Pentraxin 3 in the assessment of ventilator-associated pneumonia: an early marker of severity

Progress in the study of pentraxin-3(PTX-3) as a biomarker for sepsis

Sepsis is a intricate pathological process characterized by life-threatening organ dysfunction resulting from a dysregulated host response to infection. It stands as a prominent cause of mortality among critically ill patients globally. The pivotal focus in sepsis management lies in the early identification and prompt administration of antimicrobial agents. Owing to the constraints of current diagnostic methodologies, marked by insufficient sensitivity and delayed outcomes, extensive research has been undertaken to ascertain novel biomarkers for sepsis. In this review, we provide an overview discussing the latest advancements in the study of PTX-3 as a biomarker for sepsis. We acknowledge pivotal discoveries from preceding research and engage in discourse regarding the challenges and limitations confronted by PTX-3 as a sepsis biomarker.

Evaluation of Five Host Inflammatory Biomarkers in Early Diagnosis of Ventilator-Associated Pneumonia in Critically Ill Children: A Prospective Single Center Cohort Study

Background: Early diagnosis of ventilator-associated pneumonia (VAP) remains a challenge due to subjective clinical criteria and the low discriminative power of diagnostic tests. We assessed whether rapid molecular diagnostics in combination with Clinically Pulmonary Index Score (CPIS) scoring, microbiological surveillance and biomarker measurements of PTX-3, SP-D, s-TREM, PTX-3, IL-1β and IL-8 in the blood or lung could improve the accuracy of VAP diagnosis and follow-up in critically ill children. Methods: A prospective pragmatic study in a Pediatric Intensive Care Unit (PICU) was conducted on ventilated critically ill children divided into two groups: high and low suspicion of VAP according to modified Clinically Pulmonary Index Score (mCPIS). Blood and bronchial samples were collected on days 1, 3, 6 and 12 after event onset. Rapid diagnostics were used for pathogen identification and ELISA for PTX-3, SP-D, s-TREM, IL-1β and IL-8 measurements. Results: Among 20 enrolled patients, 12 had a high suspicion (mCPIS > 6), and 8 had a low suspicion of VAP (mCPIS < 6); 65% were male; and 35% had chronic disease. IL-1β levels at day 1 correlated significantly with the number of mechanical ventilation days (r_s = 0.67, p < 0.001) and the PICU stay (r = 0.66; p < 0.002). No significant differences were found in the levels of the other biomarkers between the two groups. Mortality was recorded in two patients with high VAP suspicion. Conclusions: PTX-3, SP-D, s-TREM, IL-1β and IL-8 biomarkers could not discriminate patients with a high or low suspicion of VAP diagnosis.

Thoracic ultrasound alone or in combination with tracheal amylase as a tool predictor of ventilator-associated pneumonia in neurocritical patients

In this study, we aim to evaluate whether thoracic ultrasound (TUS) and tracheal amylase (TA) alone or in combination can predict the development of ventilator-associated pneumonia (VAP) in neurocritical patients. Consecutive adult patients with neurocritical disease with normal chest radiographs who required intensive care unit admission and mechanical ventilation between March 2015 and July 2018 were included. TUS and Amylase levels were measured during the first 24 hours and repeated 48 hours after orotracheal intubation. Forty-three patients with a median age of 34 years (17-82) were included. TUS had a sensitivity of 100% and specificity of 96.3% as a predictor of VAP within the first 48 hours when nonpattern A was observed. TA levels > 200 UI/L in the first 48 hours had a sensitivity of 87.5%, and specificity of 63% as a predictor of VAP. Moreover, no benefit of TUS plus TA compared to TUS alone as a predictor of VAP was found. The identification of abnormal TUS patterns in the first 48 hours of orotracheal intubation is a significant predictor of VAP in neurocritical patients.

Pentraxin-3 as a predictive marker of mortality in sepsis: an updated systematic review and meta-analysis

BACKGROUND

The purpose of this study was to clarify the prognostic value of Pentraxin-3 (PTX3) on the mortality of patients with sepsis.

