Comparison of LAMP, GeneXpert, Mycobacterial Culture, Smear Microscopy, TSPOT.TB, TBAg/PHA Ratio for Diagnosis of Pulmonary Tuberculosis

Objective

To investigate the application value of loop-mediated isothermal amplification (LAMP), GeneXpert, mycobacterial culture, smear microscopy, TSPOT.TB (TSPOT), ratio of TB-specific antigen to phytohemagglutinin (TBAg/PHA ratio) in the detection of mycobacterium tuberculosis in the bronchoalveolar lavage fluid.

Methods

A retrospective analysis was performed on the patients who underwent bronchoscopy from December 2018 to November 2019 in Tongji Hospital. The patients with positive tuberculosis culture or positive GeneXpert in bronchoalveolar lavage fluid were selected as the case group, and those without tuberculosis served as the control group. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of LAMP, GeneXpert, culture, smear microscopy, TSPOT, and TBAg/PHA ratio.

Results

For the patients with positive cultures as case, the sensitivity of LAMP, GeneXpert, smear microscopy, TSPOT and TBAg/PHA ratio was 73.49%, 89.16%, 25.30%, 80.00%, 33.85%, respectively, the specificity was 99.00%, 100.00%, 99.00%, 86.00%, 100.00%, respectively, the area under the ROC curve (AUC) was 0.849, 0.938, 0.633, 0.830, 0.669, respectively. For the patients with positive GeneXpert as case, the sensitivity of LAMP, mycobacterial culture, smear microscopy, TSPOT and TBAg/PHA ratio was 73.20%, 74.23%, 22.68%, 68.92%, 29.73%, respectively, the specificity was 99.00%, 100.00%, 99.00%, 86.00%, 100.00%, respectively, the AUC was 0.853, 0.878, 0.623, 0.775, 0.649, respectively.

Conclusion

The sensitivity of GeneXpert was best. The sensitivity and diagnostic value of LAMP were slightly lower than those of GeneXpert, and were similar to tuberculosis culture. The sensitivity of smear microscopy was low. The specificity of TSPOT was low. When TBAg/PHA ratio >0.2 was used as a diagnostic index, the specificity was improved, but the sensitivity was low.

Detection of Aspergillus DNA in BALF by Real-time PCR and Galactomannan Antigen for the Early Diagnosis of Chronic Pulmonary Aspergillosis

OBJECTIVE

Studies have confirmed that real-time PCR detection of Aspergillus DNA in bronchoalveolar lavage fluid (BALF) is more valuable than blood samples in the diagnosis of invasive pulmonary aspergillosis (IPA). The latest guidelines recommend the use of serum samples for Aspergillus antibody testing for chronic pulmonary aspergillosis (CPA). However, research on CPA diagnosed by real-time PCR testing of BALF has been limited. In this study, we assessed the clinical value of BALF GM and PCR detection in diagnosing CPA.

METHODS

The diagnostic criteria of this study were based on the 2015 ESCMID/ERS guidelines for CPA. Seventy-nine patients with CPA and 74 non-CPA patients were enrolled. Aspergillus DNA in BALF was detected in the patients with CPA.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the curve (AUC) of BALF PCR in the CPA group were 87.18%, 89.80%, 87.18%, 89.80%, and 0.89 (95% CI 0.82-0.95), respectively (P<0.005). The sensitivity, specificity, PPV, and NPV of BALF Aspergillus galactomannan (GM) detection in the CPA group were 66.67%, 89.80%, 83.87%, and 77.19%, respectively, and the AUC was 0.94 (95% CI 0.89-0.99) (P<0.005). When combining BALF GM and BALF PCR detection, the sensitivity, specificity, PPV, and NPV were 92.31%, 89.80%, 87.80%, and 93.62%, respectively.

CONCLUSION

The BALF PCR detection method has good diagnostic value for CPA and combining this method with BALF GM detection can improve diagnostic sensitivity and specificity.

A Negative (1,3)-β-D-Glucan Result Alone Is Not Sufficient to Rule Out a Diagnosis of Pneumocystis Pneumonia in Patients With Hematological Malignancies

Background: Serum (1,3)-β-D-glucan (BG) testing is increasingly being used in the diagnostic armamentarium for invasive fungal diseases. Given its high sensitivity, some studies suggest that a negative BG result contributes to rule out a diagnosis of Pneumocystis pneumonia (PCP). However, recent reports described a suboptimal sensitivity in HIV-negative immunocompromised patients. In this study, we evaluated the performance of BG assay for PCP diagnosis in HIV-negative patients with diverse PCP risk factors. We also assessed the correlation between Pneumocystis jirovecii load in pulmonary samples and serum BG levels.

Methods: We retrospectively included HIV-negative patients with microscopically proven PCP and for whom a BG result was available. We also enrolled patients colonized by Pneumocystis as control group. Colonized patients were matched with PCP patients based on their underlying condition that exposed to PCP. Pulmonary fungal loads were determined by an in-house real-time PCR, and BG levels were measured by using the Fungitell® kit (Associates of Cape Cod, Inc.).

