Workplace-related chronic cough on a mushroom farm

[Diagnosis and Treatment of Hypersensitivity Pneumonitis - S2k Guideline of the German Respiratory Society and the German Society for Allergology and Clinical Immunology]

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) in sensitized individuals caused by a large variety of inhaled antigens. The clinical form of acute HP is often misdiagnosed, while the chronic form, especially the chronic fibrotic HP, is difficult to differentiate from other fibrotic ILDs. The present guideline for the diagnosis and treatment of HP replaces the former German recommendations for the diagnosis of HP from 2007 and is amended explicitly by the issue of the chronic fibrotic form, as well as by treatment recommendations for the first time. The evidence was discussed by a multidisciplinary committee of experts. Then, recommendations were formulated for twelve questions on important issues of diagnosis and treatment strategies. Recently published national and international guidelines for ILDs and HP were considered. Detailed background information on HP is useful for a deeper insight into HP and the handling of the guideline.

A case of bunashimeji mushroom‐induced hypersensitivity pneumonitis diagnosed by inhalational provocation test in a hospital room

A 66‐year‐old woman was admitted to our hospital with a 2‐month history of dry cough and exertional dyspnea. She had worked as a mushroom farmer and had been exposed to mushroom for more than 40 years. The patient showed elevated levels of KL‐6 (2966 U/mL) and surfactant protein D (410 ng/mL), and computed tomography of the chest revealed ground‐glass opacities and fine nodular shadows in both lungs, suggesting mushroom‐induced hypersensitivity pneumonitis. Pulmonary function testing revealed decreases in forced vital capacity (78% of predicted) and carbon monoxide diffusing capacity (67% of predicted). The inhalational provocation test was positive for bunashimeji mushrooms. Precipitating antibody was only identified for spores or bodies of bunashimeji mushrooms, and lymphocyte stimulation testing with spores or bodies of bunashimeji mushrooms also yielded positive results. Bunashimeji mushroom‐induced hypersensitivity pneumonitis was therefore diagnosed. Radiological findings and pulmonary function were improved by corticosteroid therapy and the patient has since remained healthy with allergen avoidance.

Latino/a Farmworkers' Concerns about Safety and Health in the Pennsylvania Mushroom Industry

The purposes of this study were to analyze Latino/a immigrant mushroom workers' perceptions of how the workplace environment shapes occupational safety and health, examine whether and how those perceptions differ by gender, and identify future areas for research on occupational safety and health in the mushroom industry. Researchers conducted structured interviews with 15 women and 45 men on 6 Pennsylvania mushroom farms to obtain their descriptions and perspectives of safety and health risk factors in their workplaces. Approximately one third of respondents had suffered an injury at work, and nearly half felt that there are workplace factors that affect their health and safety. The study found that Latino/a mushroom farmworkers perceive risks that are posed by the indoor infrastructure of mushroom production houses, including poorly maintained wooden walkways and cool indoor temperatures, and by the organization of mushroom production work, including the application of chemicals including pesticides, physical demands of the job, use of small knives, contact with compost, and the piece rate payment system. Workers commonly discussed back pain and believed it was associated with the organization of work. Women in the sample were more likely to be concerned about slips and falls than men and less likely to be concerned about aches and pains. Mushroom farm infrastructure and the specific demands of the jobs pose occupational safety and health risks to Latino/a farmworkers that merit further study to develop adequate public health interventions. Future research should obtain gender-disaggregated objective reports of injury, aches and pains, and discomfort and test for relationships between these reports and the indoor infrastructure and conditions of mushroom production work.

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.

Hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a complex syndrome caused by the inhalation of a variety of antigens in susceptible and sensitized individuals. These antigens are found in the environment, mostly derived from bird proteins and fungi. The prevalence and incidence of HP vary widely depending on the intensity of exposure, the geographical area and the local climate. Immunopathologically, HP is characterized by an exaggerated humoral and cellular immune response affecting the small airways and lung parenchyma. A complex interplay of genetic, host and environmental factors underlies the development and progression of HP. HP can be classified into acute, chronic non-fibrotic and chronic fibrotic forms. Acute HP results from intermittent, high-level exposure to the inducing antigen, usually within a few hours of exposure, whereas chronic HP mostly originates from long-term, low-level exposure (usually to birds or moulds in the home), is not easy to define in terms of time, and may occur within weeks, months or even years of exposure. Some patients with fibrotic HP may evolve to a progressive phenotype, even with complete exposure avoidance. Diagnosis is based on an accurate exposure history, clinical presentation, characteristic high-resolution CT findings, specific IgG antibodies to the offending antigen, bronchoalveolar lavage and pathological features. Complete antigen avoidance is the mainstay of treatment. The pharmacotherapy of chronic HP consists of immunosuppressive drugs such as corticosteroids, with antifibrotic therapy being a potential therapy for patients with progressive disease.

Chitinases and Chitinase-Like Proteins in Obstructive Lung Diseases - Current Concepts and Potential Applications

Chitinases, enzymes that cleave chitin’s chain to low molecular weight chitooligomers, are widely distributed in nature. Mammalian chitinases belong to the 18-glycosyl-hydrolase family and can be divided into two groups: true chitinases with enzymatic activity (AMCase and chitotriosidase) and chitinase-like proteins (CLPs) molecules which can bind to chitin or chitooligosaccharides but lack enzymatic activity (eg, YKL-40). Chitinases are thought to be part of an innate immunity against chitin-containing parasites and fungal infections. Both groups of these hydrolases are lately evaluated also as chemical mediators or biomarkers involved in airway inflammation and fibrosis. The aim of this article is to present the current knowledge on the potential role of human chitinases and CLPs in the pathogenesis, diagnosis, and course of obstructive lung diseases. We also assessed the potential role of chitinase and CLPs inhibitors as therapeutic targets in chronic obstructive pulmonary disease and asthma.

Will nonasthmatic eosinophilic bronchitis develop into chronic airway obstruction?: a prospective, observational study

OBJECTIVE

The long-term prognosis of nonasthmatic eosinophilic bronchitis (NAEB) is still unclear. The aim of this study was to observe the frequency of relapse among patients with NAEB and the likelihood of NAEB developing into chronic airflow obstruction over time.

METHODS

Patients with NAEB were followed for at least 1 year between 2003 and 2013. During this period, we evaluated clinical symptoms, sputum eosinophil count, spirometry, and bronchial hyperresponsiveness. A linear mixed model was adopted to determine the relationship between time and lung function.

RESULTS

A total of 234 patients with NAEB were identified, of whom 141 were followed for > 1 year (median, 4.1 years). Up to 59.6% of patients had a relapse after treatment. Both allergic rhinitis (OR, 4.37; 95% CI, 1.049-18.203; P = .043) and sputum eosinophilia after 4 weeks of treatment with inhaled corticosteroids (OR, 9.493; 95% CI, 2.381-37.850; P = .001) were risk factors for relapse. Among the 141 patients, mild asthma developed in eight (5.7%). During the follow-up period, no progressive decline in FVC, FEV1, and FEV1/FVC were observed (P > .05). Although the proportion of small airway dysfunction (maximum midexpiratory flow [MMEF] < 65%) significantly increased at the last visit in all groups (all P < .05), only the relapse group showed an MMEF decline at the end of follow-up (P < .05) in the linear mixed model.

CONCLUSIONS

More than 50% of patients with NAEB have repeated episodes associated with persistent sputum eosinophilia after treatment and allergic rhinitis. In the current cohort, chronic airway obstruction does not develop despite small airway dysfunction increases over time.

The prevalence of respiratory symptoms among mushroom workers in Ireland

BACKGROUND

Respiratory conditions such as asthma, bronchitis, hypersensitivity pneumonitis and upper airways symptoms have been ascribed to fungal exposures. Mushroom workers may be at risk of these as a consequence.

AIMS

To assess the prevalence of respiratory symptoms in mushroom workers.

METHODS

A cross-sectional study assessed 4 weeks of respiratory symptoms among mushroom workers divided into four categories of exposure, using a self-administered respiratory questionnaire and spirometry.