METHODS

Publications published up to January 2021 were retrieved from PubMed, EMBASE, and the Cochrane library. Data from eligible cohort and case-control studies were extracted for the meta-analysis. Multivariate regression analysis was used to evaluate the correlation of the outcomes with sample size and male proportion.

RESULTS

A total of 17 studies covering 3658 sepsis patients were included. PTX3 level was significantly higher in non-survivor compared to survivor patients (SMD (95% CI): -1.06 (-1.43, -0.69), P < 0.001). Increased PTX3 level was significantly associated with mortality (HR (95% CI): 2.09 (1.55, 2.81), P < 0.001). PTX3 showed good predictive capability for mortality (AUC:ES (95% CI): 0.73 (0.70, 0.77), P < 0.001). The outcome comparing PTX3 level in non-survivors vs. survivors and the outcome of the association between PTX3 and mortality were associated with sample size but not male proportion. AUC was associated with both sample size and male proportion.

CONCLUSIONS

PTX3 level was significantly higher in non-survivor compared to survivor patients with sepsis. Elevated PTX3 level was significantly associated with mortality. Furthermore, the level of PTX3 might predict patient mortality.

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.

A new scoring system for early diagnosis of ventilator-associated pneumonia: LUPPIS

INTRODUCTION

The Clinical Pulmonary Infection Score (CPIS) based on chest X-ray has been developed to facilitate clinical diagnosis of ventilator-associated pneumonia (VAP); however, this scoring system has a low diagnostic performance. We developed the Lung Ultrasound and Pentraxin-3 Pulmonary Infection Score (LUPPIS) for early diagnosis of VAP and evaluated the performance of this new scoring system.

MATERIAL AND METHODS

In a prospective study of 78 patients with suspected VAP, we assessed the detection accuracy of LUPPIS for pneumonia in adult patients. We also evaluated the diagnostic performance of pentraxin-3 (PTX-3) findings of infection. On the day of the study, lung ultrasound was performed, PTX-3 levels were determined, and an endotracheal aspirate was obtained for Gram staining and culture.

RESULTS

No significant differences were found between groups with respect to age, mechanical ventilation time, APACHE II score, or SOFA score (p > 0.05). Procalcitonin and PTX-3 levels were significantly higher in the VAP (+) group (p < 0.001 and p < 0.001, respectively). The threshold for LUPPIS in differentiating VAP (+) patients from VAP (-) patients was > 7. In predicting VAP, LUPPIS > 7 (sensitivity of 84%, specificity of 87.7%) was superior to CPIS > 6 (sensitivity of 40.1%, specificity of 84.5%).

CONCLUSIONS

LUPPIS appears to provide better results in the prediction of VAP compared to CPIS, and the importance of lung ultrasound and PTX-3 is emphasized, which is a distinctive property of LUPPIS.

Vitamin D Status in Neonatal Pulmonary Infections: Relationship to Inflammatory Indicators

AIM

The study aimed to evaluate serum vitamin D concentrations among neonates with pneumonia.

METHODS

This case-control study enrolled 33 neonates with pneumonia in addition to 30 healthy controls. CBC, CRP, Serum vitamin D and Pentraxin 3 levels were measured for all participants.

RESULTS

There was significant difference between patients and controls regarding Hemoglobin levels, TLC and CRP (p value < 0.01, = 0.002, < 0.01 respectively). Patients with pneumonia showed significant lower levels of Vit. D (9 ± 2.1) compared to controls (14.1 ± 2.8), P value < 0.01. However, patient group had significant higher levels of Pentraxin 3 (29.1 ± 4.8) compared with controls (12.6 ± 3), P value < 0.01. Moreover, mechanically ventilated patients revealed significant lower vit D (7.7 ± 1.8) and higher pentraxin 3 (32.2 ± 2.6) compared to patients on free oxygen (9.1 ± 2.1, 26.4 ± 3.7 respectively), P value = 0.05, 0.02 respectively. Regarding hospital stay, it had significant positive correlation with serum pentraxin 3 (r = 0.6, P value < 0.01) and significant negative correlation with serum vit D (r = -0.4, P value = 0.04). Finally a significant negative correlation between serum levels of vitamin D and Pentraxin 3 was found (r = -0.4, P value = 0.01).

