Modulation of airway inflammation in cystic fibrosis. In vivo suppression of interleukin-8 levels on the respiratory epithelial surface by aerosolization of recombinant secretory leukoprotease inhibitor.

Based on the knowledge that neutrophil elastase (NE) in cystic fibrosis (CF) epithelial lining fluid (ELF) can induce human bronchial epithelial cells to express the gene for interleukin 8 (IL-8), an 8.5-kD neutrophil chemoattractant, we have evaluated CF ELF for the presence of IL-8, and investigated the ability of aerosolized recombinant secretory leukoprotease inhibitor (rSLPI) to suppress NE, and hence IL-8, levels on the respiratory epithelial surface in CF. Enzyme-linked immunoassay revealed 21.9 +/- 4.8 nM IL-8 in CF ELF compared with none in normals. Active NE was detectable in ELF of all individuals with CF and was significantly decreased (P < 0.03) after aerosolization of rSLPI. Human bronchial epithelial cells exposed to CF ELF recovered before rSLPI therapy expressed IL-8 mRNA transcripts, but ELF recovered after rSLPI therapy induced far less bronchial epithelial cell IL-8 gene expression. Consistent with this, rSLPI aerosol therapy caused a marked reduction in CF ELF IL-8 levels (P < 0.05) and neutrophil number (P < 0.02). There was also a clear association between CF ELF active NE and IL-8 levels (r = 0.94). These data suggest that rSLPI therapy not only suppresses respiratory epithelial NE levels, but also breaks a cycle of inflammation on the CF epithelial surface.

Bronchodilator responsiveness in a ventilator-dependent infant with severe tracheobronchomalacia.

A neonatal case of severe, ventilator-dependent tracheobronchomalacia (TBM) is described. The extent of the malacic segment was determined by endoscopy and tracheobronchography. Additionally, relevant and ever increasing reversible peripheral airway obstruction was documented by measuring the mechanical properties of the respiratory system before and after salbutamol. With the combination of endoscopically guided aortopexy and salbutamol infusion, the infant was eventually weaned from mechanical ventilation at the age of 86 days. We speculate that in ventilator-dependent infants with severe TBM the determination of bronchodilator responsiveness may have clinical consequences.

Recombinant secretory leukoprotease inhibitor augments glutathione levels in lung epithelial lining fluid.

Secretory leukoprotease inhibitor (SLPI), a 12-kDa serine antiprotease, serves as the major inhibitor of neutrophil elastase (NE) on the epithelial surface of the upper airways. As a control for studies to evaluate the aerosol administration of recombinant SLPI (rSLPI) to augment the anti-NE defenses of the lung, the status of antioxidants in respiratory epithelial lining fluid (ELF) was evaluated. Unexpectedly, aerosol administration of rSLPI caused an elevation in ELF glutathione, a major component of the epithelial antioxidant screen; i.e., rSLPI may provide not only augmentation of anti-NE defenses but also antioxidant defenses. To evaluate this concept, rSLPI (100 mg) was aerosolized to sheep, and SLPI, glutathione, anti-NE capacity, and anti-H2O2 capacity were evaluated in respiratory ELF over a 30-h period. As expected, aerosolization of rSLPI increased ELF SLPI levels and anti-NE capacity. Strikingly, postaerosol levels of glutathione in ELF were also increased (5-fold 24 h after aerosol), with a concomitant increase in ELF anti-H2O2 capacity; i.e., the rSLPI augmented the antioxidant screen of ELF. This suggests that rSLPI may be particularly well suited for therapy in lung diseases characterized by excess of both serine proteases and oxidants on the respiratory epithelial surface.

Intravenous recombinant secretory leukoprotease inhibitor augments antineutrophil elastase defense.

Secretory leukoprotease inhibitor (SLPI), a 12-kDa serine antiprotease, normally protects the upper airway epithelial surface from attack by neutrophil elastase (NE). In the context that a variety of inflammatory lung diseases are characterized by large neutrophil burdens with resultant high levels of NE in the lung, recombinant SLPI (rSLPI), a molecule identical to natural SLPI, may be an effective means to augment the anti-NE protective screen of the lung. To determine whether intravenous rSLPI will augment respiratory tract and epithelial surface levels of SLPI and anti-NE capacity, rSLPI was administered intravenously to sheep and SLPI levels were quantified in plasma, lung lymph (as a measure of lung interstitial levels), lung epithelial lining fluid (ELF), and urine. rSLPI (1 g) was administered over 10 min, and after 30 min plasma levels of SLPI were 8 microM and decreased with a half-life of 1.8 h. Lymph SLPI levels paralleled the plasma levels: 4 h after infusion the lymph-to-plasma ratio was 0.8. ELF SLPI levels paralleled the lymph levels: 4 h after infusion the ELF-to-lymph ratio was 0.3. Western analysis demonstrated intact SLPI in lymph and ELF, and functional analysis showed increases in lymph and ELF anti-NE capacity that paralleled the levels of SLPI. As might be expected from a protein with a molecular mass of 12 kDa, urine excretion was high, with 20% of the SLPI excreted over 5 h. However, if the rate of infusion was slowed, SLPI excretion decreased significantly, with a 3-h infusion associated with 9% excretion and a 12-h infusion associated with less than 0.2% excretion.(ABSTRACT TRUNCATED AT 250 WORDS)

[Invasive Pseudomonas aeruginosa and Ecthyma gangrenosum infection in a child without risk factors]. / Infection invasive à Pseudomonas aeruginosa et Ecthyma gangrenosum chez un enfant sans facteurs de risques.

