A rapid dosimetric method with controlled tidal breathing for histamine challenge. Repeatability and distribution of bronchial reactivity in a clinical material

The link between early childhood lower airway symptoms, airway hyperresponsiveness, and school-age lung function

BACKGROUND

The role of early airway hyperresponsiveness (AHR) in the lung function of school-age children is currently unclear.

OBJECTIVE

To conduct a prospective follow-up study of lung function in schoolchildren with a history of lower airway symptoms and AHR to methacholine in early childhood and to compare the findings to schoolchildren with no previous or current lung diseases. We also explored symptoms and markers of type 2 inflammation.

METHODS

In 2004 to 2011, data on atopic markers, lung function, and AHR to methacholine were obtained from 193 symptomatic children under 3 years old. In 2016 to 2018, a follow-up sample of 84 children (median age, 11 years; IQR, 11-12) underwent measurements of atopic parameters, lung function, and AHR to methacholine. Moreover, in 2017 to 2018, 40 controls (median age, 11 years; IQR, 9-12) participated in the study.

RESULTS

Schoolchildren with early childhood lower airway symptoms and increased AHR had more frequent blood eosinophilia than their peers without increased AHR and lower prebronchodilator forced expiratory volume in 1 second (FEV1) and FEV1/forced vital capacity Z-scores than those without increased AHR and controls. Post-bronchodilator values were not significantly different between the two AHR groups. Atopy in early childhood (defined as atopic eczema and at least 1 positive skin prick test result) was associated with subsequent lung function and atopic markers, but not AHR.

CONCLUSION

In symptomatic young children, increased AHR was associated with subsequent obstructive lung function, which appeared reversible by bronchodilation, and blood eosinophilia, indicative of type 2 inflammation.

Long-Term Outcome of Occupational Asthma From Irritants and Low-Molecular-Weight Sensitizers

BACKGROUND

The short-term asthma outcome of irritant-induced asthma (IIA) is poorer than that of low-molecular-weight (LMW) sensitizer-induced occupational asthma (OA).

OBJECTIVES

To evaluate the long-term asthma outcome of IIA and LMW-induced OA and to determine which baseline features are associated with a poor long-term outcome.

METHODS

This follow-up questionnaire study assessed 43 patients diagnosed with IIA and 43 patients with LMW-induced OA at the Finnish Institute of Occupational Health in 2004-2018. The baseline results were analyzed to detect features associated with uncontrolled asthma (Asthma Control Test [ACT] score of ≤19, or ≥2 exacerbations or ≥1 serious exacerbation within 1 year) at follow-up.

RESULTS

The median interval since OA diagnosis was 6.3 years (interquartile range [IQR]: 4.4-11.3 years). Uncontrolled asthma was more frequent with IIA than with LMW-induced OA (58% vs 40%, adjusted odds ratio [OR]: 3.60, 95% confidence interval [CI]: 1.20-10.81). Poor symptom control was the main factor for this difference (median [IQR] ACT score of 18 [15-22] vs 21 [18-23], P = .036, respectively). Among all participants, older age (OR: 1.08 per year, 95% CI: 1.02-1.15), a fractional exhaled nitric oxide (FeNO) value <20 ppb (OR: 5.08, 95% CI: 1.45-17.80), and uncontrolled asthma at baseline (OR: 3.94, 95% CI: 1.31-11.88) were associated with uncontrolled asthma at follow-up.

CONCLUSIONS

Long-term asthma control of IIA appears to be inferior to that of LMW-induced OA. Older age, a low FeNO value, and uncontrolled asthma at baseline might indicate a worse long-term outcome among those with IIA and LMW-induced OA.

Clinical Characteristics of Irritant-Induced Occupational Asthma

BACKGROUND

Work is a substantial contributing factor of adult-onset asthma. A subtype of occupational asthma (OA) is caused by irritant agents, but knowledge of the clinical outcomes of irritant-induced asthma (IIA) is incomplete.

OBJECTIVES

To evaluate whether the clinical picture of IIA differs from that of sensitizer-induced OA.

METHODS

This retrospective study analyzed acute and subacute IIA patients diagnosed in an occupational medicine clinic during 2004 to 2018. Sixty-nine patients fulfilled the inclusion criteria, and their characteristics were analyzed at the time of the diagnosis and 6 months later. The results were compared with those of 2 subgroups of sensitizer-induced OA: 69 high-molecular-weight (HMW) and 89 low-molecular-weight (LMW) agent-induced OA patients.

RESULTS

Six months after the diagnosis, 30% of the patients with IIA needed daily short-acting β-agonists (SABA), 68% were treated with Global Initiative for Asthma, 2020 report (GINA) step 4-5 medication, and 24% of the patients had asthma exacerbation after the first appointment. IIA depicted inferiority to LMW-induced OA in daily need for SABA (odds ratio [OR]: 3.80, 95% confidence interval [CI]: 1.38-10.46), treatment with GINA step 4-5 medication (OR: 2.22, 95% CI: 1.08-4.57), and exacerbation (OR: 3.85, 95% CI: 1.35-11.04). IIA showed poorer results than HMW-induced OA in the latter 2 of these features (OR: 2.49, 95% CI: 1.07-5.79 and OR: 6.29, 95% CI: 1.53-25.83, respectively).

CONCLUSIONS

Six months after the OA diagnosis, a significant proportion of the patients with IIA remain symptomatic and the majority of these patients use asthma medications extensively suggesting uncontrolled asthma. The short-term outcomes of IIA appear poorer than that of sensitizer-induced OA.

Characterization of Occupational Eosinophilic Bronchitis in a Multicenter Cohort of Subjects with Work-Related Asthma Symptoms

BACKGROUND

Occupational eosinophilic bronchitis (OEB) has been described only as anecdotal case reports.

OBJECTIVE

We investigated the clinical and inflammatory characteristics of subjects with OEB identified in a cohort of subjects who completed a specific inhalation challenge (SIC) with occupational agents.

METHODS

In this retrospective multicenter study, OEB was defined by (1) a fall in FEV1 less than 15% during the SIC and the absence of nonspecific bronchial hyperresponsiveness both before and after the SIC and (2) a postchallenge increase of 3% or more in sputum eosinophils. The subjects who fulfilled these criteria were compared with 226 subjects with a negative SIC and 30 subjects with a positive SIC who failed to show baseline nonspecific bronchial hyperresponsiveness.

RESULTS

An isolated increase in postchallenge sputum eosinophils was documented in 33 of 259 subjects (13%) with a negative SIC. These subjects reported significantly more often an isolated cough at work compared with the negative and positive SIC controls. When compared with positive SIC controls, the subjects with OEB experienced less frequently work-related wheezing and reported a shorter duration of symptoms at work. The sensitivity of the post-SIC increase in fractional exhaled nitric oxide in identifying OEB among subjects with a negative SIC was low, ranging from 43% to 24% using cutoff values of 8 ppb to 17.5 ppb, whereas the specificity was high (90%-97%).

CONCLUSIONS

This study highlights the relevance of induced sputum analysis in the investigation of work-related asthma symptoms to identify isolated increases in sputum eosinophils that are consistent with a diagnosis of OEB.

Asthma onset after exposure to fluorinated hydrocarbons in the presence of combustion

Fluorinated hydrocarbons, which can thermally degrade into toxic hydrofluoric acid, are widely used as, for example, cooling agents in refrigerators and air conditioning systems and as medical aerosol propellants. Hydrofluoric acid is a known causative agent of irritant-induced asthma. We report on two patients with asthma initiation shortly after exposure to fluorinated hydrocarbon-based cooling agents while welding or smoking cigarettes in a confined space. Both cases developed respiratory symptoms and headache and later demonstrated nonspecific bronchial hyperresponsiveness. In follow-up, asthma was persistent and responded poorly to asthma medication. Exposure to the fluorinated hydrocarbons themselves is unlikely to have caused asthma due to their low toxicity. Instead, exposure to small amounts of hydrofluoric acid via the thermal degradation of the fluorinated hydrocarbons was considered the most likely cause of asthma onset. This is supported by the typical clinical picture of irritant-induced asthma and acute symptoms resembling hydrofluoric acid poisoning. When fluorinated hydrocarbons are used in the presence of combustion, thermal degradation may lead to the formation of hydrofluoric acid. In confined spaces, this exposure may induce asthma via irritation. Welding, smoking, and other sources of combustion in confined spaces may be a risk in workplaces and other places in which fluorinated hydrocarbons are used.