CONCLUSION

Lower concentration of serum vitamin D may be significantly associated with neonatal pneumonia. It also can predict the need for mechanical ventilation and duration of hospital stay in neonatal pneumonia. Similarly, higher levels of Pentraxin 3 may be used as an indicator for mechanical ventilation need and a longer hospital stay in neonates with pneumonia.

Long Pentraxin 3 as a Broader Biomarker for Multiple Risk Factors in End-Stage Renal Disease: Association with All-Cause Mortality

Persistent inflammation in end-stage renal disease (ESRD) patients is known to underlie the progression of chronic kidney disease and to be associated with multiple risk factors including malnutrition, atherosclerosis, and cardiovascular disease (CVD). The acute-phase protein pentraxin 3 (PTX3) has a proven potential as a local inflammatory biomarker, but its clinical utility in ESRD remains unclear. Circulating levels of PTX3 and classical inflammatory mediators, including the clinical prototypical C-reactive protein (CRP), were assessed in 246 ESRD patients on dialysis and analysed in relation to the lipid profile, adipokine levels, and nutritional, cardiac, and renal fibrosis markers. Occurrence of deaths was recorded for the following year. Contrarily to the classical inflammatory markers, PTX3 levels were negatively correlated with nutritional markers and associated with a less atherogenic lipid profile. Levels of the cardiac and renal fibrosis markers and of the oxidized LDL/LDL-C ratio were found to be independent determinants of PTX3 concentration. When comparing inflammatory mediators, the increase in the PTX3 levels was the only predictor of all-cause mortality in dialysis patients in a survival model adjusted to all markers under study, other than the inflammatory ones, besides common confounding factors in dialysis. Data support the clinical applicability of PTX3 as a broader inflammatory biomarker than the classical ones, presenting a close association with inflammation, malnutrition, CVD, and renal fibrosis and a great potential to predict all-cause mortality in dialysis patients. The pleiotropic character of PTX3 may be of clinical relevance, and it could be targeted to ameliorate the high morbidity and mortality associated with ESRD.

Biomarkers in Pneumonia-Beyond Procalcitonin

Pneumonia is the leading infectious cause of mortality worldwide and one of the most common lower respiratory tract infections that is contributing significantly to the burden of antibiotic consumption. Due to the complexity of its pathophysiology, it is widely accepted that clinical diagnosis and prognosis are inadequate for the accurate assessment of the severity of the disease. The most challenging task for a physician is the risk stratification of patients with community-acquired pneumonia. Herein, early diagnosis is essential in order to reduce hospitalization and mortality. Procalcitonin and C-reactive protein remain the most widely used biomarkers, while interleukin 6 has been of particular interest in the literature. However, none of them appear to be ideal, and the search for novel biomarkers that will most sufficiently predict the severity and treatment response in pneumonia has lately intensified. Although our insight has significantly increased over the last years, a translational approach with the application of genomics, metabolomics, microbiomics, and proteomics is required to better understand the disease. In this review, we discuss this rapidly evolving area and summarize the application of novel biomarkers that appear to be promising for the accurate diagnosis and risk stratification of pneumonia.

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.

