Bronchoalveolar lavage in children. ERS Task Force on bronchoalveolar lavage in children. European Respiratory Society

Correlation of levels of alpha-defensins determined by HPLC-ESI-MS in bronchoalveolar lavage fluid with the diagnosis of pneumonia in premature neonates

The presence of alpha-defensins in bronchoalveolar lavage fluid (BALF) was investigated in a cohort of preterm newborns with gestational age (GA) < or =30 wk. Specimens were collected during the first week of life from 24 preterm neonates mechanically ventilated. The studied population was divided into two groups: pneumonia group of nine neonates suffering from pulmonary infection (GA: 26.1 +/- 2.1 wk; birth weight: 787.4 +/- 309.9 g), with or without associated bloodstream infection, and nonpneumonia group of 15 neonates (GA: 27.7 +/- 2.0 wk; birth weight: 1019.0 +/- 319.8 g). BALF culture was positive for CONS (n = 5), Staphylococcus aureus (n = 1), and Candida spp (n = 3). BALF samples were analyzed by HPLC-electrospray Ionization-mass spectrometer. The alpha-defensins 1-4 concentration, absolute and differential white cells count were measured. Relative amounts of alpha-defensins 1-4 and the absolute number of neutrophils were found significantly higher in the pneumonia group with respect to the nonpneumonia group (p < 0.05). Moreover, positive significant correlations between the number of neutrophils and the alpha-defensins 1-3 levels were observed. In conclusion, our data show that preterm newborns, also at the lower GA, are able to produce alpha-defensins, underlining that their innate defense system is already active before the at-term delivery date.

Pediatric bronchoalveolar lavage: practical considerations and future prospects

Despite the utilization of bronchoalveolar lavage (BAL) in children since the early 1970s, several challenges remain once the procedure is complete. These include little documentation on normal controls, the limitations due to the size of the patient, and uniform processes for assessment. It was not until 1995 that a taskforce on pediatric BAL was formed by the European Respiratory Society, and to our knowledge, they remain the only committee evaluating the process [1]. We examined our procedures and reviewed the literature in an attempt to document the most fruitful practices that would allow improved data comparison and introduce possible investigations.

Relationship of proteinases and proteinase inhibitors with microbial presence in chronic lung disease of prematurity

BACKGROUND

A proteolytic imbalance has been implicated in the development of "classical" chronic lung disease of prematurity (CLD). However, in "new" CLD this pattern has changed. This study examines the longitudinal relationship between neutrophil proteinases and their inhibitors in ventilated preterm infants and their relationship to microbial colonisation.

METHODS

Serial bronchoalveolar lavage fluid was obtained from ventilated newborn preterm infants. Neutrophil elastase (NE) activity, cell counts, metalloproteinase (MMP)-9, MMP-9/TIMP-1 complex, SerpinB1 concentration and percentage of SerpinB1 and alpha(1)-antitrypsin (AAT) in complex with elastase were measured. The presence of microbial genes was examined using PCR for 16S rRNA genes.

RESULTS

Statistically more infants who developed CLD had NE activity in at least one sample (10/20) compared with infants with resolved respiratory distress syndrome (RDS) (2/17). However, NE activity was present in a minority of samples, occurring as episodic peaks. Peak levels of MMP-9, MMP-9/TIMP-1 complex, percentage of AAT and SerpinB1 in complex and cell counts were all statistically greater in infants developing CLD than in infants with resolved RDS. Peak values frequently occurred as episodic spikes and strong temporal relationships were noted between all markers. The peak values for all variables were significantly correlated to each other. The presence of bacterial 16S rRNA genes was associated with the development of CLD and with elevated elastase and MMP-9.

CONCLUSION

NE activity and MMP-9 appear to be important in the development of "new" CLD with both proteinase and inhibitor concentrations increasing episodically, possibly in response to postnatal infection.

Diagnosis of ventilator-associated pneumonia in children in resource-limited setting: a comparative study of bronchoscopic and nonbronchoscopic methods

OBJECTIVES

To compare the available methods for the diagnosis of ventilator-associated pneumonia in intubated pediatric patients and to suggest less costly diagnostic method for developing countries.

DESIGN

Prospective study.

SETTING

Pediatric intensive care unit of a tertiary care, multidisciplinary teaching hospital located in northern India.

PATIENTS

All consecutive patients on mechanical ventilation for >48 hrs were evaluated clinically for ventilator-associated pneumonia.

INTERVENTIONS

Four diagnostic procedures (tracheal aspiration, blind bronchial sampling, blind bronchoalveolar lavage, and bronchoscopic bronchoalveolar lavage) were performed in the same sequence within 12 hrs of clinical suspicion of ventilator-associated pneumonia. The bacterial density > or =104 colony-forming units/mL in a bronchoscopic bronchoalveolar lavage sample was taken as reference standard.

MEASUREMENTS AND MAIN RESULTS

Thirty patients with 40 episodes of ventilator-associated pneumonia were included in the study. Tracheal aspirate at the cutoff of > or =105 colony-forming units/mL was found to have sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 84%, 77%, 87.5%, 73%, and 80%, respectively. For blind bronchial sampling at > or =104 colony-forming units/mL cutoff, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 88%, 82%, 88%, 83%, and 87%, respectively; the most reliable results were obtained with blind bronchoalveolar lavage at the cutoff of > or =103 cfu/mL (sensitivity 96%, specificity 80%, positive predictive value 88%, negative predictive value 92%, and accuracy 90%). The area under the receiver operating characteristic curve of tracheal aspiration, blind bronchial sampling, and blind bronchoalveolar lavage was 0.87 +/- 0.06, 0.89 +/- 0.06, and 0.89 +/- 0.05, respectively. The cost of balloon-tip pressure catheter used for blind bronchoalveolar lavage was INR 1600.00 (US$40) whereas that for blind bronchial sampling was only INR 35.00 (<1 US$).

CONCLUSIONS

Blind bronchoalveolar lavage was the most reliable method followed closely by blind bronchial sampling for the diagnosis of ventilator-associated pneumonia. Considering the difference of the cost in the two procedures, blind bronchial sampling may be the preferred method in the pediatric intensive care unit of a developing country.

Chronic interstitial lung diseases in children

Interstitial lung diseases (ILDs) in children constitute a heterogeneous group of rare diseases that have been described and classified according to experiences and research in adults. However, pediatric pulmonologists have observed that the clinical spectrum is broader in children than in adults, and that many of these disorders have different courses and treatment responses. In addition, probably due to the various stages of lung development and maturation, new clinical forms have been described, particularly in infants. This has broadened the classification of ILDs in this age bracket. The understanding that neither the usual definition nor the standard classification of these disorders entirely apply to children has prompted multicenter studies designed to increase knowledge of these disorders, as well as to standardize diagnostic and therapeutic strategies. We have reviewed the conceptualization of ILDs in children, taking into consideration the particularities of this group of patients when using the criteria for the classification of these diseases in adults. We have also made a historical review of several multicenter studies in order to further understanding of the problem. We have emphasized the differences in the clinical presentation, in an attempt to highlight knowledge of newly described entities in young children. We underscore the need to standardize management of laboratory and radiological routines, as well as of lung biopsy processing, taking such knowledge into account. It is important to bear in mind that, among the recently described disorders, genetic surfactant dysfunction, which is often classified as an idiopathic disease in adults, should be included in the differential diagnosis of ILDs.

