Cord blood Clara cell protein CC16 predicts the development of bronchopulmonary dysplasia

Pneumoprotein CC16 in the Umbilical Cord Blood of Preterm Neonates

OBJECTIVE

 We examined the impact of perinatal factors on cord serum club cell protein (CC16) and the association of CC16 with mechanical ventilation and bronchopulmonary dysplasia (BPD) in preterm neonates.

STUDY DESIGN

 A retrospective cohort study including 60 neonates born with gestational age (GA) < 34 weeks. The impact of categorical perinatal factors on cord blood levels of CC16 was examined with univariate and multivariate regression analyses.

RESULTS

 In neonates with GA < 32 weeks, cord blood CC16 concentrations were significantly lower compared to neonates with GA between 320/7 and 336/7 weeks (5.4 ± 2.5 compared to 7.6 ± 2.9 ng/mL, p = 0.039). Neonates with prolonged rupture of membranes had significantly lower CC16 compared to those without prolonged rupture of membranes (4.0 ± 1.9 compared to 7.2 ± 2.2, p < 0.001). Finally, neonates with BPD had significantly lower CC16, compared to neonates without BPD (4.2 ± 2.1 compared to 7.0 ± 2.2 ng/mL, p = 0.004).Prolonged rupture of membranes was significantly negatively associated with CC16 (b = -2.67, 95% confidence interval [CI] -0.49 to -4.85, p = 0.017), after adjusting for GA (b = 0.23, 95% CI 0.03-0.42, p = 0.022), mode of conception, and mode of delivery. Finally, higher CC16 levels were significantly inversely associated with BPD (odds ratio = 0.33, 95% CI 0.12-0.88, p = 0.028), after adjusting for GA (b = 0.27, 95% CI 0.09-0.78, p = 0.015), and birth weight.

CONCLUSION

 Prolonged rupture of membranes was significantly negatively associated with cord serum CC16, after adjusting for GA, conception, and delivery mode, and CC16 was significantly inversely associated with BPD, after adjusting for GA and birth weight.

KEY POINTS

· Neonates with prolonged rupture of membranes had lower CC16 levels.. · CC16 was significantly negatively associated with BPD.. · CC16 could be a biomarker of lung injury and BPD..

Improving early diagnosis of bronchopulmonary dysplasia

INTRODUCTION

Bronchopulmonary disease (BPD) is associated with long-term neurodevelopmental and cardiorespiratory complications, often requiring significant use of resources. To reduce this healthcare burden, it is essential that those at high risk of BPD are identified early so that strategies are introduced to prevent disease progression. Our aim was to discuss potential methods for improving early diagnosis in the first week after birth.

AREAS COVERED

A narrative review was undertaken. The search strategy involved searching PubMed, Embase and Cochrane databases from 1967 to 2024. The results of potential biomarkers and imaging modes are discussed. Furthermore, the value of scoring systems is explored.

EXPERT OPINION

BPD occurs as a result of disruption to pulmonary vascular and alveolar development, thus abnormal levels of factors regulating those processes are promising avenues to explore with regard to early detection of high-risk infants. Data from twin studies suggests genetic factors can be attributed to 82% of the observed difference in moderate to severe BPD, but large genome-wide studies have yielded conflicting results. Comparative studies are required to determine which biomarker or imaging mode may most accurately diagnose early BPD development. Models which include the most predictive factors should be evaluated going forward.

Pulmonary phenotypes of bronchopulmonary dysplasia in the preterm infant

Bronchopulmonary dysplasia (BPD) remains the most common complication of premature birth, imposing a significant and potentially life-long burden on patients and their families. Despite advances in our understanding of the mechanisms that contribute to patterns of lung injury and dysfunctional repair, current therapeutic strategies remain non-specific with limited success. Contemporary definitions of BPD continue to rely on clinician prescribed respiratory support requirements at specific time points. While these criteria may be helpful in broadly identifying infants at higher risk of adverse outcomes, they do not offer any precise information regarding the degree to which each compartment of the lung is affected. In this review we will outline the different pulmonary phenotypes of BPD and discuss important features in the pathogenesis, clinical presentation, and management of these frequently overlapping scenarios.