Elevated Systemic Pentraxin-3 Is Associated With Complement Consumption in the Acute Phase of Thrombotic Microangiopathies

Pentraxin-3 (PTX3) and C-reactive protein (CRP) have been shown to regulate complement activation in vitro, but their role has not been investigated in complement consumption in vivo. Thrombotic microangiopathies (TMA) are often accompanied by complement overactivation and consumption, therefore we analyzed the relation of the systemic pentraxin levels to the complement profile, laboratory parameters and clinical outcome of TMA patients. We determined the PTX3 and CRP levels, complement factor and activation product concentrations in blood samples of 171 subjects with the diagnosis of typical hemolytic uremic syndrome (STEC-HUS) (N = 34), atypical HUS (aHUS) (N = 44), secondary TMA (N = 63), thrombotic thrombocytopenic purpura (TTP) (N = 30) and 69 age-matched healthy individuals. Clinical data, blood count and chemistry were collected from medical records. To determine the in vitro effect of PTX3 on alternative pathway (AP) activation, sheep red blood cell-based hemolytic assay and AP activity ELISA were used. We found that PTX3 levels were elevated in the acute phase of STEC-HUS, aHUS and secondary TMA, whereas PTX3 elevation was exceptional is TTP. Conversely, a significantly higher median CRP was present in all patient groups compared to controls. PTX3, but not CRP was associated with signs of complement consumption in vivo, and PTX3 significantly decreased the AP hemolytic activity in vitro. Our results provide a detailed description of acute phase-TMA patients' complement profile linked to changes in the systemic pentraxin levels that may support further molecular studies on the function of PTX3 in disease pathogenesis and add to the laboratory assessment of complement consumption in TMA.

Pentraxin-3: A new parameter in predicting the severity of diabetic foot infection?

This study was undertaken to evaluate the diagnostic and prognostic values of pentraxin-3 (PTX-3) in patients with infected diabetic foot ulcers (IDFU) as well as to assess the association between PTX-3 levels and IDFU severity. This study included 60 IDFU patients (Group 1), 45 diabetic patients without DFU (Group 2), and 45 healthy controls. Patients with IDFU were divided into mild, moderate, and severe subgroups based on classification of clinical severity. Patients who underwent amputation were also documented. Blood samples were collected to determine PTX-3 levels. PTX-3 levels in healthy controls, Group 1, and Group 2 were 5.83 (3.41-20) ng/mL, 1.47 (0.61-15.13) ng/mL, and 3.26 (0.67-20) ng/mL, respectively. A negative correlation between plasma PTX-3 and glucose levels was found. There were significant differences in terms of procalcitonin (PCT) and PTX-3 levels in the subgroup analysis of Group 1. The PTX-3 level in patients who did or did not undergo amputation was 4.1 (0.8-13.7) and 1 (0.6-15.1) ng/mL, respectively. Results suggest that PTX-3 is a particularly effective marker in patients with IDFU, both in terms of predicting disease severity and assisting in the decision to perform amputation.

The current status of biomarkers for the diagnosis of nosocomial pneumonias

PURPOSE OF REVIEW

Nosocomial pneumonia is a frequent and severe nosocomial infection divided in two distinct groups: hospital-acquired pneumonia and ventilator-associated pneumonia (VAP). In this context, the VAP is notoriously difficult to diagnose clinically, resulting from the lack of a 'gold standard' method of diagnosis.

RECENT FINDINGS

The use of biomarkers may potentially improve the early diagnosis of infections allowing earlier and better identification and treatment. An exhausting list of biomarkers has been studied and although far from perfect, procalcitonin (PCT) and C-reactive protein (CRP) are the most studied biomarkers used in clinical practice. Data coming from literature suggests the use of PCT for VAP prognosis and as a based algorithm tool for the reduction of duration of pneumonia therapy, as well as, the use of the CRP dynamics to the early prediction of VAP and the response to the antibiotics.

SUMMARY

The evidence for the use of biomarkers to diagnose nosocomial pneumonia as a stand-alone tool is low to moderate. Improved performance for both PCT and CRP can be obtained by using them in association with clinical features or scoring systems but prospective studies are still needed to validate this hypothesis.

New Biomarkers to Diagnose Ventilator Associated Pneumonia: Pentraxin 3 and Surfactant Protein D

OBJECTIVE

To detect the most effective biomarker to confirm ventilator associated pneumonia (VAP).

