Biomedical subjects

P A B Wark

Publications and source records attributed to P A B Wark.

8 recordsLinked to original sources

PubMed2006

Asthma exacerbations . 3: Pathogenesis.

Asthma exacerbations are an exaggerated lower airway response to an environmental exposure. Respiratory virus infection is the most common environmental exposure to cause a severe asthma exacerbation. Airway inflammation is a key part of the lower airway response in asthma exacerbation, and occurs together with airflow obstruction and increased airway responsiveness. The patterns of airway inflammation differ according to the trigger factor responsible for the exacerbation. The reasons for the exaggerated response of asthmatic airways are not completely understood, but recent studies have identified a deficient epithelial type 1 interferon response as an important susceptibility mechanism for viral infection.

Acute Disease↗

PubMed2005

Nebulised hypertonic saline for cystic fibrosis.

BACKGROUND: Lung disease in cystic fibrosis is characterised by impaired mucociliary clearance. Hypertonic saline has been shown to enhance mucociliary clearance in vitro and this may act to lessen the destructive inflammatory process in the airways. OBJECTIVES: To investigate the effects of treatment with nebulised hypertonic saline on people with cystic fibrosis compared to placebo and or other treatments that enhance mucociliary clearance. SEARCH STRATEGY: 'We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Most recent search of the Trials Register: September 2004. SELECTION CRITERIA: All controlled trials assessing the effect of hypertonic saline compared to placebo or other mucolytic therapy, for any duration or dose regimen in people with cystic fibrosis of any age or severity. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed all identified trials and all data collected. Trial quality was assessed along with allocation concealment. MAIN RESULTS: Fourteen controlled trials were identified. Nine trials met the inclusion criteria involving 235 participants with an age range of 6 years to 46 years. Two short-term trials of immediate effect on mucociliary clearance demonstrated that hypertonic saline increased isotope clearance compared to control. Lung function, measured by improvement in forced expiratory volume at one second (FEV1 litre per minute), was observed in four trials. When 3% to 7% saline was used in a volume of 10 ml twice-a-day, in comparison to placebo, hypertonic saline led to a significant increase in FEV1, weighted mean difference 12.20 (95%CI 4.28 to 20.10). Two further trials compared a similar concentration and volume of hypertonic saline to recombinant deoxyribonuclease. Over a three-week period one trial showed a non-significant difference, mean difference 1.60 (95% CI -7.96 to 11.16). However, in a further trial, after 12 weeks treatment in participants with moderate to severe lung disease, recombinant deoxyribonuclease led to a greater increase in FEV1 than hypertonic saline (5 ml twice-daily), mean difference 8.00 (95%CI 2.00 to 14.00). No serious adverse events were noted. AUTHORS' CONCLUSIONS: Nebulised hypertonic saline improves mucociliary clearance in short-term clinical trials and appears to increase lung function compared to control. In comparison to recombinant deoxyribonuclease it may be less effective at improving lung function after three months. Currently there is insufficient evidence to support the use of hypertonic saline as routine treatment for people with cystic fibrosis.

Administration, Inhalation↗

PubMed2004

Azoles for allergic bronchopulmonary aspergillosis associated with asthma.

BACKGROUND: Allergic bronchopulmonary aspergillosis is hypersensitivity to the fungus Aspergillus fumigatus that complicates patients with asthma and cystic fibrosis. The mainstay of treatment for allergic bronchopulmonary aspergillosis remains oral corticosteroids, though this does not completely prevent exacerbations and may not prevent the decline in lung function. OBJECTIVES: The purpose of this review was to determine the efficacy of azoles in the treatment of allergic bronchopulmonary aspergillosis. SEARCH STRATEGY: We searched the Cochrane Airways Group Asthma trials register using the terms: (allergic bronchopulmonary aspergillosis OR aspergillosis OR allergic pulmonary aspergillosis OR allergic fungal and disease OR allergic mycotic and disease) AND (azole OR triazole OR itraconazole OR ketoconazole). Date of last search January 2003. SELECTION CRITERIA: All controlled trials that assessed the effect of azole antifungal agents compared to placebo or other standard therapy for allergic bronchopulmonary aspergillosis were reviewed. Patients with cystic fibrosis were not included. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information. Adverse effects information was collected from the trials. MAIN RESULTS: Twelve trials were identified, but only three were prospective, randomised and controlled. A total of 94 participants were included. One demonstrated a reduction in immunological markers of disease activity and symptom scores using ketoconazole 400 mg daily for 12 months. There was no significant improvement in lung function. The other two examined the use of itraconazole for 16 weeks. In one there was a reduction in sputum eosinophils by 35% compared to 19% with placebo (p < 0.01). In the same trial, the number of exacerbations requiring oral corticosteroids was 0.4 per patient with itraconazole compared with 1.3 per patient with placebo (p < 0.03). Meta-analysis of data from both trials showed that itraconazole treated patients were more likely to have decline in serum IgE over 25% or more (Peto OR 3.30; 95% confidence intervals 1.30 to 8.15). REVIEWERS' CONCLUSIONS: Itraconazole modifies the immunologic activation associated with allergic bronchopulmonary aspergillosis and improves clinical outcome, at least over the period of 16 weeks. Adrenal suppression with inhaled corticosteroids and itraconazole is a potential concern.