Early Biomarkers of Bronchopulmonary Dysplasia: A Quick Look to the State of the Art

Bronchopulmonary dysplasia (BPD) is one of the most common pulmonary sequelae of extreme preterm birth, with long-lasting respiratory symptoms and reduced lung function. A reliable predictive tool of BPD development is urgent and its search remains one of the major challenges for neonatologists approaching the upcoming arrival of possible new preventive therapies. Biomarkers, identifying an ongoing pathogenetic pathway, could allow both the selection of preterm infants with an evolving disease and potentially the therapeutic targets of the indicted pathogenesis. The "omic" sciences represent well-known promising tools for this objective. In this review, we resume the current laboratoristic, metabolomic, proteomic, and microbiomic evidence in the prediction of BPD. KEY POINTS: · The early prediction of BPD development would allow the targeted implementation of new preventive therapies.. · BPD is a multifactorial disease consequently it is unlikely to find a single disease biomarker.. · "Omic" sciences offer a promising insight in BPD pathogenesis and its development's fingerprints..

Pharmacotherapy in Bronchopulmonary Dysplasia: What Is the Evidence?

Bronchopulmonary Dysplasia (BPD) is a multifactorial disease affecting over 35% of extremely preterm infants born each year. Despite the advances made in understanding the pathogenesis of this disease over the last five decades, BPD remains one of the major causes of morbidity and mortality in this population, and the incidence of the disease increases with decreasing gestational age. As inflammation is one of the key drivers in the pathogenesis, it has been targeted by majority of pharmacological and non-pharmacological methods to prevent BPD. Most extremely premature infants receive a myriad of medications during their stay in the neonatal intensive care unit in an effort to prevent or manage BPD, with corticosteroids, caffeine, and diuretics being the most commonly used medications. However, there is no consensus regarding their use and benefits in this population. This review summarizes the available literature regarding these medications and aims to provide neonatologists and neonatal providers with evidence-based recommendations.

Club Cell Secreted Protein CC16: Potential Applications in Prognosis and Therapy for Pulmonary Diseases

Club cell secretory protein (CC16) is encoded by the SCGB1A1 gene. It is also known as CC10, secretoglobin, or uteroglobin. CC16 is a 16 kDa homodimeric protein secreted primarily by the non-ciliated bronchial epithelial cells, which can be detected in the airways, circulation, sputum, nasal fluid, and urine. The biological activities of CC16 and its pathways have not been completely understood, but many studies suggest that CC16 has anti-inflammatory and anti-oxidative effects. The human CC16 gene is located on chromosome 11, p12-q13, where several regulatory genes of allergy and inflammation exist. Studies reveal that factors such as gender, age, obesity, renal function, diurnal variation, and exercise regulate CC16 levels in circulation. Current findings indicate CC16 not only may reflect the pathogenesis of pulmonary diseases, but also could serve as a potential biomarker in several lung diseases and a promising treatment for chronic obstructive pulmonary disease (COPD). In this review, we summarize our current understanding of CC16 in pulmonary diseases.

Predicting the likelihood of bronchopulmonary dysplasia in premature neonates

Introduction: Bronchopulmonary dysplasia (BPD) is the most common serious pulmonary morbidity in premature infants. Despite ongoing advances in neonatal care, the incidence of BPD has not improved. A potential explanation for this phenomenon is the limited ability for accurate early prediction of the risk of BPD. BPD continues to represent a therapeutic challenge and no single effective therapy exists for this condition. Areas covered: Here, we review risk factors of BPD derived from clinical data, biological fluid biomarkers, respiratory management data, and scientific advancements using 'omics' technologies, and their ability to predict the pathogenesis of BPD in preterm neonates. Risk factors and biomarkers were identified via literature search with a focus on the last 5 years of data. Expert opinion: The most accurate predictive tools utilize risk factors that encompass a variety of categories. Numerous predictive models have been proposed but suffer from a lack of adequate validation. An ideal model should include multiple, easily measurable variables validated across a heterogeneous population. In addition to evaluating recent BPD prediction models, we suggest approaches to enhance future models.

