Multicentre double-blind randomised controlled trial of systematic corticosteroid therapy in patients with acute exacerbations of chronic obstructive pulmonary disease admitted to hospital with higher eosinophil levels: the ECHO protocol.

INTRODUCTION: Corticosteroid is one of the most commonly used medications in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). The increasing understanding of these side-effects of systematic corticosteroids and their better response to treatment among patients with COPD with higher blood eosinophil counts has led to an interest in a more targeted approach to systematic corticosteroid treatment. However, there is a lack of evidence from high-quality randomised controlled trial (RCT) studies about whether initial systematic corticosteroids should be given to patients with AECOPD with elevated eosinophilia. The aim of the present research was to test this hypothesis. METHODS AND ANALYSIS: This is a multicentre, double-blind, superiority RCT in the respiratory departments of 12 general hospitals in China. It is anticipated that 456 patients with AECOPD with a blood eosinophil count >2% or >300 cells/µL at admission will be recruited. Eligible patients will be randomised (1:1) to the intervention group receiving 40 mg oral prednisone daily or identical-appearing placebo (control group) for five consecutive days. Follow-up visits are performed during hospitalisation, followed by clinic interviews on days 30, 60 and 90 after discharge. The primary outcome is treatment failure rates comprising requiring or receiving invasive or non-invasive mechanical ventilation, requiring or transferring to intensive care unit during the index hospitalisation, length of index hospitalisation longer than 14 days, death during the index hospitalisation or within 30 days after discharge and readmission with acute exacerbations of COPD within 30 days after discharge. The results of this trial will provide insight into the value of using blood eosinophil counts as a biomarker of eosinophilic exacerbation and initiating systematic corticosteroid treatment for patients with AECOPD with higher eosinophil levels. ETHICS AND DISSEMINATION: This study was approved by Beijing Chaoyang Hospital Institutional Review Board (approval number: 2020-KE-544) and the main results and secondary results will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05059873.

Metabolomic Profiling of Lungs from Mice Reveals the Variability of Metabolites in Pneumocystis Infection and the Metabolic Abnormalities in BAFF-R-Deficient Mice.

Purpose: The incidence of Pneumocystis pneumonia (PCP) in patients without human immunodeficiency virus (HIV) has been increasing. In this study, we aimed to investigate the metabolic changes in Pneumocystis infection and the metabolic abnormalities in B-cell-activating factor receptor (BAFF-R)-deficient mice with Pneumocystis infection. Methods: The important function of B cells during Pneumocystis infection is increasingly recognized. In this study, a Pneumocystis-infected mouse model was constructed in BAFF-R-/- mice and wild-type (WT) mice. Lungs of uninfected WT C57BL/6, WT Pneumocystis-infected, and BAFF-R-/- Pneumocystis-infected mice were used for metabolomic analyses to compare the metabolomic profiles among the groups, with the aim of exploring the metabolic influence of Pneumocystis infection and the influence of mature B-cell deficiency during infection. Results: The results indicated that many metabolites, mainly lipids and lipid-like molecules, were dysregulated in Pneumocystis-infected WT mice compared with uninfected WT C57BL/6 mice. The data also demonstrated significant changes in tryptophan metabolism, and the expression levels of key enzymes of tryptophan metabolism, such as indoleamine 2,3-dioxygenase 1 (IDO1), were significantly upregulated. In addition, B-cell development and function might be associated with lipid metabolism. We found a lower level of alitretinoin and the abnormalities of fatty acid metabolism in BAFF-R-/- Pneumocystis-infected mice. The mRNA levels of enzymes associated with fatty acid metabolism in the lung were upregulated in BAFF-R-/- Pneumocystis-infected mice and positively correlated with the level of IL17A, thus suggesting that the abnormalities of fatty acid metabolism may be associated with greater inflammatory cell infiltration in the lung tissue of BAFF-R-/- Pneumocystis-infected mice compared with the WT Pneumocystis-infected mice. Conclusion: Our data revealed the variability of metabolites in Pneumocystis-infected mice, suggesting that the metabolism plays a vital role in the immune response to Pneumocystis infection.

Secular trend and risk factors of 30-day COPD-related readmission in Beijing, China.

