宏基因二代测序技术在非中性粒细胞减少性侵袭性肺真菌感染病原检测中的价值

Value of metagenomic next-generation sequencing to the diagnosis of non-neutropenic invasive pulmonary fungal infection

目的 应用宏基因二代测序技术(metagenomic next-generation sequencing, mNGS)检测非中性粒细胞减少性侵袭性肺真菌感染(invasive pulmonary fungal infection, IPFI)患者肺泡灌洗液(bronchoalveolar lavage fluid, BALF)真菌表达,探讨其病原检测价值。方法 59例非中性粒细胞减少性IPFI患者,均行支气管肺泡灌洗术采集BALF标本,采用mNGS、传统培养、G试验/GM试验检测病原体。比较3种方法真菌检出率、检出时间;分析mNGS和传统培养检出真菌的分布情况;比较抗菌药物暴露对mNGS、传统培养及G试验/GM试验的影响。结果 mNGS真菌检出率(76.27%)高于传统培养(49.15%)和G试验/GM试验(52.54%)(P<0.05),检出时间[(22.73±0.70)h]短于传统培养和G试验/GM试验[(98.68±1.26)、(26.42±0.73)h](P<0.05)。mNGS检出真菌60株,其中念珠菌21株,曲霉菌25株,耶氏肺孢子菌6株,新生隐球菌5株,毛霉菌3株;传统培养检出真菌29株,其中念珠菌19株,曲霉菌10株。43例应用抗菌药物者mNGS真菌检出率(76.74%)高于传统培养(46.51%)和G试验/GM试验(55.81%)(χ^(2)=8.310,P=0.004;χ^(2)=4.214,P=0.040)。结论 应用mNGS技术可提高非中性粒细胞减少性IPFI患者BALF标本的真菌检出率和检出真菌的种类,缩短检测时间,且检测结果受应用抗菌药物的影响较小,但mNGS存在漏诊情况,不能完全取代传统培养。

Objective To detect the fungi expression in bronchoalveolar lavage fluid(BALF) of patients with non-neutropenic invasive pulmonary fungal infection(IPFI) using metagenomic next-generation sequencing(mNGS), and to explore its pathogenic detection value. Methods Bronchoalveolar lavage was performed to obtain BALF samples from 59 patients with non-neutropenic IPFI, and the pathogens were detected by mNGS, fungal culture, and 1, 3-β-D-glucan/galactomannan test(G/GM test). The detection rate and time of three methods were compared. The distributions of fungi detected by mNGS and fungal culture were analyzed. The influences of antimicrobial exposure on mNGS, fungal culture and G/GM test were compared. Results The detection rate of mNGS(76.27%) was higher than that of fungal culture(49.15%) and G/GM test(52.54%)(P<0.05). The detection time of mNGS [(22.73±0.70) h] was shorter than that of fungal culture [(98.68±1.26) h] and G/GM test [(26.42±0.73) h](P<0.05). In 60 strains of fungi detected by mNGS, there were 21 strains of Candida, 25 of Aspergillus, 6 of Pneumocystis, 5 of Cryptococcus and 3 of Mucor. In 29 stains of fungi detected by fungal culture, there were 19 strains of Candida, and 10 of Aspergillus. In 43 patients receiving antibacterial drugs, the detection rate of mNGS(76.74%) was higher than that of fungal culture(46.51%)(χ^(2)=8.310, P=0.004) and G/GM test(55.81%)(χ^(2)=4.214, P=0.040). Conclusions The mNGS of BALF samples can increase the detection rate, find more strains of fungi and shorten the detection time in patients with non-neutropenic IPFI, and its detection results are slightly affected by antibacterial drugs. mNGS could not replace fungal culture due to missed diagnosis.