Results: Thirty-nine patients were included in each of the two groups. Thirty-four of 39 PCP patients and one of 39 colonized patient had a positive BG test, resulting in a sensitivity of 0.87 (95% CI: 0.73–0.94), a specificity of 0.97 (95% CI: 0.87–0.99), a positive predictive value of 0.97 (95% CI: 0.85–0.99), and a negative predictive value of 0.88 (95% CI: 0.75–0.95) for BG assay. Nonetheless, median BG level differed according to the underlying condition. Among the PCP group, the lowest median level of 211 pg/ml was observed in patients with hematological malignancy (HM) and differed significantly from that observed either in solid organ transplants (3,473 pg/ml) or in patients with autoimmune or inflammatory disorder (3,480 pg/ml). Indeed, the sensitivity of BG assay was estimated at 0.64 (95% CI: 0.35–0.85) in HM patients and was lower than the one observed in the whole PCP group. Furthermore, BG level and fungal burden correlated poorly among all PCP patients.

Conclusion: BG is not a reliable biomarker for ruling out PCP in HIV-negative patients with HM. Interpretation of a negative BG result should take into account, but not be limited to, the underlying condition predisposing to PCP.

Effects of Atmospheric Fine Particulate Matter and Its Carrier Microbes on Pulmonary Microecology in Patients with COPD

Objective

The aim of this paper was to analyse the influence of atmospheric fine particulate matter (AFPM) and atmospheric microorganisms on the pulmonary microecology of chronic obstructive pulmonary disease (COPD) patients in northeast China.

Methods

Collected bronchoalveolar lavage fluid (BALF) of COPD patients in the high-risk period (group A) and low-risk period (group B) of AFPM inhalation and samples of AFPM in the same time range (group C) were collected. DNA sample sequencing, the bacterial abundance, and diversity bioinformatics of BALFs were performed by methods of Illumina MiSeq™ platform and Mothur and Uclust.

Results

A total of 58 samples were sequenced, including 22 samples from group A, 26 samples from group B and 10 samples from group C. A total of 2,005,790 bacterial sequences and 34,256 bacterial numbers were detected. Group B had the highest bacterial diversity of the three groups. Group B also had the highest bacterial abundance index value. There were differences in the classification of bacterial colonies for the three groups at the genus level. The types of bacteria in group C were more numerous than other groups, and group B was higher than group A, which indicates that there were more bacteria in BALF during the high-risk period of AFPM inhalation. The detection rates of Streptococcus, Mycoplasma, Roche, Pushia, Chlamydia trachomatis and Brucella for group C were significantly higher than group A. The COG and KEGG databases’ difference analysis results for the bacterial gene function abundance of group A and group B were 40.7% in group A and 38.9% in group B (R=0.098, P=0.006). The human disease abundance in group A and group B was 1.16% and 1.12%, respectively (P>0.05).

Conclusion

The increase in the concentration of AFPM can increase the diversity and abundance of bacteria in the BALF of stable COPD patients.

Clinical Trial Registration Number

2020XS04-02.

Detection of Chlamydia psittaci in both blood and bronchoalveolar lavage fluid using metagenomic next-generation sequencing: A case report

RATIONALE

Chlamydia psittaci (C psittaci) is a gram-negative obligate intracellular parasite, with birds as main hosts. The main route of infection in humans is inhalation of aerosols from contaminated animal excreta through the respiratory tract. The main manifestation of C psittaci infection is pneumonia. Patients suffering from severe infection are prone to sepsis and multiple organ failure. We report a case of simultaneous detection of C psittaci in blood and bronchoalveolar lavage fluid using metagenomic next-generation sequencing (mNGS) technology.

PATIENT CONCERNS

The 71-year-old male patient was a farmer with a long history of raising poultry and initial symptoms of fever and muscle pain accompanied by limb weakness and paroxysmal cough.

DIAGNOSES

The patient was diagnosed with sepsis, severe pneumonia, and multiple organ failure.

INTERVENTIONS

Anti-infective therapy with doxycycline and meropenem was applied.

OUTCOMES

The patient's body temperature and infection indicators improved and the chest X-ray findings showed the amelioration of lesions after 18 days of treatment. The patient was discharged without treatment on hospital day 19 due to financial constraints and subsequently died after 7 days.

LESSONS

mNGS is an excellent diagnostic tool when specific pathogens are undetected by traditional assays.

[Detection of drug-resistance genes of Mycoplasma pneumoniae in bronchoalveolar lavage fluid of children with refractory Mycoplasma pneumoniae pneumonia]

OBJECTIVE

To study the drug resistance of Mycoplasma pneumoniae (MP) in the bronchoalveolar lavage fluid (BALF) of children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and the distribution of drug-resistance genes, as well as the association of alleles at 2063 locus of 23SrRNA V region central ring with resistance to antimicrobial drugs.

METHODS

BALF specimens were collected from 245 children with RMPP who were admitted to the Children's Hospital Affiliated to Zhengzhou University from March 2016 to December 2020. A rapid cultured drug sensitivity assay was used to detect the resistance of MP isolates to nine commonly used antimicrobial drugs. The real-time PCR was used to measure MP DNA. The direct sequencing was used to detect gene mutations in MP 23SrRNA V region central ring.