Measurement of bronchial hyperreactivity: comparison of three Nordic dosimetric methods

Clinical testing of bronchial hyperreactivity (BHR) provides valuable information in asthma diagnostics. Nevertheless, the test results depend to a great extent on the testing procedure: test substance, apparatus and protocol. In Nordic countries, three protocols predominate in the testing field: Per Malmberg, Nieminen and Sovijärvi methods. However, knowledge of their equivalence is limited. We aimed to find equivalent provocative doses (PD) to obtain similar bronchoconstrictive responses for the three protocols. We recruited 31 patients with suspected asthma and health care workers and performed BHR testing with methacholine according to Malmberg and Nieminen methods, and with histamine according to Sovijärvi. We obtained the individual response-dose slopes for each method and predicted equivalent PD values. Applying a mixed-model, we found significant differences in the mean (standard error of mean) response-dose (forced expiratory volume in one second (FEV₁)%/mg): Sovijärvi 7.2 (1.5), Nieminen 13.8 (4.2) and Malmberg 26 (7.3). We found that the earlier reported cut-point values for moderate BHR and marked BHR between the Sovijärvi (PD₁₅) and Nieminen (PD₂₀) methods were similar, but with the Malmberg method a significant bronchoconstrictive reaction was measured with lower PD₂₀ values. We obtained a relationship between slope values and PD (mg) between different methods, useful in epidemiological research and clinical practice.

Associations Between Glutathione-S-Transferase Genotypes and Bronchial Hyperreactivity Patients With Di-isocyanate Induced Asthma. A Follow-Up Study

Introduction: Di-isocyanates TDI (toluene di-isocyanate), MDI (diphenylmethane di-isocyanate), and HDI (hexamethylene di-isocyanate) are the most common chemicals causing occupational asthma. Di-isocyanate inhalation has been reported to induce oxidative stress via reactive oxygen and nitrogen species leading to tissue injury. Glutathione transferases (GSTs) and N-acetyltransferases (NATs) are detoxifying enzymes whose general function is to inactivate electrophilic substances. The most important genes regulating these enzymes, i.e., GSTM1, GSTP1, GSTT1, NAT1, and NAT2 have polymorphic variants resulting in enhanced or lowered enzyme activities. Since inability to detoxify harmful oxidants can lead to inflammatory processes involving activation of bronchoconstrictive mechanisms, we studied whether the altered GST and NAT genotypes were associated with bronchial hyperreactivity (BHR) in patients with di-isocyanate exposure related occupational asthma, irrespective of cessation of di-isocyanate exposure, and adequacy of asthma treatment.

Methods: Polymerase chain reaction (PCR) based methods were used to analyze nine common polymorphisms in GSTM1, GSTM3, GSTP1, GSTT1, NAT1, and NAT2 genes in 108 patients with diagnosed occupational di-isocyanate-induced asthma. The genotype data were compared with spirometric lung function and BHR status at diagnosis and in the follow-up examination on average 11 years (range 1–22 years) after the asthma diagnosis. Serum IgE and IL13 levels were also assessed in the follow-up phase.

Results: An association between BHR and GSTP1 slow activity (Val105/Val105) genotype was demonstrated in the subjects at the follow-up phase but not at the diagnosis phase. Moreover, the patients with the GSTP1 slow activity genotype exhibited characteristics of Th-2 type immune response more often compared to those with the unaltered GSTP1 gene. Interestingly, all 10 patients with the GSTP1 slow activity genotype had both the GSTM3 slow activity genotype and the unaltered GSTT1 gene.

Discussion: The results suggest associations of the low activity variants of the GSTP1 gene with BHR. The fact that these associations came up only at the follow-up phase when the subjects were not any more exposed to di-isocyanates, and used asthma medication, suggest that medication and environmental factors influence the presentation of these associations. However, due to the exploratory character of the study and relatively small study size, the findings remain to be confirmed in future studies with larger sample sizes.

Comparison of mannitol and citric acid cough provocation tests

RATIONALE

Citric acid has been used as a cough provocation test for decades. However, the methods of administration have not been standardized. Inhaled mannitol is a novel cough provocation test, which has regulatory approval and can be performed utilizing a simple disposable inhaler in a standardized manner.

OBJECTIVE

To compare the mannitol and citric acid cough provocation tests with respect to their ability to identify subjects with chronic cough and their tolerability.

METHODS

Subjects with chronic cough (n = 36) and controls (n = 25) performed provocation tests with mannitol and citric acid. Both tests were video recorded. Cough sensitivity was expressed as coughs-to-dose ratios (CDR) and the cumulative doses to mannitol or concentration to citric acid evoking 5 coughs (C5). Forced expiratory volume in 1 s (FEV₁), visual analogue scales (VAS), test completion rates and the total cough frequencies were analysed.

RESULTS

Mannitol and citric acid CDR both effectively separated those with cough and the control subjects (AUC 0.847 and 0.803, respectively) as did C5 (AUC 0.823 and 0.763, respectively). There was a good correlation between the cough sensitivity provoked by the two stimuli, either expressed as CDR (r = 0.65, p < 0.001) or C5 (r = 0.53, p = 0.001). Both tests were similarly tolerated in terms of VAS, although more patients discontinued the mannitol test early, primarily due to cough.

CONCLUSIONS

Mannitol and citric acid tests correlated well, equally identified subjects with chronic cough and their tolerability was similar. The feasibility issues, strict standardisation and regulatory approval may favour mannitol to be used in clinical cough research.

Health-related quality among life of employees with persistent nonspecific indoor-air-associated health complaints

OBJECTIVE

Nonspecific health complaints associated with indoor air are common in work environments. In some individuals, symptoms become persistent without an adequate explanation. The aim was to study factors that associate with the health-related quality of life (HRQoL) of employees with persistent, nonspecific indoor-air-related symptomatology.

METHODS

We present baseline results of a randomized controlled trial of interventions targeted on the HRQoL of the employees with indoor-air-associated nonspecific symptoms. The main participant-inclusion criterion was the presence of persistent indoor-air-related multiorgan symptoms with no known pathophysiological or environment-related explanation. As a comparison for participants´ HRQoL (n = 52) we used data from the general-population Health 2011 study (BRIF8901) including information on subjects matched to the participants´ working status and age and subjects with asthma, anxiety or depressive disorder, or other chronic conditions with work disability.

RESULTS

The participants showed greater and a clinically significant impairment of HRQoL [M = 0.83, SE = 0.013] than individuals from the general population [M = 0.95, SE = 0.001, p < .001, Hedges´ g = 2.33] and those with asthma [M = 0.93, SE = 0.005, p < .001, Hedges´ g = 1.46], anxiety and depressive disorder [M = 0.89, SE = 0.006, p < .001, Hedges´ g = 0.73], or a chronic condition with work disability [M = 0.91, SE = 0.003, p < .001, Hedges´ g = 1.11]. Prevalent symptoms of depression, anxiety, and insomnia and poor recovery from work were associated with a poor HRQoL.

CONCLUSIONS

Individuals with nonspecific indoor-air-associated symptoms have a poorer HRQoL than individuals in the general population with a globally burdensome disease. Psychological distress associated with a poor HRQoL should be considered in the making of decisions about the treatment of these patients.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02069002.

Clinical Characteristics of Disability in Patients with Indoor Air-Related Environmental Intolerance

Background

Chronic nonspecific symptoms attributed to indoor nonindustrial work environments are common and may cause disability, but the medical nature of this disability is unclear. The aim was to medically characterize the disability manifested by chronic, recurrent symptoms and restrictions to work participation attributed to low-level indoor pollutants at workplace and whether the condition shares features with idiopathic environmental intolerance.

Methods

We investigated 12 patients with indoor air–related work disability. The examinations included somatic, psychological, and psychiatric evaluations as well as investigations of the autonomic nervous system, cortisol measurements, lung function, and allergy tests. We evaluated well-being, health, disability, insomnia, pain, anxiety, depression, and burnout via questionnaires.

Results

The mean symptom history was 10.5 years; for disabling symptoms, 2.7 years. Eleven patients reported reactions triggered mainly by indoor molds, one by fragrances only. Ten reported sensitivity to odorous chemicals, and three, electric devices. Nearly all had co-occurrent somatic and psychiatric diagnoses and signs of pain, insomnia, burnout, and/or elevated sympathetic responses. Avoiding certain environments had led to restrictions in several life areas. On self-assessment scales, disability showed higher severity and anxiety showed lower severity than in physician assessments.

Conclusion

No medical cause was found to explain the disability. Findings support that the condition is a form of idiopathic environmental intolerance and belongs to functional somatic syndromes. Instead of endless avoidance, rehabilitation approaches of functional somatic syndromes are applicable.

Inspiratory and Expiratory Flow Changes, Voice Symptoms and Laryngeal Findings during Histamine Challenge Tests

OBJECTIVE

The aim of this study was to analyse the associations between the spirometry parameter changes in relation to laryngeal finding changes and self-reported voice and throat symptom changes among patients undergoing a histamine challenge test.

