Brave new world for interventional bronchoscopy.
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Biopsy, Needle↗
Biomedical subjects
P L Shah
Publications and source records attributed to P L Shah.
A case-controlled study with dornase alfa to evaluate impact on disease progression over a 4-year period.
BACKGROUND: Chronic endobronchial sepsis and profuse airway secretions dominate pulmonary disease in cystic fibrosis. Recombinant human DNase I (dornase alfa) reduces the viscoelasticity of airway secretions and hence may improve clearance of airway secretions. OBJECTIVES: To evaluate the long-term influence of dornase alfa on disease progression by performing a case-controlled study with dornase alfa over a period of 4 years. METHODS: A cohort of patients with cystic fibrosis who have been treated with dornase alfa were matched with a control group of patients with cystic fibrosis who had not received treatment with dornase alfa. The patients were matched by pulmonary function, age, and then sex. All available measurements of forced expiratory volume in one second (FEV1), height, weight and sputum bacteriology were collected for periods when the patients were free from respiratory exacerbations. RESULTS: Thirty-eight patients were matched. Slopes of median changes in FEV1 were -2.19 (-3.32, -1.06) in the control group and -0.75 (-1.87, 0.36) in the dornase alfa-treated group (p = 0.076). There were more infective exacerbations per patient year in the control group [3.13 (1.25-4.25)] in comparison to the dornase alfa group [1.25 (0.63-3.0), p = 0.035] over the 4-year treatment period. Antibiotic requirements were also greater with a median 43.75 (17.5-60.0) days of intravenous antibiotic use per patient year in the control group and 16.25 (8.5-44.0) days in the dornase alfa group (p = 0.034). CONCLUSIONS: The trends suggest that dornase alfa may have some influence on disease progression but in view of the limitations of the current study the need for further long-term studies in larger cohorts of patients is emphasised.
Adult↗
Increased nitrotyrosine in exhaled breath condensate in cystic fibrosis.
Exhaled nitric oxide (ENO), a marker of inflammation in airway diseases is decreased in cystic fibrosis (CF) patients, perhaps because nitric oxide (NO) is metabolized to oxidative end-products. A stable product, 3-nitrotyrosine, may indicate local formation of reactive nitrogen species. Whether NO metabolites in exhaled breath condensate may be increased in CF patients was investigated. The fractional concentration of ENO (Feno), nitrotyrosine and oxides of nitrogen in exhaled breath condensate from 36 stable CF patients were compared to 14 normal subjects using an enzyme immunoassay and fluorescence assay. Nitrotyrosine levels in breath condensate were increased significantly in stable CF patients, compared with normal subjects (25.3 +/- 1.5 versus 6.3 +/- 0.8 ng x mL(-1), p<0.0001). There was an inverse correlation between the levels of nitrotyrosine and the severity of lung disease. Feno levels were significantly lower in CF patients than in normal subjects (4.4 +/- 0.3 versus 5.6 +/- 0.4 (parts per billion), p<0.05). No correlation was found between nitrotyrosine and Feno levels in CF. There was no significant difference in the levels of nitrite and nitrate between CF patients and normals. The elevation in nitrotyrosine may reflect increased formation of reactive nitrogen species such as peroxynitrite or direct nitration by granulocyte peroxidases, indicating increased oxidative stress in airways of cystic fibrosis patients.
Adult↗
Pulmonary alveolar proteinosis: clinical aspects and current concepts on pathogenesis.
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Bronchoalveolar Lavage↗
Exhaled ethane is elevated in cystic fibrosis and correlates with carbon monoxide levels and airway obstruction.
Ethane is produced from lipid peroxidation and can be measured in the exhaled air. Cystic fibrosis (CF) is characterized by recurrent respiratory infections, release of reactive oxygen species by inflammatory cells, and increased oxidative stress. We measured exhaled ethane in 23 CF subjects (mean age +/- SEM, 21 +/- 4 yr; 10 male, FEV(1) 62 +/- 4%) and compared it with two other noninvasive markers of oxidative stress and inflammation, carbon monoxide (CO) and nitric oxide (NO). Exhaled ethane was collected during a flow and pressure-controlled exhalation into a reservoir discarding dead space air contaminated with ambient air. A sample (2 ml) of the expired air was analyzed by chromatography. Ethane levels were elevated in patients not on steroids (n = 13, 1.99 +/- 0.20 ppb) compared with steroid-treated patients (n = 10, 0.67 +/- 0.09 ppb, p < 0.01) and with 14 nonsmoking control (8 men, age 33 +/- 2.8 yr) subjects (0.82 +/- 0.40 ppb, p < 0.05). In patients not on steroid treatment ethane was correlated to airway obstruction as assessed by the ratio of residual volume to total lung capacity (RV/ TLC) (r = 0. 66, p < 0.05) and exhaled CO (r = 0.65, p < 0.05). CO concentrations were also higher in patients not on steroid treatment (3.4 +/- 0.2 ppm) than in steroid-treated patients (2.6 +/- 0.1 ppm, p < 0.05), whereas NO concentrations were not influenced by steroid treatment (3.0 +/- 0.4 ppm and 2.9 +/- 0.2 ppm, p > 0.05) and were lower than in a control group (7.0 +/- 0.4 ppb, p < 0.05). Exhaled ethane is elevated in CF, reduced in steroid-treated patients and correlates with CO and RV/TLC; therefore, it may be a useful noninvasive marker of oxidative stress.
