Granulocyte elastase-alpha 1-antiproteinase complex in cystic fibrosis: sensitive plasma assay for monitoring pulmonary infections

Breath of fresh insight: unraveling the evolution of our understanding of cystic fibrosis pulmonary exacerbations

PURPOSE OF REVIEW

Pulmonary exacerbations are critical events with significant negative impacts in persons with cystic fibrosis, but their diagnosis and management are highly variable. Highly effective modulator therapies have greatly improved health and reduced exacerbation events, but have also reshaped how they present. This review discusses the complexities of the diagnosis and management of pulmonary exacerbations as well as the emerging work and evidence in this area.

RECENT FINDINGS

The shifting epidemiology and our understanding of risk factors for pulmonary exacerbations are discussed. As symptoms may be more subtle in the modulator context, novel technologies including studies of remote monitoring are presented. The continued relevance of pulmonary exacerbations, the heterogeneity in their management, as well as current and forthcoming clinical trials to optimize treatment approaches are detailed.

SUMMARY

In spite of the dramatic reductions in pulmonary exacerbations, airway infections persist, a proportion of persons with cystic fibrosis either on or off modulator therapies continue to experience exacerbation events, and long-term data is lacking. Innovative approaches and studies will be crucial to enable standardized and generalizable strategies to improve outcomes in persons with cystic fibrosis.

Abnormal n-6 fatty acid metabolism in cystic fibrosis contributes to pulmonary symptoms

Cystic fibrosis (CF) is a recessively inherited fatal disease that is the subject of extensive research and ongoing development of therapeutics targeting the defective protein, cystic fibrosis transmembrane conductance regulator (CFTR). Despite progress, the link between CFTR and clinical symptoms is incomplete. The severe CF phenotypes are associated with a deficiency of linoleic acid, which is the precursor of arachidonic acid. The release of arachidonic acid from membranes via phospholipase A₂ is the rate-limiting step for eicosanoid synthesis and is increased in CF, which contributes to the observed inflammation. A potential deficiency of docosahexaenoic acid may lead to decreased levels of specialized pro-resolving mediators. This pathophysiology may contribute to an early and sterile inflammation, mucus production, and to bacterial colonization, which further increases inflammation and potentiates the clinical symptoms. Advances in lipid technology will assist in elucidating the role of lipid metabolism in CF, and stimulate therapeutic modulations of inflammation.

Systematic review of blood biomarkers in cystic fibrosis pulmonary exacerbations

BACKGROUND

Biomarkers reflective of disease activity in cystic fibrosis (CF) have the potential to improve patient care, particularly during CF pulmonary exacerbations (CFPEs). Although blood-based biomarkers have been studied in CFPE for nearly 3 decades, none have been integrated into routine clinical practice. To facilitate progress in this area, we performed a systematic review evaluating blood-based biomarkers during CFPE.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched to identify relevant studies published from January 1995 to August 2012. We included all full-text studies examining systemic (blood-based) biomarkers to aid in the diagnosis of CFPE, predict outcomes of CFPE, and/or monitor the response to CFPE treatment.

RESULTS

Seventy-eight unique blood-based biomarkers have been studied to date, mainly inflammatory cytokines, acute phase reactants, and markers of oxidative stress. C-reactive protein (CRP) consistently correlated with disease activity, with a statistically significant increase from stable to exacerbation state in five of six studies, and changes in response to CFPE treatment, with a statistically significant decrease from the beginning to the end of CFPE treatment in 18 of 20 studies. Other promising biomarkers of CFPE disease activity include neutrophil elastase antiproteinase complex, IL-6, myeloperoxidase (MPO), lactoferrin, and calprotectin.

CONCLUSIONS

Although there are several blood-based biomarkers with evidence for application within the CFPE setting, CRP has been the most widely studied biomarker demonstrating the potential for clinical usefulness. Further validation studies and clinical trials are required to determine whether blood-based biomarkers can be used to ultimately improve health outcomes in the setting of a CFPE.

Macrolides in cystic fibrosis: is there a role?

