Diagnosing occupational asthma: insight from induced sputum

Implementation of a Work-Related Asthma Screening Questionnaire in Clinical Settings: Multimethods Study

Background

A work-related asthma (WRA) screening questionnaire is currently being validated for implementation in clinical settings. To minimize barriers to integrating tools into clinical practice, a discussion of strategies for the implementation of the questionnaire has begun.

Objective

This study aimed to understand the benefits, feasibility, barriers, and limitations of implementing the Work-related Asthma Screening Questionnaire–Long version (WRASQ[L]) and asthma e-tools in clinical settings and propose dissemination and implementation strategies for the WRASQ(L).

Methods

This study was conducted in Kingston, Ontario, Canada, from September 2019 to August 2021. A workshop and 2 questionnaires were used to understand the benefits of and barriers to implementing the questionnaire in clinical settings. An expert advisory committee was established to develop the implementation and dissemination strategies. Workshops were semistructured and used thematic qualitative analysis to identify themes that provided an understanding of the benefits and limitations of and barriers to using the WRASQ(L), and e-tools in general, in clinical settings. Workshop participants included patients and health care providers, including physicians, nurses, and asthma educators, who were implementation specialists and expert electronic medical record users. A questionnaire focusing on providers’ knowledge and awareness of WRA and another focusing on WRASQ(L) feedback was administered at the workshops. Advisory committee members from relevant stakeholders met 3 times to strategize implementation opportunities.

Results

A total of 6 themes were identified in the workshop: involving and addressing patient needs, novel data collection, knowledge translation, time considerations, functional and practical barriers, and human limitations. Questionnaire responses yielded positive feedback on the utility of the WRASQ(L) in clinical settings. All participants agreed that it is an easy way of collecting information on occupational and exposure history and could prompt a discussion between the health care provider and patient on how the workplace and exposures could affect one’s asthma, increase awareness of WRA in patients and providers, and increase awareness of exposures in the workplace. Implementation and dissemination strategies were generated with input from the advisory committee.

Conclusions

Stakeholders and workshop participants consider the WRASQ(L) to be a useful tool that satisfies many provider needs in their clinical settings. Once validated, dissemination strategies will include developing educational materials that include the WRASQ(L), linking the questionnaire to stakeholder websites or e-toolkits, translation into other languages, leveraging health care and research networks, conference presentations, and peer-reviewed publications. Implementation strategies will include integration into electronic medical records; designing multifaceted interventions; and targeting nontraditional settings such as workplaces, pharmacies, and research settings. The WRASQ(L) addresses many benefits of and barriers to implementation, as identified in the workshop themes. These themes will guide future implementation and dissemination strategies, noting that human limitations identified in providers and patients will need to be overcome for successful implementation.

The effect of smoking cessation on airway inflammation in young asthma patients

BACKGROUND

Smoking has been shown to have several detrimental effects on asthma, including poor symptom control, attenuated treatment response and accelerated decline in lung function. In spite of this, smoking is at least as common among asthma patients as in the rest of the population. The aggravations of smoking on asthma may be caused by effects on airway inflammation, which has been found to be changed in asthmatic smokers. It is not known whether these smoking-induced airway inflammation changes are reversible after smoking cessation.

OBJECTIVE

The aim of this study was to assess airway changes in asthmatic smokers before and during smoking cessation.

METHODS

Forty-six smokers with asthma, all steroid-free (age range: 19-40), were recruited. All participants attempted smoking cessation over a period of 3 months. Visits were performed at weeks 0, 6 and 12 and included induced sputum, FeNO, methacholine challenge, lung function, Asthma Control Questionnaire (ACQ6) and exhaled CO.

RESULTS

Twenty-six of 46 patients succeeded in quitting smoking. In the quitters, improvements in methacholine AHR (77% before and 52% after smoking cessation, respectively, P = 0.016) and ACQ6 score (1.7-0.7, P = 0.034) and FeNO (8.7-14.8 p.p.b., P = 0.002) were observed, whereas no significant changes were found regarding eosinophils or lung function. A small but significant decrease in neutrophils (54.1-52%, P = 0.003) was present in quitters compared with the non-quitters. Non-quitters experienced no changes in any parameters.

CONCLUSION

Smoking cessation improved asthma control, but the changes were not related to change in eosinophilic inflammation, and the reduction in neutrophils was small. Thus, airway inflammation with eosinophils and neutrophils may be less important drivers of asthma control in smokers than other factors.

CLINICAL RELEVANCE

Smoking cessation may improve clinically important disease parameters such as AHR and symptom score, but likely unrelated to changes in airway inflammation.

