Endotyping asthma related to 3 different work exposures.

BACKGROUND: Work exposures play a significant role in adult-onset asthma, but the mechanisms of work-related asthma are not fully elucidated. OBJECTIVE: We aimed to reveal the molecular mechanisms of work-related asthma associated with exposure to flour (flour asthma), isocyanate (isocyanate asthma), or welding fumes (welding asthma) and identify potential biomarkers that distinguish these groups from each other. METHODS: We used a combination of clinical tests, transcriptomic analysis, and associated pathway analyses to investigate the underlying disease mechanisms of the blood immune cells and the airway epithelium of 61 men. RESULTS: Compared with the healthy controls, the welding asthma patients had more differentially expressed genes than the flour asthma and isocyanate asthma patients, both in the airway epithelia and in the blood immune cells. In the airway epithelia, active inflammation was detected only in welding asthma patients. In contrast, many differentially expressed genes were detected in blood cells in all 3 asthma groups. Disease-related immune functions in blood cells, including leukocyte migration and inflammatory responses, and decreased expression of upstream cytokines such as TNF and IFN-γ were suppressed in all the asthma groups. In transcriptome-phenotype correlations, hyperresponsiveness (R ∼ |0.6|) had the highest clinical relevance and was associated with a set of exposure group-specific genes. Finally, biomarker subsets of only 5 genes specifically distinguished each of the asthma exposure groups. CONCLUSIONS: This study provides novel data on the molecular mechanisms underlying work-related asthma. We identified a set of 5 promising biomarkers in asthma related to flour, isocyanate, and welding fume exposure to be tested and clinically validated in future studies.

The Finnish Allergy Program 2008-2018: Society-wide proactive program for change of management to mitigate allergy burden.

A 10-year national program to improve prevention and management of allergic diseases and asthma was implemented in Finland (population 5.5. million) in 2008-2018. The main aim was to reduce the long-term burden of these conditions. The strategy was changed from traditional avoidance to tolerance and resilience of the population. Health was endorsed instead of medicalization of mild symptoms. Disease severity was reevaluated, and disabling clinical manifestations were given high priority. For health care, 5 quantitative goals and 1 qualitative goal were set. For each of the goals, specific tasks, tools, and outcome evaluation were stipulated. During the program, 376 educational sessions gathered 24,000 health care participants. An information campaign targeted the lay public, and social media was used to contact people. In the 10 years of the program, the prevalence of allergic diseases and asthma leveled off. Asthma caused fewer symptoms and less disability, and 50% fewer hospital days. Food allergy diets in day care and schools decreased by half. Occupational allergies were reduced by 45%. In 2018, the direct and indirect costs of allergic diseases and asthma ranged from €1.5 billion to €1.8 billion, with the 2018 figures being 30% less than in the respective figures in 2007. The Finnish proactive and real-world intervention markedly reduced the public health burden of allergic disorders. The allergy paradigm was revisited to improve management with systematic education.

Occupations and exposure events in acute and subacute irritant-induced asthma.

BACKGROUND: Exposures leading to irritant-induced asthma (IIA) are poorly documented. METHODS: We retrospectively screened the medical records of patients with IIA diagnosed in an occupational medicine clinic during 2000-2018. We classified the cases into acute (onset after single exposure) and subacute (onset after multiple exposures) IIA. We analysed in detail, occupations, causative agents and their air levels in the workplace, exposure events and the root causes of high exposure. RESULTS: Altogether 69 patients were diagnosed with IIA, 30 with acute and 39 with subacute IIA. The most common occupational groups were industrial operators (n=23, 33%), metal and machinery workers (n=16, 11%) and construction workers (n=12, 8%). Among industrial operators significantly more cases had subacute IIA than acute IIA (p=0.002). Forty cases (57%) were attributable to some type of corrosive acidic or alkaline chemical. Acute IIA followed accidents at work in different types of occupation, while subacute IIA was typical among industrial operators performing their normal work tasks under poor work hygiene conditions. The most common root cause was lack of information or false guidance in acute IIA (n=11, 36%) and neglect of workplace hygiene measures in subacute IIA (n=29, 74%). CONCLUSIONS: Accidents are the main causes of acute IIA, whereas subacute IIA can develop in normal work in risk trades with poor work hygiene. Airborne strong acids or bases seem to be the most important causative agents of acute and subacute IIA. The different risk profiles of acute and subacute IIA should be considered in the prevention and identification of the cases.