A spectrum of anti-inflammatory properties, evidence of anti-infective action against Pseudomonas aeruginosa at sub-inhibitory concentrations and positive clinical experience in patients with diffuse panbronchiolitis, a disease with features in common with cystic fibrosis (CF), has prompted research to evaluate the role of macrolide therapy in patients with CF. Newer macrolides such as azithromycin have the advantage of improved tolerability and a prolonged intracellular half-life requiring an infrequent dosing regimen. Results from initial studies suggest a benefit from several months of macrolide therapy in patients with CF. An improvement in lung function was initially shown in a small open study in children, while maintenance of lung function compared with placebo, reduced acute respiratory exacerbations, and reduced systemic markers of inflammation were demonstrated in a randomized, placebo-controlled study of macrolide therapy in adult patients with CF. Additional controlled studies are required to determine optimal drug, dosage, and duration of therapy, and long-term adverse effects of prolonged therapy with macrolides in patients with CF. The potential, with long-term use, to induce resistance against other bacteria colonizing the upper respiratory tract e.g. pneumococci has not been explored. Measurement of cytokines and inflammatory mediators from the sputum of patients with CF is technically difficult and does not correlate with disease activity. There is a need for easily measurable, reproducible and clinically meaningful end-points for evaluation of new therapies in CF. The choice of appropriate outcome measures, apart from lung function, to monitor disease activity needs careful consideration in clinical trials determining the efficacy of macrolides in patients with CF. Evidence-based recommendations for the use of macrolides in the treatment of CF are not expected for some years although macrolides are already being prescribed for long-term use in some centers. There is a need for further research into mechanisms of anti-inflammatory action of macrolides in the lungs of patients with CF and whether or not such therapy may be beneficial in the long term.

Hepatocyte growth factor and neutrophil elastase in idiopathic pulmonary fibrosis

It has been hypothesized that hepatocyte growth factor (HGF) may play an important role in regulating the growth of lung epithelium and in the regeneration of the lung as a paracrine or endocrine factor in idiopathic pulmonary fibrosis (IPF). Based on this background, serum HGF was measured in 31 IPF patients (21 male/10 female, median age 60 years). Fifteen age-matched normal non-smokers served as the control. Hepatocyte growth factor was measured by enzyme-linked immunosorbent assay with monoclonal and polyclonal antibodies against human HGF (Otsuka Assay Laboratories, Tokushima, Japan). Elastase: alpha 1-proteinase complex was also measured by enzyme-linked immunosorbent assay. No patients had significant liver or renal dysfunction. As a result, mean (standard error) serum HGF concentration of the patients with IPF was 0.384 (0.022) ng ml-1, which was significantly high compared to normal non-smokers [0.213 (0.012) ng ml-1, P < 0.001, 95% confidence interval was between 0.104 and 0.238]. Serum HGF values correlated strongly with the plasma elastase: alpha 1 proteinase inhibitor complex (R = 0.679, P < 0.001). Immunohistochemical staining of lung tissue with anti-human neutrophil elastase showed scattered immunopositive cells mainly in interstitium. Immunohistochemical staining with mouse anti-human HGF antibody showed that HGF was distributed to the lung epithelial cells in IPF lung specimens obtained by open lung biopsy. These results suggest that HGF may play an important role in the pathogenesis of IPF.

Opportunities for the use of aerosolized alpha 1-antitrypsin for the treatment of cystic fibrosis

Cystic fibrosis (CF), the most common lethal genetic disease affecting the white population, owes its morbidity and mortality primarily to the devastating effects of chronic inflammation and infection within the pulmonary airways. It has become increasingly recognized that the host's response to Pseudomonas species and Staphylococcus aureus infection plays a paramount role in CF lung destruction and eventual development of respiratory insufficiency. A massive pulmonary influx of neutrophils, and accompanying excessive levels of neutrophil elastase (NE), can be detected in the bronchoalveolar fluid of even very young children with CF. The excess of NE adversely affects the CF airways by enhancing mucus secretion, directly injuring airway tissues, exacerbating the inflammatory process by attracting more neutrophils, and derailing opsonization and elimination of bacterial pathogens, particularly Pseudomonas aeruginosa. Neutralization of excess NE by delivering supplemental alpha 1-antitrypsin to the airways via aerosolization represents an exciting new potential therapy for CF lung disease.