RESULTS

The population of 191 subjects was predominantly (66%) from Eastern Europe; 61% were women and 39% were under 30. It included 73 growers, 38 composters, 26 administrators and 52 packers. Among all workers, there was a high prevalence (67%) of one or more respiratory symptoms which did not appear to vary by age, gender, pack-years of smoking or duration of employment. There was a significant improvement in respiratory symptoms in workers during absence from the workplace (P < 0.001). Spirometry readings across all groups were within normal values. Symptom profiles suggest that as many as 22 workers had symptoms of airways disease; 18 (82%) of these were mushroom growers. Growers were significantly more likely to have symptoms consistent with airways disease than all other workers, odds ratio 9.2 (95% CI 3.0-28.4).

CONCLUSIONS

There was a high prevalence of respiratory symptoms among mushroom workers. Mushroom growers may be at high risk of airways disease, possibly from fungal antigens or related exposures.

EAACI Position Paper on assessment of cough in the workplace

Cough is a nonspecific and relatively common symptom that can present difficulties in diagnosis and management, particularly when it is reported to be associated with the workplace. The present consensus document, prepared by a taskforce of the Interest Group on Occupational Allergy of the European Academy of Allergy and Clinical Immunology by means of a nonsystematic review of the current literature, is intended to provide a definition and classification of work-related chronic cough (WRCC) to assist the daily practice of physicians facing with this symptom. The review demonstrates that several upper and lower airway work-related diseases may present with chronic cough; hence, the possible link with the workplace should always be considered. Due to the broad spectrum of underlying diseases, a multidisciplinary approach is necessary to achieve a definite diagnosis. Nevertheless, more epidemiological studies are necessary to estimate the real prevalence and risk factors for WRCC, the role of exposure to environmental and occupational sensitizers and irritants in its pathogenesis and the interaction with both upper and lower airways. Finally, the best management option should be evaluated in order to achieve the best outcome without adverse social and financial consequences for the worker.

Irritant-induced airway disorders

Thousands of persons experience accidental high-level irritant exposures each year but most recover and few die. Irritants function differently than allergens because their actions proceed nonspecifically and by nonimmunologic mechanisms. For some individuals, the consequence of a single massive exposure to an irritant, gas, vapor or fume is persistent airway hyperresponsiveness and the clinical picture of asthma, referred to as reactive airways dysfunction syndrome (RADS). Repeated irritant exposures may lead to chronic cough and continual airway hyperresponsiveness. Cases of asthma attributed to repeated irritant-exposures may be the result of genetic and/or host factors.

Response to oyster mushroom (Pleurotus ostreatus) extract by sensitized and nonsensitized guinea pig trachea

Occupational exposure to oyster mushroom (Pleurotus ostreatus) has been associated with obstructive lung disease. Previously, we studied an extract of oyster mushroom (OME) and determined that it causes dose-dependent contractions of nonsensitized guinea pig trachea (GPT). We extend these studies to the investigation of sensitized tissue. In the present study 24 animals were sensitized using ovalbumin (OA) and subsequently challenged with an aerosol of 2.5% OA. A control group of 12 nonsensitized GPs was also studied. Tracheas were removed and were divided into rings in which the epithelium was retained (EP+) or removed (EP-). Dose-related contractions of sensitized and nonsensitized GPTs were elicited with OME. In nonsensitized animals the EP+ GPTs demonstrated a significantly greater response to OME (100-1000 μl) than did the EP- GPTs (p < 0.01). By contrast, in sensitized GPTs with and without epithelium there was no difference to challenge with OME. Finally, sensitized GPTs with and without epithelium and nonsensitized GPTs with epithelium responded similarly to challenge with OME. These findings suggest that in nonsensitized animals there is an enhancement of contractile response to OME which is in part mediated by the GPT epithelium. In sensitized animals with or without epithelium, the level of bronchoconstrictor response is similar to that of the nonsensitized animals with epithelium, suggesting an enhanced constrictor response independent of epithelium in the sensitized animals.

Noninvasive methods for assessment of airway inflammation in occupational settings

The present document is a consensus statement reached by a panel of experts on noninvasive methods for assessment of airway inflammation in the investigation of occupational respiratory diseases, such as occupational rhinitis, occupational asthma, and nonasthmatic eosinophilic bronchitis. Both the upper and the lower airway inflammation have been reviewed and appraised reinforcing the concept of 'united airway disease' in the occupational settings. The most widely used noninvasive methods to assess bronchial inflammation are covered: induced sputum, fractional exhaled nitric oxide (FeNO) concentration, and exhaled breath condensate. Nasal inflammation may be assessed by noninvasive approaches such as nasal cytology and nasal lavage, which provide information on different aspects of inflammatory processes (cellular vs mediators). Key messages and suggestions on the use of noninvasive methods for assessment of airway inflammation in the investigation and diagnosis of occupational airway diseases are issued.

