scholarly journals Diagnostic Value of Metagenomic Next-Generation Sequencing of Bronchoalveolar Lavage Fluid for the Diagnosis of Suspected Pneumonia in Immunocompromised Patients

Author(s):  
Pengcheng Lin ◽  
Yi Chen ◽  
Shanshan Su ◽  
Wengang Nan ◽  
Lingping Zhou ◽  
...  

Abstract Background: To evaluate the diagnostic value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) in immunocompromised patients for the diagnosis of suspected pneumonia in comparation to that of conventional microbiological tests (CMTs).Methods: Sixty-nine immunocompromised patients with suspected pneumonia received both CMTs and mNGS of BALF were analyzed retrospectively. The diagnostic value was compared between CMTs and mNGS, using the clinical composite diagnosis as the reference standard. Results: Sixty patients were diagnosed of pneumonia including fifty-two patients with identified pathogens and eight patients with probable pathogens. The overall detection rate of mNGS for pathogens were higher than that of CMTs. However, a comparable diagnostic accuracy of mNGS and CMTs were found for bacterial and viral infections. mNGS exhibited a higher diagnostic accuracy for fungal detection than CMTs (78% vs. 54%, P<0.05), which mainly because of the high sensitivity of mNGS in patients with Pneumocystis jirovecii pneumonia (PJP) (100% vs. 28%, P<0.05). Among fifty-two patients with definite pathogens, nineteen patients (37%) were identified as pulmonary mixed infection, mNGS test showed a higher detection rate and broader spectrum for pathogen detection than that of CMTs in mixed infection. Moreover, Pneumocystis jirovecii was the most common pathogen in mix infection and mNGS have identified much more co-pathogens of PJP than CMTs.Conclusions: mNGS of BALF improved the microbial detection rate of pathogens and exhibited remarkable advantages in detecting PJP and identifying mixed infections in immunocompromised patients.

Author(s):  
Xu Chen ◽  
Shuizi Ding ◽  
Cheng Lei ◽  
Jieli Qin ◽  
Ting Guo ◽  
...  

Background. Metagenomic next-generation sequencing (mNGS) has made a revolution in the mode of pathogen identification. We decided to explore the diagnostic value of blood and bronchoalveolar lavage fluid (BALF) as mNGS samples in pneumonia. Methods. We retrospectively reviewed 467 mNGS results and assessed the diagnostic performance of paired blood and BALF mNGS in 39 patients with pneumonia. Results. For bacteria and fungi, 16 patients had culture-confirmed pathogen diagnosis, while 13 patients were culture-negative. BALF mNGS was more sensitive than blood mNGS (81.3% vs. 25.0%, p=0.003), and the specificity in BALF and blood mNGS was not statistically significant different (76.9% vs. 84.6%, p=0.317). For 10 patients without culture test, treatments were changed in 2 patients. For viruses, Epstein-Barr virus was positive in blood mNGS in 9 patients. Human adenovirus was detected in both BALF and blood mNGS in 3 patients. Conclusion. Our study suggests that BALF mNGS is more sensitive than blood mNGS in detecting bacteria and fungi, but blood also has advantages to identify the pathogens of pneumonia, especially for some viruses.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Suguru Takeuchi ◽  
Jun-ichi Kawada ◽  
Kazuhiro Horiba ◽  
Yusuke Okuno ◽  
Toshihiko Okumura ◽  
...  

Abstract Next-generation sequencing (NGS) has been applied in the field of infectious diseases. Bronchoalveolar lavage fluid (BALF) is considered a sterile type of specimen that is suitable for detecting pathogens of respiratory infections. The aim of this study was to comprehensively identify causative pathogens using NGS in BALF samples from immunocompetent pediatric patients with respiratory failure. Ten patients hospitalized with respiratory failure were included. BALF samples obtained in the acute phase were used to prepare DNA- and RNA-sequencing libraries. The libraries were sequenced on MiSeq, and the sequence data were analyzed using metagenome analysis tools. A mean of 2,041,216 total reads were sequenced for each library. Significant bacterial or viral sequencing reads were detected in eight of the 10 patients. Furthermore, candidate pathogens were detected in three patients in whom etiologic agents were not identified by conventional methods. The complete genome of enterovirus D68 was identified in two patients, and phylogenetic analysis suggested that both strains belong to subclade B3, which is an epidemic strain that has spread worldwide in recent years. Our results suggest that NGS can be applied for comprehensive molecular diagnostics as well as surveillance of pathogens in BALF from patients with respiratory infection.