METHODS

Fifty patients with VAP suspicious diagnosis and 30 healthy patients were recruited. Suspicion of VAP was established if patients met the modified CPIS score ≥ 6 points. The confirmation of VAP was defined by the quantitative culture of nonbronchoscopic bronchoalveolar lavage (BAL) >10⁵ CFU/ml of pathogenic microorganism. Serum samples for determination of C-reactive protein (CRP), procalcitonin (PCT), pentraxin 3 (PTX3), surfactant protein D (SPD) were collected on suspected VAP.

RESULTS

Twenty seven of 50 patients were accepted as confirmed VAP group whose nonbronchoscopic BAL cultures were positive and rest of them were accepted as unconfirmed VAP group. PTX3, PCT and SPD levels were significantly higher in confirmed VAP group, (P = 0.021, P = 0.007, P < 0.001 respectively). There were no significant differences in CRP levels between the two groups (P = 0.062). The most sensitive marker for diagnosing VAP was SPD (P < 0.001). Receiver operating characteristic (ROC) curve for modified clinical pulmonary infection score (CPIS) to confirm VAP was evaluated (AUC 0.741 ± 0.07, P < 0.001) and the optimal cutoff value was >7 with a sensitivity of 51.85% and a specificity of 91.3%. SPD levels were significantly higher in Acinetobacter baumannii and Pseudomonas aeruginosa infected patients than culture negative patients (P < 0.001).

CONCLUSIONS

The index findings suggest that serum SPD is the most sensitive biomarker in diagnosis of VAP and it can be used as an early and organism specific marker for Acinetobacter baumannii and Pseudomonas aeruginosa.

Sequential Measurements of Pentraxin 3 Serum Levels in Patients with Ventilator-Associated Pneumonia: A Nested Case-Control Study

Purpose

The main purpose of this study was to investigate the dynamics of pentraxin 3 (PTX3) compared with procalcitonin (PCT) and C-reactive protein (CRP) in patients with suspicion of ventilator-associated pneumonia (VAP).

Materials and Methods

We designed a nested case-control study. This study was performed in the Surgical Intensive Care Unit of a tertiary care academic university and teaching hospital. Ninety-one adults who were mechanically ventilated for >48 hours were enrolled in the study. VAP diagnosis was established among 28 patients following the 2005 ATS/IDSA guidelines.

Results

The median PTX3 plasma level was 2.66 ng/mL in VAP adults compared to 0.25 ng/mL in non-VAP adults (p < 0.05). Procalcitonin and CRP levels did not significantly differ. Pentraxin 3, with a 2.56 ng/mL breakpoint, had 85% sensitivity, 86% specificity, 75% positive predictive value, and 92.9% negative predictive value for VAP diagnosis (AUC = 0.78).

Conclusions

With the suspicion of VAP, a pentraxin 3 plasma breakpoint of 2.56 ng/mL could contribute to the decision of whether to start antibiotics.

Pentraxin-3 as a marker of sepsis severity and predictor of mortality outcomes: A systematic review and meta-analysis

OBJECTIVES

Pentraxin-3 (PTX-3) is a multi-functional pattern recognition molecule produced by various cell types of peripheral tissues in different infections. It is raised in sepsis, but its values in predicting disease severity or mortality outcomes have been controversial. Therefore, we conducted a systematic review and meta-analysis of these associations.

METHODS

PubMed and Embase were searched until July 18, 2017 for studies that evaluated the relationship between PTX-3 levels and disease severity or mortality in sepsis.