Chronic cough – occupational considerations

Chronic cough is a common symptom in a wide range of respiratory conditions, and may also occur as a result of upper airway or gastro-esophageal problems. Whilst chronic cough of any cause may be exacerbated by work, in some cases it has a direct occupational cause, resulting from a harmful acute or chronic workplace exposure. Such occupational conditions may only be suspected by taking a detailed occupational history, and directly asking employed patients whether their cough improves away from work. Early and accurate diagnosis, linked with tailored drug therapy, modification of workplace exposures, and expert compensation advice is likely to offer the best outcome for this group of patients.

Diagnosis and management of work-related asthma: American College Of Chest Physicians Consensus Statement

BACKGROUND

A previous American College of Chest Physicians Consensus Statement on asthma in the workplace was published in 1995. The current Consensus Statement updates the previous one based on additional research that has been published since then, including findings relevant to preventive measures and work-exacerbated asthma (WEA).

METHODS

A panel of experts, including allergists, pulmonologists, and occupational medicine physicians, was convened to develop this Consensus Document on the diagnosis and management of work-related asthma (WRA), based in part on a systematic review, that was performed by the University of Alberta/Capital Health Evidence-Based Practice and was supplemented by additional published studies to 2007.

RESULTS

The Consensus Document defined WRA to include occupational asthma (ie, asthma induced by sensitizer or irritant work exposures) and WEA (ie, preexisting or concurrent asthma worsened by work factors). The Consensus Document focuses on the diagnosis and management of WRA (including diagnostic tests, and work and compensation issues), as well as preventive measures. WRA should be considered in all individuals with new-onset or worsening asthma, and a careful occupational history should be obtained. Diagnostic tests such as serial peak flow recordings, methacholine challenge tests, immunologic tests, and specific inhalation challenge tests (if available), can increase diagnostic certainty. Since the prognosis is better with early diagnosis and appropriate intervention, effective preventive measures for other workers with exposure should be addressed.

CONCLUSIONS

The substantial prevalence of WRA supports consideration of the diagnosis in all who present with new-onset or worsening asthma, followed by appropriate investigations and intervention including consideration of other exposed workers.

The Measurement and Health Impact of Endotoxin Contamination in Organic Dusts from Multiple Sources: Focus on the Cotton Industry

Endotoxin is derived from Gram-negative bacterial membranes, and its inflammatory effects following inhalation are well characterized. The significance of this fact becomes apparent when the wide-ranging environments containing high levels of this microbial product are considered. Endotoxin is present in numerous industrial environments, especially where organic fibers are processed. Microbial contamination of these fibers mainly occurs at the agricultural stage. Materials such as flax and hemp are affected in this way, but the most important product in this context is cotton, from which chronic dust inhalation causes the disease byssinosis. Despite the fact that endotoxin constitutes a significant threat to public health, there are currently no occupational exposure limits for this toxicant. This communication describes the toxicology of endotoxin, and its role in inhalation-induced disease, focusing on measurement of airborne endotoxin in the occupational and domestic environments using the Limulus amebocyte lysate (LAL) enzyme assay. Following the success of the LAL assay for measuring endotoxin in dusts, our laboratory has examined its application to aqueous washes from cotton fibers. Reproducibility of the results was high, and data are presented displaying levels of endotoxin contamination in fibers from different cotton producing countries. Hence, worldwide comparison of industrial endotoxin concentrations can be readily made using this test. It would be highly desirable if the performance of the LAL assay facilitated introduction of industrial endotoxin safety limits, and in spite of minor surmountable shortcomings, the test is accurate, reliable, and well field-tested, so its continued widespread use may achieve this goal.