PATIENTS AND METHODS

Thirty adult patients with a chronic cough underwent a histamine challenge test. Videolaryngostroboscopy and voice and throat symptoms were assessed using a visual analogue scale immediately before and after the challenge test. Correlations between the relative changes in spirometry values in relation to the change in vocal fold oedema and redness and self-reported voice and throat symptom changes during the challenge test were assessed.

RESULTS

A correlation between the relative change in inspiratory and expiratory air flow values and the change in voice and throat symptoms during the histamine challenge test was found. The vocal fold oedema, visible on videolaryngostroboscopy, caused by the histamine challenge did not significantly affect the spirometry air flow values.

CONCLUSION

The relative changes in inspiratory and expiratory air flow and voice and throat symptoms during the histamine challenge test correlated. The vocal fold oedema caused by the histamine challenge, visible on videolaryngostroboscopy, did not significantly affect the spirometry air flow values.

Severe Occupational Asthma: Insights From a Multicenter European Cohort

BACKGROUND

Although sensitizer-induced occupational asthma (OA) accounts for an appreciable fraction of adult asthma, the severity of OA has received little attention.

OBJECTIVE

The aim of this study was to characterize the burden and determinants of severe OA in a large multicenter cohort of subjects with OA.

METHODS

This retrospective study included 997 subjects with OA ascertained by a positive specific inhalation challenge completed in 20 tertiary centers in 11 European countries during the period 2006 to 2015. Severe asthma was defined by a high level of treatment and any 1 of the following criteria: (1) daily need for a reliever medication, (2) 2 or more severe exacerbations in the previous year, or (3) airflow obstruction.

RESULTS

Overall, 162 (16.2%; 95% CI, 14.0%-18.7%) subjects were classified as having severe OA. Multivariable logistic regression analysis revealed that severe OA was associated with persistent (vs reduced) exposure to the causal agent at work (odds ratio [OR], 2.78; 95% CI, 1.50-5.60); a longer duration of the disease (OR, 1.04; 95% CI, 1.00-1.07); a low level of education (OR, 2.69; 95% CI, 1.73-4.18); childhood asthma (OR, 2.92; 95% CI, 1.13-7.36); and sputum production (OR, 2.86; 95% CI, 1.87-4.38). In subjects removed from exposure, severe OA was associated only with sputum production (OR, 3.68; 95% CI, 1.87-7.40); a low education level (OR, 3.41; 95% CI, 1.72-6.80); and obesity (OR, 1.98; 95% CI, 0.97-3.97).

CONCLUSIONS

This study indicates that a substantial proportion of subjects with OA experience severe asthma and identifies potentially modifiable risk factors for severe OA that should be targeted to reduce the adverse impacts of the disease.

Standardizing dose in dosimetric bronchial challenge tests

Recent technical recommendations on bronchial challenge testing aim at standardized assessment of provocative dose of causing 20% decrease in FEV1 (PD20). The aim of this study was to investigate the effect of mode of nebulization on the output of a computerized dosimeter (APS) and to compare PD20 obtained by two different dosimetric systems in vivo. The output of the APS system was tested during continuous nebulization, and using simulated breaths, for intermittent actuations with four different durations. Using output data, a modified methacholine challenge protocol was applied for APS and compared with a standard set-up using Spira dosimeter in 14 asthmatic patients attending duplicate methacholine challenges using both systems, within median (range) 3 (1-6) days apart. The calculated output (mg min^-1 ) with all the intermittent mode settings was significantly higher (P<0·001) than in the continuous mode, and in the intermittent mode, the output was dependent of the pulse duration. The PD20 values assessed with the APS and Spira systems were significantly correlated (r = 0·69; P<0·007), without systematic difference in the geometric means (P = 0·10). A moderate to good agreement was found for assessment of significant hyperresponsiveness. The results suggest that in dosimetric systems for bronchial challenge tests, the output of the nebulizer is dependent on the mode of nebulization, and this should be considered when standardizing the dose between devices and protocols. As long as the delivered dose is determined for the specified nebulization mode of the protocol, it may be possible to obtain comparable results between different devices.

3-(Bromomethyl)-2-chloro-4-(methylsulfonyl)- benzoic acid: a new cause of sensitiser induced occupational asthma, rhinitis and urticaria

OBJECTIVES

3-(Bromomethyl)-2-chloro-4-(methylsulfonyl)-benzoic acid (BCMBA) has not previously been identified as a respiratory sensitiser. We detected two cases who presented respiratory and urticaria symptoms related to BCMBA and had positive skin prick tests to the agent. Subsequently, we conducted outbreak investigations at the BCMBA-producing factory and performed clinical examinations to confirm occupational diseases.

METHODS

The outbreak investigations included observations of work processes, assessment of exposure, a medical survey with a questionnaire and skin prick tests with 0.5% BCMBA water solution on 85 exposed workers and 9 unexposed workers. We used specific inhalation or nasal challenge and open skin application test to investigate BCMBA-related occupational asthma, rhinitis and contact urticaria.

RESULTS

We identified nine workers with respiratory and/or skin symptoms and positive skin prick tests to BCMBA in a chemical factory. A survey among chemical factory workers indicated a BCMBA-related sensitisation rate of 8% among all exposed workers; the rate was highest (25%) among production workers in the production hall. Sensitisation was detected only in workers with the estimated highest exposure levels. Six cases of occupational asthma, rhinitis and/or contact urticaria caused by BCMBA were confirmed with challenge tests. Asthma-provoking doses in specific inhalation challenges were very low (0.03% or 0.3% BCMBA in lactose).

CONCLUSIONS

We identified a new low molecular weight agent causing occupational asthma, rhinitis and contact urticaria. A typical clinical picture of allergic diseases and positive skin prick tests suggest underlying IgE-mediated disease mechanisms. Stringent exposure control measures are needed in order to prevent BCMBA-related diseases.

Long-term prognosis of chronic cough: a prospective, observational cohort study

Background

The long-term prognosis of chronic cough and its determinants need to be clarified.

Methods

This is a prospective, observational cohort study. Eighty-nine unselected subjects with chronic (> 8 weeks’ duration) cough were carefully investigated: Clinical examination, symptom questionnaire, Leicester Cough Questionnaire (LCQ), skin prick tests, ambulatory peak expiratory flow monitoring, spirometry before and after 0.4 mgs of salbutamol, exhaled nitric oxide concentration measurement, hypertonic saline cough provocation test, and histamine bronchial provocation test. After five years, a letter was sent to the subjects containing questions about continuation of cough, smoking, indoor exposures, presence of co-morbidities, and current medication. It also contained LCQ and Cough Clinic diagnostic questionnaire. Sixty-eight subjects (76%) responded.

Results

At five years, continuing regular cough was present in 31 (46%) of the subjects and continuing impairment in cough-related quality of life (less than 1.3 points’ improvement in LCQ) in 32 (47%). Continuing regular cough was associated with presence of chronic rhinitis or esophageal reflux disease, baseline mild airway responsiveness to histamine, and baseline strong cough responsiveness to hypertonic saline. Continuing impairment in cough-related quality of life was associated with high body mass index, absence of atopy, absence of pets, and high number of background disorders (esophageal reflux disease, asthma, or chronic rhinitis).

Conclusions

Almost half of subjects with chronic cough suffered of the disorder at five years from initial assessment. Several possible determinants of poor prognosis could be identified.

ERS technical standard on bronchial challenge testing: general considerations and performance of methacholine challenge tests

This international task force report updates general considerations for bronchial challenge testing and the performance of the methacholine challenge test. There are notable changes from prior recommendations in order to accommodate newer delivery devices. Rather than basing the test result upon a methacholine concentration (provocative concentration (PC20) causing a 20% fall in forced expiratory volume in 1 s (FEV1)), the new recommendations base the result upon the delivered dose of methacholine causing a 20% fall in FEV1 (provocative dose (PD20)). This end-point allows comparable results from different devices or protocols, thus any suitable nebuliser or dosimeter may be used, so long as the delivery characteristics are known. Inhalation may be by tidal breathing using a breath-actuated or continuous nebuliser for 1 min (or more), or by a dosimeter with a suitable breath count. Tests requiring maximal inhalations to total lung capacity are not recommended because the bronchoprotective effect of a deep breath reduces the sensitivity of the test.

Laryngeal Mucosal Reaction during Bronchial Histamine Challenge Test Visualized by Videolaryngostroboscopy

OBJECTIVES/HYPOTHESIS

To examine the changes in the larynx, as well as self-reported voice and throat symptoms, among patients undergoing a histamine challenge test. Thus, to understand the possible clinical effects of histamine on the larynx.

STUDY DESIGN

Controlled, open prospective study.