Club cell secretory protein (CC16) in gastric fluid at birth and subsequent lung disease in preterm infants

BACKGROUND

Club cell secretory protein (CC16) probably has a role in protecting the lung from inflammation.

AIM

To evaluate if low levels of CC16 in gastric fluid at birth, reflecting low levels of CC16 in the lung, would be associated with lung inflammation and respiratory morbidity.

METHODS

A study of 64 infants with mean gestational age 26.1 weeks. CC16 was analyzed in gastric fluid at birth. CC16, pro-inflammatory cytokines, and MMP-9 were analyzed in tracheal aspirate within 24 h from birth.

RESULTS

CC16 in gastric fluid increased with gestational age (P = 0.033). Lower concentrations of CC16 in gastric fluid at birth were associated with higher concentrations of IL-1β (P = 0.028), TNF-α (P = 0.034), and MMP-9 (P = 0.015) in tracheal aspirate. Infants who needed mechanical ventilation at 24 and 72 h of age had lower CC16 in gastric fluid than those not ventilated at these ages (P = 0.011 and P = 0.024, respectively). Lower CC16 in gastric fluid was associated with higher FiO₂ at 6 h (P = 0.009), higher PaCO₂ at 24 h (P = 0.03), more ventilator days (P = 0.012) and more days with supplemental oxygen (P = 0.03). Infants who had either died or were still treated with supplemental oxygen at 36 weeks postmenstrual age had lower CC16 in gastric fluid than infants with none of these outcomes (P = 0.049).

CONCLUSION

A low CC16 concentration in gastric fluid at birth was associated with increased inflammation in the trachea within the first 24 h of life and with more need for respiratory support in the neonatal period.

Role of the Nrf2/HO-1 axis in bronchopulmonary dysplasia and hyperoxic lung injuries

Bronchopulmonary dysplasia (BPD) is a chronic illness that usually originates in preterm newborns. Generally, BPD is a consequence of respiratory distress syndrome (RDS) which, in turn, comes from the early arrest of lung development and the lack of pulmonary surfactant. The need of oxygen therapy to overcome premature newborns' compromised respiratory function generates an increasing amount of reactive oxygen species (ROS), the onset of sustained oxidative stress (OS) status, and inflammation in the pulmonary alveoli deputies to respiratory exchanges. BPD is a severe and potentially life-threatening disorder that in the most serious cases, can open the way to neurodevelopmental delay. More importantly, there is no adequate intervention to hamper or treat BPD. This perspective article seeks to review the most recent and relevant literature describing the very early stages of BPD and hyperoxic lung injuries focussing on nuclear factor erythroid derived 2 (Nrf2)/heme oxygenase-1 (HO-1) axis. Indeed, Nrf2/HO1 activation in response to OS induced lung injury in preterm concurs to the induction of certain number of antioxidant, anti-inflammatory, and detoxification pathways that seem to be more powerful than the activation of one single antioxidant gene. These elicited protective effects are able to counteract/mitigate all multifaceted aspects of the disease and may support novel approaches for the management of BPD.

Clara Cell Protein Expression in Mechanically Ventilated Term and Preterm Infants with Respiratory Distress Syndrome and at Risk of Bronchopulmonary Dysplasia: A Pilot Study

The aim of this pilot study was to determine Clara cell protein (CC16) concentration in bronchoalveolar lavages (BAL) fluid from full-term and preterm (<37 weeks' gestational age) neonates requiring respiratory support, having symptoms of neonatal respiratory distress syndrome, and at risk of bronchopulmonary dysplasia (BPD). We hypothesized that CC16 may be predictive of BPD diagnosis regardless of gestational age. BAL fluid CC16 was measured by ELISA at birth and at day 7 of life. Both groups that developed BPD showed significantly decreased BAL fluid CC16 levels compared to those infants that did not develop the disease. CC16 positively correlated with diagnosis of BPD and negatively with the severity of the disease. These results suggest that BAL fluid CC16 levels may have a diagnostic value at day 7 for BPD in both term and preterm infants. This study demonstrates the potential utility of BAL fluid CC16 levels as a biomarker for BPD in term infants.