Readmission due to chronic obstructive pulmonary disease (COPD) exacerbation contributes significantly to disease burden. Trend in readmission rate among COPD patients in China is not well characterized. We described the secular trend and identify risk factors of COPD-related 30-day readmission in Beijing during 2012-2017. In this retrospective cohort study, we used data from a citywide hospital discharge database in Beijing. We included patients ≥ 40 years with a primary diagnosis of COPD from 2012 to 2017. A total of 131 591 index admissions were identified. COPD-related 30-day readmission was defined as the initial admission with a primary diagnosis of COPD that occurs within 30 days from the discharge date of an index admission. Overall and annual 30-day readmission rates were calculated in the total population and subgroups defined by patient characteristics. We used multivariable logistic models to investigate risk factors for readmission and in-hospital mortality within 30 days. The overall 30-day COPD-related readmission rate was 15.8% (n = 20 808). The readmission rate increased from 11.5% in 2012 to 17.2% in 2017, with a multivariable-adjusted OR (95% CI) for annual change to be 1.08 (1.06-1.09) (P trend < 0.001). The upward trend in readmission rate levelled off at about 17% since 2014. The readmission rate of men was higher and increased faster than women. Comorbid osteoporosis, coronary heart disease, congestive heart failure, and cancer were associated with an increased risk of 30-day COPD-related readmission. The 30-day COPD-related readmission rate in Beijing showed an overall increasing trend from 2012 to 2017. Future efforts should be made to further improve care quality and reduce early readmissions of COPD patients.

Analysis of lncRNA and mRNA Repertoires in Lung From BAFF-R-Deficient Pneumocystis-Infected Mice.

Background: Pneumocystis pneumonia (PCP) is a common medical issue in immunosuppressive patients. Increasing evidence supports that B cells may play an essential role in PCP individuals. The present study aims to integrate lncRNA and mRNA expression profiles and further investigate the molecular function of mature B cells in PCP. Methods: The lung tissue of wild-type (WT) mice and B-cell-activating factor receptor-deficient (mature B-cell deficiency, BAFF-R-/-) mice were harvested at 3 weeks after being infected with pneumocystis. After total RNAs were extracted, transcriptome profiling was performed following the Illumina HiSeq 3000 protocol. lncRNA-targeted miRNA pairs were predicted using the online databases. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment pathways were analyzed to functionally annotate these differentially expressed genes. Additionally, the immune-related lncRNA-miRNA-mRNA-ceRNA network was subsequently performed. The quantitative real-time PCR (RT-PCR) analysis was conducted to evaluate the lncRNA and mRNA expression profiles in WT-PCP mice and BAFF-R-/- PCP mice. Results: Compared with the control group, 166 mRNAs were observed to be aberrantly expressed (fold change value ≥2; P <0.05) in the BAFF-R-/- PCP group, including 39 upregulated and 127 downregulated genes, while there were 69 lncRNAs differently expressed in the BAFF-R-/- PCP group, including 15 upregulated and 54 downregulated genes. In addition, GO and KEGG pathway analyses showed that BAFF-R deficiency played an important role in the primary and adaptive immune responses in PCP. Furthermore, the lncRNA and mRNA co-expression network was established. We noted that the core network of lncRNA-TF (transcription factor) pairs could be classified into the categories including infection and immunity pathways. Conclusion: In summary, in this study, we further explored the role of mature B cells in the pathogenesis and progression of PCP and the data demonstrated that BAFF-R deficiency could play a significant role in immune regulation in the PCP population.

Value of CT Radiomics Combined with Clinical Features in the Diagnosis of Allergic Bronchopulmonary Aspergillosis.

Objective: Early diagnosis of allergic bronchopulmonary aspergillosis (ABPA) and targeted treatment can block the process of the disease. This study explores the diagnostic value of CT radiomics combined with clinical features in allergic ABPA. Methods: A total of 40 patients with ABPA were studied retrospectively, divided into training set (n = 28) and test set (n = 12). Based on CT imaging, the radiomics features are extracted and combined with clinical features to build a diagnostic model. The diagnosis model was based on support vector machine algorithm. The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to evaluate the diagnostic efficiency of the model. Results: There was no significant difference in general information and clinical data between the training and test sets (P > 0.05). The AUC of the training set and the test set is 0.896 (95% CI: 0.836-0.963) and 0.886 (95% CI: 0.821-0.952), respectively. Conclusion: Based on the CT radiomics model combined with clinical data, it has high efficiency in the diagnosis of ABPA.

