Investigating the role of pentraxin 3 as a biomarker for bacterial infection in subjects with COPD

The Diagnostic and Assessment Value of Plasma Pentraxin 3 in Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background

Pentraxin 3 (PTX3) is an acute-phase protein and an important inflammatory mediator. We hypothesized plasma PTX3 could be a valuable diagnostic biomarker in acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

In this prospective controlled study, 458 COPD patients and 71 healthy controls from May 2019 to December 2020 in two hospitals were enrolled. COPD patients were divided into AECOPD group (n = 173) and stable COPD group (n = 285). AECOPD patients were subdivided into mild or moderate group (n = 43) and severe group (n = 130) based on severity. Plasma PTX3 levels were detected by ELISA.

Results

Plasma PTX3 levels were significantly higher in AECOPD (2.8 ng/mL) compared to stable COPD (0.87 ng/mL) and healthy controls (0.83 ng/mL). In the analysis of AECOPD subgroups, plasma PTX3 level of severe group (4.51 ng/mL) was significantly higher than that of mild or moderate group (1.25 ng/mL). Patients with respiratory failure had higher PTX3 than those without respiratory failure. No difference was observed between stable COPD patients and healthy controls. ROC analysis showed that plasma PTX3 had a considerable ability to distinguish AECOPD from stable COPD [AUC: 0.85, 95% CI (0.81-0.88), P < 0.0001; cut-off 1.25 ng/mL, sensitivity 77.5%, specificity 74%]. AUC of PTX3 was better than CRP regarding diagnosis of AECOPD. Combination of PTX3 and CRP was superior to either of them in diagnosing AECOPD.

Conclusion

Plasma PTX3 levels were significantly higher in AECOPD than stable COPD. The level was associated with the severity of exacerbation. Plasma PTX3 has potential value as a biomarker to diagnose and evaluate AECOPD.

Distinguishing Invasive from Chronic Pulmonary Infections: Host Pentraxin 3 and Fungal Siderophores in Bronchoalveolar Lavage Fluids

The multiple forms of pulmonary aspergillosis caused by Aspergillus species are the most common respiratory mycoses. Although invasive, the analysis of diagnostic biomarkers in bronchoalveolar lavage fluid (BALF) is a clinical standard for diagnosing these conditions. The BALF samples from 22 patients with proven or probable aspergillosis were assayed for human pentraxin 3 (Ptx3), fungal ferricrocin (Fc), and triacetylfusarinine C (TafC) in a retrospective study. The infected group included patients with invasive pulmonary aspergillosis (IPA) and chronic aspergillosis (CPA). The BALF data were compared to a control cohort of 67 patients with invasive pulmonary mucormycosis (IPM), non-Aspergillus colonization, or bacterial infections. The median Ptx3 concentrations in patients with and without aspergillosis were 4545.5 and 242.0 pg/mL, respectively (95% CI, p < 0.05). The optimum Ptx3 cutoff for IPA was 2545 pg/mL, giving a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100, 98, 95, and 100%, respectively. The median Ptx3 concentration for IPM was high at 4326 pg/mL. Pentraxin 3 assay alone can distinguish IPA from CPA and invasive fungal disease from colonization. Combining Ptx3 and TafC assays enabled the diagnostic discrimination of IPM and IPA, giving a specificity and PPV of 100%.

Biomarkers to guide the use of antibiotics for acute exacerbations of COPD (AECOPD): a systematic review and meta-analysis

Background

Antibiotics are frequently prescribed for acute exacerbations of COPD (AECOPD) even though most do not have a bacterial aetiology. Biomarkers may help clinicians target antibiotic use by identifying AECOPD caused by bacterial pathogens. We aimed to summarise current evidence on the diagnostic accuracy of biomarkers for detecting bacterial versus non-bacterial AECOPD.

Methods

We searched Embase and Medline using a search strategy including terms for COPD, biomarkers and bacterial infection. Data regarding diagnostic accuracy for each biomarker in predicting bacterial cause of exacerbation were extracted and summarised. We used to QUADAS-2 tool to assess risk of bias.