Predictors of neutrophilic airway inflammation in young smokers with asthma

INTRODUCTION

Asthma is one of the most widespread chronic diseases worldwide. In spite of numerous detrimental effects on asthma, smoking is common among asthma patients. These smoking-induced aggravations of asthma may be attributed to changes in airway inflammation, which is characterized by a higher degree of neutrophilic inflammation than in non-smokers. A state of neutrophilic inflammation may lead to increased steroid resistance and an accelerated loss of lung function owing to tissue destruction. The aim of this study was to elucidate predictors of neutrophilic inflammation in young asthmatic smokers not on steroid treatment, including analysis of tobacco history and bacterial colonization.

METHODS

In a cross-sectional study, 52 steroid-free, current smokers with asthma were examined with induced sputum, fractional exhaled nitric oxide (FeNO), lung function, ACQ6 score, mannitol and methacholine challenge. A sample from the sputum induction was taken for bacterial analysis using 16S gene PCR technique and sequencing.

RESULTS

Using one-way analysis of variance and binary and linear regression models, only age and ACQ6 score were found to be significant predictors for airway neutrophilia. The investigation also included analysis for effect of pack years, current tobacco consumption, body mass index, lung function, FeNO; methacholine and mannitol responsiveness, atopy, gender, asthma history and presence of bacteria. The most common potentially pathogenic bacteria found were Streptococcus spp., Haemophilus spp. and Mycoplasma spp.

CONCLUSION

In this study, no tobacco-related predictors of airway neutrophilia were found, indicating that in the younger years of asthma patients who smoke, the amount of tobacco smoked in life does not influence the degree of neutrophilia. Conversely, for asthmatic smokers, neutrophilia may be induced when a certain threshold of tobacco consumption is reached.

Variability in the diagnosis of occupational asthma and implications for clinical practice

PURPOSE OF REVIEW

The purpose of this review is to provide a summary of recent evidence relating to occupational asthma diagnosis.

RECENT FINDINGS

Recent evidence suggests that whilst prolonged asthmagen exposure worsens the prognosis, many steps in the diagnostic process are problematic for workers with possible occupational asthma. Certain workers suffer delay prior to specialist assessment, and assessment itself may be of variable quality. Emerging evidence suggests that whilst experts agree about certain aspects of case assessment, there is still likely to be variation in clinical practice. Implications of this variation for the workers assessed are relatively under researched.

SUMMARY

Future research needs to focus not only on improving diagnostic testing, but also on improving consistency and agreement over diagnosis.

Asthma overview

This article presents our current understanding of the biological heterogeneity of asthma and reviews some of the key features of the latest proposed recommendations of the National Asthma Education and Prevention Program Guidelines. The diagnosis of asthma is based on such clinical features as variable airflow obstruction that is partially if not fully reversible and airway hyperresponsiveness that predisposes to episodic bronchospasm following exposure to a variety of triggers. The underlying inflammation and airway biology of asthma is heterogeneous and is part of the explanation for the variable response to therapy. New biologics that help to characterize patients according to their underlying biology will aid in making better choices for treatment. New asthma guidelines emphasize the importance of regular monitoring.

Role of gap junctions in regulation of progesterone secretion by ovine luteal cells in vitro

To evaluate the role of gap junctions in the regulation of progesterone secretion, two experiments were conducted. In Experiment 1, luteal cells obtained on days 5, 10, and 15 were cultured overnight at densities of 50 x 10(3), 100 x 10(3), 300 x 10(3), and 600 x 10(3) cells/dish in medium containing: (1) no treatment (control), (2) LH, or (3) dbcAMP. In Experiment 2, luteal cells from days 5 and 10 of the estrous cycle were transfected with siRNA, which targeted the connexin (Cx) 43 gene. In Experiment 1, progesterone secretion, Cx43 mRNA expression, and the rates of gap junctional intercellular communication (GJIC), were affected by the day of the estrous cycle, cell density, and treatments (LH or dbcAMP). The changes in progesterone secretion were positively correlated with the changes in Cx43 mRNA expression and the rates of GJIC. Cx43 was detected on the luteal cell borders in every culture, and luteal cells expressed 3beta-hydroxysteroid dehydrogenase. In Experiment 2, two Cx43 gene-targeted sequences decreased Cx43 mRNA expression and progesterone production by luteal cells. The changes in Cx43 mRNA expression were positively correlated with changes in progesterone concentration in media. Thus, our data demonstrate a relationship between gap junctions and progesterone secretion that was supported by (1) the positive correlations between progesterone secretion and Cx43 mRNA expression and GJIC of luteal cells and (2) the inhibition of Cx43 mRNA expression by siRNA that resulted in decreased production of progesterone by luteal cells. This suggests that gap junctions may be involved in the regulation of steroidogenesis in the ovine corpus luteum.