Neutrophil elastase/alpha 1-proteinase inhibitor complex levels decrease in plasma of cystic fibrosis patients during long-term oral beta-carotene supplementation

Lung inflammation in cystic fibrosis (CF) is associated with an increased release from activated neutrophils of oxidants and proteinases. Free radical generation is not efficiently neutralized, and the major anti-proteinase, alpha 1-proteinase inhibitor (alpha 1-PI) is thought to be oxidatively inactivated. We hypothesized that enhanced antioxidant protection could represent an additional long-term strategy to attentuate the host inflammatory response. The effect on plasma neutrophil elastase/alpha 1-PI (NE/alpha 1-PI) complex levels (as a marker of lung inflammation) and plasma malondialdehyde concentrations (as a marker of lipid peroxidation) of additional oral beta-carotene supplementation was studied in 33 CF patients who had already received long-term vitamin E supplementation. In the presence of a more than 10-fold increase in plasma beta-carotene concentrations (mean +/- SEM) (0.09 +/- 0.01 to 1.07 +/- 0.19 mumol/L; p < 0.0001), a small increase in plasma alpha-tocopherol concentrations (23.8 +/- 1.31 to 28.4 +/- 1.81 mumol/L; p = 0.02), and a more than 50% decrease in plasma malondialdehyde concentrations (1.00 +/- 0.07 to 0.46 +/- 0.03 mumol/L; p < 0.0001), plasma NE/alpha 1-PI complex levels decreased from 102.2 +/- 16.0 to 83.0 +/- 10.4 micrograms/L; (p = 0.02). Plasma retinol concentrations increased (1.05 +/- 0.06 to 1.23 +/- 0.07 mumol/L; p = 0.0001) due to conversion of beta-carotene to retinol, which could have contributed to the decrease in NE/alpha 1-PI complex levels. Based on these results, we speculate that efficient antioxidant supplementation could attenuate lung inflammation in CF.

Measurements of plasma elastase alpha 1-proteinase inhibitor complexes in patients receiving cancer chemotherapy with granulocyte colony-stimulating factor

We monitored the plasma elastase alpha 1-proteinase inhibitor complex levels in 21 patients with primary lung cancer who received combination chemotherapy with or without recombinant human granulocyte colony-stimulating factor (rhG-CSF), and 15 normal nonsmokers as controls. Of the 21 patients, 14 received combination chemotherapy without rhG-CSF (among them, 6 developed pneumonia) and 7 received combination chemotherapy with rhG-CSF (among them, 1 developed pneumonia). We measured peripheral WBC counts, C-reactive protein (CRP) levels, plasma elastase alpha 1-proteinase inhibitor complex (complex) levels, and complex/WBC values during cancer chemotherapy. In patients who received cancer chemotherapy without rhG-CSF and had no complications (n = 8), WBC values decreased after chemotherapy, and then gradually increased. Complex levels also decreased slightly after chemotherapy and gradually recovered. The value obtained from dividing the complex concentration by WBC count (complex/WBC value) remained stable during cancer chemotherapy. In patients who received cancer chemotherapy with rhG-CSF and had no complications (n = 6), WBC values decreased after chemotherapy, and then rapidly increased to abnormally high values. Complex levels also decreased slightly after chemotherapy and rapidly increased to abnormally high values together with the WBC counts. The complex/WBC values remained stable during cancer chemotherapy. In patients who developed pneumonia during cancer chemotherapy with or without rhG-CSF (n = 7), their complex levels, complex/WBC values, and CRP levels were elevated at the onset of pneumonia. The maximum complex levels (the highest levels during chemotherapy) were significantly higher in patients who received cancer chemotherapy with rhG-CSF and did not develop pneumonia (583.1 +/- 114.5 ng/mL) and in patients who developed pneumonia during cancer chemotherapy (516.7 +/- 113.2 ng/mL), compared with normal nonsmokers (130.2 +/- 5.5, p < 0.01) and patients who received cancer chemotherapy without rhG-CSF and did not develop complications (211.5 +/- 23.3, p < 0.01). The maximum complex/WBC values were not increased in patients who received cancer chemotherapy with rhG-CSF (0.08 +/- 0.01) and patients who received cancer chemotherapy without rhG-CSF (0.092 +/- 0.01, p < 0.01). The maximum complex/WBC values were significantly higher in patients with pneumonia (0.56 +/- 0.12) compared with normal nonsmokers (0.026 +/- 0.002, p < 0.01) and patients without complications. These findings suggest that although rhG-CSF increases total plasma elastase burden, increased release of neutrophil elastase from individual neutrophils does not take place in vivo in the absence of pneumonia.