Early alterations of growth factor patterns in bronchoalveolar lavage fluid from preterm infants developing bronchopulmonary dysplasia

Chronic lung disease of prematurity (bronchopulmonary dysplasia; BPD) is characterized by an arrest in lung development. We hypothesized that early alterations in pulmonary expression of growth factors important for normal lung development would precede development of BPD. Bronchoalveolar lavage fluid (BALF) was obtained from ventilated preterm infants (n = 62) on postnatal d 0, 1, 3, and 7 and analyzed for total phospholipids (PL), VEGF, PDGF-BB, TGF-alpha and -beta1, granulocyte macrophage colony stimulating factor (GM-CSF), and keratinocyte growth factor (KGF). Levels (Ln transformed) were compared between infants developing BPD and BPD-free survivors, adjusted for potential confounders. BPD was associated with higher overall GM-CSF (beta (95% CI) = 0.69 (0.13;1.25); p < 0.05), lower overall latent TGF-beta1 (beta (95% CI) = -1.19 (-1.87, -0.39); p < 0.01) and total PL (beta (95% CI) = -0.64 (-1.23, -0.05); p < 0.05), and lower d 0 and 3 levels of VEGF (mean difference (95% CI) = -1.75 (-2.72, -0.77), p < 0.001; and -1.18 (-2.30, -0.06), p < 0.05, respectively) and TGF-alpha (mean difference (95% CI) = -0.73 (-1.42, -0.04), p < 0.05; and -1.01 (-1.64, -0.38), p < 0.01, respectively). Day 0 VEGF levels had the highest predictive value for BPD (area under receiver operating characteristic curve = 0.87; p < 0.01). In conclusion, substantial alterations in BALF growth factor levels are present in infants developing BPD. An early imbalance in pulmonary growth factors may contribute to the developmental arrest of the lung seen in BPD.

Corticosteroid responsiveness and clinical characteristics in childhood difficult asthma

This study describes the clinical characteristics and corticosteroid responsiveness of children with difficult asthma (DA). We hypothesised that complete corticosteroid responsiveness (defined as improved symptoms, normal spirometry, normal exhaled nitric oxide fraction (F(eNO)) and no bronchodilator responsiveness (BDR <12%)) is uncommon in paediatric DA. We report on 102 children, mean+/-sd age 11.6+/-2.8 yrs, with DA in a cross-sectional study. 89 children underwent spirometry, BDR and F(eNO) before and after 2 weeks of systemic corticosteroids (corticosteroid response study). Bronchoscopy was performed after the corticosteroid trial. Of the 102 patients in the cross-sectional study, 88 (86%) were atopic, 60 (59%) were male and 52 (51%) had additional or alternative diagnoses. Out of the 81 patients in the corticosteroid response study, nine (11%) were complete responders. Of the 75 patients with symptom data available, 37 (49%) responded symptomatically, which was less likely if there were smokers in the home (OR 0.31, 95% CI 0.02-0.82). Of the 75 patients with available spirometry data, 35 (46%) had normal spirometry, with associations being BAL eosinophilia (OR 5.43, 95% CI 1.13-26.07) and high baseline forced expiratory volume in 1 s (FEV(1)) (OR 1.08, 95% CI 1.02-1.12). Of these 75 patients, BDR data were available in 64, of whom 36 (56%) had <12% BDR. F(eNO) data was available in 70 patients, of whom 53 (75%) had normal F(eNO). Airflow limitation data was available in 75 patients, of whom 17 (26%) had persistent airflow limitation, which was associated with low baseline FEV(1) (OR 0.93, 95% CI 0.90-0.97). Only 11% of DA children exhibited complete corticosteroid responsiveness. The rarity of complete corticosteroid responsiveness suggests alternative therapies are needed for children with DA.

Pitfalls, problems, and progress in bronchopulmonary dysplasia

Bronchopulmonary dysplasia is a chronic lung disease associated with premature birth and characterized by early lung injury. In this review we discuss some pitfalls, problems, and progress in this condition over the last decade, focusing mainly on the last 5 years, limited to studies in human neonates. Changes in the definition, pathogenesis, genetic susceptibility, and recent biomarkers associated with bronchopulmonary dysplasia will be discussed. Progress in current management strategies, along with novel approaches/therapies, will be critically appraised. Finally, recent data on long-term pulmonary and neurodevelopmental outcomes of infants with bronchopulmonary dysplasia will be summarized.

Bronchoalveolar lavage MMP-9 and TIMP-1 in preschool wheezers and their relationship to persistent wheeze

Atopic preschool children are more likely to develop persistent wheezing, which could be a consequence of early airway remodeling. Protease-antiprotease balance between MMP-9 and its cognate inhibitor TIMP-1 may be involved in this process. Our hypothesis was that atopic wheezing preschool children would have an imbalance of MMP-9 to TIMP-1 in bronchoalveolar lavage (BAL). BAL from 52 preschool wheezers was compared with 14 controls without wheeze. A subgroup completed an International Study of Asthma and Allergy in Childhood symptom questionnaire 2 y later. Molar ratios of MMP-9/TIMP-1 were higher in wheezy children (p < 0.001; median 4.0%, range 0-8.7) than controls (0.6%, 0-1.8), and showed an excess of TIMP-1 in the airway. BAL TIMP-1 was raised in children with persistent wheezing (p = 0.028; 34.4 ng/mL, 9.1-93.1 compared with 10.6 ng/mL 6.1-18.6), as was serum levels of intercellular adhesion molecule-1 (p = 0.027). The absolute concentration of TIMP-1 in the airway, rather than its molar ratio with MMP-9, was associated with persistent wheezing. The processes involved with airway remodeling are complex but excess TIMP-1 may impede matrix protein turnover and thereby contribute to persistent changes in airway structure and wheezing.

Angiopoietin 2 concentrations in infants developing bronchopulmonary dysplasia: attenuation by dexamethasone

OBJECTIVES

To study the association between angiopoietin 2 (Ang2) concentrations in tracheal aspirates (TAs) and adverse outcome (bronchopulmonary dysplasia (BPD)/death) in ventilated premature infants (VPIs) and modulation of Ang2 concentrations with dexamethasone (Dex) use.

STUDY DESIGN

Serial TA samples were collected on days 1, 3, 5 and 7, and Ang2 concentrations were measured. Ang2 TA concentrations were compared prior to and after 48 to 72 h of using Dex.

RESULT

A total of 151 TA samples were collected from 60 VPIs. BPD was defined as the oxygen requirement at 36 weeks postmenstrual age (PMA). Twelve infants (mean+/-s.d.) (gestational age (GA) 26.5+/-2.1 weeks, birth weight (BW) 913+/-230 g) had no BPD, 32 infants (GA 25.8+/-1.4 weeks, BW 768+/-157 g) developed BPD and 16 infants (GA 24.5+/-1.1 weeks, BW 710+/-143 g) died before 36 weeks PMA. Ang2 concentrations were significantly lower in infants with no BPD (median, 25th and 75th percentile) (157, 16 and 218 pg mg(-1)) compared with those who developed BPD (234, 138 and 338 pg mg(-1), P=0.03) or BPD and/or death (234, 157 and 347 pg mg(-1), P=0.017), in the first week of life. Twenty-six VPIs (BW 719+/-136 g, GA 25.1+/-1.3 weeks) received 27 courses of Dex. Ang2 concentrations before starting Dex were 202, 137 and 278 pg mg(-1) and significantly decreased to 144, 0 and 224 pg mg(-1) after therapy (P=0.007).

CONCLUSIONS

Higher Ang2 concentrations in TAs are associated with the development of BPD or death in VPIs. Dex use suppressed Ang2 concentrations.

Pepsin, a marker of gastric contents, is increased in tracheal aspirates from preterm infants who develop bronchopulmonary dysplasia

OBJECTIVE

The objective of this study was to study the association between pepsin in tracheal aspirate samples and the development of bronchopulmonary dysplasia in preterm infants.

METHODS

Serial tracheal aspirate samples were collected during the first 28 days from mechanically ventilated preterm neonates. Bronchopulmonary dysplasia was defined as the need for supplemental oxygen at 36 weeks' postmenstrual age. An enzymatic assay with a fluorescent substrate was used to detect pepsin. Total protein was measured by the Bradford assay to correct for the dilution during lavage. Immunohistochemistry using antibody against human pepsinogen was performed in 10 lung tissue samples from preterm infants.

RESULTS

A total of 256 tracheal aspirate samples were collected from 59 preterm neonates. Pepsin was detected in 234 (91.4%) of 256 of the tracheal aspirate samples. Twelve infants had no bronchopulmonary dysplasia, 31 infants developed bronchopulmonary dysplasia, and 16 infants died before 36 weeks' postmenstrual age. The mean pepsin concentration was significantly lower in infants with no bronchopulmonary dysplasia compared with those who developed bronchopulmonary dysplasia or developed bronchopulmonary dysplasia/died before 36 weeks' postmenstrual age. Moreover, the mean pepsin level was significantly higher in infants with severe bronchopulmonary dysplasia compared with moderate bronchopulmonary dysplasia. The mean pepsin level in tracheal aspirate samples from the first 7 days was also lower in infants with no bronchopulmonary dysplasia compared with those who developed bronchopulmonary dysplasia or developed bronchopulmonary dysplasia/died before 36 weeks' postmenstrual age. Pepsinogen was not localized in the lung tissues by immunohistochemistry.

