Objective: To analyze the diagnostic value of cell-free plasma metagenomic next-generation sequencing (mNGS) pathogen identification for severe aplastic anemia (SAA) bloodstream infection. Methods: From February 2021 to February 2022, mNGS and conventional detection methods (blood culture, etc.) were used to detect 33 samples from 29 consecutive AA patients admitted to the Anemia Diagnosis and Treatment Center of the Hematology Hospital of the Chinese Academy of Medical Sciences to assess the diagnostic consistency of mNGS and conventional detection, as well as the impact on clinical treatment benefits and clinical accuracy. Results: ①Among the 33 samples evaluated by mNGS and conventional detection methods, 25 cases (75.76%) carried potential pathogenic microorganisms. A total of 72 pathogenic microorganisms were identified from all cases, of which 65 (90.28%) were detected only by mNGS. ②All 33 cases were evaluated for diagnostic consistency, of which 2 cases (6.06%) were Composite, 18 cases (54.55%) were mNGS only, 2 cases (6.06%) were Conventional method only, 1 case (3.03%) was both common compliances (mNGS/Conventional testing) , and 10 cases (30.3%) were completely non-conforming (None) . ③All 33 cases were evaluated for clinical treatment benefit. Among them, 8 cases (24.24%) received Initiation of targeted treatment, 1 case (3.03%) received Treatment de-escalation, 13 cases (39.39%) received Confirmation, and the remaining 11 cases (33.33%) received No clinical benefit. ④ The sensitivity of 80.77%, specificity of 70.00%, positive predictive value of 63.64%, negative predictive value of 84.85%, positive likelihood ratio of 2.692, and negative likelihood ratio of 0.275 distinguished mNGS from conventional detection methods (21/12 vs 5/28, P<0.001) . Conclusion: mNGS can not only contribute to accurately diagnosing bloodstream infection in patients with aplastic anemia, but can also help to guide accurate anti-infection treatment, and the clinical accuracy is high.
目的： 评估无细胞血浆宏基因组二代测序（mNGS）病原体识别对重型再生障碍性贫血（AA）血流感染的诊断意义。 方法： 应用mNGS与常规检测方法（血培养等）同步检测2021年2月至2022年2月中国医学科学院血液病医院贫血诊疗中心连续收治的29例AA患者共33例次送检样本，评估mNGS与常规检测的诊断一致性、对临床治疗获益的影响及临床准确度。 结果： ①33例次患者经mNGS和常规检测方法检测，其中25例次（75.76%）检出潜在病原微生物；共检出病原微生物72株，其中65株（90.28%）仅经mNGS检出。②诊断一致性评估：2例次（6.06%）组合符合（Composite），18例次（54.55%）mNGS唯一符合（mNGS only），2例次（6.06%）常规检测方法唯一符合（Conventional testing only），1例次（3.03%）共同符合（mNGS/Conventional testing），10例次（30.3%）完全不符合（None）。③临床治疗获益评估：8例次（24.24%）为启动靶向治疗（Initation of targeted treatment），1例次（3.03%）为降级治疗（Treatment de-escalation），13例次（39.39%）为确认治疗（Confirmation），11例次（33.33%）为无治疗获益（No clinical benefit）。④临床准确度：mNGS与常规检测方法差异有统计学意义（21/12对5/28，P<0.001），mNGS的敏感性80.77%，特异性70.00%，阳性预测值63.64%，阴性预测值84.85%，阳性似然比2.692，阴性似然比0.275。 结论： mNGS不仅有助于精准诊断AA患者的血流感染，而且有利于指导进行精准抗感染治疗，临床准确度高。.
Keywords: Anemia, aplastic; Bloodstream; Infection; Metagenomic; Next-generation sequencing.