RESULTS

A total of 23 and 10 entries were retrieved from both databases, respectively, of which 16 studies were included in the final meta-analysis. A total of 3001 patients (56% male, mean age 63 ± 15 years; mean follow-up duration of 207 days) were analysed. PTX-3 was significantly higher in patients with more severe sepsis compared to those with less severe sepsis (standard mean difference = 18.5 ng/mL, standard error: 4.5 ng/mL, P < 0.0001) and higher in non-survivors compared to survivors (standard mean difference = 40.3 ng/mL, standard error: 6.8 ng/mL, P < 0.0001). Elevated PTX-3 levels significantly increased the risk of all-cause mortality (hazard ratio: 1.91, 95% CI: 1.53 to 2.46, P < 0.0001).

CONCLUSIONS

PTX-3 significantly predicts disease severity and mortality in sepsis.

Long pentraxin PTX3 mediates acute inflammatory responses against pneumococcal infection

Streptococcus pneumoniae is an important human pathogen responsible for more than 2 million deaths annually worldwide. The airway epithelium acts as the first-line of defense against pneumococcal infections by regulating acute inflammation against invading pneumococcus. Despite the intact adaptive immunity, failure in early defense due to loss of pattern recognition receptors (PRRs) and/or acute phase proteins (APPs) results in detrimental damage and death. C-reactive protein (CRP), the first found APP, is a member of the pentraxin family of proteins and an important soluble PRR for pneumococcus. CRP and another short pentraxin, serum amyloid P, are critical for acute defense against pneumococcal infection. However, the role of the long pentraxin PTX3 in regulating pneumococcal infections is unknown. In this study, PTX3 expression was upregulated by pneumococcus in epithelial cells and in lungs of mice. In addition, PTX3 potentiated pneumococcal inflammation; overexpression of PTX3 enhanced pneumococcus-induced cytokine expression, whereas knock-down of PTX3 with siPTX3 inhibited the cytokine expression. Furthermore, PTX3 deficiency indeed ameliorated acute inflammation and protected mice against death following pneumococcal infection. Pneumococcal toxin pneumolysin was responsible for PTX3 expression and upregulated PTX3 expression via JNK MAPK signaling. These data implicate PTX3 as a novel therapeutic target for the control of acute inflammation by pneumococcus.

Long Pentraxin 3 as a Predictive Marker of Mortality in Severe Septic Patients Who Received Successful Early Goal-Directed Therapy

PURPOSE

Pentraxin 3 (PTX3) has been suggested to be a prognostic marker of mortality in severe sepsis. Currently, there are limited data on biomarkers including PTX3 that can be used to predict mortality in severe sepsis patients who have undergone successful initial resuscitation through early goal-directed therapy (EGDT).

MATERIALS AND METHODS

A prospective cohort study was conducted among 83 severe sepsis patients with fulfillment of all EGDT components and the achievement of final goal. Plasma PTX3 levels were measured by sandwich ELISA on hospital day (HD) 0, 3, and 7. The data for procalcitonin, C-reactive protein and delta neutrophil index were collected by electric medical record. The primary outcome was 28-day all-cause mortality.

RESULTS

28-day all-cause mortality was 19.3% and the median (interquartile range) APHCH II score of total patients was 16 (13-19). The non-survivors (n=16) had significantly higher PTX3 level at HD 0 [201.4 (56.9-268.6) ng/mL vs. 36.5 (13.7-145.3) ng/mL, p=0.008]. PTX3 had largest AUC(ROC) value for the prediction of mortality among PTX3, procalcitonin, delta neutrophil index, CRP and APACHE II/SOFA sore at HD 0 [0.819, 95% confidence interval (CI) 0.677-0.961, p=0.008]. The most valid cut-off level of PTX3 at HD 0 was 140.28 ng/mL (sensitivity 66.7%, specificity 73.8%). The PTX3 and procalcitonin at HD 0 showed strong correlation (r=0.675, p<0.001). However, PTX3 at HD 0 was the only independent predictive marker in Cox's proportional hazards model (≥140 ng/mL; hazard rate 7.16, 95% CI 2.46-15.85, p=0.001).

CONCLUSION

PTX3 at HD 0 could be a powerful predictive biomarker of 28-day all-cause mortality in severe septic patients who have undergone successful EGDT.