Induced sputum and exhaled nitric oxide as noninvasive markers of airway inflammation from work exposures

PURPOSE OF REVIEW

Noninvasive measures of airway inflammation are increasingly used in the investigation and management of asthma. Their role in the investigation of occupational lung diseases, however, is not as clearly established. The present article reviews the use of noninvasive methods - induced sputum and exhaled nitric oxide - in the assessment of airway inflammation during the investigation of occupational asthma and eosinophilic bronchitis, and reviews studies investigating the effect of exposure to various occupational agents on airway inflammation in healthy individuals.

RECENT FINDINGS

A number of studies have confirmed the association between exposure to occupational agents and the presence of eosinophilic airway inflammation after that exposure in individuals with occupational asthma. Individuals with positive specific inhalation challenges to occupational agents seem to show a greater increase in exhaled nitric oxide than those with negative specific inhalation challenges. Exposure to various agents associated with an increase in exhaled nitric oxide mainly induced a neutrophilic inflammation.

SUMMARY

Increasing evidence supports the use of induced sputum as an additional tool in the investigation of occupational asthma. The role of exhaled nitric oxide in the investigation of occupational asthma needs to be clarified due to conflicting evidence reported in the literature.

Occupational eosinophilic bronchitis in a foundry worker exposed to isocyanate and a baker exposed to flour

Eosinophilic bronchitis without asthma may occur as a consequence of occupational exposure. The cases of a foundry worker and a baker who developed symptoms, respectively, due to exposure to isocyanate and flour, are reported. Cough was not associated with variable airflow obstruction or with airway hyper-responsiveness and was responsive to inhaled corticosteroids. The eosinophilia detectable in their sputum was causally related to the occupational exposure in the workplace. The examination of induced sputum should be used in addition to the objective monitoring of lung function for workers who have asthma-like symptoms in an occupational setting.

Occupational asthma in industry

Occupational or professional asthma is defined as adult asthma, i.e., an inflammatory respiratory disease characterized by the presence of variable airflow limitation or bronchial hyperreactivity secondary to conditions and causes associated with a given occupational or working environment - not with stimuli found outside the workplace. Depending on the physiopathological mechanism involved, a distinction is made between immune asthma (with or without IgE mediation) and non-immune asthma. It is difficult to establish the relationship among the symptoms of asthma, the patient's professional activity and the presence or absence of sensitization to certain agents in the working environment. Guided compilation of the case history and measurement of nonspecific bronchial hyperreactivity and bronchial inflammation are currently essential in the diagnostic approach to occupational asthma. Whenever possible, allergists should establish the cause-effect relationship in occupational asthma, as required by the medical-legal and social implications of the disease. Occupational asthma remains a minority diagnosis among occupational diseases in general. Adequate personnel training and the creation of diagnostic centers may help to ensure correct and rapid detection of this disease.

Diagnosing occupational asthma: insight from induced sputum

The diagnosis of occupational asthma needs to be made objectively using as many criteria as possible. The latter include laboratory exposure tests with occupational agent(s), which are only available in specialized centers. Another approach is to monitor peak expiratory flow (PEF) and (or) methacholine airway responsiveness during periods at work and away from work. However, these measurements are open to misinterpretation when they are not optimally performed. Airway inflammation is one of the main characteristics of asthma. Induced sputum, a non-invasive method to assess airway inflammation, has been successfully used in the management of asthma. However, airway inflammation is seldom assessed during the investigation of occupational asthma. This article reviews the studies that have investigated and characterized the changes in sputum cell counts occurring in subjects with occupational asthma after exposure to occupational agents in the laboratory, or at the workplace to assess to place of induced sputum in the investigation of occupational asthma.

Endotoxin and occupational airway disease

PURPOSE OF REVIEW

This review provides an update on the role of bacterial endotoxin in occupational airway disease, a problem of importance from diagnostic and preventive points of view.

RECENT FINDINGS

Data from human inhalation studies have increased our understanding of the cell mechanisms underlying diseases related to endotoxin exposure. In addition, knowledge from molecular genetics may help us to identify individuals at risk. Several investigations have demonstrated that, apart from endotoxin, other microbial cell wall agents are also related to the risk for symptoms of occupational lung diseases, with pathogenic mechanisms different to those caused by endotoxin. Diagnostic methods have progressed from traditional lung function measurements to sampling of indicators of inflammation in the blood, nasal lavage and induced sputum. Investigations of a longitudinal design have provided important findings on the relationship between acute and chronic effects as well as exposures of risk and risk factors among individuals.