Biomarkers in Pediatric ARDS: Future Directions

Acute respiratory distress syndrome (ARDS) is common among mechanically ventilated children and accompanies up to 30% of all pediatric intensive care unit deaths. Though ARDS diagnosis is based on clinical criteria, biological markers of acute lung damage have been extensively studied in adults and children. Biomarkers of inflammation, alveolar epithelial and capillary endothelial disruption, disordered coagulation, and associated derangements measured in the circulation and other body fluids, such as bronchoalveolar lavage, have improved our understanding of pathobiology of ARDS. The biochemical signature of ARDS has been increasingly well described in adult populations, and this has led to the identification of molecular phenotypes to augment clinical classifications. However, there is a paucity of data from pediatric ARDS (pARDS) patients. Biomarkers and molecular phenotypes have the potential to identify patients at high risk of poor outcomes, and perhaps inform the development of targeted therapies for specific groups of patients. Additionally, because of the lower incidence of and mortality from ARDS in pediatric patients relative to adults and lack of robust clinical predictors of outcome, there is an ongoing interest in biological markers as surrogate outcome measures. The recent definition of pARDS provides additional impetus for the measurement of established and novel biomarkers in future pediatric studies in order to further characterize this disease process. This chapter will review the currently available literature and discuss potential future directions for investigation into biomarkers in ARDS among children.

Biomarkers, Early Diagnosis, and Clinical Predictors of Bronchopulmonary Dysplasia

The pathogenesis of bronchopulmonary dysplasia (BPD) is multifactorial, and the clinical phenotype of BPD is extremely variable. Several clinical and laboratory biomarkers have been proposed for the early identification of infants at higher risk of BPD and for determination of prognosis of infants with a diagnosis of BPD. The authors review available literature on prediction tools and biomarkers of BPD, using clinical variables and biomarkers based on imaging, lung function measures, and measurements of various analytes in different body fluids that have been determined to be associated with BPD either in a targeted manner or by unbiased omic profiling.

Drug therapy for the prevention and treatment of bronchopulmonary dysplasia

INTRODUCTION

As more infants are surviving at younger gestational ages, bronchopulmonary dysplasia (BPD) remains as a frequent neonatal complication occurring after preterm birth. The multifactorial nature of the disease process makes BPD a challenging condition to treat. While multiple pharmacologic therapies have been investigated over the past two decades, there have been limited advances in the field. Often multiple therapies are used concurrently without clear evidence of efficacy, with potential for significant side effects from drug-drug interactions.

METHODS

Systematic literature review.

CONCLUSION

Although there is physiologic rationale for the use of many of these therapies, none of them has single-handedly altered the incidence, severity, or progression of BPD. Future research should focus on developing clinically significant end-points (short and long term respiratory assessments), investigating biomarkers that accurately predict risk and progression of disease, and creating appropriate stratification models of BPD severity. Applying a multi-modal approach to the study of new and existing drugs should be the most effective way of establishing the optimal prevention and treatment regimens for BPD.

Correlation of serum KL-6 and CC16 levels with neurodevelopmental outcome in premature infants at 12 months corrected age