Transcriptomic Profiling of Adult-Onset Asthma Related to Damp and Moldy Buildings and Idiopathic Environmental Intolerance.

A subset of adult-onset asthma patients attribute their symptoms to damp and moldy buildings. Symptoms of idiopathic environmental intolerance (IEI) may resemble asthma and these two entities overlap. We aimed to evaluate if a distinct clinical subtype of asthma related to damp and moldy buildings can be identified, to unravel its corresponding pathomechanistic gene signatures, and to investigate potential molecular similarities with IEI. Fifty female adult-onset asthma patients were categorized based on exposure to building dampness and molds during disease initiation. IEI patients (n = 17) and healthy subjects (n = 21) were also included yielding 88 study subjects. IEI was scored with the Quick Environmental Exposure and Sensitivity Inventory (QEESI) questionnaire. Inflammation was evaluated by blood cell type profiling and cytokine measurements. Disease mechanisms were investigated via gene set variation analysis of RNA from nasal biopsies and peripheral blood mononuclear cells. Nasal biopsy gene expression and plasma cytokine profiles suggested airway and systemic inflammation in asthma without exposure to dampness (AND). Similar evidence of inflammation was absent in patients with dampness-and-mold-related asthma (AAD). Gene expression signatures revealed a greater degree of similarity between IEI and dampness-related asthma than between IEI patients and asthma not associated to dampness and mold. Blood cell transcriptome of IEI subjects showed strong suppression of immune cell activation, migration, and movement. QEESI scores correlated to blood cell gene expression of all study subjects. Transcriptomic analysis revealed clear pathomechanisms for AND but not AAD patients. Furthermore, we found a distinct molecular pathological profile in nasal and blood immune cells of IEI subjects, including several differentially expressed genes that were also identified in AAD samples, suggesting IEI-type mechanisms.

Does lung function predict the risk of disability pension? An 11-year register-based follow-up study.

BACKGROUND: Spirometry is widely used in medical surveillance in occupational health and as a diagnostic test for obstructive and restrictive lung disease. We evaluated the effect of spirometry parameters on the risk of all-cause disability pension in a follow-up study of an occupationally active general population-based cohort. METHODS: We measured the pulmonary function of 3386 currently working participants of the Health 2000 Survey in the clinical phase at baseline using spirometry. We obtained the retirement events of the cohort from the nationwide register for 2000-2011. Cox proportional hazards models were used to determine disability pensions. RESULTS: At baseline, we identified 111 (3.3%) participants with obstructive spirometry, 95 (2.8%) with restrictive spirometry, and 3180 controls without restriction or obstruction. The age, sex, educational level, body-mass index, co-morbidities (1 or ≥ 2), and the smoking-adjusted hazard ratio of disability pension was 1.07 (95% confidence interval, CI 0.64-1.78) for those with obstructive spirometry, and 1.44 (95% CI 0.89-2.32) for those with restrictive spirometry. As continuous variables, and divided into quartiles, the risk of the lowest quartile of forced ventilation capacity (FVC)% of predicted was 1.49 (95%CI 1.10-2.01) and forced expiratory volume in one second (FEV1)% of predicted 1.66 (95%CI: 1.23-2.24) in comparison to the highest quartile in the adjusted models. CONCLUSIONS: Obstructive or restrictive spirometry did not predict disability pension when dichotomized classified variables (normal compared to abnormal) were used. As continuous variables and when divided into quartiles, lower lung volumes showed an increase in the risk of disability pension. Physicians should take this into account when they use spirometry as a prognostic factor of work disability.

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.

Outbreak of invasive pneumococcal disease among shipyard workers, Turku, Finland, May to November 2019.

We report an outbreak of invasive pneumococcal disease and pneumococcal pneumonia among shipyard workers, in Turku, Southwest Finland. In total, 31 confirmed and six probable cases were identified between 3 May and 28 November 2019. Streptococcus pneumoniae serotypes 12F, 4 and 8 were isolated from blood cultures of 25 cases. Occupational hygiene measures and vaccination of ca 4,000 workers are underway to control the outbreak at the shipyard.

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.

Altered microRNA expression of nasal mucosa in long-term asthma and allergic rhinitis.

