Noninvasive methods for assessment of airway inflammation in occupational settings

Occupational exposure to petroleum products and respiratory health: a cross-sectional study from Algeria

OBJECTIVE

To investigate the possible impact of long-term occupational exposure to hydrocarbons on respiratory health.

METHODS

Respiratory health was assessed by questionnaires, spirometry, and exhaled nitric oxide in 250 male workers from a company handling and distributing refined petroleum products (exposed) and 250 electricians (controls). Exposure to hydrocarbons was assessed by personal air monitoring.

RESULTS

Aerial exposure to hydrocarbons was low. Respiratory and nasal symptoms were significantly more frequent among exposed subjects than among controls. Although forced vital capacity and forced expiratory volume in 1 second did not differ, ratio of forced expiratory volume in 1 second to forced vital capacity and maximal expiratory flows were significantly lower in exposed than in control subjects, adjusting for smoking. Exhaled nitric oxide was significantly higher among exposed subjects (30.1 ppb) than among controls (21.6 ppb), adjusting for age and smoking.

CONCLUSIONS

Even low exposure to petroleum-derived hydrocarbons is associated with more respiratory and nasal symptoms, lower pulmonary function, and airway inflammation.

Current management options for hereditary angioedema

The aim of treatment of hereditary angioedema (HAE) due to C1 esterase inhibitor deficiency (HAE-C1-INH) is either treating acute attacks or preventing attacks by using prophylactic treatment. For treating acute attacks, plasma-derived C1 inhibitor (C1-INH) concentrates, a bradykinin B2 receptor antagonist, and a recombinant human C1-INH are available in Europe. In the United States, a plasma-derived C1-INH concentrate, a bradykinin B2 receptor antagonist, and a plasma kallikrein inhibitor have been approved. Fresh frozen plasma is also available for treating acute attacks. Short-term prophylactic treatment focuses on C1-INH and attenuated androgens. Long-term prophylactic treatments include attenuated androgens such as danazol, stanozolol, and oxandrolone, antifibrinolytics, and a plasma-derived C1-INH concentrate. Plasma-derived C1-INH and a bradykinin B2 receptor antagonist are permitted for self-administration and home therapy. The number of management options has increased considerably within the last few years, thus helping to diminish the burden of HAE.

Mould sensitisation among bakers and farmers with work-related respiratory symptoms

Fungi belong to common allergens, which can be found both in occupational and non-occupational environment. The aim of the study was to determine the frequency and factors associated with mould allergy among bakers and farmers reporting work-related respiratory symptoms. The study group comprised 117 bakers and 83 farmers reporting work-related respiratory symptoms. Skin prick tests (SPT) with common, fungal and occupational allergens, estimation of serum total IgE level, spirometry, histamine test and specific inhalative challenge test with occupational allergens were performed in all subjects. The prevalence of hypersensitivity to fungal species was higher among farmers (32.5%) than bakers (16.2%). Positive SPT with mould allergens were found among 10.8% farmers and 6.8% bakers with occupational allergy. The fungi allergens giving positive SPT results most frequently were Candida albicans, Levures mélanges, Aspergillus mix. and Charbons cerealiers in both groups. Among mould allergens, hypersensitivity to Aspergillus genus was the most common in farmers and bakers group, while among Saccharomyces - Candida albicans sensitization was the most frequently detected. Mould hypersensitivity is related to occupational respiratory allergy, especially to asthma and rhinitis in farmers, and occupational asthma in bakers. Although sensitization to Saccharomyces was more frequent, similar correlation was not observed.

Induced sputum, exhaled NO, and breath condensate in occupational medicine

OBJECTIVE

Studies of fractional exhaled NO (FeNO) or induced sputum are now well standardized and the exponential increase in publications about exhaled breath condensate reflects growing interest in a noninvasive diagnosis of pulmonary diseases in occupational medicine.

METHODS

This review describes current techniques (FeNO, induced sputum, and exhaled breath condensate) for the study of inflammation and oxidative stress biomarkers.

RESULTS

These biomarkers are FeNO, cytokines, H2O2, 8-isoprostane, malondialdehyde, and nitrogen oxides. These techniques also include the study of markers of the toxic burden in the lungs (heavy metals and mineral compounds) that are important in occupational health exposure assessment.

CONCLUSIONS

In occupational medicine, the study of both volatile and nonvolatile respiratory biomarkers can be useful in medical surveillance of exposed workers, the early identification of respiratory diseases, or the monitoring of their development.