RESULTS

Among the 245 BALF specimens, 207 tested positive for MP DNA, with a positive rate of 84.5%. The results of drug susceptibility test showed that the children with RMPP had a resistance rate of > 70% to macrolide antimicrobial drugs, with the highest resistance rate to clarithromycin, followed by roxithromycin, clindamycin, acetylspiramycin, erythromycin, and azithromycin, and these children had a resistance rate of < 5% to quinolone antimicrobial drugs. Among the 207 MP DNA-positive specimens, 41 (19.8%) had no drug-resistance gene mutations and 166 (80.2%) had drug-resistance gene mutations, among which 154 (74.4%) had an A→G mutation at 2063 locus of 23SrRNA V region central ring, 7 (3.4%) had an A→G mutation at 2064 locus, and 5 (2.4%) had mutations in both 2063 and 2064 loci. Among the 166 specimens with point mutations of the MP 23SrRNA gene, 159 (95.8%) had point mutations at 2063 locus. The A→G point mutation at 2063 locus of 23SrRNA V region central ring had a great impact on resistance to macrolide antimicrobial drugs. There was a significant difference in the distribution of alleles at 2063 locus between the children with resistance to clarithromycin, roxithromycin, clindamycin, acetylspiramycin, erythromycin, and azithromycin (P < 0.05).

CONCLUSIONS

MP in the BALF of children with RMPP has a relatively high resistance rate to macrolide antimicrobial drugs. Resistance to macrolide antimicrobial drugs is closely associated with the A→G point mutation in the 23SrRNA gene, and the point mutation at 2063 locus of 23SrRNA V region central ring may affect the drug-resistance mechanism of MP.

[Detection of drug-resistance genes of Mycoplasma pneumoniae in bronchoalveolar lavage fluid of children with refractory Mycoplasma pneumoniae pneumonia]

OBJECTIVE

To study the drug resistance of Mycoplasma pneumoniae (MP) in the bronchoalveolar lavage fluid (BALF) of children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and the distribution of drug-resistance genes, as well as the association of alleles at 2063 locus of 23SrRNA V region central ring with resistance to antimicrobial drugs.

METHODS

BALF specimens were collected from 245 children with RMPP who were admitted to the Children's Hospital Affiliated to Zhengzhou University from March 2016 to December 2020. A rapid cultured drug sensitivity assay was used to detect the resistance of MP isolates to nine commonly used antimicrobial drugs. The real-time PCR was used to measure MP DNA. The direct sequencing was used to detect gene mutations in MP 23SrRNA V region central ring.

RESULTS

Among the 245 BALF specimens, 207 tested positive for MP DNA, with a positive rate of 84.5%. The results of drug susceptibility test showed that the children with RMPP had a resistance rate of > 70% to macrolide antimicrobial drugs, with the highest resistance rate to clarithromycin, followed by roxithromycin, clindamycin, acetylspiramycin, erythromycin, and azithromycin, and these children had a resistance rate of < 5% to quinolone antimicrobial drugs. Among the 207 MP DNA-positive specimens, 41 (19.8%) had no drug-resistance gene mutations and 166 (80.2%) had drug-resistance gene mutations, among which 154 (74.4%) had an A→G mutation at 2063 locus of 23SrRNA V region central ring, 7 (3.4%) had an A→G mutation at 2064 locus, and 5 (2.4%) had mutations in both 2063 and 2064 loci. Among the 166 specimens with point mutations of the MP 23SrRNA gene, 159 (95.8%) had point mutations at 2063 locus. The A→G point mutation at 2063 locus of 23SrRNA V region central ring had a great impact on resistance to macrolide antimicrobial drugs. There was a significant difference in the distribution of alleles at 2063 locus between the children with resistance to clarithromycin, roxithromycin, clindamycin, acetylspiramycin, erythromycin, and azithromycin (P < 0.05).

CONCLUSIONS

MP in the BALF of children with RMPP has a relatively high resistance rate to macrolide antimicrobial drugs. Resistance to macrolide antimicrobial drugs is closely associated with the A→G point mutation in the 23SrRNA gene, and the point mutation at 2063 locus of 23SrRNA V region central ring may affect the drug-resistance mechanism of MP.

Dependence of Xpert MTB/RIF Accuracy for Detecting Rifampin Resistance in Bronchoalveolar Lavage Fluid on Bacterial Load: A Retrospective Study in Beijing, China

INTRODUCTION

We assessed the effect of Mycobacterium tuberculosis (MTB) bacterial load on Xpert MTB/RIF accuracy for detection of rifampicin (RIF)-resistant MTB in bronchoalveolar lavage fluid (BALF) specimens obtained at a national tuberculosis (TB) specialized hospital in Beijing, China.

METHODS

A retrospective study was conducted at Beijing Chest Hospital. Patients with symptoms suggestive of pulmonary TB who provided BALF specimens for routine MTB detection between June 2019 and July 2020 were enrolled in the study. Chi-square test and Student's t-test were used to compare results across groups stratified according to BALF bacterial load.