SUMMARY

Endotoxin, as well as other agents derived from microbes, are important causative agents for occupational respiratory and other diseases, and exposure may occur in a large variety of occupational environments. Recent data from longitudinal studies provide important information on diagnostic and preventive measures.

Chronic cough due to occupational factors

Within the large variety of subtypes of chronic cough, either defined by their clinical or pathogenetic causes, occupational chronic cough may be regarded as one of the most preventable forms of the disease. Next to obstructive airway diseases such as asthma or chronic obstructive pulmonary disease, which are sometimes concomitant with chronic cough, this chronic airway disease gains importance in the field of occupational medicine since classic fiber-related occupational airway diseases will decrease in the future.

Apart from acute accidents and incidental exposures which may lead to an acute form of cough, there are numerous sources for the development of chronic cough within the workplace. Over the last years, a large number of studies has focused on occupational causes of respiratory diseases and it has emerged that chronic cough is one of the most prevalent work-related airway diseases. Best-known examples of occupations related to the development of cough are coal miners, hard-rock miners, tunnel workers, or concrete manufacturing workers.

As chronic cough is often based on a variety of non-occupational factors such as tobacco smoke, a distinct separation into either occupational or personally -evoked can be difficult. However, revealing the occupational contribution to chronic cough and to the symptom cough in general, which is the commonest cause for the consultation of a physician, can significantly lead to a reduction of the socioeconomic burden of the disease.

Hypersensitivity Pneumonitis due to Bunashimeji Mushrooms in the Mushroom Industry

BACKGROUND

Detection of hypersensitivity pneumonitis (HP) in employees involved in the Bunashimeji mushroom industry is difficult. The level of precipitating antibody is not related with the prediction of progression and resolution of HP. The aims of this study were to examine the actual prevalence of HP in the Bunashimeji industry and the clinical differences among selected employees.

METHODS

One hundred and fourteen employees worked in Bunashimeji enterprises. These subjects were divided into the following subgroups: office workers, pickers/packers with mask and pickers/packers without mask. We measured serum Krebs von der Lungen-6 (KL-6), surfactant protein (SP)-A and SP-D, and examined the stimulation index (SI) due to Bunashimeji spores. Chest high-resolution computed tomography (HRCT), pulmonary function tests and bronchoalveolar lavage (BAL) were performed for select employees who showed positive SI values (>200%) to examine the clinical differences.

RESULTS

The proportion of respiratory symptoms was significantly higher in the pickers/packers than that in the office workers. The picker/packer group had high serum KL-6 concentrations and SI compared with the office worker group. Thirty select employees were divided into the following three subgroups: HP, select employees without HP, and SI <400% and KL-6 <500 U/ml , using high SI levels (>400%) and positive serum KL-6 concentration (>500 U/ml). Four exhibited ground glass opacities with centrilobular fine nodules on HRCT, and 8 had high numbers of lymphocytes in the BAL fluid. The BAL findings and serum KL-6 concentrations showed significant differences among the three groups.

CONCLUSIONS

Four employees were evaluated as having HP. Serum KL-6 and SP-D may be related to the resolution of HP in addition to SI and chest HRCT.

HLA class II DPB1, DQA1, DQB1, and DRB1 genotypic associations with occupational allergic cough to Bunashimeji mushroom

We previously reported that two-third of workers in a Bunashimeji mushroom (Hypsizigus marmoreus) farm complained of respiratory allergic symptoms, but one-third workers did not suffer from such symptoms even when working for a long period. CD4+ T-helper (Th) cells increased, and Th2/Th1 ratio increased in the allergic workers. To address these immunological backgrounds, we have investigated whether there is any relationship between mushroom allergy and human leukocyte antigen (HLA) class II alleles of DPB1, DQA1, DQB1, and DRB1 by using the polymerase chain reaction-restriction fragment length polymorphism (RFLP) and sequencing-based typing methods. We observed that the allele frequencies of DQA1*0103, DQB1*0601, and DRB1*0803 were significantly higher in the workers having no allergic symptoms than allergic workers (DQA1*0103: 57 vs 25%, DQB1*0601: 49 vs 14%, and DRB1*0803: 29 vs 0%). However, this phenomenon was not seen in workers producing another kind of mushroom, Honshimeji (Lyophyllum aggregatum). The HLA-DRB1*0803 allele alone, the DRB1*0803, DQA1*0103, DQB1*0601 haplotype, or both were negatively associated with allergy to Bunashimeji, and these alleles might be involved in the prevention of Bunashimeji mushroom-specific respiratory allergy.

