Utility of routine screening for alpha-1 antitrypsin deficiency in patients with bronchiectasis.

Alpha-1 antitrypsin deficiency (AATD) is a cause of bronchiectasis. Guidelines for bronchiectasis from the British Thoracic Society do not recommend to routinely test patients for AATD. In contrast, guidelines for AATD recommend routine screening. This contradiction, in part, results from the lack of data from large studies performing comprehensive screening. We screened 1600 patients with bronchiectasis at two centres in the UK from 2012 to 2016. In total, only eight individuals with AATD were identified representing 0.5% of the overall population. We conclude that routine screening for AATD in bronchiectasis in the UK has a low rate of detection. Further studies are required in different geographical regions, which may have a higher prevalence of AATD.

The impact of acute air pollution fluctuations on bronchiectasis pulmonary exacerbation: a case-crossover analysis.

In bronchiectasis, exacerbations are believed to be triggered by infectious agents, but often no pathogen can be identified. We hypothesised that acute air pollution exposure may be associated with bronchiectasis exacerbations.We combined a case-crossover design with distributed lag models in an observational record linkage study. Patients were recruited from a specialist bronchiectasis clinic at Ninewells Hospital, Dundee, UK.We recruited 432 patients with clinically confirmed bronchiectasis, as diagnosed by high-resolution computed tomography. After excluding days with missing air pollution data, the final model for particles with a 50% cut-off aerodynamic diameter of 10 µm (PM10) was based on 6741 exacerbations from 430 patients and for nitrogen dioxide (NO2) it included 6248 exacerbations from 426 patients. For each 10 µg·m-³ increase in PM10 and NO2, the risk of having an exacerbation that same day increased significantly by 4.5% (95% CI 0.9-8.3) and 3.2% (95% CI 0.7-5.8) respectively. The overall (lag zero to four) increase in risk of exacerbation for a 10 µg·m-3 increase in air pollutant concentration was 11.2% (95% CI 6.0-16.8) for PM10 and 4.7% (95% CI 0.1-9.5) for NO2 Subanalysis showed higher relative risks during spring (PM10 1.198 (95% CI 1.102-1.303), NO2 1.146 (95% CI 1.035-1.268)) and summer (PM10 2.142 (95% CI 1.785-2.570), NO2 1.352 (95% CI 1.140-1.602)) when outdoor air pollution exposure would be expected to be highest.In conclusion, acute air pollution fluctuations are associated with increased exacerbation risk in bronchiectasis.

An observational study of matrix metalloproteinase (MMP)-9 in cystic fibrosis.

BACKGROUND: In cystic fibrosis (CF), cross-sectional studies have reported sputum matrix metalloproteinase (MMP)-9 to be elevated and negatively correlated with FEV1. This longitudinal study examined the association between MMP-9 and tissue inhibitors of metalloproteinases (TIMPs) to prognostic parameters in CF. METHOD: A cross-sectional survey of CF and control subjects; CF patients were followed up for a median of 49 months. MMP-9 and TIMP-1 and TIMP-2 were quantified in sputum and plasma. RESULTS: Seventy-three patients with CF, median age 22 years, and 40 controls were recruited. Fifty-three of these CF patients were followed up. Prospectively, in CF subjects, plasma MMP-9 activity was adversely associated with FEV1 (ß -1.15 (95% CI -2.10, -0.20), p = 0.019) and rate of FEV1 decline, and plasma TIMP-1 was adversely associated with mortality: hazard ratio 3.66 (1.91-7.04), p < 0.001. CONCLUSIONS: These associations further justify investigation of MMP-9 and TIMP-1 as biomarkers for short- to medium-term FEV1 decline and mortality in patients with CF.

Proof of concept study to evaluate step-down therapy with inhaled corticosteroid alone or additive therapy on surrogate inflammatory markers in asthma.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Much of the focus of inflammatory surrogates and airway challenges in asthma has been directed towards success of therapy and diagnosis. Few have considered them in the context of guiding dose reduction once sufficient control has been achieved. WHAT THIS STUDY ADDS: Adenosine monophosphate (AMP) as an indirect bronchial airway challenge, together with non invasive inflammatory surrogate measures were not found to be clinically useful when guiding therapy in a group of asthmatic patients through step 3-4 in British Thoracic Society asthma guidelines. However, they may still play a role in predicting failure of individual step-down. AIM: The aim of the study was to evaluate the usefulness of inflammatory surrogates in determining step-down therapy in asthma. METHODS: AMP challenge, serum eosinophil cationic protein (ECP), exhaled nitric oxide (eNO) and pulmonary function tests were recorded. Subjects were divided into two groups following high dose inhaled corticosteroids (ICS): Group A fixed dose ICS vs. Group B ICS alone and in combination with add on therapies. RESULTS: No differences were seen in inflammatory measures between fixed dose ICS and reduced dose ICS alone or with combination therapies. CONCLUSIONS: AMP challenge conferred no additional benefit in guiding step-down therapy. The role of inflammatory surrogates may still play a role in predicting failed step-down on an individual basis.