Adult↗
Where we are now with rhDNase.
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Aerosols↗
Increased carbon monoxide in exhaled air of patients with cystic fibrosis.
BACKGROUND: Inflammation, oxidative stress, and recurrent pulmonary infections are major aggravating factors in cystic fibrosis. Nitric oxide (NO), a marker of inflammation, is not increased, however, probably because it is metabolised to peroxynitrite. Exhaled carbon monoxide (CO), a product of heme degradation by heme oxygenase 1 (HO-1) which is induced by inflammatory cytokines and oxidants, was therefore tested as a non-invasive marker of airway inflammation and oxidative stress. METHODS: Exhaled CO and NO concentrations were measured in 29 patients (15 men) with cystic fibrosis of mean (SD) age 25 (1) years, forced expiratory volume in one second (FEV(1)) 43 (6)%, 14 of whom were receiving steroid treatment. RESULTS: The concentration of exhaled CO was higher in patients with cystic fibrosis (6.7 (0.6) ppm) than in 15 healthy subjects (eight men) aged 31 (3) years (2.4 (0.4) ppm, mean difference 4.3 (95% CI 2.3 to 6.1), p<0.001). Patients not receiving steroid treatment had higher CO levels (8.4 (1.0) ppm) than treated patients (5.1 (0.5) ppm, mean difference 3.3 (95% CI -5.7 to -0.9), p<0.01). Normal subjects had higher NO levels (6.8 (0.4) ppb) than patients with cystic fibrosis (3.2 (0.2) ppb, mean difference 3.8 (95% CI 2.6 to 4.9), p<0.05) and were not influenced by steroid treatment (3.8 (0.4) ppb and 2.7 (0. 3) ppb for treated and untreated patients, respectively, mean difference 0.8 (95% CI -0.6 to 2.3), p>0.05). Patients homozygous for the DeltaF508 CFTR mutation had higher CO and NO concentrations than heterozygous patients (CO: 7.7 (1.8) ppm and 4.0 (0.6) ppm, respectively, mean difference 3.7 (95% CI -7.1 to -0.3), p<0.05; NO: 4.1 (0.5) ppb and 1.9 (0.7) ppb, respectively, mean difference 2.2 (95% CI -3.7 to -0.6), p<0.05). CONCLUSIONS: High exhaled CO concentrations in patients with cystic fibrosis may reflect induction of HO-1. Measurement of exhaled CO concentrations may be clinically useful in the management and monitoring of oxidation and inflammatory mediated lung injury.
Adrenal Cortex Hormones↗
Determinants of chronic infection with Staphylococcus aureus in patients with bronchiectasis.
Staphylococcus aureus is an uncommon pathogen in bronchiectasis not caused by cystic fibrosis (CF). The object of this study was to identify characteristics that cause patients to be prone to infection with S. aureus. The study population consisted of patients with bronchiectasis attending the authors' unit, excluding those with a diagnosis of overt CF. All patients had a high resolution computer tomographic scan (HRCT) of the thorax which demonstrated bronchiectasis. Cases that were currently chronically infected with S. aureus (isolated consecutively on more than two occasions >3 months apart) were identified (n = 12) and compared with 74 control patients who had not been chronically infected with S. aureus. Patients were carefully evaluated to determine the aetiology of their disease. Odds ratios (OR) and 95% confidence intervals (CI) as measures of the association between disease characteristics and chronic infection with S. aureus were calculated. The results for patients chronically infected by S. aureus demonstrated significant associations with allergic bronchopulmonary aspergillosis (ABPA; OR = 8.8, 95% CI 1.8-41.9), atypical variants of CF (OR = 12.0, 95% CI 1.8-81.7) or equivocal sweat sodium values (OR = 4.0, 95% CI 1.0-15.3). The associations persisted when the analysis was based on cases (n = 28) in whom S. aureus had ever been isolated from sputum. In the latter analysis there was also a significant association with predominant upper zone disease on HRCT. These results suggest that patients with bronchiectasis in whom S. aureus is isolated from sputum should be carefully evaluated to exclude allergic bronchopulmonary aspergillosis or atypical cystic fibrosis.