RESULTS

In total, 1125 patients with positive Xpert results who were enrolled in final analysis, 263 provided BALF specimens that tested positive for RIF-resistant MTB via Xpert MTB/RIF. The RIF-resistance rate of specimens with very low MTB bacterial load was 30.9%, a resistance rate significantly greater than rates obtained for groups with high (25.0%), medium (17.3%) and low (19.2%) MTB loads (P<0.01). Notably, false-positive results obtained for the very low bacterial load group led to markedly reduced positive predictive value of Xpert MTB/RIF to provide correct RIF-resistance predictions for that group (67.1%, 95% CI: 56.1%-78.1%5) relative to the predictive value obtained for all other groups combined (about 90%, P<0.05). Sanger sequencing data obtained for 20 (32.8%) MTB isolates deemed RIF-resistant via Xpert (Probe E) lacked rpoB RRDR mutations. Meanwhile, of another group of 23 isolates deemed RIF-susceptible via DST but RIF-resistant via Xpert MTB/RIF, 20 isolate sequences (87.0%) lacked rpoB RRDR mutations, while sequences of the remaining 3 isolates harbored single rpoB RRDR mutations predicted to cause amino acid substitutions.

CONCLUSION

Xpert MTB/RIF assay performed alarmingly poorly when used to detect RIF-resistant MTB in BALF specimens with very low bacterial loads. A high rate of Xpert probe E hybridization failure was the main driver of false-positive RIF-resistant results.

The Role of CX3CL1 and ADAM17 in Pathogenesis of Diffuse Parenchymal Lung Diseases

Fractalkine (CX3CL1) is a unique chemokine that functions as a chemoattractant for effector cytotoxic lymphocytes and macrophages expressing fractalkine receptor CX3CR1. CX3CL1 exists in two forms—a soluble and a membrane-bound form. The soluble CX3CL1 is released from cell membranes by proteolysis by the TNF-α-converting enzyme/disintegrin-like metalloproteinase 17 (TACE/ADAM17) and ADAM10. In this study, we evaluated the diagnostic relevance and potential roles of CX3CL1 and ADAM17 in the pathogenesis of diffuse parenchymal lung diseases (DPLDs) in the human population. The concentration of CX3CL1 and ADAM17 was measured by the enzyme-linked immunosorbent assay (ELISA) test in bronchoalveolar lavage fluids of patients suffering from different DPLDs. The concentration of CX3CL1 was significantly higher in patients suffering from idiopathic pulmonary fibrosis (IPF) and hypersensitivity pneumonitis patients compared to the control group. A significantly higher concentration of CX3CL1 was measured in fibrotic DPLDs compared to non-fibrotic DLPD patients. We found a positive correlation of CX3CL1 levels with the number of CD8+ T cells, and a negative correlation with CD4+ T cells in BALF and diffusion capacity for carbon monoxide. The concentration of ADAM17 was significantly lower in the IPF group compared to the other DPLD groups. We noticed a significantly higher CX3CL1/ADAM17 ratio in the IPF group compared to the other DPLD groups. We suggest that CX3CL1 has a distinctive role in the pathogenesis of DPLDs. The level of CX3CL1 strongly correlates with the severity of lung parenchyma impairment. The results suggest that high values of CX3CL1/ADAM17 could be diagnostic markers for IPF.

Protective effects of isorhynchophylline against silicon-dioxide-induced lung injury in mice

Inhalation of silicon dioxide (SD) results in pulmonary inflammatory responses and fibrosis. Isorhynchophylline (Isorhy) is the main alkaloid in the traditional Chinese herb Tripterygium wilfordii, which is reported to have anti-inflammatory activities in the nervous system. However, the effects of Isorhy on SD-induced pulmonary inflammation and fibrosis in mice are unknown. Male mice were exposed to a single dose of SD (2.5 mg/kg, intranasal inoculation) to induce pulmonary fibrosis (PF). The mice were woken up and immediately treated with Isorhy (20 mg/kg, intraperitoneal injection) for 14 or 42 days. The effects of Isorhy on inflammatory responses and lung fibrosis induced by SD were then investigated. After the 14-day treatment, there was a significant reduction in inflammatory cell infiltration in the lungs of mice, with reduced recruitment of inflammatory cells to the lungs. The concentration of pro-inflammatory factors in the bronchoalveolar lavage fluid was reduced, which alleviated inflammatory injury in the lung tissue. After the 42-day treatment, Isorhy alleviated inflammation and inhibited the release of fibrogenic factors in mice with PF. Isorhy also significantly reduced collagen deposition in the lung tissues of mice. Isorhy has the ability to reduce inflammatory responses and fibrosis associated with SD-induced acute lung injury.

Role of bronchoalveolar lavage fluid and serum interleukin-27 in the diagnosis of smear-negative pulmonary tuberculosis

BACKGROUND

To evaluate the value of interleukin (IL)-27 measured in serum and bronchoalveolar lavage fluid (BALF) for the diagnosis of smear-negative pulmonary tuberculosis (TB).

METHODS

This was a prospective study of patients planned to undergo bronchoscopy at Wuxi No.5 People's Hospital between January 2017 and September 2018. The patients were grouped as the TB and control groups. BALF and serum IL-27 were measured by ELISA. Receiver operating characteristic (ROC) curves were used to assess the diagnostic value and calculate the optimal cutoff values.

RESULTS

There were 40 patients in the control group and 87 in the TB group. In the TB group, 20 had positive sputum smear results and 67 were negative. The area under the ROC curve (AUC) of BALF IL-27 for pulmonary TB was 0.897 (95% CI: 0.830-0.944) (P < .001). The AUC of serum IL-27 for pulmonary TB was 0.703 (95% CI: 0.616-0.781) (P < .001). In patients with negative sputum smear results, the AUCs of BALF IL-27 and serum IL-27 for pulmonary TB was 0.882 (95% confidence interval [CI]: 0.805-0.936) (P < .001) and 0.679 (95% CI: 0.601-0.782) (P < .001), respectively.