METHODS

Thirty adult patients with prolonged cough and suspicion of bronchial asthma underwent a histamine challenge test. Videolaryngostroboscopy was performed immediately before and after the challenge. Voice and throat symptoms immediately before and after the challenge test were assessed using a visual analog scale.

RESULTS

Videolaryngostroboscopy after exposure showed significant increases in edema (P < 0.001) as well as redness (P < 0.001) of the vocal folds after the exposure. Self-reported voice complaints increased significantly for 8 of 11 symptoms. A moderate positive correlation was found between the increase in edema of the vocal folds and reported heartburn/regurgitation symptoms (r = 0.42, P < 0.05). Atopy, asthma, nasal symptoms, or bronchial hyperreactivity during the histamine challenge test were not associated with laryngeal reactions.

CONCLUSIONS

According to the results, the laryngeal mucosal reaction during a histamine challenge test can be objectively visualized. Videolaryngostroboscopy findings, together with an increase in self-reported voice and throat symptoms, show that histamine has potential effects on vocal folds. The mucosal reaction seems to be pronounced among patients with reflux symptoms, probably reflecting the permeability features of the vocal folds.

Stepping down from combination asthma therapy: The predictors of outcome

BACKGROUND

Stepping down from combination asthma therapy (inhaled corticosteroids (ICS) + long-acting β2 agonists (LABA)) is often avoided due to fear of exacerbations, which may lead to overmedication in well-controlled asthma. A better knowledge about the predictors of outcome might encourage clinicians to start stepping down more often than previously.

METHODS

In 55 subjects with well controlled asthma and combination therapy, LABAs were discontinued first, followed by ICS dose halving, and then cessation, in six weeks' intervals. The ability of Juniper's asthma control questionnaire (ACQ), ambulatory peak flow monitoring, spirometry, and hypertonic saline challenge to predict the outcomes of medication reductions were assessed.

RESULTS

The proportions of subjects experiencing an exacerbation at each step were: 4 out of 55 subjects (7%) after LABA cessation, 4 out of 25 subjects (16%) after ICS dose halving, and 21 out of 46 subjects (46%) after ICS cessation. All exacerbations could be managed on an outpatient basis. There were 126 step-downs altogether. ACQ score < 0.29 (likelihood ratio 2.30 (1.05-5.05)), ACQ without spirometry < 0.15 (2.17 (0.96-4.90)) and FEV1 > 96% of predicted (2.18 (1.03-4.61)) predicted a successful outcome after step-down. Cough responsiveness to saline, bronchoconstrictive responsiveness to saline, and peak flow variation were not associated with the outcome.

CONCLUSION

Combination therapy can often be reduced in controlled asthma but total cessation of ICSs must be carefully considered. Simple investigations, namely asthma control assessment by validated questionnaire and spirometry, help to predict the outcome of stepping down.

TRIAL REGISTRY

The study was registered in ClinicalTrials.gov database (https://clinicaltrials.gov, KUH5801124).

Comparing cognitive-behavioural psychotherapy and psychoeducation for non-specific symptoms associated with indoor air: a randomised control trial protocol

INTRODUCTION

Indoor air-related conditions share similarities with other conditions that are characterised by medically unexplained symptoms (MUS)-a combination of non-specific symptoms that cannot be fully explained by structural bodily pathology. In cases of indoor air-related conditions, these symptoms are not fully explained by either medical conditions or the immunological-toxicological effects of environmental factors. The condition may be disabling, including a non-adaptive health behaviour. In this multifaceted phenomenon, psychosocial factors influence the experienced symptoms. Currently, there is no evidence of clinical management of symptoms, which are associated with the indoor environment and cannot be resolved by removing the triggering environmental factors. The aim of this study is to compare the effect of treatment-as-usual (TAU) and two psychosocial interventions on the quality of life, and the work ability of employees with non-specific indoor air-related symptomatology.

METHODS AND ANALYSES

The aim of this ongoing randomised controlled trial is to recruit 60 participants, in collaboration with 5 occupational health service units. The main inclusion criterion is the presence of indoor air-related recurrent symptoms in ≥2 organ systems, which have no pathophysiological explanation. After baseline clinical investigations, participants are randomised into interventions, which all include TAU: cognitive-behavioural psychotherapy, psychoeducation and TAU (control condition). Health-related quality of life, measured using the 15D-scale, is the primary outcome. Secondary outcomes include somatic and psychiatric symptoms, occupational factors, and related underlying mechanisms (ie, cognitive functioning). Questionnaires are completed at baseline, at 3, 6 and 12-month follow-ups. Data collection will continue until 2017. The study will provide new information on the individual factors related to indoor air-associated symptoms, and on ways in which to support work ability.

ETHICS AND DISSEMINATION

The Coordinating Ethics Committee of the Hospital District of Helsinki and Uusimaa, Finland, has granted approval for the study. The results will be published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02069002; Pre-results.

Associations of Early Life Exposures and Environmental Factors With Asthma Among Children in Rural and Urban Areas of Guangdong, China

BACKGROUND

Environmental factors may play important roles in asthma, but findings have been inconsistent.

OBJECTIVE

The goal of this study was to determine the associations between early life exposures, environmental factors, and asthma in urban and rural children in southeast China.

METHODS

A screening questionnaire survey was conducted in 7,164 children from urban Guangzhou and 6,087 from rural Conghua. In the second stage, subsamples of 854 children (419 from Guangzhou, 435 from Conghua) were recruited for a case-control study that included a detailed questionnaire enquiring on family history, early life environmental exposures, dietary habits, and laboratory tests (including histamine airway provocation testing, skin prick tests, and serum antibody analyses). House dust samples from 76 Guangzhou families and 80 Conghua families were obtained to analyze levels of endotoxins, house dust mites, and cockroach allergens.

RESULTS

According to the screening survey, the prevalence of physician-diagnosed asthma was lower in children from Conghua (3.4%) than in those from Guangzhou (6.9%) (P < .001). A lower percentage of asthma was reported in rural subjects compared with urban subjects (2.8% vs. 29.4%; P < .001) in the case-control study. Atopy (OR, 1.91 [95% CI, 1.58-2.29]), parental atopy (OR, 2.49 [95% CI, 1.55-4.01]), hospitalization before 3 years of age (OR, 2.54 [95% CI, 1.37-4.70]), high consumption of milk products (OR, 1.68 [95% CI, 1.03-2.73]), and dust Dermatophagoides farinae group 1 allergen (OR, 1.71 [95% CI, 1.34-2.19]) were positively associated with asthma. Living in a crop-farming family at < 1 year of age (OR, 0.15 [95% CI, 0.08-0.32]) and dust endotoxin levels (OR, 0.69 [95% CI, 0.50-0.95]) were negatively associated with asthma.

CONCLUSIONS

Rural children from an agricultural background exhibited a reduced risk of asthma. Early life exposure to crop farming and high environmental endotoxin levels might protect the children from asthma in southern China.

Lung function, airway remodeling, and inflammation in infants: outcome at 8 years

BACKGROUND

Associations between early deficits of lung function, infant airway disease, and outcome at school age in symptomatic infants are still unclear.

OBJECTIVE

To report follow-up data on a unique cohort of children investigated invasively in infancy to determine predictive value of airway disease for school-aged respiratory outcomes.

METHODS

Fifty-three infants previously studied using bronchoscopy and airway conductance were approached at 8 years of age. Symptoms, lung volumes, and airway responsiveness were reassessed. Data on lifetime purchase of asthma medication were obtained. Lung function was compared with that of 63 healthy nonasthmatic children.

RESULTS

Forty-seven children were reevaluated. Physician-diagnosed asthma was present in 39 children (83%). Twenty-five children (53%) had current and 14 children (30%) had past asthma. No pathologic feature in infancy correlated with any outcome parameter. As expected, study children had significantly reduced lung function and increased airway responsiveness compared with healthy controls, and very early symptoms were risk factors for reduced lung function. Current asthma was associated with reduced infant lung function and parental asthma. Reduced lung function in infancy was associated with purchase of inhaled corticosteroids when 6 to 8 and 0 to 8 years of age.

CONCLUSION

The lack of predictive value of any pathologic measure in infancy, reported here for the first time to our knowledge, demonstrates that pathologic processes determining the inception of asthma, which are as yet undescribed, are different from the eosinophilic inflammation associated with ongoing disease.

Airway oxidative stress in chronic cough

BACKGROUND

The mechanisms of chronic cough are unclear. Many reactive oxygen species affect airway sensory C-fibres which are capable to induce cough. Several chronic lung diseases are characterised by cough and oxidative stress. In asthma, an association between the cough severity and airway oxidative stress has been demonstrated. The present study was conducted to investigate whether airway oxidative stress is associated with chronic cough in subjects without chronic lung diseases.

