Increased Levels of serum Pentraxin 3 in Critical Coronavirus Disease-2019 Patients

Pentraxins in invertebrates and vertebrates: From structure, function and evolution to clinical applications

The immune system is divided into two broad categories, consisting of innate and adaptive immunity. As recognition and effector factors of innate immunity and regulators of adaptive immune responses, lectins are considered to be important defense chemicals against microbial pathogens, cell trafficking, immune regulation, and prevention of autoimmunity. Pentraxins, important members of animal lectins, play a significant role in protecting the body from pathogen infection and regulating inflammatory reactions. They can recognize and bind to a variety of ligands, including carbohydrates, lipids, proteins, nucleic acids and their complexes, and protect the host from pathogen invasion by activating the complement cascade and Fcγ receptor pathways. Based on the primary structure of the subunit, pentraxins are divided into short and long pentraxins. The short pentraxins are comprised of C-reactive protein (CRP) and serum amyloid P (SAP), and the most important member of the long pentraxins is pentraxin 3 (PTX3). The CRP and SAP exist in both vertebrates and invertebrates, while the PTX3 may be present only in vertebrates. The major ligands and functions of CRP, SAP and PTX3 and three activation pathways involved in the complement system are summarized in this review. Their different characteristics in various animals including humans, and their evolutionary trees are analyzed. The clinical applications of CRP, SAP and PTX3 in human are reviewed. Some questions that remain to be understood are also highlighted.

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.

Complement and COVID-19: Three years on, what we know, what we don't know, and what we ought to know

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus was identified in China in 2019 as the causative agent of COVID-19, and quickly spread throughout the world, causing over 7 million deaths, of which 2 million occurred prior to the introduction of the first vaccine. In the following discussion, while recognising that complement is just one of many players in COVID-19, we focus on the relationship between complement and COVID-19 disease, with limited digression into directly-related areas such as the relationship between complement, kinin release, and coagulation. Prior to the 2019 COVID-19 outbreak, an important role for complement in coronavirus diseases had been established. Subsequently, multiple investigations of patients with COVID-19 confirmed that complement dysregulation is likely to be a major driver of disease pathology, in some, if not all, patients. These data fuelled evaluation of many complement-directed therapeutic agents in small patient cohorts, with claims of significant beneficial effect. As yet, these early results have not been reflected in larger clinical trials, posing questions such as who to treat, appropriate time to treat, duration of treatment, and optimal target for treatment. While significant control of the pandemic has been achieved through a global scientific and medical effort to comprehend the etiology of the disease, through extensive SARS-CoV-2 testing and quarantine measures, through vaccine development, and through improved therapy, possibly aided by attenuation of the dominant strains, it is not yet over. In this review, we summarise complement-relevant literature, emphasise its main conclusions, and formulate a hypothesis for complement involvement in COVID-19. Based on this we make suggestions as to how any future outbreak might be better managed in order to minimise impact on patients.

Organokines in COVID-19: A Systematic Review

Coronavirus disease 2019 (COVID-19) is a viral infection caused by SARS-CoV-2 that induces a generalized inflammatory state. Organokines (adipokines, osteokines, myokines, hepatokines, and cardiokines) can produce beneficial or harmful effects in this condition. This study aimed to systematically review the role of organokines on COVID-19. PubMed, Embase, Google Scholar, and Cochrane databases were searched, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed, and 37 studies were selected, comprising more than 2700 individuals infected with the virus. Among COVID-19 patients, organokines have been associated with endothelial dysfunction and multiple organ failure due to augmented cytokines and increased SARS-CoV-2 viremia. Changes in the pattern of organokines secretion can directly or indirectly contribute to aggravating the infection, promoting immune response alterations, and predicting the disease progression. These molecules have the potential to be used as adjuvant biomarkers to predict the severity of the illness and severe outcomes.

The Prognostic Value of Pentraxin-3 in COVID-19 Patients: A Systematic Review and Meta-Analysis of Mortality Incidence

Over the last three years, humanity has been facing one of the most serious health emergencies due to the global spread of Coronavirus disease (COVID-19). In this scenario, the research of reliable biomarkers of mortality from COVID-19 represents a primary objective. Pentraxin 3 (PTX3), a highly conserved protein of innate immunity, seems to be associated with a worse outcome of the disease. Based on the above, this systematic review and meta-analysis evaluated the prognostic potential of PTX3 in COVID-19 disease. We included 12 clinical studies evaluating PTX3 in COVID-19 patients. From our research, we found increased PTX3 levels compared to healthy subjects, and notably, PTX3 was even more augmented in severe COVID-19 rather than non-severe cases. Moreover, we performed a meta-analysis to establish if there were differences between ICU and non-ICU COVID-19 patients in PTX3-related death. We combined 5 studies for a total of 543 ICU vs. 515 non-ICU patients. We found high significative PTX3-related death in ICU COVID-19 hospitalized individuals (184 out of 543) compared to non-ICU (37 out of 515), with an overall effect OR: 11.30 [2.00, 63.73]; p = 0.006. In conclusion, we probed PTX3 as a reliable marker of poor outcomes after COVID-19 infection as well as a predictor of hospitalized patients' stratification.

