Background Clinical impact of plasma metagenomic next-generation sequencing (mNGS) on infection diagnosis and antimicrobial therapy in immunocompromised patients with suspected infection remains unclear. Methods Between March and December 2022, 424 cases with fever, infection history, mechanical ventilation, or imaging abnormalities underwent plasma mNGS testing at a single center. Eleven patients have received solid organ transplantation, and the remaining patients were categorised into febrile neutropenia (FN), non-neutropenia (NN), and non-haematologic disease (NTHD) groups based on immunosuppression severity. The diagnostic rate of infection and the utilisation of antimicrobial agents based on mNGS were assessed. Results The use of mNGS significantly improved the diagnostic rates for fungi in the FN (56.1%, P = 0.003) and NN (58.8%, P = 0.008) groups versus the NHD group (33.3%). Positive impacts associated with therapy were significantly greater than negative impacts across all three groups (all P < 0.001), and the utilisation of escalation therapy was significantly more frequent in the FN group than in the NN groups (P = 0.006). Over 70% of cases with negative mNGS results across the three groups underwent de-escalation therapy, with >1/3 being discontinued, preventing antimicrobial overuse. Conclusions Plasma mNGS has a clinically confirmed positive impact in immunocompromised patients with neutropenia, improving the diagnosis of fungal infections and antimicrobial therapy.

中文翻译：

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血浆宏基因组下一代测序对免疫功能低下患者感染诊断和抗菌治疗的临床影响


背景 血浆宏基因组下一代测序（mNGS）对疑似感染的免疫功能低下患者的感染诊断和抗菌治疗的临床影响仍不清楚。方法 2022年3月至12月，在单中心对424例有发热、感染史、机械通气或影像学异常的病例进行血浆mNGS检测。 11名患者接受了实体器官移植，其余患者根据免疫抑制严重程度分为发热性中性粒细胞减少症（FN）、非中性粒细胞减少症（NN）和非血液疾病（NTHD）组。评估了基于 mNGS 的感染诊断率和抗菌药物的使用情况。结果 与 NHD 组（33.3%）相比，mNGS 的使用显着提高了 FN（56.1%，P = 0.003）和 NN（58.8%，P = 0.008）组的真菌诊断率。在所有三组中，与治疗相关的积极影响均显着大于消极影响（所有 P < 0.001），并且 FN 组中升级治疗的使用频率显着高于 NN 组（P = 0.006）。三组中超过 70% 的 mNGS 结果呈阴性的病例接受了降阶梯治疗，其中 >1/3 被停用，以防止抗菌药物过度使用。结论 血浆 mNGS 对患有中性粒细胞减少症的免疫功能低下患者具有临床证实的积极影响，可改善真菌感染的诊断和抗菌治疗。