Bacterial colonisation with Xanthomonas maltophilia--a retrospective study in a cystic fibrosis patient population

Xanthomonas maltophilia was isolated from 25 of 150 patients with cystic fibrosis during a period of 10 years (1983-1992). Twelve patients harboured X. maltophilia chronically, i.e. repeatedly for more than 6 months. No predisposing factors for the colonisation could be identified by studying the clinical and laboratory data of the patients, including preceding and concurrent bacterial colonisation with other bacteria, antibacterial treatments, pulmonary function and biochemical markers. Up to 2 years after the chronic colonisation was established no clinical deterioration could be verified, but the patients with X. maltophilia generally had a worse lung function at the latest follow-up (2-7 years after colonisation) than controls colonised with Pseudomonas aeruginosa (p < 0.05). Our data imply that X. maltophilia is a pathogen and the colonisation appears to follow the same pattern as the colonisation by P. aeruginosa. The development of resistance to different antibiotics, as revealed by analysis of the inhibition zones, was related to antibacterial treatment courses. X. maltophilia showed reduced sensitivity to the most commonly used antibiotics, ceftazidime and tobramycin.

Outcome measures for clinical trials in cystic fibrosis. Summary of a Cystic Fibrosis Foundation consensus conference

The CFF Consensus Conference concluded with a summary of those outcome measures that would be most useful in studies of patients 6 years of age and older and those measures that would be most useful in studies of the younger population (< 6 years of age) (Table). These measures were further divided into biologic markers most appropriate for initial (phase I and phase II) clinical trials and those especially useful in large, multicenter (phase III) pivotal trials. There is an ongoing need to improve the accuracy and validity of currently available measures of biologic activity and clinical efficacy in CF, especially in the younger population. The conference participants recommended that the following eight issues be addressed as soon as possible: (1) definition of pulmonary exacerbation, (2) broadly applicable methods of testing pulmonary function in small children (ideally a single test for all ages), (3) a comprehensive severity-of-disease score for young children, (4) reliable methods of quantifying chest x-ray and CT scan changes in young patients, (5) simple, inexpensive measures of lung inflammation, (6) a centralized, uniform approach to the establishment of data monitoring committees, (7) a quality of well-being scale for small children, and (8) reliable, reproducible aerosol delivery systems with defined characteristics. In addition, participants recommended that better methods be developed for assessing patients' adherence to research protocols.

alpha 1-Proteinase inhibitor, elastase activity, and lung disease severity in cystic fibrosis

The potential role of neutrophil elastase in exacerbating pulmonary infection and tissue damage in cystic fibrosis (CF) has led to proposals for treatment of lung disease in CF with the elastase inhibitor, alpha 1-proteinase inhibitor (alpha 1PI). Reports that alpha 1PI is inactivated in the CF lung suggest that the effectiveness of alpha 1PI therapy depends on the quantity of elastase present and the extent of alpha 1PI inactivation, both of which are expected to vary with disease severity. In this study we assessed the elastase-alpha 1PI profile in sputum and plasma from CF patients with various degrees of pulmonary involvement. Levels of active elastase in sputum samples increased with severity of pulmonary disease (F ratio = 5.63, p < 0.01), as did sputum levels of alpha 1PI (F ratio = 4.88, p < 0.01). A positive correlation was observed between sputum levels of active elastase and alpha 1PI (r = 0.68, p < 0.005). Plasma alpha 1PI levels were also elevated in CF patients compared with control subjects (p < 0.005), indicating a compensatory increase in plasma and sputum levels of alpha 1PI in response to increased elastase load. Molar levels of total immunogenic neutrophil elastase were, on average, 12 times higher than alpha 1PI in CF sputum. These results suggest that the major contributor to the elevated levels of active elastase observed in the CF lung is an increase in elastase release rather than inactivation of alpha 1PI.

The host inflammatory response prior to death in patients with cystic fibrosis and chronic Pseudomonas aeruginosa infection

The intensity of the host inflammatory response to pulmonary infection with Pseudomonas aeruginosa immediately prior to death was determined in six patients with cystic fibrosis (CF). Plasma concentrations of neutrophil elastase alpha 1-antiproteinase, tumour necrosis factor-alpha (TNF alpha) and serum C-reactive protein (CRP) were increased in the 7 days prior to death (P < 0.05) when compared with a period of clinical stability during the preceding 6 months. An increased inflammatory response was sustained for many weeks prior to death and was associated with poor symptom and lung function responses to apparently appropriate antibiotic treatment.