Results

Of 509 papers identified, 39 papers evaluating 61 biomarkers were eligible for inclusion. Moderate quality evidence was found for associations between serum C-reactive protein (CRP), serum procalcitonin (PCT), sputum interleukin (IL)-8 and sputum tumour necrosis factor alpha (TNF-α), and the presence of bacterial pathogens in the sputum of patients with AECOPD. Having bacterial pathogens was associated with a mean difference (higher) CRP and PCT of 29.44 mg/L and 0.76 ng/mL respectively. There was inconsistent or weak evidence for associations between bacterial AECOPD and higher levels of sputum IL-1β, IL-6, myeloperoxidase (MPO) and neutrophil elastase (NE). We did not find any consistent evidence of diagnostic value for other biomarkers.

Conclusions

There is moderate evidence from heterogeneous studies that serum CRP and PCT are of value in differentiating bacterial from non-bacterial AECOPD, and little evidence for other biomarkers. Further high-quality research on the role of biomarkers in identifying bacterial exacerbations is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01958-4.

Pentraxin 3 expression in lungs and neutrophils of calves

Bacterial lung disease caused by Mannheimia haemolytica inflict significant mortality and morbidity resulting in enormous economic losses to cattle industry. The use of antibiotics is becoming more challenging because of development of anti-microbial resistance. The innate immune system plays a critical role in the initiation of immune response in the lung. Pentraxin 3 (PTX3), a pattern-recognition receptor is produced at sites of inflammation by many cell types, recognizes and binds to many pathogens, activates the complement cascade, and has a role in the clearance of apoptotic and necrotic cells. Because there are very few data on the expression of PTX3 in the lungs, we examined PTX3 expression in lungs of normal and M. haemolytica-infected calves and normal and E. coli lipopolysaccharide-treated cattle neutrophils using light and electron microscopic immunochemistry and Western blots. Immunohistology showed the presence of PTX3 in airway epithelial cells, alveolar septa and macrophages in normal and inflamed lungs of calves and the blots showed a significant increase in the expression of PTX3 in lungs from infected calves. Immuno-gold electron microscopy showed PTX3 in the nuclei, cytoplasm, and vesicular organelles of alveolar macrophages, endothelial cells and pulmonary intravascular macrophages (PIMs). Immunohistochemical staining for PTX3 in peripheral blood neutrophils shows an altered staining pattern in neutrophils stimulated with lipopolysachharide (LPS). However, western blots no significant change in PTX3 amount in LPS-treated neutrophils compared to the controls. These are the first data on the expression of PTX3 in the lungs and the neutrophils of cattle which may add to our understanding of innate immunity in cattle lungs.

Comparative proteomics analysis of patients with quick development and slow development Chronic Obstructive Pulmonary Disease (COPD)

BACKGROUND

The development of Chronic Obstructive Pulmonary Disease (COPD) has been assessed and divided into slow development (SD), normal development (ND) and quick development (QD). Little is known about the plasma proteome characters among these three phenotypes.

METHODS

We performed a comparative proteomic analysis in the plasma of normal control (NC), SD, ND and QD phenotype COPD patients using isobaric tags for relative and absolute quantitation (iTRAQ) technique.

RESULTS

A total of 683 proteins were successfully identified in the plasma samples, of which 394 were considered as high-quality proteins (95% confidential peptides ≥ 2). Further, a total of 25, 19 and 27 different abundant proteins (DAPs) were identified in SD, ND and QD groups, respectively. Gene ontology (GO) classification analysis of all DAPs showed that immune system process (GO:0002376) were the most significant. The pathway enrichment analysis showed that innate immune response (GO:0045087), receptor-mediated endocytosis (GO:0006898) and proteolysis (GO:0006508) were the branch-end terms. Notably, the 15 QD special DAPs were considered as potential markers for identify patient might have quick development COPD, and thus provided more aggressive treatment strategy for these patients.