CONCLUSIONS

BALF IL-27 can be used for the diagnosis of pulmonary TB, particularly in those with a negative sputum smear result. Serum IL-27 could be an auxiliary method for TB screening.

The Relationship Between Lower Respiratory Tract Microbiome and Allergic Respiratory Tract Diseases in Children

Similar to those in the upper respiratory tract, there are microbes present in the healthy human lower respiratory tract (LRT), including the lungs and bronchus. To evaluate the relationship between LRT microbiome and allergic respiratory diseases in children, we enrolled 68 children who underwent bronchoscopy from January 2018 to December 2018 in the affiliated hospital of the Capital Institute of Pediatrics. Using the total IgE (TIgE) values, children were divided into two groups: allergy sensitivity (AS) group and non-allergy sensitivity (NAS) group. Nucleic acid was extracted from samples of bronchoalveolar lavage fluid (BALF) from the two groups of children taken during bronchoscopy treatment and the 16S rDNA gene was sequenced and analyzed. The results showed that Haemophilus, Moraxella, Streptococcus, Prevotella, Neisseria, and Rothia were detected in all patients. There was a statistically significant difference in the composition and distribution of microbiota between the AS and NAS groups (p < 0.01). Analysis of the correlation of clinical indices and microbiome showed that TIgE was positively correlated with Bacteroidetes and negatively correlated with Streptococcus. Absolute lymphocyte count showed a relationship with Streptococcus, and the absolute neutrophil count or percentage of neutrophils showed a relationship with Cardiobacterium. The LRT microbiome functioned similarly to the intestinal microbiome. That is, the decrease in microbial diversity and the change in composition could lead to an increase in allergic symptoms. The microbiome of the LRT in children, especially that of Bacteriodetes and Streptococcus, showed a correlation with respiratory allergic diseases.

Inflammatory risk factors for hypertriglyceridemia in patients with severe influenza

Objective

Inflammation and viral infections can induce significant changes in lipid metabolism. Hypertriglyceridemia (HTG) often occurs secondary to obesity, which is an independent risk factor for influenza virus infection. However, the inflammatory risk factors contributing to HTG in patients with severe influenza have yet to be elucidated.

Materials and methods

Plasma and bronchoalveolar lavage fluid (BALF) samples were collected from 33 patients with severe influenza (n = 26 control patients with normal serum triglyceride levels and n = 7 HTG patients with serum triglycerides >2.3 mM). Levels of 45 putative inflammatory risk factors were quantitated using a commercial enzyme-linked immunosorbent assay kit.

Results

Plasma levels of interferon (IFN)-γ, interleukin (IL)-18, IL-1 receptor antagonist (IL-1RA), monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, hepatocyte growth factor, stem cell factor, and vascular endothelial growth factor A were significantly higher in HTG patients compared with control patients. BALF samples from HTG patients contained significantly higher levels of IL-1RA and lower levels of IFN-γ-inducible protein-10.

Conclusion

HTG in patients with severe influenza is associated with alterations in several inflammatory risk factors. Our results provide new insights that may enable more effective clinical management of severe influenza combined with HCT.

[Value of chitinase-like protein YKL-40 in bronchoalveolar lavage fluid for predicting refractory Mycoplasma pneumoniae pneumonia in children]

OBJECTIVE

To evaluate the value of chitinase-like protein YKL-40 in bronchoalveolar lavage fluid (BALF) for predicting refractory Mycoplasma pneumoniae pneumonia (RMPP) in children.

METHODS

A total of 50 children with common Mycoplasma pneumoniae pneumonia (MPP) and 22 children with RMPP were enrolled. The two groups were compared in terms of clinical features, laboratory examination results, imaging findings, and YKL-40 levels in BALF. The receiver operating characteristic (ROC) curve was used to evaluate the value of YKL-40 in BALF for predicting RMPP.

RESULTS

Compared with the common MPP group, the RMPP group had significantly higher incidence rates of fever, shortness of breath, lung consolidation, and pleural effusion (P < 0.05) and significantly higher serum levels of C-reactive protein and lactate dehydrogenase (P < 0.05). The RMPP group had a significantly higher level of YKL-40 in BALF than the common MPP group (P < 0.05). The ROC curve plotted based on the level of YKL-40 in BALF had an area under the ROC curve of 0.750, a sensitivity of 72.7% and a specificity of 64.0% for predicting RMPP.

CONCLUSIONS

There is an increase in the level of YKL-40 in BALF in children with RMPP, and the level of YKL-40 in BALF has a certain value for predicting RMPP.