2020 ◽  
Vol 11 ◽  
Author(s):  
Xiaowei Fang ◽  
Qing Mei ◽  
Xiaoqin Fan ◽  
Chunyan Zhu ◽  
Tianjun Yang ◽  
...  

Objective: To evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS) using bronchoalveolar lavage fluid (BALF) in patients with ventilator-associated pneumonia (VAP).Methods: BALF samples of 72 patients with VAP were collected from August 2018 to May 2020. The diagnostic performance of conventional testing (CT) and mNGS methods were compared based on bacterial and fungal examinations. The diagnostic value of mNGS for viral and mixed infections was also analyzed.Results: The percentage of mNGS positive samples was significantly higher than that estimated by the CT method [odds ratio (OR), 4.33; 95% confidence interval (CI), 1.78–10.53; p < 0.001]. The sensitivity and specificity of mNGS for bacterial detection were 97.1% (95% CI, 93.2–101.0%) and 42.1% (95 CI, 30.7–53.5%), respectively, whereas the positive predictive value (PPV) and the negative predictive value (NPV) were 60.0% (95% CI, 48.7–71.3%) and 94.1% (95% CI, 88.7–99.6%), respectively. A total of 38 samples were negative for bacterial detection as determined by the CT method, while 22 samples were positive as shown by the mNGS method. Conflicting results were obtained for three samples between the two methods of bacterial detection. However, no significant differences were noted between the mNGS and CT methods (OR, 1.42; 95% CI, 0.68–2.97; p = 0.46) with regard to fungal infections. The sensitivity and specificity of mNGS were 71.9% (95% CI, 61.5–82.3%) and 77.5% (95% CI, 67.9–87.1%), respectively. mNGS exhibited a PPV of 71.9% (95% CI, 61.5–82.3%) and an NPV of 77.5% (95% CI, 67.9–87.1%). A total of 9 out of 40 samples were found positive for fungi according to mNGS, whereas the CT method failed to present positive results in these samples. The mNGS and CT methods produced conflicting results with regard to fungal detection of the two samples. A total of 30 patients were virus-positive using mNGS. Furthermore, 42 patients (58.3%) were identified as pulmonary mixed infection cases.Conclusions: mNGS detection using BALF improved the sensitivity and specificity of bacterial identification in patients who developed VAP. In addition, mNGS exhibited apparent advantages in detecting viruses and identifying mixed infections.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Meiqin Chen ◽  
Weili Lu ◽  
Shugen Wu ◽  
Shun Wang ◽  
Tao Lu ◽  
...  

Abstract Background Leptospirosis is a common infectious disease in tropical and semitropical regions, and it is typically neglected. Leptospirosis-associated acute diffuse alveolar hemorrhage is one of its fatal complications. The use of bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing in the diagnosis of Leptospira interrogans infection has rarely been reported. Case presentation We present the case of a 62-year-old female who was transferred to our hospital with dyspnea, and severe hemoptysis and was supported by a tracheal intubation ventilator. Bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing (mNGS) reported Leptospira interrogans. A diagnosis of diffuse alveolar hemorrhage caused by leptospirosis was made. After immediately receiving antibiotics and hormone therapy, the patient achieved a complete recovery upon discharge. Conclusion Leptospirosis presenting as severe diffuse alveolar hemorrhage is rare but should be considered in the differential diagnosis. mNGS can help identify pathogens and treat them early, which can improve prognosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Wanghui Shi ◽  
Shanshan Zhu