Clinical Utility of Circulating Pentraxin 3 as a Prognostic Biomarker in Coronavirus Disease 2019: A Systematic Review and Meta-analysis

INTRODUCTION

Pentraxin 3 (PTX3) is involved in inflammation regulation and has a certain association with infectious diseases. However, its specific correlation with infectious diseases remains controversial. This study aimed to analyze the association between them and explore the possible role of PTX3 in the prognosis of coronavirus disease 2019 (COVID-19).

METHODS

Five databases (PubMed, Cochrane Library, Embase, Clinicaltrials.gov, and gray literature) were searched. Outcomes were expressed as a standardized mean difference (SMD) and 95% confidence intervals (CI). The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of included articles. Stata 12 and Meta-DiSc were applied to analyze the pooled data. Receiver operating characteristic (ROC) curves were conducted to determine the prognostic value of PTX3 for mortality.

RESULTS

Six articles met the inclusion criteria. Circulating PTX3 levels had a nonsignificant difference between intensive care unit (ICU) and non-ICU patients with COVID-19 [SMD 1.37 (-0.08, 2.81); I² = 93.9%, P < 0.01], while the PTX3 levels in nonsurvival COVID-19 patients was significantly lower than those in survival patients [SMD -1.41 (-1.92, -0.91); I² = 66.4%, P = 0.051]. Circulating PTX3 had good mortality prediction ability (area under ROC curve, AUC = 0.829) in COVID-19. Funnel plots and Egger's tests showed low probabilities of publication bias. Through sensitivity analysis, the results of this study were robust.

CONCLUSION

This study found that PTX3 was differentially expressed between survival and nonsurvival patients with COVID-19, while there was no significant difference between ICU and non-ICU patients. Meanwhile, circulating PTX3 may be a good biomarker for monitoring the prognosis of COVID-19, which may provide new ideas and directions for clinical and scientific research.

Diagnostic performance of serum pentraxin-3 in pediatric acute appendicitis: a prospective diagnostic validation study

INTRODUCTION

Pediatric acute appendicitis (PAA) is a pathology with a high rate of diagnostic error. The search for new diagnostic tools is justified by the high morbidity and healthcare costs associated with diagnostic error.

METHODS

We designed a prospective study to validate serum pentraxin-3 (PTX3) as a diagnostic tool in PAA. Participants were divided into three groups: (1) patients with no underlying pathology (2) patients with non-surgical abdominal pain and (3) patients with a confirmed diagnosis of PAA. For further analyses, patients in group 3 were divided into complicated or uncomplicated PAA. Quantitative variables were expressed as medians and interquartile ranges and categorical variables as percentages. Quantitative variables were compared using the Kruskal-Wallis test and the Mann-Whitney U test. Diagnostic performance was evaluated with ROC curves.

RESULTS

This study included 215 patients divided into group 1 (n = 63), group 2 (n = 53) and group 3 (n = 99). Median serum PTX3 values were 2.54 (1.70-2.95) ng/mL, 3.29 (2.19-7.64) ng/mL and 8.94 (6.16-14.05) in groups 1, 2 and 3, respectively (p = 0.001). Patients with complicated PAA showed significantly higher values than patients with uncomplicated PAA (p = 0.04). The AUC (group 2 vs. 3) was 0.77 (95% CI 0.69-0.85) and the best cut-off point was at 7.28 ng/mL, with a sensitivity of 61.3% and a specificity of 73.1%. The AUC (complicated vs. uncomplicated PAA) was 0.65 (95% CI 0.54-0.77) and the best cut-off point was 12.33 ng/mL, with a sensitivity of 51.72% and a specificity of 72.73%.

CONCLUSIONS

The diagnostic ability of serum PTX3 in PAA is only moderate and therefore it cannot be considered a definitive diagnostic test. The discriminatory ability of PTX3 between complicated and uncomplicated PAA is poor. These findings, which contrast with those reported to date, should be validated with future properly designed prospective studies.

Pan-Cancer Analysis of Pentraxin 3: A Potential Biomarker of COVID-19

Pentraxin 3 (PTX3), a potential biomarker of the severity and mortality of COVID-19 patients, is aberrantly expressed in human tumors. However, a comprehensive pan-cancer analysis of PTX3 remains to be elucidated. PTX3 data profiles and clinical information in TCGA cancers were obtained from different public databases to clarify the expression levels, genetic alterations, prognostic significance, underlying mechanisms, and the predicted role in immunotherapy of PTX3 across TCGA cancers. Our analyses showed that PTX3 was aberrantly expressed in most tumors and was significantly related to prognosis and tumor stage. Interaction network and enrichment analyses revealed that PTX3 participated in tumor immuno-related progression. In addition, PTX3 levels were critically associated with immune cell components and immune scores, and PTX3 strongly coexpressed with immune-related genes in TCGA cancers. Meanwhile, PTX3 expression was associated with immune checkpoint genes, and immunotherapy potential biomarkers in multiple cancers, predicting special immunotherapy responses in different tumor types. In kidney renal clear cell carcinoma (KIRC), PTX3 emerged as an independent prognostic factor through multivariable Cox regression analyses. Blocking PTX3 with siRNA could suppress the growth of KIRC cells and invasion. Conclusively, our study shows a comprehensive bioinformatic analysis of PTX3, which might serve as a pan-cancer prognostic biomarker.