The aim of this study was to evaluate KL-6 and CC16 levels and their correlation with neurodevelopmental outcome among very low birth weight pre-term infants at 12 months corrected age. This prospective cohort study was performed from 2011 to 2013 by enrolling pre-term neonates of gestational age ≤ 32 weeks and birth weight ≤ 1500 g. Serum KL-6 and CC16 levels were determined 7 days after birth and their correlation with neurodevelopment was evaluated using Gesell Mental Developmental Scales. Of the 86 eligible pre-term infants, 63 completed follow-up, of which 15 had bronchopulmonary dysplasia. At 12 months corrected age, 49 infants had favorable outcomes and 14 infants had poor neurodevelopmental outcome. KL-6 levels were higher and CC16 levels were lower in infants with poor neurodevelopmental outcome compared with those infants who had favourable neurodevelopmental outcome. Serum KL-6 levels less than 90.0 ng/ml and CC16 levels greater than 320.0 pg/ml at 7 days of life were found to be predictive of a favourable outcome at 12 months corrected age. These biological markers could predict neurodevelopmental outcome at 12 months corrected age in very low birth weight premature infants, and help the clinician plan early therapeutic interventions to minimize or avoid poor neurodevelopmental outcome.

A comparison of KL-6 and Clara cell protein as markers for predicting bronchopulmonary dysplasia in preterm infants

OBJECTIVES

To evaluate the predictive characteristics of KL-6 and CC16 for bronchopulmonary dysplasia (BPD) in preterm infants, either independently or in combination.

STUDY DESIGN

This prospective cohort study was performed from 2011 to 2013 with preterm neonates of gestational age ≤32 weeks and birth weight ≤1500 g. Serum KL-6 and CC16 levels were determined 7 and 14 days after birth.

RESULTS

Seventy-three preterm infants were studied. BPD was identified in 24 of these infants. After adjusting for potential confounders, serum KL-6 concentrations were found to be elevated in BPD infants at both time points relative to non-BPD infants, while serum CC16 concentrations were lower at 14 days. At both 7 d and 14 d of life the predictive power of KL-6 levels exceeded that of CC16 (area under receiver operating characteristic curve: at 7 d, 0.91 cf. 0.73, P = 0.02; at 14 d, 0.95 cf. 0.85, P = 0.05). The combination of these markers enhanced the sensitivity further.

CONCLUSIONS

Serum KL-6 levels higher than 79.26 ng/mL at 14 days postpartum in preterm infants predict the occurrence of BPD. CC16 was less predictive than KL-6 at this time point, but KL-6 and CC16 together enhanced the prediction.

Predictive value of soluble urokinase plasminogen activator receptor, soluble ST2, and IL-33 in bronchopulmonary dysplasia

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains an important complication of preterm births. The soluble form of ST2 (sST2), interleukin-33 (IL-33), and soluble form of the urokinase plasminogen activator receptor (suPAR) have attracted increasing attention as biomarkers for different diseases. The aim of the current study was to assess the predictive value of plasma sST2, IL-33, and suPAR levels in patients with risk of BPD development.

METHODS

A total of 38 babies were studied prospectively on delivery to the neonatal intensive care unit. Serum levels of IL-33, sST2, and suPAR were measured using enzyme-linked immunosorbent assay. Serum samples were collected from umbilical cord (at the time of delivery, termed CB) and peripheral blood (on day 14, termed PB).

RESULTS

Levels of suPAR (PB-suPAR) and sST2 (PB-sST2) in the peripheral blood of the BPD group were significantly higher than the corresponding levels in the non-BPD group (P < 0.001, P = 0.028, respectively. There was a statistically significant correlation between PB-suPAR levels and the severity of BPD (P < 0.001)) when the suPAR results were analyzed using the receiver operating characteristic curve.

CONCLUSION

PB-suPAR and PB-sST2 levels are sensitive and specific independent predictive biomarkers in preterm babies with BPD.

Early biomarkers as predictors for bronchopulmonary dysplasia in preterm infants: a systematic review

BACKGROUND

Bronchopulmonary dysplasia (BPD) is usually diagnosed in preterm infants at least 28 days after birth. Great interest lies in the potential to identify biomarkers that predict development of the disease and future neurodevelopmental outcomes. We have reviewed the existing literature on early biomarkers as predictors for BPD in preterm infants.

METHODS

Two reviewers independently searched the databases of PubMed, EMBASE, and Google Scholar for studies pertaining to biomarkers for BPD. Studies were assessed using Quality Assessment of Diagnostic Accuracy Studies criteria.