Ruscogenin attenuates particulate matter-induced acute lung injury in mice via protecting pulmonary endothelial barrier and inhibiting TLR4 signaling pathway

The inhalation of particulate matter (PM) is closely related to respiratory damage, including acute lung injury (ALI), characterized by inflammatory fluid edema and disturbed alveolar-capillary permeability. Ruscogenin (RUS), the main active ingredient in the traditional Chinese medicine Ophiopogonis japonicus, has been found to exhibit anti-inflammatory activity and rescue LPS-induced ALI. In this study, we investigated whether and how RUS exerted therapeutic effects on PM-induced ALI. RUS (0.1, 0.3, 1 mg·kg-1·d-1) was orally administered to mice prior to or after intratracheal instillation of PM suspension (50 mg/kg). We showed that RUS administration either prior to or after PM challenge significantly attenuated PM-induced pathological injury, lung edema, vascular leakage and VE-cadherin expression in lung tissue. RUS administration significantly decreased the levels of cytokines IL-6 and IL-1β, as well as the levels of NO and MPO in both bronchoalveolar lavage fluid (BALF) and serum. RUS administration dose-dependently suppressed the phosphorylation of NF-κB p65 and the expression of TLR4 and MyD88 in lung tissue. Furthermore, TLR4 knockout partly diminished PM-induced lung injury, and abolished the protective effects of RUS in PM-instilled mice. In conclusion, RUS effectively alleviates PM-induced ALI probably by inhibition of vascular leakage and TLR4/MyD88 signaling. TLR4 might be crucial for PM to initiate pulmonary lesion and for RUS to exert efficacy against PM-induced lung injury.

Co-infection of Pneumocystis jirovecii pneumonia and pulmonary CMV in a infant with X-linked severe combined immunodeficiency

We herein report a rare case of co-infection of Pneumocystis jirovecii pneumonia and pulmonary CMV in a 3-month-old infant with X-linked severe combined immunodeficiency, in which diagnostic clues were obtained from the bronchoalveolar lavage fluid. We focus on the value of cytological diagnosis of P. jirovecii pneumonia and pulmonary CMV in the bronchoalveolar lavage fluid. Recognizing morphological characteristics of these pathogenic microorganisms is important to get timely diagnosis and treatment for the patients. Furthermore, repeated severe infections in infants should remind us to screen for immunosuppressed states.

Investigating Cellular Trajectories in the Severity of COVID-19 and Their Transcriptional Programs Using Machine Learning Approaches

Single-cell RNA sequencing of the bronchoalveolar lavage fluid (BALF) samples from COVID-19 patients has enabled us to examine gene expression changes of human tissue in response to the SARS-CoV-2 virus infection. However, the underlying mechanisms of COVID-19 pathogenesis at single-cell resolution, its transcriptional drivers, and dynamics require further investigation. In this study, we applied machine learning algorithms to infer the trajectories of cellular changes and identify their transcriptional programs. Our study generated cellular trajectories that show the COVID-19 pathogenesis of healthy-to-moderate and healthy-to-severe on macrophages and T cells, and we observed more diverse trajectories in macrophages compared to T cells. Furthermore, our deep-learning algorithm DrivAER identified several pathways (e.g., xenobiotic pathway and complement pathway) and transcription factors (e.g., MITF and GATA3) that could be potential drivers of the transcriptomic changes for COVID-19 pathogenesis and the markers of the COVID-19 severity. Moreover, macrophages-related functions corresponded more to the disease severity compared to T cells-related functions. Our findings more proficiently dissected the transcriptomic changes leading to the severity of a COVID-19 infection.

Interstitial Score and Concentrations of IL-4Rα, PAR-2, and MMP-7 in Bronchoalveolar Lavage Fluid Could Be Useful Markers for Distinguishing Idiopathic Interstitial Pneumonias

Idiopathic interstitial pneumonia (IIP) entails a variable group of lung diseases of unknown etiology. Idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, interstitial lung diseases related to connective tissue disease (CTD-ILD), and hypersensitivity pneumonitis (HP) can manifest with similar clinical, radiological, and histopathological features. In a differential diagnosis, biomarkers can play a significant role. We assume that levels of specific cyto- or chemokines or their receptors can signal pathogenetic processes in the lungs. Eighty patients with different types of idiopathic interstitial pneumonia were enrolled in this study. Cell counts and concentrations of tumor necrosis factor (TNF)-α, interleukin-4 receptor α, proteinase-activated receptor (PAR)-2, matrix metalloproteinase (MMP)-7, and B cell-activating factor were measured in bronchoalveolar lavage fluid using commercial ELISA kits. High resolution computer tomography results were evaluated using alveolar and interstitial (IS) score scales. Levels of TNF-α were significantly higher in HP compared to fibrosing IIP (p < 0.0001) and CTD-ILD (p = 0.0381). Concentrations of IL-4Rα, PAR-2, and MMP-7 were positively correlated with IS (p = 0.0009; p = 0.0256; p = 0.0015, respectively). Since TNF-α plays a major role in inflammation, our results suggest that HP is predominantly an inflammatory disease. From the positive correlation with IS we believe that IL-4Rα, PAR-2, and MMP-7 could serve as fibroproliferative biomarkers in differential diagnosis of IIP.

