Non-invasive tools beyond lung function before and after specific inhalation challenges for diagnosing occupational asthma

Factors related with lung functions among Orang Asli in Tasik Chini, Malaysia: a cross-sectional study

BACKGROUND

Orang Asli lifestyle and household setting may influence their health status especially respiratory system and lung functions. This cross-sectional study was carried out to investigate the status of lung functions of Orang Asli community and the associated factors.

METHODS

Data collection was carried out from November 2017 until May 2018 among 211 Orang Asli respondents aged 18 years old and above, who lived in five villages in Tasik Chini, Pahang. All respondents who fulfilled the inclusion criteria were recruited in this study. Interview-guided questionnaire was administered, and spirometry test that include Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC), and Peak Expiratory Flow Rate (PEFR) was carried out. Data were analyzed using SPSS software version 23.0. In the first stage, descriptive analysis was done to describe the characteristics of the respondents. In the second stage, bivariable analysis was carried out to compare proportions. Finally, multiple logistic regression was performed to assess the effects of various independent predictors on spirometry parameters.

RESULTS

The respondents' age ranged from 18 to 71 years old in which 50.2% of them were female. The majority ethnicity in Tasik Chini was Jakun tribe (94.3%). More than half of the respondents (52.1%) were current smoker, 5.2% were ex-smoker and 41.7% were non-smoker. More than half of them (62.1%) used woodstove for cooking, compared to only 37.9% used cleaner fuel like Liquefied Petroleum Gas (LPG) as a fuel for everyday cooking activity. The lung function parameters (FEV1 and FVC) were lower than the predictive value, whereas the ratio of Forced Expiratory Volume in one second and Forced Vital Capacity (FEV1/FVC) (%) and PEFR were within the predictive value. The FEV1 levels were significantly associated with age group (18-39 years old) (p = 0.002) and presence of woodstove in the house (p = 0.004). FVC levels were significantly associated with presence of woodstove in the house (p = 0.004), whereas there were no significant associations between all factors and FEV1/FVC levels.

CONCLUSIONS

FEV1 levels were significantly associated with age group 18-39 years old, whereas FVC levels were significantly associated with the presence of woodstove in the house. Thus, environmental interventions such as replacing the use of woodstove with LPG, need to be carried out to prevent further worsening of respiratory health among Orang Asli who lived far from health facilities. Moreover, closer health monitoring is crucial especially among the younger and productive age group.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

The value of fractional exhaled nitric oxide in occupational diseases - a systematic review

Fractional exhaled nitric oxide (FeNO) is a non-invasive biomarker of respiratory tract inflammation, originally designated to identify eosinophilic airway inflammation and to predict steroid response. The main field of application of this biomarker is asthma, but FeNO has also been used for other allergic and non-allergic pulmonary disorders such as chronic obstructive pulmonary disease, hypersensitivity pneumonitis and interstitial lung disease. A substantial part of respiratory diseases are related to work, and FeNO, a safe and easy measure to conduct, is a potential valid examination in an occupational setting.

This systematic review assesses the value of measuring FeNO related to three types of airborne exposures: allergens, irritants, and respiratory particles inhaled during occupational activities. The review covers results from longitudinal and observational clinical studies, and highlights the added value of this biomarker in monitoring effects of exposure and in the diagnostic criteria of occupational diseases. This review also covers the possible significance of FeNO as an indicator of the efficacy of interventions to prevent work-related respiratory diseases.

Initially, 246 articles were identified in PUBMED and SCOPUS. Duplicates and articles which covered results from the general population, symptoms (not disease) related to work, non-occupational diseases, and case reports were excluded. Finally, 39 articles contributed to this review, which led to the following conclusions:

a) For occupational asthma there is no consensus on the significant value of FeNO for diagnosis, or on the magnitude of change needed after specific inhalation test or occupational exposure at the workplace. There is some consensus for the optimal time to measure FeNO after exposure, mainly after 24 h, and FeNO proved to be more sensitive than spirometry in measuring the result of an intervention. b) For other occupational obstructive respiratory diseases, current data suggests performing the measurement after the work shift. c) For interstitial lung disease, the evaluation of the alveolar component of NO is probably the most suitable.