METHODS

Exhaled breath condensate samples were obtained in 43 non-smoking patients with chronic cough and 15 healthy subjects. Exclusion criteria included a doctor's diagnosis of any lung disorders and any abnormality in lung x-ray. The concentration of 8-isoprostane was measured. In addition, the patients filled in Leicester Cough Questionnaire and underwent hypertonic saline cough provocation test, spirometry, ambulatory peak flow monitoring, nitric oxide measurement, and histamine airway challenge. In a subgroup of patients the measurements were repeated during 12 weeks' treatment with inhaled budesonide, 800 ug/day.

RESULTS

The 8-isoprostane concentrations were higher in the cough patients than in the healthy subjects (24.6 ± 1.2 pg/ml vs. 10.1 ± 1.7 pg/ml, p = 0.045). The 8-isoprostane concentration was associated with the Leicester Cough Questionnaire total score (p = 0.044) but not with the cough sensitivity to saline or other tests. Budesonide treatment did not affect the 8-isoprostane concentrations.

CONCLUSIONS

Chronic cough seems to be associated with airway oxidative stress in subjects with chronic cough but without chronic lung diseases. This finding may help to develop novel antitussive drugs.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov database (KUH5801112), identifier NCT00859274.

Very low birth weight and respiratory outcome: association between airway inflammation and hyperresponsiveness

BACKGROUND

The respiratory outcomes after preterm birth have changed, and it is unclear whether increased airway hyperresponsiveness (AHR) later in childhood is associated with airway inflammation.

OBJECTIVE

To investigate the association between AHR and fractional exhaled nitric oxide (FeNO), including the alveolar concentration of nitric oxide, in school-age children with very low birth weight (VLBW).

METHODS

Twenty-nine children with VLBW, 33 children with a history of early wheeze, and 60 healthy controls underwent a FeNO measurement and bronchial challenge test with histamine. Atopy was assessed with skin prick tests.

RESULTS

Children with VLBW had well-preserved baseline lung function but significantly increased AHR, expressed as the dose response slope (P < .001). Geometric mean FeNO levels were similar between VLBW children and healthy controls, and a history of bronchopulmonary dysplasia had no effect. In the VLBW and early wheeze groups, AHR was associated with FeNO (r = 0.47, P = .01, and r = 0.43, P = .013, respectively), but in a stratified analysis, this association was significant only in atopic individuals. By using the multiple flow FeNO technique, the bronchial nitric oxide flux rather than alveolar nitric oxide concentrations were associated with AHR in both children with early wheeze and VLBW.

CONCLUSION

We conclude that in VLBW children AHR is related to FeNO but only in atopic individuals. Similar to children with early wheeze, this association is dependent on bronchial flux rather than alveolar nitric oxide concentration. It is likely that AHR is modified by atopic inflammation rather than by inflammatory process due to prematurity.

Capability of hypertonic saline cough provocation test to predict the response to inhaled corticosteroids in chronic cough: a prospective, open-label study

BACKGROUND

Many patients with chronic cough respond to treatment with inhaled corticosteroids but it is difficult to predict which patients are likely to respond. The primary aim of the present study was to define the capability of hypertonic saline cough provocation test to predict the responsiveness to inhaled corticosteroids in chronic cough. The secondary aim was to assess the ability of the saline test to monitor the healing of cough during corticosteroid treatment.

METHODS

Forty-three patients with chronic cough were recruited. Before therapy, spirometry, ambulatory peak flow monitoring, nitric oxide measurement, histamine airway challenge, and saline test were performed. Those responding to the first saline test repeated it and the nitric oxide measurement during the subsequent visits. The patients used inhaled budesonide, 400 ug twice daily, for twelve weeks. The treatment response was assessed by Leicester Cough Questionnaire at baseline, and at one, four, and twelve weeks.

RESULTS

Seventy-seven % of the patients demonstrated the minimal important difference in the Leicester Cough Questionnaire indicating a symptomatic response. Neither the response magnitude nor the speed was predicted by the saline test. Histamine challenge showed the strongest predictive ability: The maximal improvement in Leicester Cough Questionnaire total score was 5.08 (3.76 - 6.40) points in the histamine positive and 2.78 (1.55 - 4.01) points in the histamine negative subjects (p = 0.006). Baseline nitric oxide level also associated with the improvement in Leicester Cough Questionnaire total score (p = 0.02). During the treatment, the cough sensitivity to saline gradually decreased among the budesonide responders but not in the non-responders. Nitric oxide levels decreased very rapidly among the responders.

CONCLUSIONS

Saline test cannot predict the responsiveness to inhaled corticosteroids in chronic cough but it may be utilized to monitor the effect of this treatment.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov database (KUH5801112). ClinicalTrials.gov Identifier: NCT00859274.

Exhaled nitric oxide indicates poorly athlete's asthma

INTRODUCTION

In athletes, exercise-induced respiratory symptoms are common and their assessment is time and resource consuming.

OBJECTIVE

The objective was to evaluate fractional concentration of exhaled nitric oxide (FENO) as a predictor of bronchial hyperresponsiveness (BHR) and of asthma.

MATERIALS AND METHODS

Eighty-seven elite athletes and a control group of 87 sedentary patients with symptoms suggesting asthma underwent measurements of FENO and of BHR by using methacholine provocation test (MCH) and eucapnic voluntary hyperpnoea (EVH) (athletes) or histamine provocation test (HIST) (controls).

RESULTS

In athletes, elevated FENO (>30 ppb) was not associated with lung function-confirmed asthma or with MCH positivity, but receiver operating characteristics (ROC) analysis showed some predictive value for EVH positivity [Area Under Curve (AUC) 0.652, 95% confidence interval (CI): 0.53 to 0.78, P = 0.020]. However, the sensitivity (55%) and the specificity (71%) were poor. In sedentary patients, FENO was significantly associated with both confirmed asthma and HIST positivity, ROC analysis showing FENO to be significantly predictive for HIST positivity (AUC 0.83, 95% CI: 0.70 to 0.96, P = 0.001) and for asthma (AUC 0.74, 95% CI: 0.63 to 0.85, P < 0.001).

CONCLUSION

The results suggest that in contrast to sedentary patients, FENO seems to be a poor predictor of BHR and of clinical asthma in elite athletes. We find it unlikely that FENO could be a useful screening tool in athletes with exercise-induced respiratory symptoms.

Bronchial hyperresponsiveness in an adult population in Helsinki: decreased FEV1 , the main determinant

Introduction

Bronchial hyperresponsiveness (BHR) elevates the risk for development of respiratory symptoms and accelerates the decline in forced expiratory volume in the first second (FEV₁). We thus aimed to assess the prevalence, determinants and quantity of BHR in Helsinki.

Objectives

This study involved 292 randomly selected subjects age 26–66 years, women comprising 58%.

Methods

Following a structured interview, a spirometry, a bronchodilation test, and a skin-prick test, we assessed a bronchial challenge test with inhaled histamine using a dosimetric tidal breathing method. Results included the provocative dose inducing a decrease in FEV₁ by 15% (PD₁₅FEV₁) and the dose-response slope. For statistical risk factor-analyses, the severity of BHR was considered; PD₁₅ values ≤1.6 mg (BHR) and ≤0.4 mg [moderate or severe BHR (BHR_ms)] served as cut-off levels.

Results

BHR presented in 21.2% and BHR_ms in 6.2% of the subjects. FEV₁ < 80% of predicted [odds ratio (OR) 4.09], airway obstruction (FEV₁/forced vital capacity < 88% of predicted) (OR 4.33) and history of respiratory infection at age <5 (OR 2.65) yielded an increased risk for BHR as ORs in multivariate analysis. For BHR_ms, the determinants were decreased FEV₁ below 80% of predicted (OR 27.18) and airway obstruction (OR 6.16). Respiratory symptoms and asthma medication showed a significant association with BHR.

Conclusions

Of the adult population of Helsinki, 21% showed BHR to inhaled histamine. The main determinants were decreased FEV₁ and airway obstruction. Quantitative assessment of BHR by different cut-off levels provides a tool for characterization of phenotypes of airway disorders in epidemiologic and clinical studies.

Please cite this paper as: Juusela M, Pallasaho P, Sarna S, Piirilä P, Lundbäck B and Sovijärvi A. Bronchial hyperresponsiveness in an adult population in Helsinki: decreased FEV₁, the main determinant. Clin Respir J 2013; 7: 34–44.

Reactive airways dysfunction syndrome from acute inhalation of a dishwasher detergent powder

Reactive airway dysfunction syndrome, a type of occupational asthma without a latency period, is induced by irritating vapour, fumes or smoke. The present report is the first to describe a case of reactive airway dysfunction syndrome caused by acute exposure to dishwater detergent containing sodium metasilicate and sodium dichloroisocyanurate. The diagnosis was based on exposure data, clinical symptoms and signs, as well as respiratory function tests. A 43-year-old nonatopic male apprentice cook developed respiratory symptoms immediately after exposure to a cloud of detergent powder that was made airborne by vigorous shaking of the package. In spirometry, combined obstructive and restrictive ventilatory impairment developed, and the histamine challenge test revealed bronchial hyper-responsiveness. Even routine handling of a strongly caustic detergent, such as filling a dishwasher container, is not entirely risk free and should be performed with caution.