Proteomic Profiling and Functional Analysis of B Cell-Derived Exosomes upon Pneumocystis Infection.

Pneumocystis is a life-threatening fungal pathogen that frequently causes fatal pneumonia (PCP) in immunocompromised individuals. Recently, B cells have been reported to play a crucial role in the pathogenesis of PCP through producing antibodies and activating CD4+ T cell response. Exosomes are nanoscale small extracellular vesicles abundant with protein cargo and can mediate immune response during infectious disease. In this study, using tandem mass tag-based quantitative proteomics coupled with bioinformatic analysis, we attempted to characterize exosomes derived from B lymphocytes in response to PCP. Several proteins were verified by parallel reaction monitoring (PRM) analysis. Also, the effects of B cell exosomes on CD4+ T cell response and phagocytic function of macrophages were clarified. Briefly, 1701 proteins were identified from B cell exosomes, and the majority of them were reported in Vesiclepedia. A total of 51 differentially expressed proteins of B cell exosomes were found in response to PCP. They were mainly associated with immune response and transcription regulation. PRM analysis confirmed the significantly changed levels of histone H1.3, vimentin, and tyrosine-protein phosphatase nonreceptor type 6 (PTPN6). Moreover, a functional study revealed the proinflammatory profile of B cell exosomes on CD4+ T cell response in PCP. Taken together, our results suggest the involvement of exosomes derived from B cells in cell-to-cell communication, providing new information on the function of B cells in response to PCP.

Long-Term Trends in Hospitalization and Outcomes in Adult Patients with Exacerbation of Chronic Obstructive Pulmonary Disease in Beijing, China, from 2008 to 2017.

Background and Objective: Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. We aimed to evaluate the temporal trends in hospitalization and mortality from acute exacerbation of COPD (AECOPD) and the associated financial costs over a 10-year period in Beijing, China. Methods: Hospital admission records from 2008 to 2017 for all patients aged ≥20 years with a primary discharge diagnosis of AECOPD were retrieved from the Beijing Public Health Information Center Database. Joinpoint regression was used to analyze trends and calculate the annual percentage change (APC) and average annual percent change (AAPC) for AECOPD hospitalization and mortality. Results: A total of 337,802 AECOPD cases were recorded from 2008 to 2017. An inverse U-shaped trend in the AECOPD hospitalization rate was observed, showing an increase from 150.2 per 100,000 inhabitants in 2008 to 218.7 per 100,000 inhabitants in 2014 (APC: 5.5%, 95% CI: 2.9-8.2), before declining to 161.13 per 100,000 inhabitants in 2017 (APC: -9.7%, 95% CI: -16.0 to-2.9). In-hospital mortality from AECOPD decreased significantly from 3.91% to 2.21% (AAPC: -11.4%, 95% CI: -15.5 to-7.0). A decline in the median length of hospital stay from 13.0 days in 2008 to 12.0 days in 2017 (Ptrend < 0.001) was accompanied by a decrease in the use of mechanical ventilation from 2012 to 2017 (Ptrend < 0.001). However, the total hospitalization cost per case increased from 15953.5 yuan (USD $2281.4) to 19874.5 yuan ($2842.1) during the same period. Conclusion: AECOPD remains a heavy burden on the health care system in Beijing. Strategies to better manage COPD and reduce hospitalizations from AECOPD are needed.

PD-1 Deficiency Promotes Macrophage Activation and T-Helper Cell Type 1/T-Helper Cell Type 17 Response in Pneumocystis Pneumonia.

Pneumocystis is an unusual, opportunistic fungal pathogen capable of causing Pneumocystis pneumonia (PCP) in immunocompromised hosts. Although PCP was discovered >100 years ago, its pathogenesis remains unclear. The inhibitory receptor PD-1 (programmed death 1), a negative regulator of activated T cells, has been reported to take part in tumor escape, immune tolerance, and infection immunity. In this study, we examined the role of the PD-1/PD-L1 (programmed death-ligand 1) pathway in patients with PCP and in mice. The expression levels of PD-1/PD-L1 in patients with PCP and in mice were measured by real-time PCR and flow cytometry. The effects of PD-1 deficiency are demonstrated using wild-type and PD-1-/- mice. Our data show that Pneumocystis infection promotes PD-1/PD-L1 expression; PD-1 deficiency enhances the phagocytic function of macrophages and the pulmonary T-helper cell type 1 (Th1)/Th17 response, which might contribute to Pneumocystis clearance; and PD-1 deficiency affects the polarization of macrophages. PCP mice treated with anti-PD-1 antibody showed improved pulmonary clearance of Pneumocystis. Collectively, our results demonstrate that the PD-1/PD-L1 pathway plays a role in regulating the innate and adaptive immune responses, suggesting that manipulation of this pathway may constitute an immunotherapeutic strategy for PCP.