Serum pentraxin 3 is a novel marker in Crohn's disease

In Crohn's disease (CD), clinical symptoms correspond poorly to inflammatory disease activity. Biomarkers, which reflect the level of intestinal inflammation are considered to enable effective monitoring of disease activity. The present study evaluated the role of serum pentraxin 3 (PTX3) as a marker of disease activity in patients with CD. Serum PTX3 levels were determined using an enzyme-linked immunosorbent assay in patients with CD (n=240), ulcerative colitis (UC; n=240) and healthy controls (HC; n=80). The expression levels of PTX3 were also evaluated in 35 fresh colonic tissue samples by western blot analysis. The association between levels of serum PTX3 with disease activity and its diagnostic role were analyzed. The levels of serum PTX3 were significantly increased in patients with active CD compared with patients in remission (UC and HC; P<0.01). A significant increase in the expression levels of PTX3 was identified at a protein level in inflamed colonic tissues compared with uninflamed colonic tissues. The levels of serum PTX3 were also positively correlated with disease activity in CD. These results indicated that serum and colonic expression of PTX3 were upregulated in patients with active CD, suggesting serum PTX3 is superior to CRP in predicting CD activity.

Pentraxin 3 as a prognostic biomarker in patients with systemic inflammation or infection

Purpose. The long pentraxin 3 (PTX3) is a key component of the humoral arm of the innate immune system. PTX3 is produced locally in response to proinflammatory stimuli. We reviewed the usefulness of systemic levels of PTX3 in critically ill patients with systemic inflammatory response syndrome (SIRS), sepsis, and bacteremia, focusing on its diagnostic and prognostic value. Methods. A PubMed search on PTX3 was conducted. The list of papers was narrowed to original studies of critically ill patients. Eleven papers on original studies of critically ill patients that report on PTX3 in SIRS, sepsis, or bacteremia were identified. Results. Systematic levels of PTX3 have little diagnostic value in critically ill patients with SIRS, sepsis, or bacteremia. Systemic levels of PTX3, however, have superior prognostic power over other commonly used biological markers in these patients. Systemic levels of PTX3 correlate positively with markers of organ dysfunction and severity-of-disease classification system scores. Finally, systemic levels of PTX3 remain elevated in the acute phase and decreased on recovery. Notably, the age of the patients and underlying disease affect systemic levels of PTX3. Conclusions. The diagnostic value of PTX3 is low in patients with sepsis. Systemic levels of PTX3 have prognostic value and may add to prognostication of patients with SIRS or sepsis, complementing severity-of-disease classification systems and other biological markers.

Alveolar pentraxin 3 as an early marker of microbiologically confirmed pneumonia: a threshold-finding prospective observational study

Introduction

Timely diagnosis of pneumonia in intubated critically ill patients is rather challenging. Pentraxin 3 (PTX3) is an acute-phase mediator produced by various cell types in the lungs. Animal studies have shown that, during pneumonia, PTX3 participates in fine-tuning of inflammation (for example, microbial clearance and recruitment of neutrophils). We previously described an association between alveolar PTX3 and lung infection in a small group of intubated patients. The aim of the present study was to determine a threshold level of alveolar PTX3 with elevated sensitivity and specificity for microbiologically confirmed pneumonia.

Methods

We recruited 82 intubated patients from two intensive care units (San Gerardo Hospital, Monza, Italy, and Massachusetts General Hospital, Boston, MA, USA) undergoing bronchoalveolar lavage (BAL) as per clinical decision. We collected BAL fluid and plasma samples, together with relevant clinical and microbiological data. We assayed PTX3 and soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) in BAL fluid and PTX3, sTREM-1, C-reactive protein (CRP) and procalcitonin (PCT) in plasma. Two blinded independent physicians reviewed patient data to confirm pneumonia. We determined the PTX3 threshold in BAL fluid for pneumonia and compared it to other biomarkers.