CONCLUSION

The concentration of pepsin was increased in the tracheal aspirate of preterm infants who developed bronchopulmonary dysplasia or died before 36 weeks' postmenstrual age. Recovery of pepsin in tracheal aspirate samples is secondary to gastric aspiration, not by hematogenous spread or local synthesis in the lungs. Chronic aspiration of gastric contents may contribute in the pathogenesis of bronchopulmonary dysplasia.

[Bronchoalveolar lavage]

Bronchoalveolar lavage (BAL) has become an established method for the diagnosis of infectious and interstitial lung diseases. Using a bronchoscope material from the peripheral airways and alveolar spaces can be obtained. When standard protocols are followed the procedure is generally well tolerated and in combination with clinical tests allows a reliable diagnosis in many cases. Certain clinical entities, e.g. alveolar proteinosis and Langerhans cell histiocytosis can be diagnosed by BAL alone without resorting to invasive diagnostic tests. In other diseases, BAL allows to narrow the range of the differential diagnosis. However, biopsies can often still not be avoided completely. A combination of both methods together with the clinical findings represents a powerful tool for diagnosis and research into the pathologic alterations in inflammatory and fibroising lung diseases.

Severe respiratory syncytial virus bronchiolitis in infants is associated with reduced airway interferon gamma and substance P

Background

Severe human respiratory syncytial virus (hRSV) bronchiolitis in previously well infants may be due to differences in the innate immune response to hRSV infection. Aim: to determine if factors mediating proposed mechanisms for severe bronchiolitis differ with severity of disease.

Methodology/Principle Findings

197 infants admitted to hospital with hRSV bronchiolitis were recruited and grouped according to no oxygen requirement (n = 27), oxygen dependence (n = 114) or mechanical ventilation (n = 56). We collected clinical data, nasopharyngeal aspirate (NPA) and if ventilated bronchoalveolar lavage (BAL). Interferon-gamma (IFN-γ), substance P (SP), interleukin 9 (IL-9), urea and hRSV load, were measured in cell free supernatant from NPA and BAL. Multivariate analysis compared independent effects of clinical, virological and immunological variables upon disease severity. IFN-γ and SP concentrations were lower in NPA from infants who required oxygen or mechanical ventilation. Viral load and IL-9 concentrations were high but did not vary with severity of disease. Independent predictors of severe disease (in diminishing size of effect) were low weight on admission, low gestation at birth, low NPA IFN-γ and NPA SP. Nasal airway sampling appears to be a useful surrogate for distal airway sampling since concentrations of IFN-γ, SP, IL-9 and viral load in NPA correlate with the same in BAL.

Conclusions

Our data support two proposed mechanisms for severe hRSV disease; reduced local IFN-γ response and SP mediated inflammation. We found large amounts of hRSV and IL-9 in airways secretions from the upper and lower respiratory tract but could not associate these with disease severity.

Comparison of atopic and nonatopic children with chronic cough: bronchoalveolar lavage cell profile

Chronic cough is a common complaint in children and its relationship with asthma is controversial. The aim of the present study was to determine the pattern of airway inflammation in atopic and nonatopic children with chronic cough, and to investigate whether atopy is a predictive factor for eosinophilic inflammation in cough. Bronchoalveolar lavage (BAL; three aliquots of 1 ml/kg saline) was performed in the right middle lobe of 24 (11 atopic and 13 nonatopic) children with persistent cough (8 females, 16 males), mean age 4.7 years (range: 1-11). Atopy was defined as an elevated total serum IgE or a positive RAST test. Both atopic and nonatopic children with persistent cough had an increase in total cells/ml in BAL (atopic: median 39 x 10(4), range: 20-123; nonatopic: median 22 x 10(4), range: 17-132) compared to nonatopic controls (median 11 x 10(4), range 9-30). The increases were mainly in neutrophils (atopic: median 17%, range 2.5-88.5%; nonatopic: median 6%, range 1.0-55.0%) compared to controls (median 1.55%, range 0.5-7.0%; atopics vs. controls, P < 0.005). There were no significant increases in eosinophils, lymphocytes, epithelial cells, or mast cells. Eosinophils were elevated in only 5/11 atopic and none of the nonatopic children. The increased percentage of neutrophils in the BAL fluid of atopic and nonatopic children with persistent cough could be due to an underlying inflammatory process driving the cough, or even conceivably, due to the effect of coughing itself. In this highly selected series, the absence of eosinophilic inflammation in the majority suggests that most would be predicted not to respond to inhaled corticosteroid therapy. This study underscores the need to be cautious about treating coughing children with inhaled corticosteroids, even in the context of a tertiary referral practice.

Lung inflammation and pulmonary function in infants with meconium aspiration syndrome

OBJECTIVE

To evaluate the relationship between inflammation and pulmonary function, we quantified changes in inflammatory cellular profile, pro-inflammatory cytokines, and pulmonary function in intubated neonates with meconium aspiration syndrome (MAS).

METHODS

Sixteen term infants were studied. Tracheal aspirate fluids, obtained within the first 6, 24, 48, and 96 hr of life were used for measurements of: (1) cellular profile changes; (2) mRNA and protein levels for pro-inflammatory cytokines, IL-1beta, IL-6, IL-8, and TNF-alpha, using RT-PCR and ELISA. Using the same time points as above, we determined mean airway pressure, oxygenation index (OI), alveolar-arterial oxygen gradient, and arterial/alveolar oxygen ratio. Baseline tidal volume and pulmonary compliance were obtained.

RESULTS

Birth weight was 3,820 +/- 656 g, gestational age 39.8 +/- 1.4 weeks. Mean airway pressure and OI significantly decreased from the first 6-96 hr of age (P = 0.01, P = 0.027). Cell counts were elevated in the first 6 hr compared to 96 hr (17.4 x 10(6)/ml vs. 1.5 x 10(6)/ml, P < 0.05). Pro-inflammatory cytokines decreased from the first 6-96 hr: IL-1beta (187 vs. 37 pg/ml, P < 0.05); IL-6 (3,469 vs. 150 pg/ml, P < 0.05); IL-8 (16,230 vs. 6,334 pg/ml, P = 0.01).

CONCLUSIONS

MAS is associated with an inflammatory response characterized by the presence of elevated cell count and pro-inflammatory cytokines which significantly decreased by 96 hr of life. This decrease in lung inflammation has a positive correlation with corresponding decreases in mean airway pressure and oxygenation index, two parameters associated with improved pulmonary function.

Selective medicated (normal saline and exogenous surfactant) bronchoalveolar lavage in severe aspiration syndrome in children

OBJECTIVE

To study the ability of volume-controlled ventilation and medicated (normal saline plus surfactant) bronchoalveolar lavage in aspiration to reduce the duration of intubation and improve gas exchange.

DESIGN

: Randomized controlled clinical trial.

SETTING

Pediatric intensive care unit.

PATIENTS

Twenty children, 1 month to 16 yrs old, who were intubated and mechanically ventilated, were randomized within 6 hrs of aspiration to receive volume-controlled ventilation plus medicated bronchoalveolar lavage (treatment group) or the same ventilation and bronchosuction (control group).

INTERVENTIONS

Volume-controlled ventilation and positive end-expiratory pressure (10-12 cm H2O) were applied. Medicated bronchoalveolar lavage was performed using five aliquots of 5 mL of saline plus 10 mg/mL Curosurf (porcine surfactant, Chiesi Pharmaceutical SpA, Parma, Italy) in infants, five boluses of 10 mL of saline plus 5 mg/mL Curosurf in children, and four boluses of 25 mL of saline with 2.4 mg/mL Curosurf in adolescents for each affected lobe. One hour after bronchoalveolar lavage, 240 mg of Curosurf was administered locally.