Comparison of a Multidose Powder Inhaler Containing Beclomethasone Dipropionate (BDP) with a BDP Metered Dose Inhaler with Spacer in the Treatment of Asthmatic Patients

OBJECTIVE

The clinical efficacy, tolerability and acceptability of a new multidose powder inhaler (MDPI) [Easyhaler((R)), Orion Pharma, Finland] containing a high dose (500 microg/dose) of beclomethasone dipropionate (BDP) were compared with those of BDP metered dose inhaler administered with a large volume spacer (MDI-spacer).

PATIENTS AND STUDY DESIGN

Recruited patients were adult asthmatics currently receiving 800 to 1000 microg/day of inhaled corticosteroid. The dose of BDP during the study was 1000 mg/day. The study was an open, randomised, parallel-group multicentre study and included a 2-week run-in period followed by a 12-week treatment period.

RESULTS

74 patients were randomised to both groups. During the run-in period the mean morning peak expiratory flow (PEF) was 489 and 478 L/min in the MDPI and MDI-spacer groups, respectively. During the last 2 weeks of the study the morning PEF was 485 L/min in the MDPI group and 477 L/min in the MDI-spacer group. Asthma symptom scores and use of rescue medication were low in both groups. The median dose of histamine required to decrease forced expiratory volume in 1 second (FEV(1)) by 15% was 1.05mg in the MDPI group and 0.64mg in the MDI-spacer group. The most frequent adverse events were hoarseness and sore throat. Mean serum cortisol levels were not affected in either treatment group. Patients' personal opinion regarding acceptability of the devices clearly favoured the MDPI.

CONCLUSION

In conclusion, the novel powder inhaler was well tolerated and at least equally effective compared with the conventional MDI-spacer combination in the treatment of asthma with BDP. However, in everyday use the patients clearly favoured the powder inhaler.

Occupational asthma related to low levels of airborne methylene diphenyl diisocyanate (MDI) in orthopedic casting work

Orthopedic plaster casts contain methylene diphenyl diisocyanate (MDI). A few case reports have suggested occupational asthma to MDI in casting work. However, the knowledge of the exposure levels related to the occupational asthma cases is lacking. We report on two occupational asthma cases due to MDI in nurses irregularly applying orthopedic plaster casts, verified with placebo controlled specific inhalation challenge. The levels of MDI in the air were measured in the exposure chamber during the specific inhalation challenges with a quantitative method including filter collection and subsequent liquid chromatography-mass spectrometry (LC-MS) analysis of the isocyanate groups. In order to estimate the level of airborne MDI in casting work, measurements were conducted also in two hospitals during the application and removal of synthetic plaster casts using the same method. The concentrations were well below the occupational exposure limit in both specific inhalation challenge and hospital measurements. Based on our findings, even minor exposure to airborne MDI in casting work can cause an asthmatic reaction in some patients.

Cough response to isocapnic hyperpnoea of dry air and hypertonic saline are interrelated

Background

Mechanisms behind asthmatic cough are largely unknown. It is known that hyperosmolar challenges provoke cough in asthmatic but not in the healthy subjects. It has been postulated that isocapnic hyperpnea of dry air (IHDA) and hypertonic aerosols act via similar mechanisms in asthma to cause bronchoconstriction. We investigated whether there is an association between cough response induced by IHDA and hypertonic saline (HS) challenges.

Methods

Thirty-six asthmatic and 14 healthy subjects inhaled HS solutions with increasing osmolalities administered via ultrasonic nebuliser until 15 cumulative coughs were recorded. The IHDA consisted of three three-minute ventilation steps: 30%, 60% and 100% of maximal voluntary ventilation with an end-point of 30 cumulative coughs. The challenges were performed on separate days at least 48 hours between them and within one week. Inhaled salbutamol (400 mcg) was administered before the challenges to prevent bronchoconstriction. The cough response was expressed as the cough-to-dose ratio (CDR) which is the total number of coughs divided by the maximal osmolality inhaled or the maximal ventilation achieved.

Results

Cough response to IHDA correlated with the HS challenge (Rs = 0.59, p < 0.001). Cough response to IHDA was at its strongest during the first minute after the challenge. IHDA induced more cough among asthmatic than healthy subjects CDR being (mean ± SD) 0.464 ± 0.514 and 0.011 ± 0.024 coughs/MVV%, p < 0.001, respectively. Salbutamol effectively prevented bronchoconstriction to both challenges.

Conclusions

Asthmatic patients are hypersensitive to the cough-provoking effect of hyperpnoea, as they are to hypertonicity. Cough response induced by IHDA and HS correlated well suggesting similar mechanisms behind the responses.

Ten-year follow-up of early intensive self-management guidance in newly diagnosed patients with asthma

OBJECTIVE

We assessed the 10-year effectiveness of self-management guidance in a prospective follow-up study of patients with asthma when inhaled corticosteroids were used from the beginning in the treatment.

METHODS

Consecutive newly diagnosed asthmatics (n = 162) were randomized: 80 to an intervention group (IG) and 82 to a control group (CG). Lung function (LF), airway hyperresponsiveness (AHR), and health-related quality of life (HRQoL) were examined at 10 years.

RESULTS

The advantages of intensive education with regards to LF measured by forced expiratory volume in 1 second and forced vital capacity were seen only after the first year. Later, there were no statistically significant differences in any parameters between the groups. However, during 10-year follow-up, peak expiratory flow, AHR, and HRQoL improved significantly in both groups (no differences as regards gender, smoking, or atopy). At 10 years, 68% of the IG and 75% of the CG patients still showed AHR after histamine challenge. Generic HRQoL scores in both groups equaled that of the age-standardized group a general population but only 50% in the IG and 55% in the CG had normal disease-specific HRQoL scores. According to Global Initiative for Asthma (GINA) criteria 23% of patients in the IG and 25% in the CG had asthma under control.

CONCLUSIONS

The effectiveness of intensive self-management education could be shown only in the short term. The groups did not differ significantly in any of the parameters investigated, and showed nearly normal LF and HRQoL. AHR improved only partly and only a minority of the patients had asthma under good control according to GINA criteria. This study showed that evaluation of asthma using LF alone does not show the whole truth about asthma treatment results. HRQoL should be used in conjunction with GINA criteria, to assess asthma treatment outcomes. The value and importance of AHR for the evaluation of treatment remains obscure.

Long-term respiratory symptoms following oesophageal atresia

Background

Oesophageal atresia (OA) is a congenital malformation that can lead to persistent respiratory symptoms in adulthood.

Aim

To describe the prevalence of respiratory symptoms in adulthood in a population-based study of patients with repaired OA and to compare this with the prevalence in the general population.

Methods

Of 80 patients operated for OA in Gothenburg in 1968–1983, 79 were located. The patients received a questionnaire on respiratory symptoms. Controls were 4979 gender- and age-matched subjects who answered the same questions.

Results

The questionnaire was answered by 73 of 79 (92%) patients. Physician-diagnosed asthma was reported by 30% in the OA group vs 10% in the control group (OR 4.1; 95% CI 2.4–6.8), and recurrent wheeze in 29% vs 5.5% (OR 6.9; 4.1–11.6). Also wheeze during the last year, asthma medication, a long-standing cough, cough with sputum production and chronic bronchitis were significantly more common among the patients with OA. In contrast, there was no significant difference regarding risk factors for asthma. The prevalence of respiratory symptoms did not appear to decrease with age.

Conclusion

A high prevalence of respiratory symptoms remains among adult patients with repaired OA. Many of the patients had an asthma diagnosis. However, asthma heredity or allergic rhinitis was not overrepresented.

Prolonged exposure to damp and moldy workplaces and new-onset asthma

PURPOSE

Epidemiological evidence shows that indoor dampness is associated with respiratory symptoms, the aggravation of preexisting asthma, and the development of new-onset asthma. Follow-up studies indicate that symptoms compatible with asthma constitute risk factors for the future development of asthma. The aims of the study were (1) to assess whether asthma-like symptoms (cough, dyspnea, and wheeze) that occur in relation to exposure to damp and moldy work environments lead to the later development of asthma and (2) to assess the importance of continued exposure to indoor dampness and molds at work in the development of asthma.

METHODS

We followed 483 patients with asthma-like symptoms related to damp workplaces but without objective evidence of asthma in baseline examinations. The development of asthma and present work conditions were established with the use of a questionnaire 3-12 years later.