Antifungal Agents↗

PubMed2003

Induced sputum IL-8 gene expression, neutrophil influx and MMP-9 in allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity reaction to the fungus Aspergillus fumigatus, causing severe asthma that may progress to bronchiectasis. Sputum neutrophilia can occur in association with sputum eosinophilia and correlates with the degree of bronchiectasis. The mechanisms of sputum neutrophilia in ABPA are not known. The aim of this study was to investigate the role of the chemokine interleukin (IL)-8 in sputum neutrophilia in ABPA. Induced sputum was obtained from subjects with ABPA (n=29), and compared to nonsensitised asthma (n=9) and healthy controls (n=21). Semiquantitative polymerase chain reaction was used to assess IL-8 gene expression in induced sputum and IL-8 protein was measured by enzyme-linked immunosorbent assay. Sputum IL-8 protein was significantly higher in ABPA compared to asthma and controls. IL-8 messenger ribonucleic acid/glyceraldehyde-3-phosphate dehydrogenase ratio was elevated in ABPA compared to asthma and controls. Sputum IL-8 correlated with sputum neutrophils, matrix metalloproteinase-9 levels and forced expiratory volume in one second. Interleukin-8 gene expression and protein release were increased in allergic bronchopulmonary aspergillosis and correlated with airway neutrophilia and airway obstruction. The interleukin-8-mediated neutrophil influx in allergic bronchopulmonary aspergillosis may induce lung damage via release of matrix metalloproteinase-9, potentially leading to bronchiectasis.

Adult↗

PubMed2002

Airway inflammation in thunderstorm asthma.

BACKGROUND: Epidemics of acute asthma associated with thunderstorms occur intermittently worldwide, though airway inflammation during these acute episodes has not been characterized. The aim of this study was to characterize airway inflammation in thunderstorm asthma. METHODS: Cases were recruited after presentation to the emergency room with acute asthma immediately following a thunderstorm (n = 6). They were compared to two control groups: a group of atopic asthmatics that had presented with acute asthma to the emergency room prior to the thunderstorm (n = 12), and a second group of corticosteroid naive asthmatics who presented to the emergency room in the prior 12 months (n = 6). Subjects had spirometry, sputum induction and allergy skin tests acutely and at review 4 weeks later. RESULTS: Thunderstorm (TS) cases were more likely to have a history of hay fever and grass pollen allergy, and less likely to be on inhaled corticosteroids (ICS) prior to presentation. Cases and control groups had a similar degree of moderate to severe acute airway obstruction (P = 1.0). TS cases had elevated sputum eosinophils (14.8% of total cell count) compared to controls (1%, 2.6%, P < 0.01). TS cases had higher sputum eosinophil cationic protein (ECP; 11,686 ng/mL) compared to controls (1,883, 3,300, P = 0.02) acutely. TS cases had more cells positive for IL-5 (30%) compared to controls (1, 1.5%, P = 0.02). When adjusted for ICS use, TS cases had a risk ratio for elevated sputum eosinophils of 2.4 (1.23-4.69). CONCLUSION: Thunderstorm asthma is characterized by airway inflammation with IL-5-mediated sputum eosinophilia and eosinophil degranulation. These results are consistent with allergen exposure as the cause of the exacerbation, and are consistent with the thunderstorm-induced grass pollen deluge as the cause of epidemic asthma after thunderstorms.

Acute Disease↗

PubMed2002

Chlamydia pneumoniae immunoglobulin A reactivation and airway inflammation in acute asthma.