MEASUREMENTS AND MAIN RESULTS

All patients survived. In the treatment group, days of intubation were 4.6 (+/-1.07), oxygenation index and Pao2/Fio2 improved significantly at 24 hrs, and statistical reduction in tidal volume mL/kg was observed from 36 hrs. In the control group, days of intubation were 11.8 (+/-3.22) (p < .0001), no improvement in oxygenation was noted, and pneumonia was observed in seven children (70%).

CONCLUSIONS

Even though this was an unblinded small clinical trial and low tidal volume strategy was not employed at an early stage after lung injury, there is some evidence that bronchoalveolar lavage with normal saline and surfactant may have clinical value in treating severe aspiration syndrome in children. More clinical studies are warranted to overcome study limitations and potential bias.

Incidence rate and factors related to post-bronchoalveolar lavage fever in children

BACKGROUND

Post-bronchoscopy and bronchoalveolar lavage (BAL) fever in children has been described by several authors.

OBJECTIVES

This study aimed at assessing the occurrence of fever after these examinations and associated risk factors.

METHODS

The study was performed in the Bronchoscopy Unit of Hôpital Necker-Enfants Malades, Paris, France, from June 2004 to July 2005. 148 children who underwent fiberoptic bronchoscopy and BAL, and remained in the Unit for 24 h, were included.

RESULTS

37.8% of the patients presented post-BAL fever. In the multivariate analysis of the selected factors (age, immunodeficiency, general or local anesthesia, mucosal biopsy, inflammation and suppuration at the moment of the examination, abnormal bronchoalveolar fluid cellularity and infection), only age <2 years and presence of infection remained associated with fever.

CONCLUSIONS

The occurrence of fever is a frequent event in children who underwent BAL. In order to reduce post-BAL fever, antibiotic strategies should be devised based on prospective studies assessing identification of predictive air-way infection criteria and/or rapid bacteriological result analysis.

Postinfectious bronchiolitis obliterans accompanied by pulmonary hemosiderosis in childhood

In the present report, we describe an unusual presentation of post-infectious bronchiolitis obliterans accompanied by pulmonary hemosiderosis in a nine-year-old boy with persistent respiratory symptoms subsequent to an episode of acute bronchiolitis occurring at the age of seven months. After the episode, the persistent respiratory symptoms worsened significantly, and, by the age of seven, the patient began to have difficulty breathing after minimal exertion. Computed tomography of the chest presented findings consistent with bronchiolitis obliterans. Open lung biopsy revealed numerous hemosiderin-laden macrophages, as well as other findings consistent with bronchiolitis obliterans. Pulmonary hemosiderosis can occasionally be accompanied by bronchiolitis obliterans in children with severe sequelae after an episode of viral infection.

Transient airway colonization is associated with airway inflammation after lung transplantation

Lower airway tract colonization may trigger neutrophil-mediated airway inflammation. We investigated whether transient airway colonization influences airway inflammation and pulmonary function after lung transplantation (LTx). In this retrospective study, stable LTx patients with consecutive broncho-alveolar lavages (BAL), the first colonized and the second noncolonized, were included to create a Pooled group (P, n=32) and a Gram Negative (GN, n=14), Gram Positive (GP, n=9) and Fungi (F, n=9) subgroup. Similarly, LTx patients with consecutive, noncolonized BAL samples were included as Control group (C, n=19). BAL analysis (cell counts, IL6, IL8) and forced expiratory volume (FEV(1)) were compared between groups. In the P group and the GN subgroup, colonized BAL samples showed a significant increase in total cells, neutrophilia and IL8-concentration and a significant decrease in FEV(1), even when compared with the matched samples of the C group. A significant increase in neutrophilia was observed in the GP subgroup, but no other significant difference was found either in the GP and F subgroup or the C group. IL6 levels were not significantly different between groups. Transient airway colonization, especially with Pseudomonas-like GN bacteria, in stable LTx patients may be associated with IL8-dependent neutrophilic airway inflammation and a, albeit subtle, decrease in FEV(1).

Reduced toll-like receptor 4 and substance P gene expression is associated with airway bacterial colonization in children

Neuro-immune interactions are increasingly relevant to human health and disease. The neuropeptide Substance P also has antibacterial activity and bears similarities to the innate immune antibacterial defensins. This suggests possible co-regulation of neuropeptide and innate immune mediators. In this study, non-bronchoscopic bronchoalveolar lavage (BAL) was performed on 69 children. BAL was examined for cellular profile, microbiology (bacteria, virus) and gene expression for TLRs 2, 3, 4; chemokine receptors (CCR3, CCR5, CXCR1); neurotrophins and neurokinin genes (TAC1, TAC3, CGRP, NGF). In children with bacterial colonization (n=10) there was an airway inflammatory response with increased BAL neutrophils, IL-8 protein, and CXCR1 expression. Substance P (TAC1) and TLR4 RNA expression were reduced in children with bacterial colonization. TLR3 mRNA was increased in 7.2% (n=5) children with rhinovirus, and there was a non-significant trend to increased TLR2. There is evidence for co-regulation of neurokinin (TAC1) and TLR4 gene expression in airway cells from children with airway bacterial colonization and their reduced expression may be associated with an impaired bacterial clearance.

Inflation lung mechanics deteriorates markedly after saline instillation and open endotracheal suctioning in mechanically ventilated healthy piglets

INTRODUCTION

Non-bronchoscopic bronchoalveolar lavage is an alternative to diagnostic bronchoscopy in pediatric patients, as fiberoptic bronchoscopes with aspiration channels are too large for small infants. There are many variations of the method in clinical practice, and saline instillation followed by open endotracheal suctioning is still commonly used. Lung function can deteriorate with these procedures, and we have investigated the effects on lung mechanics and oxygenation in healthy piglets.

METHODS

The lungs of anesthetized and mechanically ventilated piglets were recruited with CPAP 35 cmH2O. Thereafter we instilled 5 ml of saline into the endotracheal tube, followed by three breaths from the ventilator. Saline was retrieved through a suction catheter wedged far distally in the airway. The procedure was followed by a new recruitment maneuver. Complete inspiratory/expiratory pressure - volume loops (PV-loops) were obtained just before and 5 min after saline instillation. Arterial blood gases were collected at equivalent times in 14 similar piglets submitted to exactly the same procedure.

RESULTS

The inspiratory limb of the PV-loops changed markedly, as the lower inflection point was displaced towards higher pressures (P=0.004), and hysteresis measured at 15 and 30 cmH2O increased (P=0.004 and P=0.012, respectively). Although PaO2 decreased significantly (P=0.001), values after saline instillation/suctioning were still in the high normal range, that is, 22.2 +/- 2.6 kPa.

CONCLUSIONS

Opening pressures of the lungs increase markedly after saline instillation/suctioning in healthy piglets. In this situation, adequate recruitment maneuvers and PEEP might prevent lung collapse and deteriorations in arterial oxygenation.

Quantification of siderophages in bronchoalveolar fluid in transfusional and primary pulmonary hemosiderosis

Transfusional iron overload may occur in the lungs. We hypothesized that quantitating siderophages in the bronchoalveolar fluid (BALF) of heavily transfused patients may prove to be a useful tool in determining lung iron overload in transfusion-dependent patients. The study included six patients (7-20 years) with thalassemia major (TM) who had received multiple blood transfusions, one with hereditary spherocytosis (four blood transfusions) and one with sickle cell disease (never transfused); they were compared to three children with idiopathic pulmonary hemosiderosis (IPH) (2.5-7.0 years) as positive controls. Fiberoptic bronchoscopy with bronchoalveolar lavage was performed in seven patients under general anesthesia for elective surgery and the rest were bronchoscoped electively under sedation. Spirometry was also performed in eight patients. There was no significant difference between children with TM and IPH in siderophages as percentage of total count (95% CI -31.0 to 1.5, P = 0.068). There were positive relationships between both mean serum ferritin values during the preceding year and the total number of units of transfused blood, and percent siderophage count among multiply transfused patients (P = 0.010, P = 0.052, respectively); similar findings were noted for the Golde score (P = 0.001, P = 0.031, respectively). None of the patients showed lung function impairment. In conclusion, in this small study, we found that the BALF of multiply transfused patients with benign hematological disorders contain similar numbers of siderophages to that of patients with IPH; this is strongly suggestive of secondary pulmonary hemosiderosis. The correlation between the patients' serum ferritin, and the BALF siderophages suggests that the later may serve as a marker of pulmonary iron overload in patients requiring blood transfusion and appear to be more sensitive than standard pulmonary function tests.