RESULTS

We identified 46 relevant articles that are summarized in the review. These studies assessed over 30 potential biomarkers. Sensitivity and specificity of biomarkers were reported or could be calculated for only 16 articles, and ranged from 0 to 100 %. Based on the nine highest quality studies, serum KL-6, CC16, neutrophil gelatinase-associated lipocalin, and end-tidal carbon monoxide (etCO) perform extremely well in predicting the early diagnosis of established BPD, highlighting these biomarkers as promising candidates for future research.

CONCLUSIONS

Published data from studies on serum biomarkers and etCO suggest that biomarkers may have great potential to predict the subsequent BPD and neurodevelopmental outcomes. These biomarkers need validation in larger studies, and the generalizability of biomarkers for predicting BPD, as well as the neurodevelopmental outcomes, needs to be further explored.

Neonatal hyperoxic exposure persistently alters lung secretoglobins and annexin A1

Altered functions of the lung epithelial surface likely contribute to the respiratory morbidities in infants with bronchopulmonary dysplasia (BPD). Infants with BPD exhibit decreased expressions of secretoglobins (SCGBs), including Clara cell secretory protein (CCSP). Expression of lung SCGB and annexin A1 (ANXA1) is persistently altered in CCSP knockout mice suggesting that CCSP indirectly influences innate immune responses. The present studies tested the hypothesis that neonatal hyperoxic exposure induces deficits in CCSP expression that are associated with persistent alterations in lung SCGB and ANXA1 expression. Newborn C3H/HeN mice were exposed to room air (RA) or 85% O2 from birth and were sacrificed at 14 d or returned to RA for 14 d. Neonatal hyperoxia followed by RA recovery was associated with decreased lung CCSP and SCGB3A1 protein but not mRNA expression. Hyperoxia-induced alterations in the charge characteristics of ANXA1 were unchanged by RA recovery and were associated with elevated lung macrophage numbers. These findings support a model in which hyperoxia-induced alterations in Clara cell function influence lung innate immune function through effects on immunomodulatory proteins. Studies to determine the mechanism(s) by which CCSP alterations affect SCGBs, ANXA1, and innate immune responses in BPD are warranted.

Biomarkers in bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is a complex disorder secondary to gene-environment interactions, and is the commonest chronic lung disease in infancy. There is no specific or effective treatment available to date for BPD. Since the aetiopathogenesis of BPD is multifactorial, involving diverse molecular signaling pathways, a variety of biomarkers detected in biological fluids have been proposed for early identification of infants predisposed to BPD. This review will be restricted to biomarker studies in human infants, conducted mostly in the last decade. The majority of the studies have been conducted using blood, urine or tracheal aspirate samples. Despite the multitude of biomarkers proposed, most studies have been conducted in small numbers of infants, with few being replicated by independent investigators. Confirmatory studies with adequate sample sizes and assessment of the role of putative biomarkers in the aetiology of BPD in developmentally appropriate animal models and human lungs with BPD will enhance the potential for therapeutic interventions. Genomic and proteomic approaches have the greatest potential to significantly advance the field of biomarkers in BPD.

Genome-wide transcriptional profiling reveals connective tissue mast cell accumulation in bronchopulmonary dysplasia

RATIONALE

Bronchopulmonary dysplasia (BPD) is a major complication of premature birth. Risk factors for BPD are complex and include prenatal infection and O(2) toxicity. BPD pathology is equally complex and characterized by inflammation and dysmorphic airspaces and vasculature. Due to the limited availability of clinical samples, an understanding of the molecular pathogenesis of this disease and its causal mechanisms and associated biomarkers is limited.

OBJECTIVES

Apply genome-wide expression profiling to define pathways affected in BPD lungs.