Adult↗
Current developments in the treatment of pulmonary disease in patients with cystic fibrosis.
Cystic fibrosis is a genetic disease that affects one in 2500 live births. A basic defect in chloride transport leads to impaired clearance of airway secretions and a susceptibility to bacterial infection. Once infection is established there is a vicious cycle that leads to progressive inflammation and infection. Although cystic fibrosis is a multisystem disorder, pulmonary disease is the main cause of morbidity and respiratory failure remains the main cause of death. This review discusses the strategies for treating pulmonary disease in patients with cystic fibrosis and focuses on some of the therapeutic developments.
Journal Article↗
Ongoing planned clinical trials investigating the pulmonary management of cystic fibrosis.
Cystic fibrosis (CF) is a genetic disease where abnormalities in ion transport lead to poor clearance of viscoelastic secretions and a susceptibility to bacterial colonisation. Once established the infection/inflammatory cascade appears to be self-perpetuating. Treatment is therefore based on a number of strategies. Recently, advances have been concentrated at correcting the gene defect. Other strategies include correction of the ion transport defect. These may be crucial in patients if started before there is significant pulmonary disease. Developments aimed at improving the rheological properties of secretions, controlling airway infection and inflammation are essential once bronchopulmonary sepsis is established. This report looks at some of the clinical trials that are ongoing or planned in the treatment of pulmonary disease in CF.
Journal Article↗
The overuse or underuse of dornase alfa.
The poor clearance of airway secretions in patients with cystic fibrosis perpetuates the chronic bronchopulmonary sepsis that is predominant. In recent years, novel drugs have been developed to alter the rheologic properties of the secretions in an attempt to improve airway clearance. Dornase alfa reduces the viscoelasticity of sputum from patients with cystic fibrosis and may enhance the clearance of secretions. Current clinical knowledge suggests that it is a safe treatment that improves pulmonary function and reduces respiratory exacerbations. The response, however, is heterogeneous and unpredictable. Scientific studies support the therapeutic rationale for the use of dornase alfa in that treatment reduces the viscoelasticity of airway secretions. Its effect on bacterial persistence and airway inflammation, however, is marginal. The key piece of information that would influence the long-term use of dornase alfa is how it affects disease progression, and at present this is unknown.
Bacterial Infections↗
An evaluation of two aerosol delivery systems for rhDNase.
Increasingly, proteins are delivered to the respiratory tract as an aerosol, and clinical efficacy is dependent on optimal delivery of the protein in an intact form. The object of this study was to compare the in vivo and in vitro results of two aerosol delivery systems for the aerosolization of recombinant human deoxyribonuclease I (rhDNase) in patients with cystic fibrosis (CF). Patients with CF who were to be initiated on rhDNase were randomized either to the Hudson nebulizer and Pulmo-Aide compressor or to the Sidestream nebulizer driven by the CR50 air compressor. An in vitro study was performed in six sets of the two aerosol delivery systems. One hundred and seventy three patients were randomized in this open study, where rhDNase was administered for 7 days. Improvements in pulmonary function were observed in both groups following 1 week of therapy with rhDNase. Changes in the Sidestream/CR50 and Hudson/Pulmo-Aide groups, respectively, were: 16 and 11% for forced expiratory volume in one second (p=0.14); 12 and 10% for forced vital capacity (p=0.70); and 14 and 7% for forced expiratory flow at 25-75% of expiration (FEF(25-75)) (p=0.18). A greater proportion of patients in the Sidestream/CR50 group (58%) had a >10% response in FEF(25-75) compared to the Hudson/Pulmo-Aide group (42%; p=0.03). The Sidestream nebulizer had a faster nebulization rate (p<0.05), lower mass median diameter for the aerosol mass produced (p<0.001), higher percentage of particles in the respirable range (p<0.001) and greater respirable output (p<0.005), compared to the Hudson nebulizer. The Sidestream/CR50 combination is a quicker, more efficient system in vitro than the Hudson/Pulmo-Aide combination, whereas the in vivo study only suggested a difference. Clinically, the two systems have similar efficacy.
Adult↗
In vivo effects of recombinant human DNase I on sputum in patients with cystic fibrosis.