A bronchoscopic scoring system for airway secretions--airway cellularity and microbiological validation

There is currently no validated scoring system for quantification of airway secretions in children. A user friendly, valid scoring system of airway secretions during flexible bronchoscopy (FB) would be useful for comparative purposes in clinical medicine and research. The objective of this study was to validate our bronchoscopic secretion (BS) scoring system by examining the relationship between the amount of secretions seen at bronchoscopy with airway cellularity and microbiology. In 106 children undergoing FB, the relationship of BS grades with bronchocalveolar lavage (BAL) cellularity and infective state (bacterial and viral infections) were examined using receptor operator curves (ROC). BAL was obtained according to European Respiratory Society guidelines; first lavage for microbiology and second lavage for cellularity. Area under the ROC was significant for total cell count (TCC) and neutrophil % but not for lymphocyte %. BS grade significantly related to infection positive state (chi(trend) (2) = 5.85, P = 0.016). The area under the ROC for infection positive state versus BS grade was 0.645, 95% CI 0.527-0.763. The BS scoring system is a valid method for quantifying airway secretions in children undergoing bronchoscopy. The system related well to airway cellularity and neutrophilia, as well as to an airway infective state. However, the system is only complementary to cell counts and cultures and cannot replace these laboratory quantification techniques.

Bronchial hyperresponsiveness, atopy, and bronchoalveolar lavage eosinophils in persistent middle lobe syndrome

Most cases of middle lobe syndrome (MLS) in children are considered to be due to asthma and may recover spontaneously; however, in persistent MLS, repeated episodes of infection often institute a vicious cycle that may lead to persistent symptoms and bronchial hyperresponsiveness (BHR). The present study was undertaken to investigate whether asthma, as an underlying diagnosis, is predictive of a favorable outcome of children with persistent MLS. We evaluated 53 children with MLS who underwent an aggressive management protocol that included fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL). These patients were compared to two other groups: one consisting of children with current asthma but no evidence of MLS (N = 40) and another of non-asthmatic controls (N = 42), matched for age and sex. Prevalence of sensitization (>or=1 aeroallergen) did not differ between patients with MLS and "non-asthmatics" but was significantly lower than that of "current asthmatics." A positive response to methacholine bronchial challenge was observed with increased frequency among children with MLS when compared to "current asthmatic" and non-asthmatic children. Multivariate logistic regression analysis revealed a positive correlation between an increased number of eosinophils in the BAL fluid (BALF) and a favorable outcome, whereas no correlation was detected between sensitization or BHR and BAL cellular components. In conclusion, children with MLS have an increased prevalence of BHR, even when compared to asthmatics, but exhibit prevalence of atopy similar to that of non-asthmatics. An increased eosinophilic BALF count is predictive of symptomatic but not radiographic improvement of MLS patients after aggressive anti-asthma management.

Physiologic, bronchoscopic, and bronchoalveolar lavage fluid findings in young children with recurrent wheeze and cough

Assessing airway disease in young children with wheeze and/or cough is challenging. We conducted a prospective, descriptive study of lung function in children <3 years old with recurrent wheeze and/or cough, who had failed empiric antiasthma and/or antireflux therapy and subsequently underwent flexible bronchoscopy. Our goals were to describe radiographic, anatomical, microbiological, and physiological findings in these children, and generate hypotheses about their respiratory physiology. Plethysmography and raised-volume rapid thoracoabdominal compression (RVRTC) techniques were performed prior to bronchoscopy. Mean Z-scores (n = 19) were -1.34 for forced expiratory volume at 0.5 sec (FEV(0.5)), -2.28 for forced expiratory flows at 75% of forced vital capacity (FVC) (FEF(75)), -2.25 for forced expiratory flows between 25-75% of FVC (FEF(25-75)), 2.53 for functional residual capacity (FRC), and 2.23 for residual volume divided by total lung capacity (RV/TLC). Younger, shorter children had markedly depressed FEF(75) and FEF(25-75) Z-scores (P = 0.002 and P = <0.001, respectively). As expected, lower airway anatomical abnormalities, infection, and inflammation were common. Elevated FRC was associated with anatomical lower airway abnormalities (P = 0.03). FVC was higher in subjects with neutrophilic inflammation (P = 0.03). There was no association between other physiologic variables and bronchoscopic/bronchoalveolar lavage fluid findings. Half of those with elevated RV/TLC ratios (Z-score >2) had no evidence of chest radiograph hyperinflation. We conclude that in this population, plethysmography and RVRTC techniques are useful in identifying severity of hyperinflation and airflow obstruction, and we hypothesize that younger children may have relatively small airways caliber, significantly limiting airflow, and thus impairing secretion clearance and predisposing to lower airway infection.

Pneumococcal serogroups and serotypes in severe pneumococcal pneumonia in Belgian children: theoretical coverage of the 7-valent and 9-valent pneumococcal conjugate vaccines

BACKGROUND

Although the causative pneumococcal serotypes of invasive diseases are already extensively studied, few data are available about the pneumococcal serotypes additionally isolated from broncho-alveolar lavage samples in childhood pneumonia.

STUDY AIM

To identify the causative pneumococcal serotypes in culture proven childhood community acquired pneumonia (CAP) and to calculate the effectiveness of the heptavalent and nonavalent pneumococcal vaccine (7- and 9-valent PnV) in severe pneumococcal pneumonia.

METHODS

All pneumococcal isolates stored from broncho-alveolar lavage, blood culture and pleural fluid in healthy children with CAP were characterized.

RESULTS

Seventy children (median age 2 years 3.5 months) could be included. The most prevalent serotypes were: SGT1 (21.4%), SGT6 (20.0%), SGT19 (12.8%), SGT23 (10.0%), and SGT14 (7.1%). SGT1 was especially prevalent in complicated cases and children >5 years. This first ranking of SGT1 is not reported in invasive pneumococcal disease studies. The overall theoretical coverage of the 7-valent PnV and the 9-valent PnV for pneumococcal pneumonia was 45.7% and 72.8%. The theoretical coverage of both vaccines was equal for non-invasive pneumonia (64%) but the theoretical coverage of the 9-valent PnV for invasive pneumonia was much higher (79% vs. 37.2%). Antibiotic susceptibility to penicillin was 84%, 70% to tetracycline and 61% to erythromycin; however only one strain (MIC = 4 mg/L) was highly resistant to penicillin.

CONCLUSIONS

Based on this serotyping, the theoretical coverage of the 7-valent PnV for proven pneumococcal pneumonia is good but decreases with age. A 9-valent PnV containing SGT1 could significantly increase the coverage, especially for invasive pneumonia. According to these data, penicillin remains the first choice antibiotic treatment for childhood CAP in Belgium.

Dexamethasone suppresses expression of Nuclear Factor-kappaB in the cells of tracheobronchial lavage fluid in premature neonates with respiratory distress

Nuclear Factor-kappaB (NF-kappaB) plays a central role in regulating the key mediators of inflammation involved in acute lung injury. The anti-inflammatory effect of steroids by suppressing pro-inflammatory cytokines may be mediated by inhibition of transcription factor NF-kappaB. The objective of this study was to determine the effect of glucocorticoid therapy on the expression of NF-kappaB in the cells of tracheobronchial lavage fluid (TBLF) in premature neonates with respiratory distress. Nineteen premature neonates requiring mechanical ventilation and receiving glucocorticoids were enrolled. Their gestational age (mean +/- SD) was 25.0 +/- 1.2 wk, birth weight 714 +/- 105 g and age of starting dexamethasone was 33 +/- 15 d. Tracheobronchial lavage fluid was collected before and 48-72 h after starting dexamethasone. NF-kappaB expression was measured by immunocytochemistry using mouse MAb against the p65 subunit of NF-kappaB on cytospin slides. The percent of cells stained and the intensity staining index were significantly higher before starting dexamethasone compared with after steroid therapy. Localization of NF-kappaB was significantly decreased in the cytoplasm and nuclei of mononuclear cells after initiation of dexamethasone therapy. The concentration of IL-8 was also significantly lower after starting dexamethasone. In conclusion, dexamethasone suppressed the expression of NF-kappaB in the cytoplasm and nuclei of mononuclear cells and decreased levels of IL-8 in TBLF from premature neonates with respiratory distress. The anti-inflammatory effects of corticosteroids may be mediated through NF-kappaB.