IL-17 Inversely Correlated with IL-10 via the STAT3 Gene in Pneumocystis-Infected Mice.

BACKGROUND: Pneumocystis pneumonia (PCP) remains a common opportunistic infection in immunosuppressed individuals. Current studies showed that multiple immune cells and cytokines took part in the host defense against Pneumocystis (PC). However, the roles of IL-17 and IL-10 in the development of PCP have not been elucidated. METHODS: IL-10 and IL-17 levels in serum from PCP mice were detected via ELISA. The percentages of B10 cells, IL-10+ macrophages, and IL-10+ T cells in the lung from IL-17-/- PCP mice and Th17 cells and IL-17+ γδT cells in IL-10-/- PCP mice were examined via flow cytometry. Also, antibody neutralization examination was also performed to elucidate the relationship of IL-17 and IL-10 in the PCP model. RESULTS: We noted the increase of IL-17 and IL-10 levels in serum from mice infected with Pneumocystis. Furthermore, deficiency of IL-17 or IL-10 could lead to the delayed clearance of Pneumocystis and more severed lung damage. Our data also demonstrated that IL-17 deficiency enhanced the serum IL-10 level and the percentages of B10 cells, IL-10+ macrophages, and IL-10+ T cells in the lung from PCP mice. Interestingly, we also noted an increase of the IL-17 level in serum and Th17 cell and IL-17+ γδT cell percentages in the lung from IL-10-/- PCP mice. Using antibody neutralization experiments, we found that the STAT3 gene might play a critical role in the interplay of IL-17 and IL-10 in PCP. CONCLUSION: Taken together, our results demonstrated that IL-17 and IL-10 could play the protective roles in the progression of PCP and the inverse correlation of them might be mediated by STAT3.

IL-10-producing B cells regulate Th1/Th17-cell immune responses in Pneumocystis pneumonia.

Pneumocystis pneumonia (PCP) is a common opportunistic infectious disease that is prevalent in immunosuppressed hosts. Accumulating evidence shows that B cells play an important role in infectious diseases. In the present study, the immune regulatory role of mature B cells in host defense to Pneumocystis was evaluated. Pneumocystis infection resulted in a decrease in B cells in patients and mice, and the Pneumocystis burden in B cell-deficient mice also progressively increased from weeks 1 to 7 after infection. The clearance of Pneumocystis was delayed in B cell-activating factor receptor (BAFF-R)-deficient mice (BAFF-R-/- mice), which had few B cells and Pneumocystis-specific IgG and IgM antibodies, compared with clearance in wild-type (WT) mice. There were fewer effector CD4+ T cells and higher percentages of T helper (Th)1/Th17 cells in BAFF-R-/- mice than in WT mice. Adoptive transfer of naive B cells, mRNA sequencing, and IL-1ß neutralization experiments indicated that IL-1ß is a likely determinant of the IL-10-producing B cell-mediated suppression of Th1/Th17-cell immune responses in BAFF-R-/- PCP mice. Our data indicated that B cells play a vital role in the regulation of Th cells in response to Pneumocystis infection.

IL-9 Deficiency Promotes Pulmonary Th17 Response in Murine Model of Pneumocystis Infection.