Results

Microbiologically confirmed pneumonia of bacterial (n =12), viral (n =4) or fungal (n =8) etiology was diagnosed in 24 patients (29%). PTX3 levels in BAL fluid predicted pneumonia with an area under the receiving operator curve of 0.815 (95% CI =0.710 to 0.921, P <0.0001), whereas none of the other biomarkers were effective. In particular, PTX3 levels ≥1 ng/ml in BAL fluid predicted pneumonia in univariate analysis (β =2.784, SE =0.792, P <0.001) with elevated sensitivity (92%), specificity (60%) and negative predictive value (95%). Net reclassification index PTX3 values ≥1 ng/ml in BAL fluid for pneumonia indicated gain in sensitivity and/or specificity vs. all other mediators. These results did not change when we limited our analyses only to confirmed cases of bacterial pneumonia. Moreover, when we considered only the 70 patients who fulfilled the clinical criteria for the diagnosis of pneumonia at BAL fluid sampling, the diagnostic accuracy of PTX levels was confirmed in univariate and ROC curve analysis.

Conclusions

In this hypothesis-generating convenience sample, a PTX3 level ≥1 ng/ml in BAL fluid was discriminative of microbiologically confirmed pneumonia in mechanically ventilated patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0562-5) contains supplementary material, which is available to authorized users.

Diagnostic accuracy of pulmonary host inflammatory mediators in the exclusion of ventilator-acquired pneumonia

BACKGROUND

Excessive use of empirical antibiotics is common in critically ill patients. Rapid biomarker-based exclusion of infection may improve antibiotic stewardship in ventilator-acquired pneumonia (VAP). However, successful validation of the usefulness of potential markers in this setting is exceptionally rare.

OBJECTIVES

We sought to validate the capacity for specific host inflammatory mediators to exclude pneumonia in patients with suspected VAP.

METHODS

A prospective, multicentre, validation study of patients with suspected VAP was conducted in 12 intensive care units. VAP was confirmed following bronchoscopy by culture of a potential pathogen in bronchoalveolar lavage fluid (BALF) at >10(4) colony forming units per millilitre (cfu/mL). Interleukin-1 beta (IL-1β), IL-8, matrix metalloproteinase-8 (MMP-8), MMP-9 and human neutrophil elastase (HNE) were quantified in BALF. Diagnostic utility was determined for biomarkers individually and in combination.

RESULTS

Paired BALF culture and biomarker results were available for 150 patients. 53 patients (35%) had VAP and 97 (65%) patients formed the non-VAP group. All biomarkers were significantly higher in the VAP group (p<0.001). The area under the receiver operator characteristic curve for IL-1β was 0.81; IL-8, 0.74; MMP-8, 0.76; MMP-9, 0.79 and HNE, 0.78. A combination of IL-1β and IL-8, at the optimal cut-point, excluded VAP with a sensitivity of 100%, a specificity of 44.3% and a post-test probability of 0% (95% CI 0% to 9.2%).

CONCLUSIONS

Low BALF IL-1β in combination with IL-8 confidently excludes VAP and could form a rapid biomarker-based rule-out test, with the potential to improve antibiotic stewardship.

A translational approach to ventilator associated pneumonia

The management of Ventilator Associated Pneumonia (VAP) presents many difficulties because of the heterogeneity of the disease; the way the immunocompromised host and the aggressive ICU environment interact is only partially discovered, the available biomarkers for diagnosis are not sufficient to ensure prompt differentiation between sick patients and patients at risk, the microbiological cultures require invasive techniques and time consuming methods. A translational medicine and bio-informatics approach can enable the identification of the main players of pathology, which may represent novel therapeutic targets or biomarker candidates. Analysis of proteome i.e. allows to individuate proteins that act as biomarkers, for patient-centered research strategies. Similarly, the genomic approach has proved useful to individuate those patients who are prone to develop VAP, and, in the future, we could be able to immunomodulate their responses to save them from nosocomial infections.