A Paired Comparison of Plasma and Bronchoalveolar Lavage Fluid for Metagenomic Next-Generation Sequencing in Critically Ill Patients with Suspected Severe Pneumonia

Abstract

Ting Sun,1 Yijie Liu,2 Ying Cai,3 Tianshu Zhai,3 Yun Zhou,4 Bin Yang,5 Xiaojing Wu,3,* Qingyuan Zhan1,3,* 1Capital Medical University China-Japan Friendship School of Clinical Medicine, Beijing, People’s Republic of China; 2Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 3Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing, People’s Republic of China; 4Laboratory Medicine, China-Japan Friendship Hospital, Beijing, People’s Republic of China; 5Vision Medicals Center for Infection Diseases, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qingyuan Zhan, Capital Medical University China-Japan Friendship School of Clinical Medicine, No. 2 Yinghua East Road, Chaoyang District, Beijing, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected] Xiaojing Wu, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Center for Respiratory Medicine, China-Japan Friendship Hospital, No. 2 Yinghua East Road, Chaoyang District, Beijing, 100029, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected]: Plasma metagenomic next-generation sequencing (mNGS) has emerged as an attractive and minimally invasive technique for pathogen detection. However, few studies have demonstrated the need for simultaneous plasma and bronchoalveolar lavage fluid (BALF) mNGS in patients with severe pneumonia.Patients and Methods: This study retrospectively performed a paired comparison of BALF and plasma mNGS in critically ill patients with suspected severe pneumonia from April 2019 to December 2020. The diagnostic performance of BALF and plasma mNGS was compared using the clinical composite diagnosis as the reference standard.Results: In total, 57 patients were included in this study. Patients with positive plasma mNGS had shorter hospital stay days at the time of specimen acquisition (4.5 vs 11, P = 0.028) and a higher positivity rate of BALF culture (50% vs 22.9%, P = 0.033) than patients with negative plasma mNGS. Fifty-three patients (93%) were finally diagnosed with severe pneumonia. Significant differences were observed in the sensitivity of BALF and plasma mNGS (100% vs 42%, P < 0.001), and the diagnostic accuracy was 96% and 46%, respectively. The proportion of virus in positive plasma mNGS results was higher than that in BALF mNGS (23% vs 11%, P = 0.173) without significant difference. Although plasma mNGS detected additional microorganisms in 11/53 patients, the beneficial effect was observed in only 5/53 (9%) patients.Conclusion: In this study, the clinical effect of simultaneously conducting mNGS of BALF and plasma samples was found to be limited. For patients with the suspected virus infection, plasma mNGS may be a supplementary test. Further studies are needed to identify the optimal indications for plasma mNGS.Keywords: mNGS, infection, cell-free DNA, diagnosis, pathogen

Keywords

• mngs
• infection
• cell-free dna
• diagnosis
• pathogen