摘要目的:评价宏基因组二代测序(mNGS)在骨关节感染诊断中的潜在应用价值。方法:回顾性分析青岛市胸科医院脊柱外科2019年1月至12月临床确诊为骨关节感染的37例住院患者临床资料。所有患者均经过穿刺或手术途径获取感染病灶核心部位组织样本，分别对样本进行分枝杆菌、需氧菌和厌氧菌常规培养，结核分枝杆菌(MTB)-DNA扩增检测及mNGS检测。采用卡方检验或Fisher确切概率法比较mNGS和常规培养病原体及单纯细菌感染检出率。以临床确诊为金标准，比较常规培养、mNGS和MTB-DNA扩增检测对骨关节结核分枝杆菌感染的诊断效能，同时采用受试者工作特征曲线(ROC)评估三种方法在骨关节结核诊断中的价值。采用配对 t检验比较患者抗感染治疗前后白细胞(WBC)计数、红细胞沉降率和C-反应蛋白。 P<0.05为差异有统计学意义。 结果:37例患者年龄32～90岁。感染部位：31例为脊柱，6例为其他骨关节。入院前症状：12例患者表现为感染部位疼痛和发热，11例表现为疼痛，5例表现为疼痛和活动受限，5例表现为疼痛、发热、乏力及食欲减退，2例表现为疼痛、发热及活动受限，1例表现为疼痛伴体质量减轻，1例表现为疼痛、发热伴腹泻。mNGS共发现3类病原微生物，累计检出频次为42例次，其中细菌39例次(包括10个菌属)，占92.8%(39/42)；真菌2例次，占4.8%(2/42)；柯克斯体1例次，占2.4%(1/42)。37例患者中单纯细菌感染29例，占78.4%(29/37)；单纯真菌感染2例，占5.4%(2/37)；单纯柯克斯体感染1例，占2.7%(1/37)；5例患者同时检测出两种及以上病原体，占13.5%(5/37)。37例患者mNGS和常规培养病原体检出率分别为100.0%(37/37)和67.6%(25/37)，差异有统计学意义( χ2＝13.987， P<0.05)；29例单纯细菌感染患者mNGS和常规培养检出率分别为100.0%(29/29)和69.0%(20/29)，差异有统计学意义( χ2＝16.913， P<0.05)。常规培养、mNGS和MTB-DNA扩增检测诊断骨关节结核分枝杆菌感染的ROC曲线下面积分别为0.958(95% CI：0.866～1.000， P<0.05)、1.000(95% CI：1.000～1.000， P<0.05)和0.958(95% CI：0.866～1.000， P<0.05)，诊断效能均较好。37例患者均根据mNGS及常规培养结果进行针对性抗感染药物治疗，其中28例接受手术干预。随访至2020年4月30日，1例患者死亡。随访3个月后患者WBC计数、红细胞沉降率和C-反应蛋白分别为(5.5±1.5)×10 9/L、(41±38)mm/h和(5.0±4.6)mg/L，均低于抗感染治疗前水平[(8.0±2.9)×10 9/L、(79±42)mm/h和(63±52)mg/L]，差异均有统计学意义( t＝6.536、8.302和6.373， P均<0.05)。 结论:mNGS对于骨关节感染的鉴别诊断可能具有重要临床价值。

abstractsObjective:To evaluate the application of metagenomic next-generation sequencing (mNGS) in the diagnosis of osteoarticular infection.Methods:The clinical data of 37 inpatients aged 32-90 year with osteoarticular infection admitted in the Department of Spine Surgery of Qingdao Chest Hospital from January to December 2019 were retrospectively analyzed. There were 31 cases of spine infection and 6 cases of other joint infection. The tissue samples were obtained from the infected sites through puncture or surgical approach in all patients. The tissue samples were subjected to routine culture of mycobacteria, aerobic bacteria and anaerobic bacteria, respectively. The gene amplification and mNGS were performed for detection of mycobacterium tuberculosis DNA (MTB-DNA). The chi-square test or Fisher’s exact test were used to compare the detection rates of pathogen and simple bacterial infection between mNGS and conventional culture. The conventional culture, mNGS and MTB-DNA amplification detection were performed for all samples; with clinical diagnosis as the gold standard, the diagnostic values of 3 methods were evaluated with receiver operating characteristic curve (ROC). Paired sample t test was used to compare white blood cell(WBC) count, erythrocyte sedimentation rate, C-reactive protein of patients before and after treatment. P<0.05 was considered statistically significant. Results:The pathogens were detected by mNGS for 42 times: bacteria for 39 times (92.8%), fungi for twice (4.8%) and Kirks body for once (2.4%). Among 37 patients there were 29 cases of pure bacterial infection (78.4%), 2 cases of pure fungi infection (5.4%), 1 case of pure Kirks body infection (2.7%), and 5 cases of mixed infection of two or more pathogens (13.5%). The detection rates of mNGS and conventional culture were 100.0% (37/37) and 67.6% (25/37), respectively ( χ2=13.987, P<0.05). The detection rates of mNGS and conventional culture in 29 patients with pure bacterial infection were 100.0% (29/29) and 69.0% (20/29), respectively ( χ2=16.913, P<0.05). The area under the ROC curve (AUC) of conventional culture, mNGS, and MTB-DNA in the diagnosis of osteoarticular tuberculosis infection was 0.958 (95% CI: 0.866-1.000, P<0.05), 1.000 (95% CI: 1.000-1.000, P<0.05) and 0.958 (95% CI: 0.866-1.000, P<0.05). All the 37 patients were treated with anti-infective drugs according to the results of mNGS and conventional culture. Among them, 28 patients received surgical intervention. The patients were followed up until April 30, 2020, 1 patient died. After 3 months of follow-up, the WBC count, erythrocyte sedimentation rate and C-reactive protein were (5.5±1.5)×10 9/L, (41±38)mm/h and (5.0±4.6) mg/L, respectively, which were lower than those before anti-infection treatment [(8.0±2.9)×10 9/L, (79±42)mm/h and(63±52)mg/L] ( t=6.536, 8.302 and 6.373, all P<0.05). Conclusion:The metagenomic next-generation sequencing may have important clinical value in the differential diagnosis of osteoarticular infection.