Infection with Chlamydia pneumoniae can trigger acute asthma and is associated with severe chronic asthma. The aim of the present study was to examine the relationship between airway inflammation and serological response to C. pneumoniae in acute severe asthma. Subjects (n=54) were recruited within 4 h of presentation to the emergency department with an acute exacerbation of asthma. Clinical history taking, sputum induction (0.9% saline), spirometry and acute and convalescent serology for C. pneumoniae immunoglobulins A and G were performed. At presentation, 47% of subjects had antibodies directed against C. pneumoniae, and 38% (20) demonstrated an increase in C. pneumoniae antibody levels, with 15 demonstrating a rise in immunoglobulin A concentration. C. pneumoniae responders exhibited significantly higher sputum neutrophil levels (4.6 x 10(6) cells x mL(-1)) compared to nonresponders (1.2 x 10(6) cells x mL(-1), p=0.02) and elevated sputum eosinophil cationic protein concentration (3,981 versus 1,122 ng x mL(-1), p=0.02). An acute antibody response to Chlamydia pneumoniae is common in exacerbations of asthma. The serological features suggest that Chlamydia pneumoniae reactivation may trigger neutrophilic airway inflammation in acute asthma.

Adult↗

PubMed2002

Neutrophil degranulation and cell lysis is associated with clinical severity in virus-induced asthma.

Acute exacerbations of asthma are frequently caused by viral infections, but the inflammatory mechanisms in virus-induced asthma are poorly understood. The aim of the present study was to determine whether viral infection in acute asthma was associated with increased sputum neutrophil degranulation and increased cellular lysis and whether these changes are related to clinical severity. Adults (n=49) presenting to the emergency department with acute asthma were examined for infection by means of sputum direct-fluorescence antigen detection, sputum culture, and sputum polymerase chain reaction for Mycoplasma, Chlamydia and Legionella pneumophila, and all common respiratory viruses. Subjects infected with one of these agents were classed as having an infective exacerbation. Spirometry and sputum induction were performed on presentation and 4-5 weeks later. Thirty-seven subjects (76%) had virus infection and acute asthma. Those with virus infection had increased sputum neutrophils (p<0.05) and increased neutrophil elastase (p<0.05), this was related to increased elevated sputum lactate dehydrogenase (LDH). Subjects with noninfective asthma had an increase in the proportion of sputum eosinophils. Both groups had elevated sputum eosinophil cationic protein (ECP) concentrations. Higher levels of sputum LDH and ECP were associated with a longer hospital stay. Virus infection and acute asthma is associated with neutrophilic inflammation, cell lysis and more severe clinical disease.

Adolescent↗

PubMed2000

Azoles for allergic bronchopulmonary aspergillosis.

BACKGROUND: Allergic Broncho-pulmonary Aspergillosis (ABPA) is hypersensitivity to the fungus Aspergillus Fumigatus that complicates patients with asthma and cystic fibrosis. The condition usually results in an increase in symptoms, a greater reliance on corticosteroids to control the disease process and may lead to a progressive decline in lung function. The mainstay of treatment for ABPA remains oral corticosteroids, though this does not completely prevent exacerbations and may not prevent the decline in lung function. OBJECTIVES: The purpose of this review is to determine the efficacy of azoles in the treatment of ABPA SEARCH STRATEGY: An initial search was carried out using the Cochrane Airways Group Asthma RCT register. The register was searched using the following terms: (asthma or wheeze) and (allergic bronchopulmonary aspergillosis or aspergillosis or allergic pulmonary aspergillosis or allergic fungal and disease or allergic mycotic and disease) and (azole or triazole or itraconazole or ketoconazole). SELECTION CRITERIA: All controlled trials that assessed the effect of azole antifungal agents compared to placebo or other standard, for any duration or dose regimen in subjects with ABPA of any age or severity were reviewed. Studies in languages other than English were included. DATA COLLECTION AND ANALYSIS: All identified trials were independently reviewed by both reviewers & all data collected. Trial quality was scored by the Cochrane assessment of allocation concealment & the Jadad scale of methodological quality. MAIN RESULTS: A total of 11 trials were identified concerning the use of azoles in ABPA. Only two prospective controlled trials were identified. The first trial examined the use of Ketoconazole 400 mg daily for 12 months and demonstrated a reduction in immunological markers of disease activity and symptom scores, there was no significant improvement in lung function. The other trial examined the use of itraconazole for 16 weeks. This demonstrated a reduction in corticosteroid usage, an improvement in immunological markers, an improvement in pulmonary function and exercise tolerance. This study was only available as an abstract and limited details were available. REVIEWER'S CONCLUSIONS: There is insufficient information available to recommend the use of azole anti-fungal agents in the routine treatment of patients with ABPA.

Antifungal Agents↗