病原体靶向测序技术在疑似肺部感染患者中的应用价值分析

Application value of pathogen targeted next generation sequencing technology in patients with suspected pulmonary infection

目的 探讨病原体靶向测序(tNGS)技术在疑似肺部感染患者中的应用价值。方法 回顾性分析2021年1月-2023年7月湖北省第三人民医院呼吸与危重症医学科收治的80例疑似肺部感染患者的临床资料,所有患者均行支气管肺泡灌洗液(BALF)tNGS及常规病原学检测。分析患者人口学特征,比较t NGS与常规方法检测的病原体分布结果,并比较确诊肺部单一感染者与混合感染者的临床资料。结果 80例中,74例确诊感染。大部分感染者存在基础疾病,以慢性心脏疾病(42.5%)、慢性呼吸系统疾病(35.0%)和糖尿病(20.0%)为主。t NGS检测结果致35例患者(43.8%)的治疗策略改变。共检出45种病原体,其中tNGS检出病原体169株,常规方法检出病原体63株;两者联合检测出的病原体以细菌较多。tNGS检出的病原体株数排序:细菌>病毒>真菌>非典型病原体>人结核分枝杆菌。常规方法检出的病原体株数排序:真菌>病毒>细菌>非典型病原体>人结核分枝杆菌。两种方法检测结果的一致性较差(Kappa值0.172,P=0.020)。t NGS检出病原菌阳性比例及在细菌、病毒、非典型病原体的阳性检出率均明显高于常规方法(P<0.05),但在真菌、人结核分枝杆菌的阳性检出率与常规方法比较差异无统计学意义(P>0.05)。以临床诊断为金标准,tNGS检测的敏感度明显高于常规方法(P=0.026),而两者特异度比较差异无统计学意义(P>0.05)。在74例确诊肺部感染者中,6例无明确的病原体,单一感染者23例,混合感染者45例。在混合感染者中,常见的组合是细菌-病毒混合感染(12/45,26.7%)。混合感染者的病死率和住院天数均明显高于或长于单一感染者(P<0.05);两者性别、年龄、基础疾病、白细胞计数、中性粒细胞百分比等差异均无统计学意义(P>0.05)。结论 tNGS技术较常规方法的病原体检测敏感度高,尤其对细菌、病毒、非典型病原体及少见病原体更为敏感。此技术有利于识别混合感染,可作为临床常规病原学检测方法的补充。

Objective To explore the application value of pathogen-targeted next-generation sequencing(tNGS technology in patients with suspected pulmonary infections.Methods A retrospective analysis was conducted on the clinical data of 80 patients with suspected pulmonary infections admitted to the Department of Respiratory and Critical Care Medicine at the Third People's Hospital of Hubei Province from January 2021 to July 2023.All patients underwent bronchoalveolar lavage fluid(BALF)tNGS and conventional pathogen detection.Demographic characteristics of the patients were analyzed,and the distribution of pathogens detected by tNGS and conventional methods were compared.The clinical data of patients diagnosed with single pulmonary infections and those with mixed infections were also compared.Results Among the 80 patients,74 were diagnosed with infections.Most of the infected patients had underlying conditions,mainly chronic heart disease(42.5%),chronic respiratory disease(35%),and diabetes(20%).The tNGS test results led to changes in treatment strategy for 35 patients(43.8%).A total of 45 types of pathogens were detected,with 169 strains identified by tNGS and 63 strains by conventional methods.Within pathogens detected by both methods,bacteria were detected the most.The order of pathogen types detected by tNGS was bacteria > viruses > fungi > atypical pathogens > Mycobacterium tuberculosis.The order of pathogen types detected by conventional methods was fungi > viruses >bacteria > atypical pathogens > Mycobacterium tuberculosis.The consistency between the two pathogen detection methods was poor(kappa value 0.172,P=0.020).The number of positive cases and the positive detection rates for bacteria,viruses,and atypical pathogens detected by tNGS were significantly higher than those of conventional methods(P<0.05),but there was no statistically significant difference in the positive detection rates for fungi and Mycobacterium tuberculosis between the two methods(P>0.05).Using clinical diagnosis as the gold standard,the sensitivity of tNGS detection was significantly higher than that of conventional methods(P=0.026),while there was no statistically significant difference in specificity between the two methods(P>0.05).Among the 74 confirmed pulmonary infection cases,6 had no clear pathogen,23 had single infections,and 45 had mixed infections.Among the mixed infections,the most common combination was bacterial-viral mixed infections(12/45,26.7%).The mortality rate and hospitalization duration of patients with mixed infections were significantly higher than those with single infections(P<0.05);there were no statistically significant differences in gender,age,underlying conditions,white blood cell count,and neutrophil percentage between the two groups(P>0.05).Conclusions tNGS technology has higher pathogen detection sensitivity compared to conventional methods,especially for bacteria,viruses,atypical pathogens,and rare pathogens.This technology is beneficial for identifying mixed infections and can serve as a supplement to conventional pathogen detection methods in clinical practice.