Serial measurements of plasma elastase alpha 1-proteinase inhibitor complexes in patients receiving cancer chemotherapy

We monitored the plasma elastase:alpha 1-proteinase inhibitor complexes during chemotherapy for cancer and investigated the relationship between the elastase burden and the onset of adult respiratory distress syndrome (ARDS) in 20 patients with primary lung cancer who received combination chemotherapy; 15 normal nonsmokers served as controls. Of the 20 patients, 6 developed pneumonia, and 6 developed ARDS. We measured peripheral WBCs, C-reactive protein (CRP), plasma elastase:alpha 1-proteinase inhibitor complex (complex), and the ratio of complex/WBC during chemotherapy for cancer. In patients who did not experience complications during combination chemotherapy, WBC counts changed, but levels of complex were normal. In patients who developed pneumonia, levels of complex were abnormally high during the WBC nadir, and the complex/WBC count increased along with the level of CRP. In patients who developed ARDS during chemotherapy for cancer, levels of complex were abnormally high immediately after chemotherapy and remained high after the onset of ARDS. In addition, complex/WBC counts and CRP levels increased at the onset of ARDS. The maximum complex concentration was significantly higher in patients with pneumonia (414.3 +/- 57.2 ng/ml) and ARDS (683.2 +/- 72.8 ng/ml), compared with normal nonsmokers (130.2 +/- 5.5 ng/ml; p < 0.01) and patients who did not develop complications (211.5 +/- 23.3 ng/ml; p < 0.01). The maximum complex/WBC count was also significantly higher in patients with pneumonia (0.56 +/- 0.12) and ARDS (1.03 +/- 0.27), compared with normal nonsmokers (0.03 +/- 0.002; p < 0.01) and patients without complications (0.09 +/- 0.01; p < 0.01). These findings suggested a possible correlation between increased levels of complex and the onset of ARDS.

Host inflammatory responses to first isolation of Pseudomonas aeruginosa from sputum in cystic fibrosis

Pseudomonas aeruginosa infection of the respiratory tract in patients with cystic fibrosis is a major determinant of morbidity and mortality. However, it has been postulated that the earliest phase of colonization is not associated with injury. To test this hypothesis we determined the association of the first recorded isolation of P. aeruginosa from the sputum on circulating markers of the inflammatory response in 6 patients with cystic fibrosis. At this time circulating C-reactive protein was increased in all 6 and neutrophil elastase alpha 1-antitrypsin complex (elastase-complex) was increased in 5 patients compared with healthy controls. This inflammatory response was associated with a reduction in the FEV1 and FVC of all patients [FEV1, 1.42 +/- 0.87 L (mean +/- SD) at first isolation vs. 2.08 +/- 0.74 L before isolation; P < 0.05; FVC, 1.94 +/- 0.93 L vs. 2.87 +/- 1.01 L, P < 0.05]. At a median interval of 10 months, 5 patients had raised titres of positive IgG antibody to P. aeruginosa, indicating significant exposure to this organism. At this time, lung function had returned to preinfection levels, whilst 3 patients showed continuing features of an inflammatory response, and the group mean value for elastase-complex was raised. Our findings demonstrate that at the time of first isolation of P. aeruginosa from the sputum of patients with cystic fibrosis, there is a concomitant systemic host response and an acute deterioration of pulmonary function.

Elevation of plasma truncated elastase alpha 1-proteinase inhibitor complexes in patients with inflammatory lung diseases