Evaluation and outcome of young children with chronic cough

OBJECTIVE

To evaluate the use of an adult-based algorithmic approach to chronic cough in a cohort of children with a history of > 3 weeks of cough and to describe the etiology of chronic cough in this cohort.

METHODS

A prospective cohort study of children referred to a tertiary hospital with a history of > 3 weeks of cough between June 2002 and June 2004. All included children followed a pathway of investigation (including flexible bronchoscopy and evaluation of airway cytology via BAL) until diagnosis was made and/or their cough resolved.

RESULTS

In our cohort of 108 young children (median age 2.6 years), the majority had wet cough (n = 96; 89%), and BAL fluid samples obtained during bronchoscopy led to a diagnosis in 45.4% (n = 49). The most common final diagnosis was protracted bacterial bronchitis (n = 43; 39.8%). These patients had neutrophil levels on BAL samples that were significantly higher than those in other diagnostic groups (p < 0.0001). Asthma, gastroesophageal reflux disease (GERD), and upper airway cough syndrome (UACS), which are common causes of chronic cough in adults, were found in < 10% of the cohort (n = 10).

CONCLUSIONS

The adult-based anatomic pathway, which involves the investigation and treatment of patients with asthma, GERD, and UACS first is largely unsuitable for use in the management of chronic cough in young children as the common etiologies of chronic cough in children are different from those in adults.

Intrapulmonary application of a 5-lipoxygenase inhibitor using surfactant as a carrier reduces lung edema in a piglet model of airway lavage

Leukotriene-generated effects on microvascular integrity and polymorphonuclear leukocytes (PMNL) play a key role in the inflammatory process of the alveolar-capillary unit in neonatal acute respiratory distress syndrome. We asked if intrapulmonary application of MK886, a 5-lipoxygenase inhibitor, and the use of a porcine surfactant preparation (Curosurftrade mark) as a carrier substance would improve lung function in a neonatal piglet model of airway lavage. Anesthetized, mechanically ventilated newborn piglets (n = 19) underwent repeated airway lavage to induce acute lung injury. Piglets then received either surfactant alone (S, n = 6), or MK886 admixed with surfactant (S + MK, n = 7), or an air-bolus injection as control (C, n = 6). Measurements of gas exchange, lung function, extravascular lung water (EVLW), cell counts, and leukotriene B(4) (LTB(4)) concentrations in bronchoalveolar lavage fluid (BAL) were performed during 6 hr of mechanical ventilation. Arterial oxygen partial pressure (PaO(2)) (S, 13.8 +/- 4.2 kPa, vs. S + MK, 20 +/- 6.6; P < 0.05), functional residual capacity (S, 15.1 +/- 6.8 ml/kg, vs. S + MK, 18.8 +/- 3.7 ml/kg; P < 0.05), and EVLW (S, 29 +/- 14 ml/kg, vs. S + MK 24 +/- 4 ml/kg; P < 0.05) were significantly improved in the MK886 group. This clinical effect was linked with a decrease in LTB(4) concentration in BAL (S, 3.5 (1.9-5.4) pg/ml, vs. S + MK, 1.6 (0.7-4.7) pg/ml; P < 0.05) and an increase in IL-8 (S, 2,103 (852-4,243) pg/ml, vs. S + MK, 3,815 (940-26,187) pg/ml; P < 0.05). PMNL counts in BAL were reduced (S, 570 +/- 42 cells/ml, vs. 275 +/- 35 cells/ml; P < 0.05). In conclusion, intrapulmonary application of the 5-lipoxygenase inhibitor MK886 with surfactant as a carrier improves lung function by decreasing EVLW as the main response to LTB(4) reduction.

High incidence of pulmonary bacterial co-infection in children with severe respiratory syncytial virus (RSV) bronchiolitis

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of viral lower respiratory tract infections (LRTI). Viral LRTI is a risk factor for bacterial superinfection, having an escalating incidence with increasing severity of respiratory illness. A study was undertaken to determine the incidence of pulmonary bacterial co-infection in infants and children with severe RSV bronchiolitis, using paediatric intensive care unit (PICU) admission as a surrogate marker of severity, and to study the impact of the co-infection on morbidity and mortality.

METHODS

A prospective microbiological analysis was made of lower airways secretions on all RSV positive bronchiolitis patients on admission to the PICU during three consecutive RSV seasons.

RESULTS

One hundred and sixty five children (median age 1.6 months, IQR 0.5-4.6) admitted to the PICU with RSV bronchiolitis were enrolled in the study. Seventy (42.4%) had lower airway secretions positive for bacteria: 36 (21.8%) were co-infected and 34 (20.6%) had low bacterial growth/possible co-infection. All were mechanically ventilated (median 5.0 days, IQR 3.0-7.3). Those with bacterial co-infection required ventilatory support for longer than those with only RSV (p<0.01). White cell count, neutrophil count, and C-reactive protein did not differentiate between the groups. Seventy four children (45%) received antibiotics prior to intubation. Sex, co-morbidity, origin, prior antibiotics, time on preceding antibiotics, admission oxygen, and ventilation index were not predictive of positive bacterial cultures. There were 12 deaths (6.6%), five of which were related to RSV.

CONCLUSIONS

Up to 40% of children with severe RSV bronchiolitis requiring admission to the PICU were infected with bacteria in their lower airways and were at increased risk for bacterial pneumonia.

Effects of pressure support ventilation plus volume guarantee vs. high-frequency oscillatory ventilation on lung inflammation in preterm infants

The aim of the present study was to evaluate if high-frequency oscillatory ventilation (HFOV) might reduce lung inflammation in preterm infants with infant respiratory distress syndrome (RDS) in comparison with the early application of another potentially lung-protective ventilation strategy, such as pressure support ventilation plus volume guarantee (PSV + VG). Infants at less than 30 weeks of gestation with RDS were enrolled consecutively in the study if they required mechanical ventilation, and were randomly allocated to receive HFOV or PSV + VG. Bronchial aspirate samples for the measurement of interleukin (IL)-1beta, IL-8, and IL-10 were obtained before surfactant treatment (T1), after 6-18 hr of ventilation (T2), after 24-48 hr of ventilation (T3), and before extubation (T4). Thirteen patients were enrolled in the HFOV group, and 12 in the PSV + VG group. The mean values of IL-1beta, IL-8, and IL-10 at T4 were lower in the HFOV group than in the PSV + VG group. The present study demonstrates that early treatment with HFOV is associated with a reduction of lung inflammation in comparison with PSV + VG in preterm infants with RDS.

Cough and reflux esophagitis in children: their co-existence and airway cellularity

BACKGROUND

There are no prospective studies that have examined for chronic cough in children without lung disease but with gastroesophageal reflux (GER). In otherwise healthy children undergoing flexible upper gastrointestinal endoscopy (esophago-gastroscopy), the aims of the study were to (1) define the frequency of cough in relation to symptoms of GER, (2) examine if children with cough and reflux esophagitis (RE) have different airway cellularity and microbiology in bronchoalveolar lavage (BAL) when compared to those without.

METHODS

Data specific for chronic cough (> 4-weeks), symptoms of GER and cough severity were collected. Children aged < 16-years (n = 150) were defined as 'coughers' (C+) if a history of cough in association with their GER symptoms was elicited before BAL were obtained during elective esophago-gastroscopy. Presence of esophagitis on esophageal biopsies was considered reflux esophagitis positive (E+).

RESULTS

C+ (n = 69) were just as likely as C- (n = 81) to have esophagitis, odds ratio 0.87 (95%CI 0.46, 1.7). Median neutrophil percentage in BAL was significantly different between groups; highest in C+E- (7, IQR 28) and lowest in C-E+ (5, IQR 6). BAL positive bacterial culture occurred in 20.7% and were more likely present in current coughers (OR 3.37, 95%CI 1.39, 8.08). Airway neutrophilia (median 20%, IQR 34) was significantly higher in those with BAL positive bacterial cultures than those without (5%, 4; p = 0.0001).