METHODS

Lung tissue was obtained at autopsy from 11 BPD cases and 17 age-matched control subjects without BPD. RNA isolated from these tissue samples was interrogated using microarrays. Standard gene selection and pathway analysis methods were applied to the data set. Abnormal expression patterns were validated by quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

We identified 159 genes differentially expressed in BPD tissues. Pathway analysis indicated previously appreciated (e.g., DNA damage regulation of cell cycle) as well as novel (e.g., B-cell development) biological functions were affected. Three of the five most highly induced genes were mast cell (MC)-specific markers. We confirmed an increased accumulation of connective tissue MC(TC) (chymase expressing) mast cells in BPD tissues. Increased expression of MC(TC) markers was also demonstrated in an animal model of BPD-like pathology.

CONCLUSIONS

We present a unique genome-wide expression data set from human BPD lung tissue. Our data provide information on gene expression patterns associated with BPD and facilitated the discovery that MC(TC) accumulation is a prominent feature of this disease. These observations have significant clinical and mechanistic implications.

Early postnatal surge of serum Clara cell secretory protein in newborn infants

BACKGROUND

Clara cell secretory protein (CCSP) is an anti-inflammatory mediator, but its role in neonatal lung adaptation and diseases is uncertain.

OBJECTIVE

To characterize postnatal changes in serum CCSP in relation to gestation, respiratory disease (RDS) and bronchopulmonary dysplasia (BPD) in comparison with other anti-inflammatory cytokines (IL-4, -10 and -13).

METHODS

Blood was collected from 76 infants (26 of 23-29 weeks' gestation, 33 of 30-36 weeks' gestation and 17 term infants) at birth (preterm cord blood); on admission; at 12, 24 and 48 h; and on days 3-4 and 7 of life. CCSP was assayed by ELISA and cytokines by Bio-Plex.

RESULTS

Median serum CCSP in extremely and moderately preterm infants rose from a baseline of 13.6 and 15.9 to 33.4 ng/ml (p = 0.04) and 59.8 ng/ml (p = 0.03) at 12 h of age, respectively. CCSP levels were highest in term infants (80.7 ng/ml at 12 h). CCSP then decreased to 22.5 ng/ml on days 3-4 (p = 0.001). CCSP of 37 RDS infants fell to a lower baseline on days 4 and 7 than that of the 22 non-RDS preterms. The 8 infants who developed BPD had persistently low serum CCSP (12.7 ng/ml at 12 h). In contrast, early postnatal changes were not seen in IL-4, -10 and -13 levels, but low IL-10 and -13 levels were found on day 7 in BPD infants.

CONCLUSIONS

Serum CCSP levels were characterized by an early postnatal surge. This apparent gestation-influenced surge may represent an initiation of a protective cascade against postnatal lung injury during extrauterine adaptation.

Comparable effect of conventional ventilation versus early high-frequency oscillation on serum CC16 and IL-6 levels in preterm neonates

OBJECTIVE

Clara cell 16 kD protein (CC16) and interleukin (IL)-6 have been used as peripheral blood biomarkers of alveolar leakage and inflammation, respectively. Thus, their measurement in the bloodstream could be used to assess ventilator-induced lung injury. The objective of this study was to evaluate the effect of optimized synchronized intermittent mandatory ventilation (SIMV) and high-frequency oscillatory ventilation (HFOV) on circulating CC16 and IL-6 levels when used as the initial ventilation modes in preterm neonates.

STUDY DESIGN

Single center, prospective, randomized clinical study in preterm neonates (gestational age 30 weeks) requiring mechanical ventilation within the first 2 h of life. Serum CC16 and IL-6 were measured on establishment of the assigned ventilation mode after admission, at days 3 and 14 of life as well as at 36 weeks postmenstrual age. Demographic-perinatal data and clinical parameters were also recorded.

RESULT

Of the 30 neonates studied, 24 (gestational age 27.1±1.7 weeks, birth weight 942±214 g) were finally analyzed, equally assigned into the SIMV and HFOV groups. Both groups had comparable demographic-perinatal characteristics and clinical parameters. Serum CC16 and IL-6 altered significantly over time (repeated-measures analysis of variance, both P<0.001). However, changes were not affected by the ventilation mode. Post hoc analysis showed a significant decrease in CC16 and IL-6 from birth up to 36 weeks postmenstrual age in both groups.