RESULTS

A total of 62 patients (13%) reported having developed asthma during the study period. Continued exposure to a damp or moldy environment was associated with a more than fourfold increase in the risk of asthma (odds ratio 4.6, 95% confidence interval 1.8-11.6). Working in a non-remediated environment at follow-up was the strongest risk factor for developing asthma. The remediation of damp buildings seemed to be associated with a decrease in the risk of asthma.

CONCLUSIONS

The results indicate that exposure at work to dampness and molds is associated with the occurrence of new-onset asthma. Exposed workers suffering from asthma-like symptoms represent a risk group for the development of asthma. The risk appears especially high if the exposure continues. Due to inherent weaknesses of patient series, the findings need corroborative studies.

Gum arabic as a cause of occupational allergy

Background. Gum arabic is a potential sensitizer in food industry. Methods. We examined 11 candy factory workers referred to examinations due to respiratory and skin symptoms paying attention to exposure and sensitization to gum arabic. Skin tests, pulmonary function tests, and respiratory provocation tests were carried out as indicated by the symptoms and findings. Results. Occupational asthma, caused by gum arabic was diagnosed in 4/11 candy factory workers and two of them had also occupational contact urticaria and one had occupational rhinitis. One of them had oral symptoms associated with ingestion of products containing gum arabic. Conclusions. Airborne exposure to gum arabic may cause sensitization leading to allergic rhinitis, asthma, and urticaria.

Occupational asthma in professional cleaning work: a clinical study

BACKGROUND

Several epidemiological studies have reported an increased risk of asthma among professional cleaners. To date, however, no analysis of large patient series from clinic of occupational medicine has been published.

AIMS

To describe the cases of occupational asthma (OA) diagnosed at the Finnish Institute of Occupational Health (FIOH) during the period 1994-2004 in workers employed in professional cleaning work.

METHODS

OA was diagnosed according to patient history, lung function examinations and specific challenge tests with measurements of the forced expiratory volume in 1 second and peak expiratory flow values.

RESULTS

Our series comprised 20 patients, all female, with a mean age of 48.8 years (range 27-60 years). The mean duration of cleaning work before the onset of the respiratory symptoms was 14.3 years (range 1-36 years), and the mean duration of cleaning work before the FIOH examinations was 18.6 years (range 3-38 years). OA was triggered by chemicals in 9 cases (45%) and by moulds in 11 cases (55%). The chemicals were cleaning chemicals (wax-removing substances containing ethanolamines in five cases and a cleaning agent containing chloramine-T in one case) and chemicals used in the industrial processes at workplaces (three cases). Of the moulds, the most frequently associated with OA was Aspergillus fumigatus (nine cases).

CONCLUSIONS

OA was attributed not only to cleaning chemicals but also to other chemicals used in work environments. Moulds are presented as a new cause of OA in cleaners.

Mannitol as an indirect bronchoprovocation test for the 21st century

OBJECTIVES

To review mannitol challenge data and advocate the approval of this testing modality in the United States.

DATA SOURCES

A literature review was performed using the MEDLINE database for English-language articles published between January 1, 1993, and July 31, 2009, using the following keywords: mannitol bronchoprovocation test, inhaled mannitol, inhaled mannitol and asthma, and inhaled mannitol and exercise-induced asthma.

STUDY SELECTION

Trials were selected that established the effect of mannitol as a bronchoprovocation challenge, explored mannitol's mechanism of action, and compared mannitol to other accepted bronchoprovocation challenges.

RESULTS

Mannitol has demonstrated the ability to detect airway hyperreactivity in individuals. The mechanism of action is through the release of mast cell mediators. The sensitivity and specificity compare well with other indirect challenge testing methods.

CONCLUSION

Mannitol is a polyol sugar that can be converted to a powdered form and encapsulated. Once encapsulated it can be inhaled and causes narrowing of the airways in susceptible individuals. Mannitol likely triggers the release of inflammatory and/or bronchospasm mediators, causing the smooth muscle of the airway to contract and resulting in airway narrowing. The magnitude of decrease in forced expiratory volume in 1 second and the dose of mannitol needed to provoke the airway response provide a readily measurable and clinically useful assessment of airway hyperreactivity. Mannitol challenge is an accepted testing method in Australia, Europe, and Korea. Acceptance of the mannitol challenge in the United States would complement existing methods for assessing bronchial hyperreactivity and likely improve patient care.

Utility of hypertonic histamine challenge in distinguishing difficult-to-diagnose asthma

INTRODUCTION

Although classical asthma is associated with airway hyperresponsiveness (AHR), this condition is also present in many cardiopulmonary disorders undermining the rational basis of its measurement in the differential diagnosis of asthma. We have recently introduced a new method to investigate AHR, the hypertonic histamine challenge (HHC).

OBJECTIVE

The aim of this study was to evaluate the differential diagnostic power of HHC in a clinically representative sample of 138 patients.

METHODS

Fifty-seven patients from the outpatient clinic of the authors' hospital with symptoms indicative of asthma were consecutively recruited. Asthma was confirmed in 31 subjects. The remaining 26 subjects formed the control group, in conjunction with seven patients with COPD, 15 patients with interstitial lung disease, 21 patients with rhinitis, 13 patients with heart failure and 25 healthy controls. Hypertonic histamine solution was administered with an ultrasonic nebuliser.

RESULTS

Only the PC(20) values of asthmatic subjects differed statistically significantly from those of the healthy group (P < 0.0001). The receiver operator characteristic curve indicated that a PC(20) value of 0.83 mg/mL would be the optimal cut-off point of HHC to separate the asthmatics from the symptomatic controls with a sensitivity of 81% and specificity of 70%. With the PC(20) values of 0.1 and 4.0 mg/mL, the sensitivities were 42% and 100%, and the specificities were 96% and 40%, respectively. In these limits, HHC either confirmed or excluded asthma in 64 out of 138 patients (46%).

CONCLUSION

The authors' attempt to improve the accuracy of the airway challenge test by combining direct and indirect challenges did not overcome the diagnostic limitations of previously utilised airway challenges.

A 10-year open follow-up of eczema and respiratory symptoms in patients with atopic dermatitis treated with topical tacrolimus for the first 4 years

OBJECTIVES

To examine the 10-year outcome of affected body surface area (BSA), respiratory symptoms, and serum IgE in adult AD patients 6 years after a 4-year intervention with topical tacrolimus.

METHODS

Patients who 10 years ago participated in a 4-year, open tacrolimus study (n = 65) were contacted for assessment of affected BSA, bronchial hyper-reactivity (BHR), respiratory symptoms, skin prick tests and serum IgE.

RESULTS

Altogether, 50 (77%) patients attended the follow-up visit. The median affected BSA decreased from 19% to 1.6% during the 10-year follow-up (p < 0.0001). Patients with active asthma and rhinitis symptoms at baseline reported a significant decrease at the follow-up (p = 0.02 andp = 0.01). In patients with BHR at baseline, the provocative dose of inhaled histamine producing a 15% decrease in FEV(1) increased. Responders (>or= 60% improvement of affected BSA) to tacrolimus treatment at the 1-year visit had a significantly smaller affected BSA at the 4- and 10-year visits than non-responders (< 60% improvement). Responders also showed a significant decrease in serum IgE at the follow-up visit compared to baseline (p = 0.002).

CONCLUSIONS

The long-term, effective treatment of patients with AD may have a beneficial effect on affected BSA, respiratory symptoms, and serum IgE.

Short-term prognosis of occupational asthma in a Finnish population

BACKGROUND

Causative agents of occupational asthma (OA) are well described in literature but far less is known about factors affecting the outcome of OA. Short duration of exposure, early diagnosis when symptoms appear and further avoidance of exposure have been suggested as good prognostic factors. This study was designed to investigate a short-term outcome of OA.

METHODS

The medical records of 47 Caucasian patients from a Finnish population diagnosed with OA in year 2003 were reviewed retrospectively. Employment status at 6-month follow-up of all patients was determined. We assessed the following potential predictors of unemployment at follow-up: the causative agents of OA, asthma medication, spirometry results, smoking status, gender, age, occupation, atopy status, bronchial hyperresponsiveness and time to diagnosis. We calculated odd ratios (ORs) to predict employment status at follow-up.

RESULTS

At the follow-up examination, 23 persons (49%) were not working. At the time of follow-up there were no significant differences in pulmonary function between those employed and those who discontinued to work. Atopy at baseline predicted diminished lung function at the 6-month follow-up. In addition, atopy was the only prognostic factor and was inversely related to the work discontinuation at the follow-up [OR 0.18, 95% confidence interval (CI) 0.04-0.79]. Work continuation as an OA outcome at 6 months could not be predicted by gender, age, occupational status, exposure antigen, smoking habits or duration of symptoms before diagnosis.