BACKGROUND: Pseudomonas aeruginosa sepsis, well known in immunocompromised patients, is rare in previously healthy children. CASE REPORT: A previously healthy 4 month-old boy was admitted with the suspicion of meningococcal septicemia. Three days prior to admission, he had developed high fever and two 4 cm-diameter skin lesions on his right leg, with dark red colour and a central haemorrhagic blister. He subsequently developed generalized seizures; meningitis and urinary tract infection were excluded. Despite topical therapy with an antistaphylococcal drug skin lesions extended, particularly at the level of the head. The patient was given oral amoxicillin-clavulanate, but his condition worsened; he was transferred to our intensive care unit with septic shock and a diagnosis of meningococcemia. Blood cultures grew Pseudomonas aeruginosa. Despite intensive therapy and appropriate antibiotic therapy, the patient died. CONCLUSION: To allow early diagnosis and adequate treatment, it is mandatory to diagnose Ecthyma gangrenosum as the most frequent manifestation of invasive infection with Pseudomonas aeruginosa.

Proteases and antiproteases in cystic fibrosis: pathogenetic considerations and therapeutic strategies.

The association between abnormal chloride transport, resulting from mutations in the cystic fibrosis transmembrane regulator (CFTR) gene, and the immunologic processes involved in the development of CF lung disease is poorly understood. However, neutrophil-dominated inflammation on the respiratory epithelial surface is a common finding in CF patients and suggests a mechanism for the immunologic abnormalities described in CF. Of particular importance for the pathophysiology of CF are proteases such as neutrophil elastase (NE) which are released from neutrophils in CF airways and cause direct structural damage to respiratory tissue. In healthy individuals, the deleterious effects of excess protease activity in the respiratory system are inhibited by antiproteases such as alpha 1-antitrypsin (alpha 1AT) and secretory leukoprotease inhibitor (SLPI). However, in CF, antiproteases are outnumbered by proteases and this protective mechanism is rendered ineffective. Restoration of this protease/antiprotease balance through antiprotease replacement therapy is currently under clinical investigation and preliminary results are promising.

Consequences of unbalanced protease in the lung: protease involvement in destruction and local defense mechanisms of the lung.

Complex mechanisms regulate sequestration, retention and migration of neutrophils in the lung. Neutrophils can migrate into the lung without producing significant damage under some circumstances, whereas at other times great structural alteration occurs. A potential explanation lies in the phenomenon of priming, a state of altered responsivity of neutrophils. A wide variety of molecules are able to induce this higher degree of responsiveness including PAF, TNF, GM-CSF, and IL-1. Enhanced cellular responses include secretion, adhesion and synthetic function. Unprimed neutrophils can migrate through lung tissues, secreting but little of their contents, in the context of "normal" inflammatory response. On the other hand neutrophils primed before the emigration phase, injury to the tissue they are migrating through would be likely by virtue of releasing toxic mediators. One of these mediators is neutrophil elastase, a potent protease. It is the purpose of this review to highlight the duality function of neutrophils as (i) one of the bodies highly effective host defense weapons and (ii) mediator of destruction and host defense impairment in the lung by releasing mediators such as neutrophil elastase.

Pulmonary surfactant in cystic fibrosis.

Cystic fibrosis (CF) leads to a chronic inflammation of the airways with significant air flow limitations developing early in the course of the disease. As a well-functioning pulmonary surfactant is necessary to keep the alveoli and the small conducting airways open during expiration, we hypothesized that the biochemical and biophysical properties of surfactant may be impaired in CF. Bronchoalveolar lavage fluid obtained during a clinically stable period was analysed from 20 CF patients (5.9-20 yrs) and 17 healthy children and adults. CF patients had significantly elevated total and polymorphonuclear neutrophil cell counts, whereas the concentrations of total protein and phospholipids did not differ from controls. The percentage of surface active phospholipids, phosphatidylcholine and phosphatidylglycerol, and the concentration of surfactant protein A were significantly reduced in CF patients. Surfactant protein B was unchanged. Although the relative proportion of large aggregates was higher in CF, their surface active properties were inferior, as assessed in the pulsating bubble surfactometer. Because the capacity of CF lavage fractions to inhibit surfactant function was the same as that of controls, impaired minimal surface tension was more likely to be due to the biochemical alterations detected, than to inhibition of a well-functioning surfactant. The impaired pulmonary surfactant system in clinically stable patients with cystic fibrosis is in agreement with the view that surfactant dysfunction may contribute to lung disease in cystic fibrosis.