CONCLUSION

This work provides an insight into global plasma proteome profiles among the SD, ND and QD phenotypes of COPD patients. The most significant GO terms that the DAPs enriched in were immune system related terms. In addition, the 15 QD specific DPAs provided candidates of potential markers to predict the development types of COPD patients.

Biomarkers of sepsis: time for a reappraisal

INTRODUCTION

Sepsis biomarkers can have important diagnostic, therapeutic, and prognostic functions. In a previous review, we identified 3370 references reporting on 178 different biomarkers related to sepsis. In the present review, we evaluate the progress in the research of sepsis biomarkers.

METHODS

Using the same methodology as in our previous review, we searched the PubMed database from 2009 until September 2019 using the terms "Biomarker" AND "Sepsis." There were no restrictions by age or language, and all studies, clinical and experimental, were included.

RESULTS

We retrieved a total of 5367 new references since our previous review. We identified 258 biomarkers, 80 of which were new compared to our previous list. The majority of biomarkers have been evaluated in fewer than 5 studies, with 81 (31%) being assessed in just a single study. Apart from studies of C-reactive protein (CRP) or procalcitonin (PCT), only 26 biomarkers have been assessed in clinical studies with more than 300 participants. Forty biomarkers have been compared to PCT and/or CRP for their diagnostic value; 9 were shown to have a better diagnostic value for sepsis than either or both of these biomarkers. Forty-four biomarkers have been evaluated for a role in answering a specific clinical question rather than for their general diagnostic or prognostic properties in sepsis.

CONCLUSIONS

The number of biomarkers being identified is still increasing although at a slower rate than in the past. Most of the biomarkers have not been well-studied; in particular, the clinical role of these biomarkers needs to be better evaluated.

Diagnostic value of pentraxin 3 in respiratory tract infections: A meta-analysis

BACKGROUND

Pentraxin 3 is an acute inflammatory protein of the long pentraxin subfamily. A meta-analysis was performed to assess diagnostic accuracy of pentraxin 3 for respiratory tract infections.

METHODS

We identify studies examining diagnostic value of pentraxin 3 for respiratory tract infections by searching Pubmed, Web of Knowledge, and Cochrane Library. The sensitivity, specificity, negative likelihood ratio (LR), positive LR, and diagnostic odds ratio were pooled. The area under the summary receiver operator characteristic (SROC) curve and Q point value (Q*) were calculated.

RESULTS

A total of 8 studies with 961 individuals were eligible for this meta-analysis. The pooled sensitivity of pentraxin 3 in diagnosis of respiratory tract infections was 0.78, the pooled specificity was 0.73, the area under the SROC curve was 0.84, and the Q* was 0.77. The area under the SROC curve of serum and bronchoalveolar lavage fluid (BALF) pentraxin 3 was 0.85 and 0.89, respectively. Meta-regression analysis revealed that cutoff value was the source of heterogeneity among the included studies. The Deek funnel plot test suggested no evidence of publication bias. Subgroup analyses showed that the area under the SROC curve of pentraxin 3 in diagnosis of ventilator-associated pneumonia (VAP) was 0.89.

CONCLUSION

Pentraxin 3 has a moderate accuracy for diagnosing respiratory tract infections and VAP. The overall diagnostic value of BALF level of pentraxin 3 is superior to its serum concentration.

Host-response biomarkers for the diagnosis of bacterial respiratory tract infections

Appropriate antibiotic treatment for respiratory tract infections (RTIs) necessitates rapid and accurate diagnosis of microbial etiology, which remains challenging despite recent innovations. Several host response-based biomarkers due to infection have been suggested to allow discrimination of bacterial and non-bacterial microbial RTI etiology. This review provides an overview of clinical studies that investigated the diagnostic performance of host-response proteomic biomarkers to identify RTI microbial etiology. Procalcitonin and C-reactive protein have been studied most extensively; whereof procalcitonin has demonstrated the strongest diagnostic performance compared to other biomarkers. Proadrenomedullin, soluble triggering receptor expressed on myeloid cells-1, neopterin and pentraxin-3 need more studies to confirm their diagnostic value. For syndecan-4 and lipocalin-2 currently insufficient evidence exists. Common limitations in several of the studies were the relatively small scale setting, heterogeneous patient population and the absence of statistical power calculation.