Fractional exhaled nitric oxide levels in relation to work-related respiratory burden and sensitization to wheat flour and multigrain in bakers

Background

Work‐related lower airway symptoms (WR‐LAS), rhinitis (WRR), and asthma (WRA) are very common among bakers, due to airborne exposure to wheat flour and multigrain. Limited data is available regarding fractional exhaled nitric oxide (FeNO) in bakers in relation to respiratory burden and occupational sensitization in a real‐life situation.

Objective

To analyze FeNO levels in relation to WRR, WR‐LAS, and WRA with regard to allergic sensitization to occupational allergen in bakers.

Methods

Cross‐sectional, observational study of 174 bakers employed in traditional small bakeries in the Verona District. Subjects did FeNO measurements, spirometry, methacholine challenge, and skin prick test to common inhalant aeroallergens and bakeries occupational allergens.

Results

FeNO levels were higher in subjects sensitized to occupational allergens compared with bakers not sensitized to occupational allergens (22.8 ppb (18.9, 27.6) vs. 12.0 ppb (9.9, 14.5), p < 0.05). FeNO levels were higher in bakers with WRR and occupational sensitization (25.4 (20.6, 31.3)) than in bakers with WRR without occupational sensitization compared and bakers without respiratory burden (13.4 (9.6, 18.6) and 11.9 (9.8, 14.5), both p < 0.001). Similar findings were found for WR‐LAS with regard to the same categories (31.2 (24.1, 40.4) vs 13.3 (11.4, 15.6) and 15.3 (8.5, 27.5), p < 0.001 and p = 0.005). Bakers with WRA, with or without occupational allergic sensitization, had higher levels of FeNO than bakers without respiratory burden (both p ≤ 0.001). These findings were consistent after adjustments for gender, age, height, weight, smoking, and sensitization to common inhalant aeroallergens and lung function.

Conclusions

WRR and lower airway symptoms in bakers sensitized to occupational allergens relate to increased FeNO. Our study suggests that FeNO is associated with work‐related allergic inflammation in occupational sensitized bakers, but future studies are needed to assess how FeNO should be integrated in the diagnostic work‐up of occupational disease in bakers.

Workplace-related inhalation test - Specific inhalation challenge: S2k Guideline of the German Society for Occupational and Environmental Medicine e.V. (DGAUM), the German Society for Pneumology and Respiratory Medicine e.V. (DGP) and the German Society for Allergology and Clinical Immunology e.V. (DGAKI)

Not available.

Occupational Respiratory Allergy: Risk Factors, Diagnosis, and Management

Occupational allergies are among the most common recorded occupational diseases. The skin and the upper and lower respiratory tract are the classical manifestation organs. More than 400 occupational agents are currently documented as being potential "respiratory sensitizers" and new reported causative agents are reported each year. These agents may induce occupational rhinitis (OR) or occupational asthma (OA) and can be divided into high-molecular weight (HMW) and low-molecular weight (LMW) agents. The most common occupational HMW agents are (glycol)proteins found in flour and grains, enzymes, laboratory animals, fish and seafood, molds, and Hevea brasiliensis latex. Typical LMW substances are isocyanates, metals, quaternary ammonium persulfate, acid anhydrides, and cleaning products/disinfectants. Diagnosis of occupational respiratory allergy is made by a combination of medical history, physical examination, positive methacholine challenge result or bronchodilator responsiveness, determination of IgE-mediated sensitization, and specific inhalation challenge tests as the gold standard. Accurate diagnosis of asthma is the first step to managing OA as shown above. Removal from the causative agent is of central importance for the management of OA. The best strategy to avoid OA is primary prevention, ideally by avoiding the use of and exposure to the sensitizer or substituting safer substances for these agents.

Occupational immediate type allergy to soapnut and quillaja bark

A 58-year-old non-atopic chemical worker complained about work-related asthma and rhinoconjunctivitis about 4 years after exposure to quillaja bark and soapnut. Bronchial hyperresponsiveness was demonstrated after withdrawal of medication for 12 hours. Skin prick tests with extracts from quillaja bark and soapnut from the workplace were positive, but ImmunoCAP was positive only with quillaja bark, probably due to the low protein content of the extract from soapnut. Sensitizations to quillaja bark and soapnut, but not to saponin were demonstrated by immunoblot. An inhalation test with a dosimeter was positive with the soapnut extract. A link between disease and exposure was documented by serial measurements of exhaled nitric oxide at and off work, despite preventive measures. A diagnosis of occupational allergy due to quillaja bark and soapnut was made. Further exposure reduction was recommended.