外周血宏基因组二代测序对肺孢子菌肺炎的诊断价值

目的:研究探讨外周血宏基因组二代测序技术(mNGS)在免疫抑制剂治疗的肾脏疾病患者合并肺孢子菌肺炎(PCP)的诊断价值。方法:选取肾脏疾病接受免疫抑制治疗后合并弥漫性肺部感染、临床拟诊为PCP的患者37例作为观察组,另选取25例临床确诊为其他病原导致肺部感染的患者作为对照。使用mNGS检测患者外周血中的病原种类和序列,评价mNGS对PCP的检测效能,比较mNGS与传统临床诊断PCP方法(真菌G联合乳酸脱氢酶检测)的效能差异。结果:观察组患者送检外周血样本37份,其中35份mNGS检出耶氏肺孢子菌(PJ)序列,敏感度94.59%,特异度100%;31例患者为混合型感染,27例检出病毒序列(19例为巨细胞病毒),8例合并细菌感染。对照组25份血标本PJ序列均为阴性。真菌G联合乳酸脱氢酶检测的敏感度89.19%,特异度56.0%;mNGS的特异度显著高于真菌G联合乳酸脱氢酶检测。结论:mNGS较传统诊断PCP的方法有明显优势,可同时检出混合感染的病原,对免疫抑制合并肺部感染的诊断有重要意义。

Diagnosis of pneumocystis pneumonia by metagenomic next-generation sequencing in patients with kidney disease

Objective:To evaluate the diagnostic value of metagenomic next-generation sequencing(mNGS) for pneumocystis pneumonia(PCP) in patients with kidney disease receiving immunosuppressive therapy. Methodology:37 cases of clinical diagnosed PCP patients after immunosuppressant therapy were selected,25 cases with pneumonia caused by other pathogens were selected as control group. mNGS was used to analyze the pathogen types and sequences in peripheral blood samples to evaluate the detection efficiency to PCP. Efficacy of mNGS and traditional clinical diagnosis(fungal G test combined with lactate dehydrogenase detection) of PCP were compared. Results:37 peripheral blood samples were collected from 37 clinical diagnosed PCP patients,of which 35 were identified by mNGS,with a sensitivity of 94.59%,specificity of 100%. 31 patients were complicated with mixed infection,19 with cytomegalovirus infection and 8 with bacterial infection. The sensitivity of fungal G test combined with lactate dehydrogenase was 89.19%,the specificity was 56.0%. Pneumocystis sequences were negative in all controls. Conclusion:mNGS has obvious advantages over the traditional method of diagnosing PCP. It has the characteristics of accuracy,simplicity and noninvasiveness,and is of great value for the early diagnosis of PCP.