BACKGROUND: Viscoelastic secretions in cystic fibrosis cause impaired mucus clearance and persistence of bacteria within the lung. The abnormal rheology is partly due to the presence of high molecular weight deoxyribonucleic acid (DNA). Recombinant human DNase I (rhDNase) has been shown to depolymerise DNA and thereby reduce the in vitro viscoelasticity of sputum in patients with cystic fibrosis. A phase II double blind placebo controlled study showed that rhDNase improved pulmonary function in patients with cystic fibrosis. The object of the present study was to evaluate the in vivo effects of rhDNase on sputum rheology and to determine whether these were correlated with changes in pulmonary function. METHODS: Patients were randomised to receive either placebo or rhDNase 2.5 mg twice daily for 10 days. Sputum samples were collected in sterile containers during screening and during treatment with the study drug. Pulmonary function and rheological analysis were the primary outcomes evaluated. Other parameters assessed were quantitative sputum bacteriology, sputum DNA concentration, and change in molecular mass of DNA polymers. RESULTS: The viscoelasticity of the sputum in untreated patients with cystic fibrosis was high and treatment with rhDNase reduced all the rheological parameters measured: dynamic storage modulus (a measure of elasticity), dynamic loss modulus (a measure of viscosity), and log complex modulus (a measure of mucus rigidity). The calculated cough clearance index was also improved following treatment with rhDNase. These rheological parameters showed a correlation with forced expiratory volume in one second (FEV1) which was improved by a mean (SE) of 13.3 (5.6)% on day 10 of treatment with rhDNase compared with a change of 0.2 (3.1)% in the placebo group. There was no change in bacterial colony counts or sputum DNA concentrations following treatment with rhDNase, but a small decrease in high molecular weight DNA was observed. CONCLUSIONS: Patients with cystic fibrosis treated with rhDNase show an improvement in rheological properties and pulmonary function, one of the mechanisms being a reduction in the proportion of high molecular weight DNA.
Adolescent↗
The effects of recombinant human DNase on neutrophil elastase activity and interleukin-8 levels in the sputum of patients with cystic fibrosis.
In cystic fibrosis (CF), neutrophil-dominated airway inflammation results in high levels of neutrophil elastase (NE). Some of these proteases are sequestered by the large amounts of deoxyribonucleic acid (DNA) present in purulent sputum. Recombinant human deoxyribonuclease (rhDNase), a new treatment in CF, depolymerizes DNA. Our concerns were that this might release proteases bound to DNA, which could be potentially harmful. The in vitro and in vivo effects of rhDNase on NE and interleukin-8 (IL-8) were evaluated. The acute effects of rhDNase were evaluated in CF patients during the first 6 days of treatment. Medium-term effects were evaluated in stable CF patients observed in rhDNase over 6 months. Sputum samples were collected at regular intervals and NE activity was measured by a fluorimetric assay and IL-8 with a radioimmunoassay. In vitro addition of rhDNase resulted in a twofold increase in protease activity and this was reflected in an acute transient rise on initiation of treatment with rhDNase. Medium-term treatment was associated with a decline in NE activity and IL-8. These in vivo results are encouraging, since the increase in protease activity was transient and the trend over 6 months was a reduction in both inflammatory markers.
Cystic Fibrosis↗
New treatment strategies in cystic fibrosis: rhDNase.
Cystic fibrosis (CF) is the commonest inherited disease of the Caucasian population, with a high morbidity and mortality from pulmonary disease. The high viscoelasticity of CF sputum is due, in part, to the high deoxyribonucleic acid (DNA) content. Recombinant human deoxyribonuclease I (rhDNase) has been developed and in vitro studies have shown that it reduces the viscoelasticity of CF sputum. This article reviews the in vivo clinical studies conducted to determine the safety and efficacy of rhDNase in the treatment of pulmonary disease in CF. Initial Phase I studies showed preliminary safety and some evidence of clinical benefit. Subsequently, two Phase II studies were conducted in the US and UK during which patients received rhDNase for 10 days. A Phase III study of 24 weeks duration involving 968 patients in 51 centres in North America is also reported in detail. Longer term open-label studies, the results of intermittent administration, administration to severely ill patients and the use of different delivery systems are reviewed. The Phase II study reported improvements in pulmonary function and had a good safety profile. The Phase III study showed improvement in forced expiratory volume in one second (FEV1) of 5.8 and 5.6% in patients treated once and twice daily, respectively. The risk of developing an exacerbation was reduced by 28% with once daily treatment and 37% with twice daily treatment compared to placebo. The drug was safe and there was some improvement in quality of life data. Recombinant human deoxyribonuclease is a new therapy for pulmonary disease in cystic fibrosis which has been shown to benefit patients when used in conjunction with conventional therapy.