Human neutrophil elastase plays an important role in the development of several inflammatory lung diseases; however, there have been relatively few investigations using plasma samples. In this report, we describe alterations in the plasma elastase:alpha 1-PI complex in patients with chronic obstructive pulmonary disease (COPD) (15 cases), COPD with infection (8), diffuse panbronchiolitis (DPB) (8), bronchiectasis (9), pneumonia (10), and the adult respiratory distress syndrome (ARDS) (14), and in 15 normal volunteers. The elastase:alpha 1-PI complex concentration was determined by an enzyme-linked immunosorbent assay. Western immunoblot analysis of the elastase:alpha 1-PI complex was also performed. Plasma elastase:alpha 1-PI complex was also performed. Plasma elastase:alpha 1-PI complex levels in patients with COPD with infection (504 micrograms/L +/- 93 micrograms/L) were significantly higher, as compared with those with COPD but without infection (118 micrograms/L +/- 9 micrograms/L) and normal volunteers (122 micrograms/L +/- 4 micrograms/L). Increased complex concentrations were also found in patients with DPB and bronchiectasis (643 micrograms/L +/- 222 micrograms/L and 558 micrograms/L +/- 198 micrograms/L, respectively) as compared with normal volunteers. Increased complex concentrations were also found in patients with pneumonia and ARDS (450 micrograms/L +/- 101 micrograms/L and 1,400 micrograms/L +/- 438 micrograms/L, respectively). Western immunoblot analysis using anti-alpha 1-PI antibody and antineutrophil elastase antibody showed two types of elastase:alpha 1-PI complexes, one with a molecular weight of 60,000 daltons (60 kilodaltons [KD]) and the other at 50,000 daltons (50 KD). Although the native 80-KD elastase:alpha 1-PI complex was detected in bronchoalveolar lavage fluid, it was not found in plasma. In summary, these results demonstrated that levels of the truncated complex were increased in patients with various inflammatory lung diseases. This truncated form may play an important role in the pathophysiology of inflammatory processes.

Modification of some markers of inflammation during treatment for acute respiratory exacerbation in cystic fibrosis

An objective approach for monitoring the treatment of acute pulmonary exacerbation in cystic fibrosis was evaluated. Eleven biochemical markers of inflammation (erythrocyte sedimentation rate, neutrophil count, C-reactive protein, alpha-1 antitrypsin, haptoglobin, ceruloplasmin, fibronectin, alpha-1 glycoprotein, alpha-2 macroglobulin, C3, granulocyte elastase and anti-Pseudomonas IgG) were measured in blood serum and plasma from 46 cystic fibrosis patients with chronic Pseudomonas aeruginosa colonization before and after treatment. The overall outcome in each patient was evaluated by means of a pondered sum of clinical, chest X-ray and lung function scores. Biochemical markers were related to the overall clinical improvement: haptoglobin, ceruloplasmin, fibronectin and alpha-1 glycoprotein showed a good sensitivity (64-70%), specificity (60-70%) and positive predictive value (86-89%). Granulocyte elastase showed a similar sensitivity (67%) and positive predictive value (85%) but a lower specificity (33%). The negative predictive value was generally poor (32-39%). Our data suggest that the combined measurement of some markers of inflammation and of conventional clinical parameters, may help in evaluating the efficacy of anti-infective treatment in cystic fibrosis.

Human neutrophil elastase and elastase/alpha 1-antiprotease complex in cystic fibrosis. Comparison with interstitial lung disease and evaluation of the effect of intravenously administered antibiotic therapy

In cystic fibrosis (CF), extracellular lung matrix is progressively damaged, neutrophils invade the air spaces, and activated neutrophils may release large amounts of neutrophil elastase (NE). Although alpha 1-antiprotease (alpha 1-AP) binds and inactivates NE and is the major antielastase of the lower respiratory tract, antielastase defenses may be overwhelmed in CF, leading to progressive lung damage. To determine whether the ability of alpha 1-AP to neutralize NE is impaired in CF, we compared NE activity in bronchoalveolar lavage (BAL) fluid and human neutrophil elastase/alpha 1-antiprotease (NE/alpha 1-AP) complex in both BAL fluid and peripheral blood serum from patients with CF, normal volunteers, and patients with interstitial lung disease. We detected a considerable amount of NE activity in BAL fluid from all but one patient with CF but none in that from normal volunteers or from patients with interstitial lung disease. Although in interstitial lung disease there was a significant correlation between increased NE/alpha 1-AP complex in BAL or peripheral blood and the degree of neutrophil influx, NE/alpha 1-AP complex was disproportionately low in CF BAL compared with significantly elevated values in serum. These data suggest that in CF, alpha 1-AP-mediated defense against free NE in the lower respiratory tract is significantly impaired, and high levels of uncomplexed, enzymatically active, NE are present in CF respiratory secretions. To determine whether intravenously administered antipseudomonal antibiotic therapy for exacerbations of CF lung disease diminished the amount of free NE in respiratory secretions, we used BAL to investigate the effect of such therapy on neutrophils and NE in patients with CF colonized with pseudomonads.(ABSTRACT TRUNCATED AT 250 WORDS)