Introduction: Pneumocystis pneumonia (PCP) remains a severe complication with high mortality in immunocompromised patients. It has been well accepted that CD4+ T cells play a major role in controlling Pneumocystis infection. Th9 cells were the main source of IL-9 with multifaced roles depending on specific diseases. It is unclear whether IL-9/Th9 contributes to the immune response against PCP. The current study aims to explore the role of IL-9 and the effect of IL-9 on Th17 cells in murine model of PCP. Materials and methods: Mice were intratracheally injected with 1 × 106Pneumocystis organisms to establish the murine model of Pneumocystis infection. Pneumocystis burden was detected by TaqMan real-time PCR. Using IL-9-deficient (IL-9-/-) mice, flow cytometry, real-time PCR and enzyme-linked immunosorbent assay (ELISA) were conducted to investigate the immune function related to Th17 response in defense against Pneumocystis infection. Results: Reduced Pneumocystis burden was observed in lungs in IL-9-/- mice compared with WT mice at 3-week postinfection. IL-9-/-mice exhibited stronger Th17 immune responses than WT PCP mice through flow cytometer and real-time PCR. ELISA revealed higher levels of IL-17 and IL-23 in bronchoalveolar lavage fluid from IL-9-/- mice than WT mice. And IL-9 deficiency promoted Th17 differentiation from CD4+ naive T cells. IL-17A neutralization increased Pneumocystis burden in IL-9-/- mice. Conclusion: Although similar basic clearance of Pneumocystis organisms was achieved in both WT and IL-9-/- PCP mice, IL-9 deficiency could lower Pneumocystis organism burden and promote pulmonary Th17 cells response in the early stage of infection.

Diagnosis of Pneumocystis jirovecii pneumonia with serum cell-free DNA in non-HIV-infected immunocompromised patients.

Conventional respiratory tract specimens, such as bronchoalveolar lavage (BAL) fluid and induced sputum for diagnosing Pneumocystis jirovecii pneumonia (PCP) in immunocompromised patients are difficult to obtain. Besides, bronchoscopy is an invasive procedure that carries the risk of causing rapidly progressive respiratory insufficiency. By contrast, serum cell-free DNA (cfDNA) is easy to obtain and has been proven useful in diagnosing cancer, pregnancy associated complications, parasite infection and sepsis. In this study, we performed quantitative polymerase chain reaction (qPCR) to assess the diagnostic efficiency of using serum cfDNA, BAL fluid, and sputum DNA for PCP. Seventy-one patients (35 PCP patients and 36 non-PCP patients) were enrolled according to the clinical PCP diagnostic criteria. The sensitivity, specificity, positive predictive value, and negative predictive value of PCR using serum cfDNA were 68.6% (95% CI, 50.7-83.1), 97.2% (95% CI, 85.5-99.9), 96.0%, and 76.1%, respectively. PCR using BAL fluid and sputum had a high sensitivity (97.1% and 91.4%, respectively) but relatively low specificity (86.1% and 86.1%, respectively). The combination of the sputum PCR OR serum cfDNA PCR yielded a sensitivity of 97.1%.These results indicated that serum cfDNA might be a valuable method in PCP diagnosis.

Serum procalcitonin levels distinguish Gram-negative bacterial sepsis from Gram-positive bacterial and fungal sepsis.

BACKGROUND: Serum procalcitonin (PCT) levels differ in patients with bacterial or fungal infections and are significantly elevated in patients with Gram-negative bacteremia. We evaluated the diagnostic accuracy of different inflammatory markers to discriminate sepsis caused by different pathogens. MATERIALS AND METHODS: We included 328 episodes of bacteremia from 292 patients with sepsis and 31 patients with suspected sepsis in this study. Medical records of patients who had bacteremia caused by Gram-negative bacteria (Gram-negative), Gram-positive bacteria (Gram-positive) or fungi were reviewed, and information about PCT and other inflammatory markers was recorded. The diagnostic performance of inflammatory markers was calculated via receiver operating characteristic (ROC) curves. RESULTS: Serum PCT levels in Gram-negative, Gram-positive, and fungal sepsis were 7.47 (interquartile range [IQR]: 1.09-41.26) ng/mL, 0.48 (IQR: 0.15-2.16) ng/mL, and 0.60 (IQR: 0.14-2.06) ng/mL, respectively (P < 0.001). ROC analysis revealed an optimal cut-off value of 2.44 ng/mL for PCT in discriminating Gram-negative sepsis from Gram-positive sepsis, which yielded a sensitivity of 68.4% and a specificity of 77.1%. An optimal cut-off value of 3.11 ng/mL for PCT in discriminating Gram-negative sepsis from fungal sepsis, led to a sensitivity of 63.9% and specificity of 93.3%. Neither PCT nor other inflammatory markers could be used to distinguish between Gram-positive and fungal sepsis. CONCLUSION: Serum PCT levels were significantly higher in patients with Gram-negative sepsis than in those with Gram-positive or fungal sepsis. PCT is a potential sensitive biomarker for distinguishing Gram-negative sepsis from Gram-positive and fungal sepsis.