A proof of concept study to evaluate stepping down the dose of fluticasone in combination with salmeterol and tiotropium in severe persistent asthma.

We conducted a double blind, randomised, placebo-controlled, crossover study evaluating the effects of halving inhaled steroid dosage plus salmeterol, or salmeterol and tiotropium. Eighteen life-long non-smoking severe asthmatics [mean FEV(1) 1.49 l (51%)] were run-in for 4 weeks on HFA-fluticasone propionate 1000 microg daily, and were subsequently randomised to 4 weeks of either (a) HFA-fluticasone propionate 500 microg BD/salmeterol 100 microg BD/HFA-tiotropium bromide18 microg od; or (b) fluticasone propionate 500 microg BD/salmeterol 100 microg BD matched placebo. Measurements of spirometry and body plethysmography were made. Adding salmeterol to half the dose of fluticasone led to a mean improvement (95% CI) vs. baseline in morning PEF of 41.5 (14.0-69.0)l/min [p<0.05]; and RAW of 0.98 (0.14-1.8)cm H(2)O/l/s [p<0.05]. Adding salmeterol/tiotropium produced similar improvements in PEF and RAW, but also improved FEV(1) by 0.17 (0.01-0.32)l [p<0.05]; FVC 0.24 (0.05-0.43)l [p<0.05] and reduced exhaled NO by 2.86 (0.12-5.6)ppb [p<0.05]. RV and TLC were not altered by either treatment; there were no significant changes in symptoms or quality of life compared with baseline. Addition of salmeterol/tiotropium to half the dose of fluticasone afforded small, but significant improvements in pulmonary function. These effects were not associated with commensurate changes in subjective symptoms or quality of life.

Respiratory symptoms, pulmonary function, and markers of inflammation among bar workers before and after a legislative ban on smoking in public places.

CONTEXT: Scotland prohibited smoking in confined public places on March 26, 2006. OBJECTIVE: To investigate the association of smoke-free legislation with symptoms, pulmonary function, and markers of inflammation of bar workers. DESIGN, SETTING, AND PARTICIPANTS: This prospective observational study was conducted in Tayside, Scotland from February-June 2006. One hundred five nonasthmatic and asthmatic nonsmoking bar workers were initially enrolled, of whom 77 completed the study per protocol. MAIN OUTCOME MEASURES: Respiratory and sensory symptoms, spirometry measurements, serum cotinine levels, peripheral inflammatory cell count, asthma quality-of-life scores, and exhaled nitric oxide levels were evaluated before and after introduction of the smoking ban. RESULTS: For the per-protocol analysis, the percentage of bar workers with respiratory and sensory symptoms decreased from 79.2% (n = 61) before the smoke-free policy to 53.2% (n = 41) (total change, -26%; 95% confidence interval [CI], -13.8% to -38.1%; P<.001) and 46.8% (n = 38) (-32.5%; 95% CI, -19.8% to -45.2%; P<.001) 1 and 2 months afterward. Forced expiratory volume in the first second increased from 96.6% predicted to 104.8% (change, 8.2%; 95% CI, 3.9% to 12.4%; P<.001) and then 101.7% (change, 5.1%; 95% CI, 2.1% to 8.0%; P = .002), and serum cotinine levels decreased from 5.15 ng/mL to 3.22 ng/mL (change, -1.93 ng/mL; 95% CI, -2.83 to -1.03 ng/mL; P<.001) and then 2.93 ng/mL (-2.22 ng/mL; 95% CI, -3.10 to -1.34 ng/mL; P<.001). The total white blood cell and neutrophil count was reduced from 7610 to 6980 cells/microL at 2 months (-630 cells/muL; 95% CI, -1010 to -260 cells/microL; P = .002) and from 4440 to 4030 cells/microL (-410 cells/microL; 95% CI, -740 to -90 cells/microL; P = .03), respectively. Asthmatic bar workers also had less airway inflammation, with a reduction in exhaled nitric oxide from 34.3 parts per billion (ppb) to 27.4 ppb 1 month after the ban (0.8-fold change; 95% CI, 0.67 to 0.96 ppb; P = .04), and Juniper quality-of-life scores increased from 80.2 to 87.5 points (7.3 points; 95% CI, 0.1 to 14.6 points; P = .049). CONCLUSIONS: Smoke-free legislation was associated with significant early improvements in symptoms, spirometry measurements, and systemic inflammation of bar workers. Asthmatic bar workers also had reduced airway inflammation and improved quality of life.

Addition of fexofenadine to inhaled corticosteroid therapy to reduce inflammatory biomarkers in atopic asthma.