Inflammatory markers in cystic fibrosis

Plasma neutrophil elastase-alpha 1 antiproteinase complex, lactoferrin and C-reactive protein (CRP) were determined over a 15-month period in 26 patients with cystic fibrosis, of whom 21 were chronically infected with Pseudomonas aeruginosa. Median concentrations of both neutrophil products and CRP were greater in patients who were clinically stable than in healthy subjects without cystic fibrosis. CRP concentrations increased further at the onset of symptomatic exacerbations. Thirty-five courses of intravenous antibiotics and 22 courses of oral ciprofloxacin were reviewed and revealed similar improvements in clinical scores and lung function tests for both forms of treatment. Intravenous antibiotics reduced the plasma concentrations of both neutrophil products and CRP, while oral ciprofloxacin only significantly reduced the concentration of neutrophil elastase-alpha 1 antiproteinase complex. Plasma concentrations of inflammatory markers were significantly greater in exacerbations associated with fever and leukocytosis. Statistical modelling demonstrated negative within-patient relationships between lung function and both CRP and lactoferrin, and positive relationships between the three inflammatory markers. Neutrophil granule products and CRP reflect the pulmonary inflammatory state in cystic fibrosis and may be of value in monitoring treatment.

Plasma tumour necrosis factor alpha in cystic fibrosis

Plasma tumour necrosis factor alpha (alpha) concentration is increased in acute Gram negative sepsis, but the effect of chronic infection on plasma concentrations is unknown. A study was carried out in patients with cystic fibrosis to determine the effect of chronic lung infection with Pseudomonas aeruginosa on the plasma concentration of tumour necrosis factor and two other indicators of the inflammatory response, circulating C reactive protein and neutrophil elastase-alpha 1 antiproteinase complex (elastase complex). The concentration of immunoreactive tumour necrosis factor in plasma was greater than the upper 95% confidence interval for healthy subjects (2.6 U/ml) on 129 out of 189 occasions in 14 patients observed for about a year. The increase in tumour necrosis factor was associated with increased circulating C reactive protein and elastase complex. Twelve patients with an exacerbation of respiratory symptoms were studied before and after two weeks' treatment with anti-pseudomonal antibiotics. All three indicators of the inflammatory response fell after treatment, though median tumour necrosis factor (4.8 U/ml) and elastase complex (0.41 microgram/ml) concentrations remained above the upper limits for healthy subjects. During a period of clinical stability plasma tumour necrosis factor was increased in 10 of the 12 patients, elastase complex was increased in 10 of the 12, and C reactive protein was increased in seven. Increased plasma immunoreactive tumour necrosis factor was a feature of the near continuous inflammatory response to chronic P aeruginosa infection in cystic fibrosis and may be a factor contributing to the progressive lung destruction seen in this disease.

Antineutrophil elastase activity in cystic fibrosis serum

The antigenic concentrations of alpha-1-antitrypsin (alpha 1AT) were measured in 13 patients with cystic fibrosis (CF) and in 11 healthy subjects. Serum alpha 1AT was purified by immunoaffinity chromatography and the antielastase activity of the purified alpha 1AT was determined by measuring the molar ratio necessary to inhibit human neutrophil elastase (HNE). The association rate constant of alpha 1AT with HNE was determined in a timed assay. The capacity of CF serum alpha 1AT to form complexes with porcine pancreatic elastase was studied by polyacrylamide gel electrophoresis. Antigenic concentrations of alpha 1AT mumol/L were markedly increased in the serum of all patients with CF (61.9 +/- 4.3 mumol/L) in comparison to a reference standard (36.7 +/- 1.8 mumol/L; P less than 0.0001). CF serum alpha 1AT was fully active against HNE, and its association rate constant in the presence of HNE was similar to that of healthy subjects. In addition, CF serum alpha 1AT formed complexes with porcine pancreatic elastase that were electrophoretically indistinguishable from those of normal serum alpha 1AT. These results indicate that patients with CF have increased serum alpha 1AT concentrations and that this antiprotease, when purified from serum, functions normally.

Cystic fibrosis, pathophysiological and clinical aspects

Cystic fibrosis is a lethal, hereditary, until recently little understood disease, which leads to progressive functional disturbances in various organs, including the lungs, liver and pancreas. Knowledge of the genetic and cellular abnormalities is rapidly progressing, but therapy is still symptomatic and based on insufficiently controlled and short-term studies. At present the therapeutic approach aims to combat respiratory infections by optimal antibiotic therapy, combined with techniques to promote sputum evacuation. Additional measures attempt to optimise both nutritional state and physical condition. Median survival has improved from approximately 1 year to about 25 years during the past 3 decades. This article summarises present information on disease mechanisms and treatment.