CONCLUSIONS

The socio-economic short-term prognosis of OA was relatively poor since half of the patients were not at work at the 6 months follow-up.

Cobalt asthma--a case series from a cobalt plant

BACKGROUND

Cobalt has been shown to induce mainly asthma, allergic contact dermatitis and hard metal disease. The data on cobalt asthma are mainly based on case reports.

AIMS

To characterize all the cases of occupational cobalt asthma encountered in a cobalt plant at the time of diagnosis and 6 months later. We also evaluated the incidence of cobalt asthma in different departments on the basis of data on occupational exposures.

METHODS

We identified cases of cobalt asthma confirmed with specific bronchial challenge tests in the Kokkola cobalt plant in Finland where exposure levels have been regularly monitored.

RESULTS

Between 1967 and 2003, a total of 22 cases of cobalt asthma were diagnosed in the cobalt plant. On challenge tests, mostly late or dual asthmatic reactions were observed. The incidence of cobalt asthma was the highest in the departments with the highest cobalt exposure levels. All cases of cobalt asthma were encountered in departments where irritant gases were present in the ambient air in addition to cobalt. At the time of the follow-up examination 6 months later, non-specific hyperreactivity had mostly remained at the same level or increased.

CONCLUSIONS

The incidence of cobalt asthma correlated with the exposure levels of cobalt in corresponding departments. An irritating effect of gaseous compounds may enhance the risk of cobalt asthma and even the smallest amounts of cobalt may be harmful to susceptible workers. Symptoms of asthma may continue despite the fact that occupational exposure to cobalt has ceased.

New-onset adult asthma in relation to damp and moldy workplaces

OBJECTIVE

Damp and moldy indoor environments aggravate pre-existing asthma. Recent meta-analyses suggest that exposure to such environments may also induce new-onset asthma. We assessed the probability of molds being the cause of asthma in a patient series examined because of respiratory symptoms in relation to workplace dampness and molds.

METHODS

Altogether 694 such patients had been clinically assessed between 1995 and 2004. According to their histories, they had all been exposed to molds at work and had suffered from work-related lower respiratory symptoms. The investigations had included specific inhalation challenge (SIC) tests with mold extracts and serial peak expiratory flow (PEF) recordings. Using internationally recommended diagnostic criteria for occupational asthma (OA), we categorized the patients into three groups: probable, possible, and unlikely OA (156, 45, and 475 patients, respectively). The clinical details of 258 patients were analyzed, and their levels of microbial exposure were evaluated.

RESULTS

The agreement between the serial PEF recordings and SIC tests (both being either positive or negative) was 56%. In the group of probable OA, mold sensitization was found in 20%. The level of exposure and sensitization to molds was associated with probable OA. At 6 months, the follow-up examinations of 136 patients with probable OA showed that the symptoms were persistent, and no improvement in spirometry was noted despite adequate treatment. Only 58% of the patients had returned to work.

CONCLUSIONS

Exposure to damp and moldy workplaces can induce new-onset adult asthma. IgE mediation is a rare mechanism, whereas other mechanisms are unknown.

Matrix metalloproteinases-7, -8, -9 and TIMP-1 in the follow-up of diisocyanate-induced asthma

BACKGROUND

Diisocyanate-induced asthma (DIA) is known to be associated with poor prognosis. We wished to clarify if matrix metalloproteinases (MMP)-7, -8 or -9 or tissue inhibitor of matrix metalloproteinases (TIMP-1) are associated with the functional or inflammatory outcome in DIA patients.

METHODS

This is a longitudinal study where 17 patients with DIA diagnosed by a specific challenge test to diisocyanates were monitored. Exposure to diisocyanates was terminated seven (mean) months before the challenge test. The studies included spirometry, histamine challenge test and bronchoscopy. MMP-7, MMP-8, TIMP-1 [Enzyme-linked immunosorbent assay (ELISA)- and immunofluorometric assay-methods], MMP-9 (ELISA and zymography), interferon-gamma, tumour necrosis factor-alpha, interleukin-6, -8, -15, -17, CXCL-5/ENA-78, monocyte chemoattractant protein-1 and macrophage inhibitory factor (MIF) (ELISA) were assayed from bronchoalveolar lavage (BAL) fluid. Inhaled steroid therapy was initiated after the examinations, which were repeated at 6 months and at 3 years during the treatment. The results were compared with those of 15 healthy controls.

RESULTS

Inhaled steroid medication increased BAL levels of MMP-9 and MMP-9/TIMP-1 and decreased MMP-7 and MMP-7/TIMP-1. The increase in MMP-9 levels was associated with a decline in the TH-2 type inflammation.

CONCLUSIONS

Our data suggest that reduced TH-2 type inflammation in DIA after inhaled steroid medication is reflected as elevated MMP-9 and MMP-9/TIMP-1 levels in BAL. MIF may be the inducer of MMP-9. This might point to some protective role for MMP-9 in DIA.

Reactive airway dysfunction syndrome (RADS) in a chemistry teacher induced by fumes of mixed iodine compounds

The reactive airway dysfunction syndrome (RADS) is a type of occupational asthma without a latency period, and it is induced by irritating vapour, fume, or smoke. Although the onset of RADS has been related to over 30 different agents, it has not been previously associated with acute exposure to iodine, aluminium iodide, or hydrogen iodide. The diagnosis was based on exposure data, clinical symptoms and signs, as well as respiratory function tests and bronchoscopy. A 48-yr-old non-atopic, never-smoking female chemistry teacher developed respiratory symptoms immediately after a demonstration of oxidation-reduction reactions in a school classroom. Spirometry showed bronchial obstruction, and the histamine challenge test revealed bronchial hyperresponsiveness. These findings were still evident seven years after the incident. The prognosis of RADS was unfavourable: the patient had to quit her job as a teacher. A case of RADS following acute exposure to mixed iodine compounds is presented for the first time. Demonstrations of potentially dangerous chemical reactions should always be carried out in a fume cupboard, and appropriate personal protective equipment should be worn.

BAL fluid 8-isoprostane concentrations in eosinophilic bronchitis and asthma

BACKGROUND

Oxidative stress has an important role in the pathophysiology of asthma. But oxidative stress of airway has not been assessed in patients with nonasthmatic eosinophilic bronchitis (EB). 8-epi-prostaglandin F2alpha (8-isoprostane) is a biomarker of oxidative stress.

OBJECTIVES

We sought to determine whether oxidative stress (measured by 8-isoprostane) occurs in EB and whether 8-isoprostane is associated with airway function in EB and asthma.

METHODS

We measured 8-isoprostane concentrations in the bronchoalveolar lavage (BAL) fluid from 11 subjects with EB, 10 subjects with asthma, and 9 healthy control subjects. 8-isoprostane was measured by enzyme immunoassays.

RESULTS

We found that BAL fluid 8-isoprostane concentrations were raised both in EB and asthma. The median concentrations of 8-isoprostane in BAL fluid were significantly higher in subjects with asthma (12.78 pg/mL) when compared with EB (8.34 pg/mL) and healthy control subjects (5.07 pg/mL).

CONCLUSIONS

Our study shows that oxidative stress is increased significantly in asthmatic subjects and the degree of oxidative stress in EB subjects is milder than that in asthma, as reflected by 8-isoprostane concentrations in the BAL fluid. The difference in airway function observed in subjects with EB and asthma could be associated with different elevation in 8-isoprostane concentration in the airways.

Military service-aggravated asthma improves at two-year follow-up

BACKGROUND

During military service young men (age 19-21 years) are exposed to many predisposing factors for asthma. We aimed to study the short-term prognosis of asthma after the military service.

METHODS

All 216 men with verified asthma in 2004-2005 from the register of the Central Military Hospital were included in the study. A questionnaire was mailed to them in autumn 2007 and the 146 responders (68%) formed the final study population. Asthma severity was evaluated during military service according to the medical records of the subjects and two years later based on the questionnaire using modified GINA guidelines. The results on lung function and allergy tests during military service and asthma history were used as predictors of asthma severity at two-year follow-up.

RESULTS

Two groups of asthmatics were identified: those who already had asthma when entering the military service (n=71, 48.6%) and those, who had a new onset of asthma during the service (n=75, 51.4%). Overall asthma was less severe at two-year follow-up than during military service (p=0.036). Both during military service and at two-year follow-up, asthma was milder among the men, who had a new onset of asthma during military service. Atopy (p=0.002), number of positive skin-prick tests (p=0.005) and higher total serum IgE (p=0.001) were significant predictors for persistent asthma at follow-up.

CONCLUSIONS

Asthma, which had aggravated or started during military service, was significantly less severe two years later. The degree of atopy was a major determinant of the two-year prognosis of asthma after military service.