Case Report: Next-Generation Sequencing in Diagnosis of Pneumonia Due to Pneumocystis jirovecii and Cytomegalovirus in a Patient With HIV Infection

Background: Pulmonary infections remain a significant cause of morbidity and mortality in immunocompromised patients. The pathogens spectrum of pulmonary infection that can affect patients with human immunodeficiency virus (HIV) is wide such as bacterial, fungal, viral, parasitic organisms, and so on. The risk of multi-pathogenic pneumonia is higher in HIV-infected patients. However, the fast and accurate diagnosis of multi-pathogenic pneumonia is challenging because of the limitations of current conventional tests. Case Presentation: Here, we report a case of pneumonia due to Pneumocystis jirovecii and cytomegalovirus (CMV) in a 22-year-old male with newly diagnosed HIV infection. Blood tests revealed a low CD4 count, a chest computed tomography (CT) scan showed extensive ground-glass opacities in the bilateral lung with multiple cavity lesions in the left upper lung. Microscopic examination of stained sputum and bronchoalveolar lavage fluid (BALF) smear specimens did not find any pathogens. There was also no evidence of pathogens known to cause pneumonia in bacteria and fungi culture tests and virus antibodies such as EBV, CMV, and COVID-19. The nucleic acid of CMV in blood was reported by quantitative PCR. Next-generation sequencing (NGS) analysis of BALF specimens identified a large number of P. jirovecii and CMV reads, and confirmed the diagnosis of pneumonia due to P. jirovecii and CMV. Following the patient's treatment with anti-PCP and anti-CMV, the patient was cured and discharged. Conclusions: This case highlights the combined application of NGS in the clinical diagnosis of multi-pathogenic pneumonia in an HIV-infected patient. NGS is proposed as an important adjunctive diagnostic approach for identifying pathogens of multi-pathogenic pneumonia in HIV-infected patients.

Value of Xpert MTB/RIF Using Bronchoalveolar Lavage Fluid for the Diagnosis of Pulmonary Tuberculosis: a Systematic Review and Meta-analysis

The performance of Xpert MTB/RIF using bronchoalveolar lavage fluid (BAL) for the diagnosis of pulmonary tuberculosis (PTB) remains unclear. Therefore, a systematic review/meta-analysis was conducted. Studies published before 31 December 2019 were retrieved from the PubMed, Embase, and Web of Science databases using the keywords "pulmonary tuberculosis," "Xpert MTB/RIF," and "BAL." Two independent evaluators extracted the data and assessed the bias risk of the included studies. A random-effects model was used to calculate the overall sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR, respectively), diagnostic odds ratio (DOR), and the area under the curve (AUC), as well as the respective 95% confidence intervals (CIs). Nineteen trials involving 3,019 participants met the inclusion criteria. Compared to the culture method, the pooled sensitivity, specificity, PLR, NLR, DOR, and the AUC with 95% CIs of Xpert MTB/RIF were 0.87 (0.84 to 0.90), 0.92 (0.91 to 0.93), 10.21 (5.78 to 18.02), 0.16 (0.12 to 0.22), 78.95 (38.59 to 161.53), and 0.9467 (0.9462 to 0.9472), respectively. Relative to the composite reference standard, the observed values were 0.69 (0.65 to 0.72), 0.98 (0.98 to 0.99), 37.50 (18.59 to 75.62), 0.30 (0.21 to 0.43), 171.98 (80.82 to 365.96), and 0.9691 (0.9683 to 0.9699), respectively. All subgroups, except children, showed high sensitivity and specificity. In conclusion, the use of Xpert MTB/RIF in the context of BAL samples has a high diagnostic performance for PTB (except for children) and may serve as an alternative rapid diagnostic tool.

Waterproofing spray-associated pneumonitis review: Comparison with acute eosinophilic pneumonia and hypersensitivity pneumonitis

Waterproofing spray-associated pneumonitis (WAP) proceeds to acute respiratory failure and is characterized by diffuse bilateral ground-glass opacities on computed tomography; however, the detailed characteristics of WAP are unknown. Therefore, this study identified the characteristics of WAP from comparisons with those of acute eosinophilic pneumonia (AEP) and hypersensitivity pneumonitis (HP), which show similar features to WAP.Adult patients with WAP, AEP, and HP treated in Fukujuji Hospital from 1990 to 2018 were retrospectively enrolled. Furthermore, data from patients with WAP were collected from publications in PubMed and the Japan Medical Abstracts Society and combined with data from our patients.Thirty-three patients with WAP, eleven patients with AEP, and thirty patients with HP were reviewed. Regarding age, sex, smoking habit, and laboratory findings (white blood cell count, C-reactive protein level, and serum Krebs von den Lungen-6 level), WAP and AEP were not significantly different, while WAP and HP were significantly different. The duration from symptom appearance to hospital visit was shorter in patients with WAP (median 1 day) than in patients with AEP (median 3 days, P = .006) or HP (median 30 days, P < .001). The dominant cells in the bronchoalveolar lavage fluid of patients with WAP, AEP, and HP were different (macrophages, eosinophils, and lymphocytes, respectively).The characteristic features of WAP were rapid disease progression and macrophage dominance in the bronchoalveolar lavage fluid, and these characteristics can be used to distinguish among WAP, AEP, and HP.

Circulating Rather Than Alveolar Extracellular Deoxyribonucleic Acid Levels Predict Outcomes in Influenza

BACKGROUND

High levels of circulating neutrophil extracellular traps (NETs) are associated with a poor prognosis in influenza A infection. It remains unclear whether NETs in the plasma or bronchoalveolar lavage fluid (BALF) can predict clinical outcomes in influenza.