BACKGROUND: Asthma and allergic rhinitis (AR) commonly coexist and can be taken as manifestations of one syndrome. Evidence exists that microRNAs (miRNAs) are important in controlling inflammatory processes and they are considered promising biomarkers. However, little is known about the differences in miRNA expression in patients with chronic allergic airway disease. This study evaluated the inflammatory and miRNA profiles of the nasal mucosa of patients with long-term asthma with and without AR. METHODS: We analyzed inflammatory cells, cytokines, and miRNAs in nasal biopsies and measured exhaled and nasal nitric oxide levels during the nonpollen season in 117 middle-aged men who had suffered mainly from allergic asthma for approximately 20 years and also in 33 healthy controls. RESULTS: The differences in the number of nasal eosinophils and cytokine expression levels were modest in nasal biopsies taken from asthmatics. Downregulation of miR-18a, miR-126, let-7e, miR-155, and miR-224 and upregulation of miR-498, miR-187, miR-874, miR-143, and miR-886-3p were observed in asthmatic patients in comparison to controls. The differences in miRNA expression were mainly similar in asthmatics with and without AR. With regard to asthma severity, a trend of increased miRNA expression in persistent asthma was seen, whereas the downregulation of certain miRNAs was most distinct in nonpersistent-asthma patients. CONCLUSIONS: Differences in miRNA expression in the nasal mucosa of subjects with long-term asthma and AR can be seen also when no markers of Th2-type inflammation are detected. Asthma severity had only a minor impact on miRNA expression.

[Work aggravated asthma]. / Tyon pahentama astma.

One out of five working persons with asthma has work-related respiratory symptoms. When exploring the symptoms of a working-age patient it is essential to survey the job description and working conditions. Early intervention in the factors aggravating the respiratory symptoms will decrease morbidity, maintain working capacity and improve the quality of life. Occupational health service and the employer play a central role in identifying and decreasing the exposure factors in the working environment as well as in patient guidance for asthma therapy and protecting from the stimuli. The working capacity of an asthmatic person can be improved by applying vocational rehabilitation.

[Irritant-induced asthma]. / Ärsytyksen aiheuttama astma.

Irritant-induced asthma is a rare disease, usually being caused by an accidental or other exceptionally strong exposure to substances irritating the respiratory passages. High-dose inhaled corticosteroid medication is immediately started at the emergency call service. If severe exposure is suspected, it is important to monitor the patient at least for a couple of days in hospital. Immediately after the acute stage diagnostic investigations are carried out, including a metacholine or histamine challenge test, since demonstration of airway hyperreactivity is of diagnostic and prognostic significance. The asthma may remain permanent.

Long-term outcome of occupational asthma with different etiology.

PURPOSE OF REVIEW: This review summarizes the recent literature on the long-term outcome of sensitizer-induced and irritant-induced occupational asthma. RECENT FINDINGS: Recent studies of sensitizer-induced occupational asthma show that after the offending exposure has ceased, most patients report at least partial relief of symptoms. However, in the long term, the diagnosis may negatively impact their careers, incomes, and quality of life. The studies also offer new insights into diisocyanate-induced occupational asthma phenotypes and asthma remission rates. One third of these cases were in remission in long-term after reduction or cessation of exposure. The long-term prognosis of irritant-induced occupational asthma was demonstrated to be poorer than sensitizer-induced occupational asthma. Older age, low fractional exhaled nitric oxide levels and uncontrolled asthma at the time of diagnosis predicted uncontrolled asthma in the long term in patients with irritant and low-molecular-weight sensitizer induced occupational asthma. SUMMARY: Recent studies provide further evidence of the long-term outcome of different occupational asthma phenotypes and the factors that affect them. These findings help us identify patients at risk of poor asthma outcomes, who need close monitoring and support. It should also be borne in mind that occupational asthma diagnosis may have wider-ranging negative impacts on patients' lives.

Long-term impairment from irritant-induced occupational asthma.

OBJECTIVE: To assess the long-term physical condition, health-related quality of life, employment, and work ability of irritant-induced asthma (IIA) patients. METHODS: Forty-three IIA patients completed a follow-up questionnaire a median of eight (interquartile range 4-11) years after asthma diagnosis. We compared their results with those of 43 low-molecular-weight (LMW) sensitizer-induced occupational asthma (OA) patients and those of 206 adult-onset asthmatics in the general population. RESULTS: Of the IIA patients, 40% reported depressive symptoms. Of the <65-year-olds, 56% were employed, of whom 39% assessed their work ability as limited. IIA patients had more difficulty climbing several flights of stairs than LMW-induced OA patients (70% vs. 47%, OR 4.83 95%CI 1.51-15.47). Most of the IIA patients' outcomes were inferior to those of the adult-onset asthmatics in the general population. CONCLUSION: IIA prognosis appeared poor but resembled that of LMW-induced OA.