CONCLUSION

In children without lung disease, the common co-existence of cough with symptoms of GER is independent of the occurrence of esophagitis. Airway neutrophilia when present in these children is more likely to be related to airway bacterial infection and not to esophagitis.

Children with stable asthma have reduced airway matrix metalloproteinase-9 and matrix metalloproteinase-9/tissue inhibitor of metalloproteinase-1 ratio

BACKGROUND

Childhood asthma is characterized by inflammation of the airways. Structural changes of the airway wall may also be seen in some children early in the course of the disease. Matrix metalloproteinases (MMPs) are key mediators in the metabolism of the extracellular matrix (ECM).

OBJECTIVE

To investigate the balance of MMP-8, MMP-9 and tissue inhibitor of metalloproteinases (TIMP)-1 in the airways of children with asthma.

METHODS

One hundred and twenty-four children undergoing elective surgical procedures also underwent non-bronchoscopic bronchoalveolar lavage (BAL). MMP-8, MMP-9 and TIMP-1 were measured by ELISA.

RESULTS

There was a significant reduction in MMP-9 in atopic asthmatic children (n=31) compared with normal children (n=30) [median difference: 0.57 ng/mL (95% confidence interval: 0.18-1.1 ng/mL)]. The ratio of MMP-9 to TIMP-1 was also reduced in asthmatic children. Levels of all three proteins were significantly correlated to each other and to the relative proportions of particular inflammatory cells in BAL fluid (BALF). Both MMP-8 and MMP-9 were moderately strongly correlated to the percentage neutrophil count (r=0.40 and 0.47, respectively, P<0.001).

CONCLUSIONS

An imbalance of MMPs and their inhibitors occurs in children with well-controlled asthma, which may indicate early derangement of the metabolism of the ECM.

Early Increased Levels of Matrix Metalloproteinase-9 in Neonates Recovering from Respiratory Distress Syndrome

AIM

Matrix metalloproteinases (MMPs) play an eminent role in airway injury and remodelling. We explored the hypothesis that pulmonary MMP levels would differ early after birth (2-4 days) between infants with resolving respiratory distress syndrome (RDS) and infants developing chronic lung disease of prematurity (CLD).

METHODS

Thirty-two prematurely born infants (gestational age < or =30 weeks) diagnosed with RDS were included. In 13 infants RDS resolved while 19 developed CLD. MMP-2 and MMP-9 in bronchoalveolar lavage (BAL) fluids collected on postnatal days 2, 4, 7 and 10 were analyzed by zymography and densitometry. Immunochemistry was performed on BAL cells and lung tissue to identify cellular sources of MMP-9 in RDS and CLD.

RESULTS

Median MMP-9 levels increased significantly on day 2 in BAL fluid from patients with resolving RDS (median values MMP-9 = 42.0 arbitrary units (AU)) compared to CLD patients (MMP-9 = 5.4 AU). MMP-9 and neutrophil lipocalin-associated MMP-9 (NGAL) were significantly higher on day 4 in BAL fluid from resolving RDS (MMP-9 = 65.8 AU; NGAL = 16.1 AU) compared to CLD (MMP-9 = 25.4 AU; NGAL = 2.0 AU), Levels of MMP-9 and NGAL increased subsequently on days 7 and 10 in CLD. No differences in MMP-2 levels were detected between RDS and CLD. Neutrophils, macrophages and alveolar type-II epithelial cells were identified as potential sources of MMP-9.

CONCLUSION

Our findings indicate differences in early MMP-9 BAL fluid levels between resolving RDS and developing CLD, which may relate to the ability to raise an early and adequate response to the initial injury.

Bird breeder's disease: a rare diagnosis in young children

Bird breeder's lung disease is the most common form of hypersensitivity pneumonitis and is a rare entity in young children. We report three cases of children under 7 years of age in whom this diagnosis was confirmed early in the course of the disease. Three children aged 4.4 to 6.5 years presented with dry cough lasting for more than 1 month, dyspnoea, variable loss of appetite, weight loss, fatigue, fever and mild signs of respiratory distress. Chest X-ray films and CT scans showed a bilateral micronodular infiltrate. All three patients had strongly suggestive bronchoalveolar lavage fluid findings with lymphocytosis; two had elevated cell counts and decreased CD4/CD8 ratios. Lung biopsy confirmed the diagnosis in all children. Contact with allergens was identified in all children: two had spent holidays close to a farm in the previous month and one was living next to a pigeon house. In all children, avian precipitins were positive. The symptoms rapidly resolved after allergen avoidance and treatment with oral prednisone. Corticoid treatment was given between 11 and 15 weeks. One child relapsed and required long-term low-dose corticotherapy for 1 year. Lung function tests were normal in all three patients, 3.9 to 5.7 years after diagnosis.

CONCLUSION

Bird breeder's lung disease is a rare entity but should be considered in young children presenting long lasting cough. While rapid allergen exclusion and start of treatment can avoid the evolution into irreversible lung fibrosis, clinical and biological evolution should be monitored carefully even after stopping corticoid treatment because of the possibility of relapse.

The Role of Timely Intervention in Middle Lobe Syndrome in Children

STUDY OBJECTIVES

Middle lobe syndrome (MLS) in children is characterized by a spectrum of clinical and radiographic presentations, from persistent or recurrent atelectasis to pneumonitis and bronchiectasis of the right middle lobe (RML) and/or lingula. This study was undertaken to evaluate the effect of early intervention, including fiberoptic bronchoscopy (FOB), in the development of bronchiectasis in MLS.

DESIGN

Children with atelectasis of the RML and/or lingula persisting for > 1 month or recurring two or more times despite conventional treatment underwent high-resolution CT (HRCT) scanning and FOB. Appropriate treatment and follow-up were provided, and the effect of the duration of symptoms on clinical outcome and the development of bronchiectasis was investigated. The patient cohort was retrospectively reviewed.

PATIENTS

We evaluated 55 children with MLS. The median age at diagnosis, duration of symptoms, and duration of clinical deterioration before diagnosis were 5.5 years (range, 3 months to 12 years), 14.5 months (range, 3 to 48 months), and 8 months (range, 3 to 36 months), respectively.

MEASUREMENTS AND RESULTS

FOB revealed marked obstruction in two children (ie, a foreign body and an endobronchial tumor) and positive findings for a culture of BAL fluid in 49.1% of patients. The remaining 53 patients were followed up for a median duration of 24 months (range, 5 to 96 months). The clinical outcome was "cure" in 60.4% of patients, "improvement" in 32.1% of patients, and "no change" in the remaining patients. Bronchiectasis was documented prior to FOB by HRCT scan in 15 patients (27.3%). The duration of the deterioration of symptoms prior to presentation positively correlated with the development of bronchiectasis (p = 0.03) and an unfavorable clinical outcome (ie, improvement or no change) [p = 0.02]; a positive correlation was also found between the duration of symptoms and the development of bronchiectasis (p = 0.04).

CONCLUSIONS

Timely medical intervention in patients with MLS that includes FOB with BAL prevents bronchiectasis that may be responsible for an ultimately unfavorable outcome.

Airway cellularity, lipid laden macrophages and microbiology of gastric juice and airways in children with reflux oesophagitis

BACKGROUND

Gastroesophageal reflux disease (GORD) can cause respiratory disease in children from recurrent aspiration of gastric contents. GORD can be defined in several ways and one of the most common method is presence of reflux oesophagitis. In children with GORD and respiratory disease, airway neutrophilia has been described. However, there are no prospective studies that have examined airway cellularity in children with GORD but without respiratory disease. The aims of the study were to compare (1) BAL cellularity and lipid laden macrophage index (LLMI) and, (2) microbiology of BAL and gastric juices of children with GORD (G+) to those without (G-).

METHODS

In 150 children aged < 14-years, gastric aspirates and bronchoscopic airway lavage (BAL) were obtained during elective flexible upper endoscopy. GORD was defined as presence of reflux oesophagitis on distal oesophageal biopsies.