The Long Pentraxin PTX3 as a Humoral Innate Immunity Functional Player and Biomarker of Infections and Sepsis

The first line of defense in innate immunity is provided by cellular and humoral mediators. Pentraxins are a superfamily of phylogenetically conserved humoral mediators of innate immunity. PTX3, the first long pentraxin identified, is a soluble pattern recognition molecule rapidly produced by several cell types in response to primary pro-inflammatory signals and microbial recognition. PTX3 acts as an important mediator of innate immunity against pathogens of fungal, bacterial and viral origin, and as a regulator of inflammation, by modulating complement activation and cell extravasation, and facilitating pathogen recognition by myeloid cells. In sepsis, PTX3 plasma levels are associated with severity of the condition, patient survival, and response to therapy. In combination with other established biomarkers, PTX3 could improve stratification of sepsis patients and thus, complement the system of classification and monitoring of this disease.

Relationship between serum Pentraxin 3 and pro-adrenomedullin levels with acute cholecystitis

OBJECTIVES

The perforation of the gallbladder (GP) is one of the most significant complications of acute cholecystitis. A biochemical marker indicating the GP has not been determined fully to date. Pentraxin 3 and pro-adrenomedullin (Pro-ADM) proteins are novel acute phase reactants. We aimed to investigate the relationship between serum Pentraxin 3 and Pro-ADM and the GP in patients with acute cholecystitis.

METHODS

This prospective cross-sectional study was conducted on patients with acute cholecystitis in a tertiary care emergency department during the six-month period. The acute cholecystitis patients were divided into two groups as with GP, and without GP. Additionally, patients with GP were evaluated according to pericholecystic fluid and gallbladder wall thickness. Serum levels of pro-ADM and pentraxin 3, WBC, CRP and sedimentation rate were measured in all patients.

RESULTS

A total of 60 patients with acute cholecystitis were included in the study. Pro-ADM and pentraxin 3 levels were significantly higher in patients with GP and the with pericholecystic free fluid (p < 0.0001). There was no significant relationship between serum pentraxin 3 and pro-ADM with gallbladder wall thickness (p > 0.05) According to the ROC analysis, serum Pentraxin 3 levels of ≥4.9 ng/mL could predict GP with a sensitivity of 75% and a specificity of 85% and serum pro-ADM levels of ≥97 nmol/L with sensitivity and specificity of 100% and 95%.

CONCLUSION

Our study results reveal that serum Pentraxin 3 and pro-ADM may be novel biochemical parameters in the detection of GP in acute cholecystitis cases.

Is It Time to Change the Definition of Acute Exacerbation of Chronic Obstructive Pulmornary Disease? What Do We Need to Add?

Acute exacerbations in chronic obstructive pulmonary disease (AECOPD) are associated with increased mortality, rate of hospitalization, use of healthcare resources, and have a negative impact on disease progression, quality of life and lung function of patients with chronic obstructive pulmonary disease (COPD). There is an imperative need to homogenize the definition of AECOPD because the incidence of exacerbations has a significant influence or implication on treatment decision making, particularly in pharmacotherapy and could impact the outcome or change the statistical significance of a therapeutic intervention in clinical trials. In this review, using PubMed searches, we have analyzed the weaknesses and strengths of the different used AECOPD definitions (symptom-based, healthcare-based definition or the combinations of both), as well as the findings of the studies that have assessed the relationship of different biomarkers with the diagnosis, etiology and differential diagnosis of AECOPD and the progress towards the development of a more precise definition of COPD exacerbation. Finally, we have proposed a simple definition of AECOPD, which must be validated in future clinical trials to define its accuracy and usefulness in daily practice.