Diagnostic Utility of Bronchoalveolar Lavage Metagenomic Next-Generation Sequencing for Pulmonary Mucormycosis: A Single-Center Retrospective Cohort Study

Xiao Yao,1 Haiyang Sang,2 Shuguang Gao,3 Xiaohang Hu,2,4 Jinyan Yan,2 Ting Liu,2 Hong Chang,2 Guohang Pang,2 Haixin Dong,2,4 Xiujuan Meng,5 Liqing Jiang,2,4 Min Kong6 1Health Management Center, Affiliated Hospital of Jining Medical University, Jining, Shandong, People’s Republic of China; 2Department of Medical Laboratory, Affiliated Hospital of Jining Medical University, Shandong, People’s Republic of China; 3Department of Medical Laboratory, Jining Geriatric Vascular Disease Hospital, Jining, Shandong, People’s Republic of China; 4Key Laboratory of Multi-Disciplinary Molecular Diagnosis Precision Medicine, Jining, Shandong, People’s Republic of China; 5Infection Management Center, Affiliated Hospital of Jining Medical University, Jining, Shandong, People’s Republic of China; 6Medical Laboratory of Jining Medical University, Lin He’s Academician Workstation of New Medicine and Clinical Translation in Jining Medical University, Jining Medical University, Jining, Shandong, People’s Republic of ChinaCorrespondence: Liqing Jiang, Email [email protected] Min Kong, Email [email protected]: Although pulmonary mucormycosis is rare, it is highly invasive and carries a significant mortality rate. Due to its nonspecific clinical manifestations, it is often misdiagnosed as other invasive fungal diseases. Bronchoalveolar lavage fluid metagenomic next-generation sequencing is a rapid, precise, and comprehensive method for pathogen detection, showing great potential in the early diagnosis of pulmonary mucormycosis in a single-center retrospective series. It provides clinicians with faster and more accurate etiological information, thereby improving patient outcomes and reducing mortality rates.Methods: This study conducted a retrospective analysis of the clinical data from 14 patients diagnosed with pulmonary mucormycosis between 1/6/2021 and 30/6/2024. Peripheral blood samples were collected to perform a complete blood count, measure C-reactive protein levels, and conduct 1,3-β-D-glucan and Galactomannan tests. Lung tissue samples were sent to the pathology laboratory for histological examination. Bronchoalveolar lavage fluid was subjected to fungal culture and metagenomic next-generation sequencing. Additionally, a three-month follow-up on the patients’ survival status was carried out via telephone.Results: Males accounted for 57.14% of the cases. Diabetes mellitus was present in 12 patients (85.71%, 12/14), and fever was observed in 12 patients (85.71%, 12/14). The 14 patients were categorized as proven cases (4 cases), probable cases (4 cases), and possible cases (6 cases). Two patients (14.29%, 2/14) were diagnosed with disseminated mucormycosis. Chest Computed Tomography scans revealed cavities in half of the patients (50.00%, 7/14). Fungal hyphae were identified in all the histopathological examinations (100%, 4/4). Metagenomic next-generation sequencing detected Mucorales pathogens in all the (100%, 14/14) cases, which is higher positivity than the positive rates of the 1,3-β-D-glucan test (35.71%, 5/14), Galactomannan test (42.86%, 6/14) and fungal culture (7.14%, 1/14). The turnaround time for metagenomic next-generation sequencing reports is 1– 3 days, which is much shorter than the time required to obtain results from fungal culture (2– 5 days). Additionally, metagenomic next-generation sequencing identified bacterial and viral co-infections, with 11 patients diagnosed as having mixed infections. All patients were treated with antifungal agents targeting Aspergillus species, such as voriconazole, posaconazole, isavuconazole, or amphotericin B, resulting in 9 patients improving, 2 patients being transferred to higher-level hospitals, and 3 patients discontinuing treatment. The 90-day follow-up revealed a mortality rate of 28.57%.Conclusion: Metagenomic next-generation sequencing can serve as an important complement to traditional diagnostic methods, enabling rapid and accurate differentiation of Mucorales from other fungi. This allows patients to receive timely and targeted antifungal therapy, playing a critical role in early intervention and improving prognosis.Keywords: pulmonary mucormycosis, clinical features, metagenomic next-generation sequencing, bronchoalveolar lavage fluid, treatment strategy