Antistaphylococcal antibodies in cystic fibrosis

Chronic colonization with Staphylococcus aureus is found in 40-50% of the sputum producing patients with cystic fibrosis treated at Stockholm's Cystic Fibrosis Center, Huddinge University Hospital. 30-40% of these patients had increased ELISA IgG antibody titres against teichoic acid and against alpha-toxin. About half of the number of patients showed increased antibody titres to either antigen during infection. Increased antibody titres against staphylococcal antigens were only found in less than or equal to 10% of patients not chronically colonized with S. aureus (no different from the normal population). The serum titres of antistaphylococcal antibodies were significantly higher in the chronically colonized patients (p less than 0.001). Patients who were also chronically harbouring Pseudomonas aeruginosa had the highest titres of both antibodies. The titres increased with clinical signs of infection and were normalized by antimicrobial chemotherapy. To conclude, the use of ELISA IgG antibodies may prove suitable for routine evaluation of the need for, and control of the efficacy of antistaphylococcal chemotherapy in cystic fibrosis.

Relation between tumor necrosis factor-alpha and granulocyte elastase-alpha 1-proteinase inhibitor complexes in the plasma of patients with cystic fibrosis

Patients with cystic fibrosis suffer from a chronic, progressively destructive bronchitis characterized by colonization of the airways by Pseudomonas aeruginosa. Cell wall lipopolysaccharides from P. aeruginosa may stimulate secretion of cytokines such as tumor necrosis factor alpha (TNF alpha) by monocytes/macrophages. We found elevated levels of TNF alpha (150 +/- 60 pg/ml), interleukin-1 alpha (144 +/- 205 pg/ml), and interleukin-1 beta (62 +/- 100 pg/ml) in plasma from 25 patients with cystic fibrosis. In patients with less advanced disease, elevated plasma levels of TNF alpha correlated with high levels of complexes between neutrophil elastase and alpha 1-proteinase inhibitor, suggesting that TNF alpha may be a mediator of neutrophil degranulation. TNF alpha, by its chemotactic effect on neutrophils, may also contribute to the massive influx of neutrophils into and around the bronchial tree. Our findings raise the questions whether in patients with cystic fibrosis TNF alpha acts as cachectin and whether it mediates the anorexia that often results in weight loss.

Sputum changes associated with therapy for endobronchial exacerbation in cystic fibrosis

We sought to define objective indicators of the resolution of Pseudomonas aeruginosa endobronchial infection in patients with cystic fibrosis. We prospectively studied 75 patients admitted for treatment of a pulmonary exacerbation and quantitated sputum bacterial density, DNA content, and the concentration of albumin and total protein in sputum, and compared these values with clinical evaluation. Eleven of the 75 patients had systemic signs, fever, and leukocytosis, which we arbitrarily defined as due to endobronchial infection. At the end of hospitalization, these 11 patients were afebrile, had peripheral leukocyte counts in the normal range, and were judged improved. Sputum P. aeruginosa density, DNA content, and total protein content on admission were similar in the two illness groups. Hospitalization and parenteral antibiotic administration for an average of 14.6 days were associated with improved pulmonary function in all 75 subjects (P values for forced vital capacity, forced expiratory volume at 1 second, and peak expiratory flow rate were all less than 0.001). With improvement, there was a decrease in sputum P. aeruginosa density (mean of both groups decreased from 10(7.80) CFU/g on admission to 10(5.96) CFU/g; P less than 0.001), and a decreased DNA concentration (overall mean 4.73 +/- 4.75 on admission to 2.76 +/- 2.49 mg/g; P less than 0.002). The decrease in sputum total protein concentration for both groups was not significant (overall mean 60.5 +/- 48.4 to 43.9 +/- 38.2 mg/g; P = 0.06). Sputum albumin concentrations did not change in either group. We conclude that in cystic fibrosis subjects with a pulmonary exacerbation, bacterial density, sputum DNA and protein content decrease with hospitalization and parenteral antibiotic therapy. At the end of treatment, these indices of sputum infection and inflammation correlate with improved pulmonary function and clinical improvement. These changes are independent of the presence or absence of fever on admission.