=23)与晚期组(n=30)。分析 两组细胞免疫功能及CT影像学表现差异。 结果 早中期组CD3 + 、CD4 + 、CD4 + /CD8 + 、NK 细胞水平均明显高于晚期组(P＜0.05)。 两组CT影像常见征象中，磨玻璃影、斑 片状影、网格结节影、小叶间隔增厚， 组间出现频率比较均无统计学意义(P＞ 0.05)；早中期组纤维条索状影、气囊或 空腔性变征象出现频率明显低于晚期组， 而”月弓征”出现频率则明显高于晚期组 (P＜0.05)。结论 AIDS合并PCP患者免疫 功能恶化趋势显著，不同分期下CT征象有 一定差异，能为临床诊治措施提供可靠依 据。

Objective To explore the cellular immune function and CT imaging features of patients with acquired immune deficiency syndrome (AIDS) and pneumocystis pneumonia (PCP). Methods The clinical data of 53 patients with AIDS and PCP were analyzed retrospectively. According to the clinical stages, they were divided into early-middle stage group (n=23) and late stage group (n=30). The differences of cellular immune function and CT imaging findings were analyzed in the two groups. Results The levels of CD3 + , CD4 + , CD4 + /CD8 + and NK cells in early-middle stage group were significantly higher than those in late stage group (P<0.05). Among the common signs of CT images in the two groups, there were no statistically significant differences in the occurrence frequencies of ground-glass opacity, patchy shadow, mesh nodule shadow and interlobular septal thickening, between-groups (P>0.05). The occurrence frequencies of fiber cord blocklike shadow and balloon or cavity signs in early-middle stage group were significantly lower than those in late stage group, and the occurrence frequency of lunar arch sign was significantly higher than that in late stage group (P<0.05). Conclusion The immune function of AIDS patients with PCP has a significant deterioration trend. There are certain differences in CT signs under different stages, and they can provide a reliable basis for clinical diagnosis and treatment.