Aerosols↗
Two years experience with recombinant human DNase I in the treatment of pulmonary disease in cystic fibrosis.
Recombinant human DNase I (rhDNase) has been shown to improve pulmonary function in patients treated for up to 6 months. A cohort of 52 cystic fibrosis patients with a FVC > 40% predicted were enrolled into an open label study in order to evaluate longer-term effects of rhDNase. They received 2.5 mg rhDNase twice daily for 6 months followed by a 2-week wash-out period, and for the subsequent 18 months were treated with rhDNase once daily. Twenty-six male and 26 female patients with a mean FVC of 2.941 and FEV1 of 1.471 were recruited. Thirteen patients did not complete the study; there were seven deaths, three patients withdrew consent and three patients were lost to follow-up. Improvement in pulmonary function was seen following treatment and changes were evaluated as mean percent change from baseline. The maximum improvement occurred in the first month followed by a plateau at a lower level of improvement. The mean improvement in FEV1 over the first month was 13.3% (range 12-14.1%), followed by a plateau at around 7.1% (range 4.6-11.0%) for the subsequent 23 months. Mean FVC was improved by 12.03% (range 9.0-14.3%) over the first month and subsequently 4.2% (range - 2.2-10.2%). The effects on pulmonary function were similar for both treatment doses of rhDNase. There was also a steady improvement in weight from a mean of 54.2 kg to 55.7 kg at the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Medium term treatment of stable stage cystic fibrosis with recombinant human DNase I.
BACKGROUND: A phase II multicentre double blind placebo controlled study in 1993 showed that short term treatment (10 days) with recombinant human DNase I (rhDNase) was safe and improved pulmonary function in patients with cystic fibrosis with stable stage lung disease. A six month open label treatment study was conducted in some of the patients who participated in the short term study to assess the medium term effects of rhDNase. METHODS: Patients who completed the phase II study and were stable for 14 days prior to treatment were eligible. They were treated with rhDNase 2.5 mg twice daily for six months and reviewed at regular intervals to assess safety and efficacy. RESULTS: Fifty nine patients (31M,28F) of age range 16-55 years were recruited. Mean baseline values for forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were 41.5% and 72.4% of predicted, respectively. The mean increase in FEV1 over the first month of treatment was 13.1% (range 12-14.1%) and then stabilised at 6.2% (4.6-7.8%) for the subsequent five months. FVC was similarly improved. Administration of rhDNase improved the severity of dyspnoea, cystic fibrosis related symptoms, and the modified Taussig/NIH score (not statistically significant). Fifty seven of the 59 patients completed the study; two died from progression of their pulmonary disease unrelated to treatment with rhDNase. The adverse events and intercurrent illnesses were no different from those expected in a cystic fibrosis population. Pharyngitis was the only possible drug related adverse event which occurred at least once in 14% of patients during the six month period. CONCLUSIONS: Administration of rhDNase was safe, well tolerated, and improved pulmonary function in patients with cystic fibrosis. When rhDNase was stopped at day 169 there was a deterioration in pulmonary function and dyspnoea score.
Adolescent↗
DNase trials in cystic fibrosis.
Cystic fibrosis (CF) is a disease with a high morbidity and mortality from pulmonary disease. Sputum from CF patients contains high levels of deoxyribonucleic acid (DNA), which contribute to its viscoelasticity. Recombinant deoxyribonuclease (rhDNase) has been developed and in vitro studies have showed reduction in the viscoelasticity of CF sputum. This article reviews the in vivo clinical trials conducted to determine the safety and efficacy of this treatment. Phase 1 studies showed preliminary safety data and some evidence of clinical benefit. The two Phase 2 short-term studies showed improvement in pulmonary function and important safety data. The Phase 3 study, which included 968 patients, showed improvement in forced expiratory volume in one second (FEV1) of 5.8% and 5.6% in patients treated once and twice daily, respectively. The risk of developing an exacerbation of infection was reduced by 28% with once daily and 37% with twice daily treatment, compared to placebo. The drug was safe and there was some improvement in quality of life data. Longer-term open labelled studies, the results of intermittent administration, administration to severely ill patients, and the use of different delivery systems are reviewed. In conclusion, recombinant deoxyribonuclease is a new treatment which has been shown to benefit patients with cystic fibrosis when used in conjunction with conventional treatment.
Clinical Trials as Topic↗