BACKGROUND: We previously showed that H1-antihistamines may shift the PC20 (provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20%) threshold to adenosine monophosphate (AMP) challenge but may paradoxically prolong recovery. OBJECTIVES: To measure AMP recovery using a constant predetermined AMP PC20 and to evaluate whether fexofenadine use confers add-on effects to treatment with either fluticasone propionate alone or combined fluticasone propionate-salmeterol. METHODS: Fourteen atopic patients with mild-to-moderate asthma (forced expiratory volume in 1 second of 76%) completed a double-blind, randomized, crossover study consisting of 3-week treatment blocks of either fluticasone propionate-salmeterol, 250 microg twice daily, or fluticasone propionate alone, 250 microg twice daily, in conjunction with either fexofenadine, 180 mg once daily, or matched placebo. Recovery after a predetermined AMP PC20 challenge was measured (primary outcome), along with exhaled nitric oxide levels, plasma eosinophil cationic protein levels, peripheral eosinophil counts, pulmonary function, diary card outcomes, and quality of life (all secondary outcomes). RESULTS: There were no differences in any of the primary or secondary outcomes when fexofenadine was added to treatment with either fluticasone propionate-salmeterol or fluticasone propionate alone. The mean AMP recovery time was 25.0 vs 23.4 minutes for fexofenadine and placebo, respectively, as add-on to fluticasone-salmeterol and 22.5 vs 23.9 minutes, respectively, as add-on to fluticasone alone. CONCLUSION: Fexofenadine did not affect recovery to a fixed dose of AMP challenge or any other surrogate inflammatory markers when given as add-on therapy to corticosteroid-treatedatopic asthmatic patients.

Evaluation of an abbreviated adenosine monophosphate bronchial challenge.

RATIONALE: Airway hyperresponsiveness to adenosine monophosphate (AMP) has been validated as a surrogate marker for airway inflammation. We wished to know whether an abbreviated challenge at the final threshold dose would produce the same fall in FEV1 as a full, conventional dose-response challenge. METHODS: Seventeen patients with mild-to-moderate asthma (mean FEV1, 75.5% predicted) attended for a full dose-response protocol, where the highest concentration of AMP to produce > 20% fall in FEV1 was noted, along with the maximum percentage fall and recovery time. Patients returned within 2 days for a further challenge, when they received only the highest concentration (as a single bolus) reached on the previous visit. RESULTS: The mean (+/- SEM) percentage fall in FEV1 after the full challenge was 25.5 +/- 1.3%, and after the abbreviated challenge was 9.4 +/- 2.4%. The mean recovery after the full challenge was 28.13 +/- 4.65 min, and after the abbreviated test was 10.81 +/- 4.27 min. CONCLUSION: An abbreviated challenge using a single bolus dose of AMP grossly underestimates bronchial hyperresponsiveness. Although the pharmacologic half-life of AMP is short (90 s), the lesser response and shortened recovery with the abbreviated challenge suggest a more prolonged physiologic half-life, which in turn may have implications for abbreviated challenge protocols.

Comparative cutoff points for adenosine monophosphate and methacholine challenge testing.

BACKGROUND: Current use of the PC20 (provocation concentration that causes a decrease in forced expiratory volume in 1 second of 20%) cutoff point for bronchial challenge precludes its use in patients with more severe airflow obstruction. OBJECTIVE: To evaluate the efficacy and safety of lower cutoff points for adenosine monophosphate (AMP) and methacholine (MCH) bronchial challenge tools to monitor response to treatment in chronic asthma. METHODS: We retrospectively examined data from 5 previously published studies (2 using AMP, 2 using MCH, and 1 with MCH and AMP arms) and recalculated 10% and 15% cutoff points for AMP and MCH. Data were analyzed for correlation of single results and doubling dose shifts after anti-inflammatory treatment intervention. RESULTS: A total of 175 individual MCH challenges and 152 AMP challenges were evaluated. Evaluating the doubling dose shift produced by the addition of anti-inflammatory treatment (inhaled corticosteroids or montelukast) produced the following Pearson correlation coefficients: MCH PD20 (provocation dose that causes a decrease in forced expiratory volume in 1 second of 20%) vs PD15, 0.80; MCH PD20 vs PD10, 0.65; AMP PC20 vs PC15, 0.96; and AMP PC20 vs PC10, 0.84 (P < .001 for all). Subgroup analysis of AMP for before and after inhaled corticosteroids only (n = 41) shows AMP PC20 vs PC15 of 0.92 and AMP PC20 vs PC10 of 0.84 (P < .001 for both). CONCLUSIONS: The 10% and 15% cutoff points strongly predict the 20% cutoff value for AMP and MCH, as do the doubling dose shifts after anti-inflammatory treatment. The lower thresholds are suitable for monitoring response to therapy, and they expose patients to significantly less provocation agent.