Objective. To uncover the application value of metagenomic next-generation sequencing (mNGS) in the detection of pathogen in bronchoalveolar lavage fluid (BALF) and sputum samples. Methods. Totally, 32 patients with pulmonary infection were included. Pathogens in BALF and sputum samples were tested simultaneously by routine microbial culture and mNGS. Main infected pathogens (bacteria, fungi, and viruses) and their distribution in BALF and sputum samples were analyzed. Moreover, the diagnostic performance of mNGS in paired BALF and sputum samples was assessed. Results. The pathogen culture results were positive in 9 patients and negative in 13 patients. No statistical differences were recorded on the sensitivity (78.94% vs. 63.15%, p = 0.283 ) and specificity (62.50% vs. 75.00%, p = 0.375 ) of mNGS diagnosis in bacteria and fungus in two types of samples. As shown in mNGS detection, 10 patients’ two samples were both positive, 13 patients’ two samples were both negative, 7 patients were only positive in BALF samples, and 2 patients’ sputum samples were positive. Main viruses mNGS detected were EB virus, human adenovirus 5, herpes simplex virus type 1, and human cytomegalovirus. Kappa consensus analysis indicated that mNGS showed significant consistency in detecting pathogens in two samples, no matter bacteria ( p < 0.001 ), fungi ( p = 0.026 ), or viruses ( p = 0.008 ). Conclusion. mNGS showed no statistical differences in sensitivity and specificity of pathogen detection in BALF and sputum samples. Under certain conditions, sputum samples might be more suitable for pathogen detection because of invasiveness of BALF samples.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S658-S659
Author(s):  
Suguru Takeuchi ◽  
Jun-ichi Kawada ◽  
Kazuhiro Horiba ◽  
Yusuke Okuno ◽  
Toshihiko Okumura ◽  
...  

Abstract Background In the field of infectious diseases, identification of etiologic pathogen is essential for definitive diagnosis and decisions regarding appropriate management. Bronchoalveolar lavage fluid (BALF) is considered a sterile type of specimen that is suitable for detecting pathogens of respiratory infections. Recently, next-generation sequencing (NGS) has been applied in the field of infectious diseases and has enabled us to identify pathogenic microorganisms comprehensively. The aim of this study was to comprehensively identify pathogens using NGS in BALF samples from immunocompetent pediatric patients with respiratory failure. Methods Ten patients hospitalized in the pediatric intensive care unit with respiratory failure were included. BALF samples obtained in the acute phase were used to prepare DNA- and RNA-sequencing libraries. The libraries were sequenced on MiSeq, and the sequence data were analyzed using metagenome analysis tools. Results A mean of 2,041,216 total reads were sequenced for each library. A significant number of four types of bacterial reads was detected in three BALF samples with DNA-sequencing, whereas pathogenic respiratory viruses were detected in seven of 10 patients with RNA-sequencing.Candidate pathogens were detected in three patients in whom etiologic agents were not identified by conventional methods. A summary of the detected pathogens is listed in Table 1. Sequence coverage and depth of each reference bacterial and viral genome are shown in Figures 1 and 2, respectively. The complete genome of enterovirus D68 was identified in two patients without underlying diseases, and phylogenetic analysis suggested that both strains belong to subclade B3, which is an epidemic strain that has spread worldwide in recent years. Conclusion We demonstrated the utility of the NGS-based approach for detection of candidate pathogens in BALF from pediatric patients with severe respiratory failure. Our results suggest that NGS can be applied for comprehensive molecular diagnostics as well as surveillance of pathogens in the field of infectious diseases. Disclosures All authors: No reported disclosures.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lu Qin ◽  
Fei-Zhou Zhang ◽  
Tong-Yu Yang ◽  
Xiao-Fen Tao ◽  
Lan-Fang Tang

Abstract Background Idiopathic pulmonary hemosiderosis (IPH) encompasses a rare and agnogenic group of diffuse alveolar capillary hemorrhagic diseases. Corticosteroid treatment is the globally preferred therapeutic strategy for IPH; however, it can cause immunodeficiency. Nocardia infection often occurs in immunocompromised patients and primarily involves the pleura and lungs. Herein, we describe a case of pediatric pulmonary Nocardia infection after the corticosteroid treatment of IPH. Case presentation A 7-year-old girl presented with chief complaints of pale complexion persisting for 1 year and a cough for 20 days. Abundant hemosiderin-laden macrophages were detected in the gastric juice, which supported the diagnosis of IPH. Uninterrupted doses of corticosteroids were administered during the last hospitalization. After nearly 2 months of corticosteroids therapy, the patient began to cough and produce a purulent sputum. Next-generation sequencing of the bronchoalveolar lavage fluid revealed Nocardia abscessus (N. abscessus) DNA. Linezolid was administered with good response, and the patient was discharged after 18 days of hospitalization. Her symptoms and pulmonary lesions had recovered, and the IPH appeared to be well-controlled with low dose of corticosteroids in follow-up. Conclusions Nocardia infection should be considered in the differential diagnoses for IPH patients receiving corticosteroid therapy, especially in patients with poor response to conventional empirical antibiotic therapy. Next-generation sequencing of bronchoalveolar lavage fluid may be used to quickly identify the Nocardia. Sulfonamides or linezolid are effective for pediatric pulmonary Nocardia infection.


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