Hypersensitivity Pneumonitis Associated with Mushroom Worker’s Lung: An Update on the Clinical Significance of the Importation of Exotic Mushroom Varieties

Hypersensitivity pneumonitis remains an important industrial disease in mushroom workers. It has a significant morbidity, and early diagnosis and removal from exposure to the antigen are critically important in its management. Recently, several new allergens have been described, particularly those from mushroom species originating in the Far East, which are of clinical significance to workers occupationally exposed to such allergens in cultivation, picking, and packing of commercial mushroom crops. Importing of exotic mushrooms including Shiitake is common in EU countries, and some of the exotic species of mushrooms are cultivated for local markets. This practice may contribute to an increase in clinical cases of mushroom hypersensitivity pneumonitis. This update reviews the recent literature and examines changing trends of mushroom worker's lung, with increased movement of commercial product and labour markets worldwide.

Pharmacological Study of Oyster Mushroom (Pleurotus Ostreatus) Extract on Isolated Guinea Pig Trachea Smooth Muscle

Mushroom farm workers suffer from respiratory symptoms during the farming of mushrooms. The objective of this study was to analyze the effects of oyster mushroom (Pleurotus ostreatus) extract (OME) on isolated guinea pig tracheal smooth muscle in vitro. Isolated guinea pig tracheal tissue from 27 nonsensitized guinea pigs were studied. The OME was obtained from indoor mushroom growing fields and prepared as a 1:10 w/v aqueous solution. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using these extracts. The OME contained significant quantities of bacterial components (eg., endotoxin: 43,072.92 EU/mg). Parallel, pharmacological studies were performed by pre-treating the tissues with mediator-modifying agents including atropine, indomethacin, pyrilamine, BPB, acivicin, NDGA, captopril, TMB8 and capsaicin. Atropine consistently and strikingly reduced the contractile effects of this extract. These observations suggest an interaction of the OME with parasympathetic nerves or more directly with muscarinic receptors. Pretreatment with TMB8 (inhibitor of intracellular calcium mobilization) also significantly blocked the constrictor effect of OME, indicating a role of calcium mobilization in the constricting effect of OME. Inhibition of contraction by blocking of other mediators was less effective and varied depending on the drug. We conclude that OME causes a dose-related airway smooth muscle constriction by nonimmunological mechanisms involving a variety of airway mediators and possibly cholinergic receptors. This effect is not dependent on pre-sensitization of the guinea pigs.

Eosinophilic bronchitis in the workplace

PURPOSE OF REVIEW

The purpose of this review is to report that eosinophilic bronchitis without asthma may occur as an occupational airway disease. This condition is characterized by cough that is responsive to corticosteroids and eosinophilia detectable in the sputum, without variable airflow obstruction or airway hyperresponsiveness.

RECENT FINDINGS

Eosinophilic bronchitis can be regarded as an occupational respiratory disorder when it develops as a consequence of work exposures. Recently, exposure to certain occupational allergens or sensitizers, such as natural rubber latex, mushroom spores, acrylates and an epoxy resin hardener, have been reported to cause eosinophilic bronchitis without asthma. Several hypotheses have been put forward trying to explain why patients with eosinophilic bronchitis do not have airway hyperresponsiveness. It is unknown whether eosinophilic bronchitis may progress to typical occupational asthma, or if eosinophilic airway inflammation may persist when asthma symptoms and airway hyperresponsiveness have waned after the cessation of exposure to the occupational agent.

SUMMARY

Eosinophilic bronchitis, like asthma, may arise from occupational exposures. The examination of induced sputum should be added to the objective monitoring of lung function during periods at work and away from work, as well as before and after specific inhalation challenges with occupational agents.