RESULTS

BAL neutrophil% in G- group (n = 63) was marginally but significantly higher than that in the G+ group (n = 77), (median of 7.5 and 5 respectively, p = 0.002). Lipid laden macrophage index (LLMI), BAL percentages of lymphocyte, eosinophil and macrophage were similar between groups. Viral studies were negative in all, bacterial cultures positive in 20.7% of BALs and in 5.3% of gastric aspirates. BAL cultures did not reflect gastric aspirate cultures in all but one child.

CONCLUSION

In children without respiratory disease, GORD defined by presence of reflux oesophagitis, is not associated with BAL cellular profile or LLMI abnormality. Abnormal microbiology of the airways, when present, is not related to reflux oesophagitis and does not reflect that of gastric juices.

Neurotrophin overexpression in lower airways of infants with respiratory syncytial virus infection

RATIONALE

Nerve growth factor and its receptors are upregulated in the lungs of weanling rats with lower respiratory tract infection caused by the respiratory syncytial virus (RSV), and this is a major mechanism of the inflammatory response against the virus. However, no information is available in humans.

OBJECTIVES

We sought to determine whether the expression of neurotrophic factors and receptors is increased in human infants infected with RSV.

METHODS

We used a highly sensitive immunoassay to measure the concentrations of nerve growth factor and brain-derived neurotrophic factor proteins in serum samples and in the supernatants and cell fractions of nonbronchoscopic bronchoalveolar lavage fluid. We also used immunofluorescence to detect expression in airway cells of the tyrosine kinase receptor TrkA, which binds nerve growth factor with high affinity. Samples were obtained at 24 and 48 hours postintubation from 31 mechanically ventilated infants: 15 patients with RSV infection, 5 patients with respiratory infection negative for RSV, and 11 postsurgical patients without respiratory infection.

MAIN RESULTS

Data show significantly higher concentrations of both neurotrophins in the cell fractions of bronchoalveolar lavage samples obtained from infants with RSV infection compared with control infants, whereas no significant difference was found in supernatants or serum samples. We also detected tyrosine kinase receptor immunoreactivity only in cells from airways infected with RSV.

CONCLUSIONS

We conclude that neurotrophic factors and receptors are overexpressed in human airways infected by RSV, and may contribute to airway inflammation and hyperreactivity.

Detection of human metapneumovirus RNA sequences in nasopharyngeal aspirates of young French children with acute bronchiolitis by real-time reverse transcriptase PCR and phylogenetic analysis

Human metapneumovirus (HMPV) was the unique viral pathogen detected by a real-time reverse transcriptase PCR (RT-PCR) assay in 6 (6.4%) of 94 consecutive French children hospitalized for acute bronchiolitis from September 2001 to June 2002. This virus was identified as the third etiological cause of bronchiolitis, after respiratory syncytial virus and rhinovirus (35 [37%] and 21 [22%] of 94 cases, respectively). Phylogenetic analysis of F-gene sequences demonstrated the cocirculation of distinct HMPV genotypes during this study. These findings highlight the need to implement a rapid HMPV RT-PCR detection assay for the clinical diagnosis of respiratory infections in pediatric patients with bronchiolitis.

Reduction of Oxidative Stress Marker in Lung Fluid of Preterm Infants after Administration of Intra-Tracheal Liposomal Glutathione

BACKGROUND

Low levels of glutathione are associated with subsequent chronic lung disease in preterm infants. Incorporation of glutathione into liposomes offers a method of increasing levels with a prolonged half-life compared with direct inhalation.

OBJECTIVES

The aim of this study was to examine the clinical feasibility of administering a single dose of liposomal glutathione and its effectiveness at raising glutathione at 12 and 24 h after treatment.

METHODS

Fourteen ventilated preterm infants from the Regional Neonatal Intensive Care Unit at Liverpool Women's Hospital received 1 mg/kg or 10 mg/kg liposomal glutathione intra-tracheally and bronchoalveolar lavage fluid was collected prior to treatment, 12 and 24 h after dosing for glutathione and malondialdehyde estimation.

RESULTS

Mean glutathione was initially 12.2 micromol/l, increasing to 52.8 micromol/l at 12 h (p = 0.006). Mean malondialdehyde was initially 265.6 nmol/l decreasing to 11.2 nmol/l at 12 h (p = 0.018).

CONCLUSIONS

Intra-tracheal liposomal glutathione instillation offers a feasible method of raising pulmonary glutathione in preterm infants and shows biochemical antioxidant effects.

Connatal tuberculosis in a very premature infant

Connatal tuberculosis is increasing in incidence and the mortality and morbidity of this disease remains high. We report a 27-week-old, 896 g female premature infant who had mild respiratory distress syndrome after birth. She developed signs of infection, progressive pneumonia and atelectasis which did not respond to mechanical ventilation and antibiotics. At 41 days of age, Mycobacterium tuberculosis was isolated from the non-bronchoscopic bronchoalveolar lavage. The isolate was sensitive to isoniazid, rifampin, streptomycin, and pyrazinamide. Miliary tuberculosis was subsequently diagnosed in her mother on a chest X-ray film and sputum cultures. The infant was treated successfully with anti-tuberculosis drugs. She had normal growth and development at the chronological age of 20 months old.

CONCLUSION

Connatal tuberculosis should be considered in premature infants with symptoms of sepsis refractory to antibiotics. Most premature infants with connatal tuberculosis have lung involvement, and non-bronchoscopic bronchoalveolar lavage can be a useful procedure to establish the diagnosis.

Relationship between antenatal inflammation and antenatal infection identified by detection of microbial genes by polymerase chain reaction

Although antenatal infection is thought to play an important role in the pathogenesis of preterm labor and neonatal diseases, the exact mechanisms are largely unknown. We sought to clarify the relationship between antenatal infection and intrauterine and neonatal inflammation. Samples were obtained from 41 preterm infants of <33 wk gestation delivered to 36 mothers and analyzed for the presence of 16s ribosomal RNA (16s rRNA) genes using PCR and for the proinflammatory cytokines IL-6 and IL-8. In 16 (44%) mother-baby pairings, at least one sample was found to be positive for the presence of 16s rRNA genes. All but one of the positive samples were from mothers presenting with preterm prelabor rupture of membranes (pPROM) or in spontaneous idiopathic preterm labor. A strong association was found between the presence of 16s rRNA genes and chorioamnionitis and with funisitis. A marked increase in IL-6 and IL-8 was noted in all tissues positive for 16s rRNA genes, including placenta, fetal membranes, cord blood serum, and, where samples were available, in bronchoalveolar lavage fluid (BAL) and in amniotic fluid. Interestingly, gastric fluid was always positive for 16s rRNA genes if any other intrauterine or BAL sample was positive, suggesting that this sample may provide an alternative to amniotic fluid to identify antenatal infection. In conclusion, we have found that microbial genes are particularly prevalent in pPROM and spontaneous preterm labor groups and that their presence is strongly associated with a marked intrauterine inflammatory response.

BALF nitrite as an indicator of inflammation in children with cystic fibrosis

BACKGROUND

A unique substance reflecting the degree of inflammation localized to the lower respiratory tract in patients with cystic fibrosis (CF) has been the concern of several investigators and nitric oxide has gained interest for this purpose in the last decades.

OBJECTIVES

The aim of this study was to evaluate the cytokine and nitrite levels by showing the relationship between them in serum and bronchoalveolar lavage fluid (BALF) of patients with CF and patients in which flexible fiberoptic bronchoscopy (FFB) was applied because of indications other than infection.

METHODS

20 children with CF with mean age 8.2 years and 10 children as control group with mean age 4.2 years were included in the study. Cultures for aerobes, anaerobes, fungi and mycobacteria, cell differentials, cytokine and nitrite measurements were made from BALF specimens. White blood cell (WBC) count, erythrocyte sedimentation rate (ESR), quantitative C-reactive protein (QCRP), cytokine and nitrite levels were measured from serum samples.

RESULTS

BALF neutrophil, TNF-alpha, IL-8 and nitrite levels were significantly higher in patients with CF than control patients. There was no correlation between serum and BALF cytokine and nitrite levels. However, there was a significantly positive correlation between BALF IL-8 and nitrite levels in patients with CF (r = 0.5) and also in control patients (r = 0.6).

CONCLUSIONS

The results suggest that BALF nitrite levels reflect the degree of inflammation localized to lower respiratory tract and may be a useful indicator of airway inflammation for patients with CF.