[PFAPA syndrome: periodic fever, adenitis, pharyngitis and aphthous stomatitis]. / PFAPA-Syndrom: periodisches Fieber, Adenitis, Pharyngitis und aphthöse Stomatitis.

A syndrome involving periodic fever, pharyngitis, adenitis and aphthous stomatitis is described in 8 children. Attacks are characterized by abrupt onset of fever and, in addition to the above symptoms, by malaise, headache and abdominal pain. Mild leukocytosis and elevation of the erythrocyte sedimentation rate are found in the laboratory. Patients exhibit normal growth and development and are otherwise healthy. PFAPA is clinically benign, with no long-term sequelae. Recognition and diagnosis of the syndrome eliminate the need for intensive work-up. The cause remains unknown. No evidence linking bacterial, viral, or fungal pathogens to this syndrome has been found. No patient has exhibited atypical lymphocytosis or neutropenia, and all patients had normal levels of immunoglobulin. All had received antibiotics early in the course of their illness but without effect. Cimetidine has been discussed in the literature as a possible treatment, but the results are controversial.

Dose-response relationships and time course of the response to systemic beta adrenoreceptor agonists in infants with bronchopulmonary disease.

The lung function response to three doses of salbutamol 0.075 mg/kg given at 10 minute intervals by gastric tube was studied in 31 infants aged 2-22 months with bronchopulmonary disease (eight after the respiratory distress syndrome, 15 with wheezy bronchitis, and eight with cystic fibrosis). Lung function was measured by whole body plethysmography. Seven of 31 infants had normal lung function and 10 of the remaining 24 had an increase in thoracic gas volume (TGV), 10 an increase in airway resistance (Raw), and four an increase in both the TGV and Raw. The response of TGV and Raw to salbutamol was analysed by circular statistics, enabling analysis of coupled, directional data. Thirty minutes after administration of the first dose of salbutamol there was a reduction in TGV or Raw in 21 of the 24 infants, 11 showing a decrease in TGV ("volume responder") and 10 a fall in Raw ("flow responder"). These results indicate that in most infants with bronchopulmonary disease an improvement in lung function can be documented after systemic administration of beta agonists if both TGV and Raw are measured.

Reduced proteolysis of surfactant protein A and changes of the bronchoalveolar lavage fluid proteome by inhaled alpha 1-protease inhibitor in cystic fibrosis.

In cystic fibrosis (CF), the chronic neutrophilic inflammation of the airways results in proteolytic degradation of lung tissue early in the course of the disease. Inhalation of alpha 1-protease inhibitor (alpha 1-PI) may restore the protease-antiprotease imbalance and thus lead to less tissue damage. To monitor its impacts on bronchoalveolar lavage (BAL) fluid protein pattern (proteome) and on surfactant protein A (SP-A), eight young adults with CF inhaled 100 mg of alpha 1-PI twice daily over eight weeks. BAL fluids were obtained before and after inhalation. Total protein, the number and amount of proteins with a molecular mass < 20 kDa were reduced compared to pretreatment values. Degradation products of SP-A were shown by immunoblotting, being reduced after alpha 1-PI treatment. This pilot study demonstrates that inhalation of alpha 1-PI is associated with biochemical changes consistent with reduced proteolysis. The display of the BAL proteome by two-dimensional electrophoresis may be helpful to quantify the overall molecular changes associated with proteolytic or other lung injuries and offers the possibility to monitor directly therapeutic interventions.

Inhalation of alpha(1)-protease inhibitor in cystic fibrosis does not affect surfactant convertase and surface activity.

The inhalation of alpha(1)-protease inhibitor (alpha(1)-PI) was assessed in a pilot study to restore the protease-antiprotease balance in the lungs of cystic fibrosis (CF) patients. In addition, the effect of this treatment on the surface active properties of lung surfactant and the metabolic conversion of aggregate forms was studied. Eight young adults with CF inhaled 100 mg of alpha(1)-PI twice daily over 8 weeks and bronchoalveolar lavages (BAL) were obtained before and 12 h after the last inhalation. Large aggregate (LA) forms of surfactant were isolated from the in vivo material by ultracentrifugation and their conversion into small aggregates (SA) was assessed by an in vitro surface area cycling assay. Although alpha(1)-PI partially restored the protease-anti-protease imbalance and reduced BAL protein content, no effects were noted on the impaired minimal surface tension and on the in vivo and in vitro conversion of LA to SA. Antiserum against the specific carboxyl esterase ES-2, previously identified in mice and rats as the putative surfactant convertase, did not detect a protein of the appropriate size in CF BAL. Whereas short-term inhalation of alpha(1)-PI was beneficial for the proteolytic aspects of CF lung injury, this appeared not to be the case for surfactant conversion and surface activity.