CONCLUSION

In preterm neonates, SIMV and HFOV are associated with comparable circulating CC16 and IL-6 levels. These findings suggest a similar alveolar leakage and systemic inflammation with any of the ventilation modes evaluated when their usage is optimized.

Clara cell protein in bronchoalveolar lavage fluid: a predictor of ventilator-associated pneumonia?

Introduction

Clara cell protein 10 (CC-10) has been associated with inflammatory and infectious pulmonary diseases. This study evaluates CC-10 concentrations in bronchoalveolar lavage (BAL) fluid as a potential marker of ventilator-associated pneumonia (VAP).

Methods

Between January 2003 and December 2007, BAL fluid samples obtained from critically ill patients at the intensive care unit of the Maastricht University Medical Centre clinically suspected of having VAP were included. Patients were divided into two groups: (1) microbiologically confirmed VAP (the VAP group) and (2) microbiologically unconfirmed VAP (the non-VAP group). The concentration of CC-10 was measured by means of a commercially available enzyme-linked immunosorbent assay kit, and retrospective analysis was performed. Areas under the curve of receiver operating characteristic curves were calculated for CC-10 concentrations.

Results

A total of 196 patients (122 men, 74 women) were included. A total of 79 (40%) of 196 cases of suspected VAP were microbiologically confirmed. The median CC-10 concentration in the VAP group was 3,019 ng/mL (range, 282 to 65,546 ng/mL) versus 2,504 ng/mL (range, 62 to 30,240 ng/mL) in the non-VAP group (P = 0.03). There was no significant difference in CC-10 concentrations between patients treated with or without corticosteroids (P = 0.26) or antibiotic therapy (P = 0.9). The CC-10 concentration did not differ significantly between patients with Gram-positive versus Gram-negative bacteria that caused the VAP (P = 0.06). However, CC-10 concentrations did differ significantly between the late-onset VAP group and the non-VAP group.

Conclusions

The CC-10 concentration in BAL fluid yielded low diagnostic accuracy in confirming the presence of VAP.

Clara cell protein in full-term pregnancies: the influence of intrauterine growth restriction

BACKGROUND

Clara cell protein (CC16) is an immunomodulatory/anti-inflammatory broncho-alveolar-derived molecule and a biomarker of pulmonary epithelial cells maturity and alveolo-capillary membrane injury. Intrauterine growth-restricted (IUGR) neonates may present with structural lung immaturity, impaired immunocompetence and increased risk for respiratory infections and chronic obstructive lung disease in later life.

OBJECTIVES

To investigate circulating CC16 concentrations in maternal, fetal, and neonatal samples from IUGR and appropriate for gestational age (AGA) pregnancies.

METHODS

Serum CC16 concentrations were determined by EIA in 40 mothers and their 20 IUGR and 20 AGA singleton full-term fetuses-neonates on postnatal days 1 (N1) and 4 (N4).

RESULTS

No significant differences in CC16 concentrations were observed between IUGR and AGA groups. In both groups, maternal CC16 concentrations were lower compared to N1 and N4 ones (P < 0.001 in each case). Fetal CC16 concentrations were significantly lower compared to N1 and N4 ones (P < 0.001 in each case). In the AGA group, N1 CC16 concentrations were significantly higher than N4 ones (P < 0.001). Combining groups, N1 CC16 concentrations positively correlated with gestational age (r = 0.364, P = 0.021). Finally, the effect of gender, parity, and maternal age on CC16 concentrations was not significant.

CONCLUSIONS

The lack of differences in CC16 concentrations between IUGR and AGA groups possibly suggests that the lung immaturity and later respiratory diseases, associated with the former, may not be related to early CC16 deficiency. CC16 concentrations increase with advancing gestational age and peak on the first day of life, possibly indicating a vital role of the protein in fetal lung maturation and extrauterine pulmonary adaptation.