METHODS

One hundred eighteen patients who were diagnosed with H1N1 influenza in 2017-2018 were recruited. The NETs were assessed in plasma and BALF samples by quantifying cell-free deoxyribonucleic acid (cfDNA) and protein-DNA complexes. Predictions of severe illness and 60-day mortality were analyzed with receiver operating characteristic curves.

RESULTS

The NET levels were significantly elevated in the BALF and contributed to the pathology of lungs, yet it was not associated with disease severity or mortality in patients severely infected with H1N1. Plasma NET levels were significantly increased in the patients with severe influenza and positively correlated with the oxygen index and sequential organ failure assessment scores. High levels of plasma cfDNA (>286.6 ng/mL) or histone-bound DNA (>9.4 ng/mL) discriminated severe influenza from mild, and even higher levels of cfDNA (>306.3 ng/mL) or histone-bound DNA (>23.1 ng/mL) predicted fatal outcomes in severely ill patients.

CONCLUSIONS

The cfDNA and histone-bound DNA in plasma represent early predictive biomarkers for the prognosis of influenza.

Dexamethasone and losartan combination treatment protected cigarette smoke-induced COPD in rats

Chronic Obstructive Pulmonary Disease (COPD) is a dangerous prevalent smoking-related disease characterized by abnormal inflammation and oxidative stress and expected to be the third cause of death in the world next decade. Corticosteroids have low effects in decreasing numbers of inflammatory mediators specifically in long-term use. Our study designed to investigate the possible protective effects of combined dexamethasone (Dex) (2mg/kg) and losartan (Los) (30mg/kg angiotensin receptor blocker, it possesses antioxidant and anti-inflammatory properties in lung injury in mice) against cigarette -smoke (CS) induced COPD in rats compared with dexamethasone and losartan. Male Sprague Dawley rats (N = 40) divided into five groups (n = 8): control group, CS group, Dex group, Los group, and Dex +Los group. COPD induced in rats by CS exposure twice daily for 10 weeks. After the specified treatment period, bronchoalveolar lavage fluid (BALF) and lung tissue were collected for measurement of SOD, NO, MDA, ICAM-, MMP-9, CRP, NF-κB and histopathology scoring. Our results indicated that Los+Dex significantly prevent CS-induced COPD emphysema, congested alveoli, and elevation of lung injury parameters in BALF. They also showed a significant decrease in MDA, ICAM-1, MMP-9, CRP, and NF-κB and a significant increase in SOD and NO. In conclusion, adding Los to Dex potentiating their activity in inhibition the progression of COPD based on its activity on oxidative stress, inflammation, and NF-κB protein expression.

Airway Microbiology in Tracheostomized Children

BACKGROUND

Potentially pathogenic microorganisms are frequently isolated from tracheostomized children, although evidence for empirical therapy of respiratory exacerbation is limited. We aimed to describe upper airway microbiology as found on endotracheal aspirate (ETA) in tracheostomized children and to correlate it with lower airway microbiology through bronchoalveolar lavage fluid.

METHODS

We retrospectively reviewed records and airway microbiology of all tracheostomized children under the follow-up care of Queensland Children's Hospital. Subanalysis was based on ventilatory and multidrug-resistant organism status. Sensitivity and specificity of ETA for predicting Pseudomonas aeruginosa and Staphylococcus aureus lower airway isolation were calculated using concomitant bronchoalveolar lavage fluid culture as the accepted standard.

RESULTS

From 43 children (18 female, median [interquartile range (IQR)] age 68 (41-115) months, 14 ventilated), 15 different potentially pathogenic microorganisms were isolated (mean ± SD: 3.30 ± 2.23), with S. aureus (n = 33, 77%) and P. aeruginosa (n = 29, 67%) predominating. Significantly more types of potentially pathogenic microorganisms were isolated from ventilated children (median 4.00 [IQR 3.25-5.75]) than from nonventilated children (median 2.00 [IQR 1.00-4.00] (P = .007), with 93% of ventilated children isolating S. aureus and 86% P. aeruginosa. Multidrug-resistant organisms were present in 12 (28%) children, of whom 8 were ventilated. Methicillin-resistant S. aureus (MRSA) was isolated in 9 (21%) children, of whom 6 were ventilated. For P. aeruginosa and S. aureus isolation, ETA had high sensitivity (95% and 100%, respectively) but low specificity (64.7% and 33.3%, respectively) when compared with bronchoalveolar lavage fluid.

CONCLUSIONS

In children with tracheostomy, the predominant respiratory bacterial pathogens were S. aureus and P. aeruginosa, with MRSA being isolated less frequently than previously described. Multidrug-resistant organisms are isolated more frequently from ventilated children. ETA microbiology is a good screening modality, with negative ETA potentially ruling out lower airway S. aureus and P. aeruginosa. Adequately powered prospective studies with quantitative cultures could enhance understanding and guide therapy.

Rapid Diagnosis of IPA Relied on Calcofluor White Fluorescence Staining: Two Cases Report

Invasive pulmonary aspergillosis (IPA) is a serious infectious disease with high mortality. However, the rapid diagnosis of IPA remains difficult since the microbiological evidence is difficult to obtain or time-consuming. Thus, we attempted to rapidly diagnose two pediatric cases with respiratory failure due to IPA via bronchoalveolar lavage fluid with Calcofluor White fluorescence staining, which has rarely been used before.