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.

Occupational lung disease: when should I think of it and why is it important?

Exposure to toxic inhalants in the workplace has the potential to cause (in susceptible individuals) almost any major type of lung disease, such as asthma, COPD and interstitial lung diseases. Patients with occupational lung disease will often present to or will be managed by respiratory specialists without training in occupational respiratory medicine, and patients (or their clinicians) may not identify a link between their disease and their current or a past job. Without an awareness of the range of different occupational lung diseases that exist, their similarity to their non-occupational counterparts, and without directed questioning, these conditions may go unidentified. Patients with occupational lung diseases are often in lower paid work and are disproportionally affected by health inequality. Both clinical and socioeconomic outcomes generally improve if cases are identified early. This allows appropriate advice to be given about the risks of ongoing exposure, clinical management, occupational mobility and, in some cases, eligibility for legal compensation. As respiratory professionals, it is important that these cases are not missed, and if needed, are discussed with a physician with specialised expertise. Here we describe some of the most common occupational lung diseases and outline the diagnostic and treatment approach.

Positive exercise test and obstructive spirometry in young male conscripts associated with persistent asthma 20 years later.

BACKGROUND: Asthma often begins in childhood or early adulthood and is a common disease among conscripts. The identification of long-term predictive factors for persistent asthma may lead to improved treatment opportunities and better disease control. OBJECTIVE: Our aim was to study the prognostic factors of the severity of asthma among 40-year-old male conscripts whose asthma began in youth. METHODS: We studied 119 conscripts who were referred to the Central Military Hospital during 1987-1990 due to asthma and who attended a follow-up visit approximately 20 years later. Asthma severity was evaluated during military service according to the medical records, and 20 years later during a follow-up visit using Global Initiative for Asthma guidelines. We used the results of lung function and allergy tests at baseline as predictors of current persistent asthma. RESULTS: Compared with baseline, asthma was less severe at follow-up: 11.8% of subjects were in remission, 42.0% had intermittent asthma, 10.9% had mild persistent asthma, and 35.3% had moderate/severe persistent asthma (p < .001). In multivariate models, a positive exercise test at baseline yielded an odds ratio (OR) of 3.2 (95% CI 1.0-9.8, p = .046), a decreased FEV1/FVC % predicted an OR of 4.0 (95% CI 1.7-9.3, p = .002), and a decreased FEF50% % predicted an OR of 2.8 (95% CI 1.3-6.4, p = .012) for current persistent asthma. CONCLUSIONS: About half of the men had persistent asthma at the 20-year follow-up. Positive exercise tests and obstructive spirometry results were related to the persistence of asthma and may be useful long-term prognostic factors for asthma severity.

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 ß-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.

[Peak expiratory flow monitoring--the basis for diagnosing occupational asthma--guidelines by the Finnish Expert Group on Occupational Lung Diseases]. / Ammattikeuhkosairauksien asiantuntijaryhmän (AKAR) suositus. PEF-työpaikkaseuranta--ammattiastma-diagnostiikan perusta.

Occupational exposures can cause adult-onset asthma. Early diagnosis and early avoidance of further exposure to causative agent improves the prognosis of occupational asthma. Occupational and primary care health services have an important role in the identification of new cases of occupational asthma. For the diagnosis of occupational asthma, serial peak expiratory flow (PEF) measurements should be performed in an early stage. Although it requires an effort from the patient, high quality recordings offer the best approach to assess the relationship between workplace exposure and respiratory symptoms. Good guidance and performance of serial PEF measurements in primary care is recommended and is worth the effort.

[Specific challenge tests in occupational asthma--guidelines by the Finnish Expert Group on Occupational Lung Diseases]. / Ammattikeuhkosairauksien asiantuntijaryhmän (AKAR) suositus. Hengitysteiden spesifiset altistuskokeet ammattiastman osoittamisessa.

In a specific inhalation challenge (SIC) test the patient inhales an occupational agent in controlled environment and the subsequent asthmatic reaction is monitored. SIC is considered as the reference standard when confirming the diagnosis of sensitizer-induced occupational asthma. However, SIC is not always needed for the diagnosis; in many cases the causal relationship between an occupational agent and asthma can be shown also with serial peak flow measurements and specific immunologic testing. SIC is invaluable in identifying new occupational airway sensitizers. This is essential for preventing occupational asthma in the future.