Work-related airway symptoms, nasal reactivity and health-related quality of life in female hairdressers: a follow-up study during exposure

Objectives

Hairdressers often complain of work-related rhinitis (WR). They are infrequently sensitized to persulphates. The cause and mechanism of the symptoms and the effects on their health-related quality of life (HRQoL) remains unclear. The objectives were to follow female hairdressers with WR mainly from bleaching powder regarding nasal reactivity to persulphate and to evaluate symptoms, HRQoL and inflammatory markers in nasal lavage during a working period after vacation and compared with hairdressers without symptoms and pollen allergic women.

Methods

Skin prick tests to persulphate were performed in the hairdressers. Participants kept a diary of symptoms and of work tasks (hairdressers only). They completed HRQoL questionnaires. Eosinophil cationic protein (ECP) in nasal lavage fluid was examined. The symptomatic hairdressers performed nasal challenges with persulphate before and after the exposure.

Results

Skin prick tests were negative. Although the nasal reactivity to persulphate did not change a steady increase in nasal symptoms, especially blockage, and in ECP was noticed in the symptomatic hairdressers. The HRQoL deteriorated in the symptomatic hairdressers indicating an effect on their working situation and daily life. The atopics had more, but varying symptoms (itching, sneezing and secretion).

Conclusions

The difference in the clinical picture between the symptomatic hairdressers and the pollen allergic women, the increase in symptoms and ECP in the nasal lavage support the view that a sensitization to hairdresser chemicals by a mechanism not yet understood is operating. The deterioration of the HRQoL in the symptomatic hairdressers indicates a considerable effect on their life.

Fractional exhaled nitric oxide among cement factory workers: a cross sectional study

BACKGROUND

It has been suggested that dust exposure causes airway inflammation among cement factory workers. However, there is limited information on the mechanisms of this effect. We explored any associations between total dust exposure and fractional exhaled nitric oxide (FENO) as a marker of airway eosinophilic inflammation among cement production workers in Tanzania. We also examined possible differences in FENO concentration between workers in different parts of the production line.

METHODOLOGY

We examined 127 cement workers and 28 controls from a mineral water factory. An electrochemistry-based NIOX MINO device was used to examine FENO concentration. Personal total dust was collected from the breathing zone of the study participants using 37 mm cellulose acetate filters placed in three-piece plastic cassettes. Interviews on workers' background information were conducted in the Swahili language.

RESULTS

We found equal concentrations of FENO among exposed workers and controls (geometric mean (GM)=16 ppb). The GM for total dust among the exposed workers and controls was 5.0 and 0.6 mg/m(3), respectively. The FENO concentrations did not differ between the exposed workers with high (GM≥5 mg/m(3)) and low (GM<5 mg/m(3)) total dust exposure. There was no significant difference in FENO concentration between workers in the two main stages of the cement production process.

CONCLUSIONS

We did not find any difference in FENO concentration between dust-exposed cement workers and controls, and there were similar FENO concentrations among workers in the two main stages of cement production.

Occupational non-immediate type allergic asthma due to ammonium persulfate

While numerous cases of immediate-type occupational asthma due to persulfates with positive skin prick test reactions to ammonium persulfate are well documented, few non-immediate type reactions have been described in the literature. We report the case of an atopic worker who developed work-related asthmatic symptoms shortly after he began his job in persulfate production. The diagnosis of asthma was corroborated by methacholine testing. The patient showed a positive patch test reaction to ammonium persulfate, while skin prick test was negative. He presented an isolated late symptomatic airway obstruction after a cumulative dose of 0.6 mg ammonium persulfate administered by a dosimeter method. An immunologic mechanism was demonstrated by a significant increase in exhaled nitric oxide and the number of eosinophils in induced sputum. These findings suggest that isolated late bronchial reactions to persulfates are mediated by eosinophilic inflammatory responses.

Occupational immediate-type allergic asthma due to potassium tetrachloroplatinate in production of cytotoxic drugs

Allergic immediate-type reactions by halogenated compounds of platinum (Pt) (platinum salts) have been described in workers in precious metal refineries and catalyst productions. In both industries there are exposures to many different Pt compounds. It is believed that the most important allergens are those compounds with the highest number of halide ligands. It is unknown whether sensitizations to compounds with a lower number of halide ligands represent co-sensitizations or are due to cross-reactivity. We report a worker engaged in the production of cytotoxic drugs with occupational asthma and exposure to only one Pt salt with four halide ligands. The 22-year-old worker developed work-related sneezing, runny nose, and variable dyspnea about a year after he had started to work in the cytotoxic drugs production with exposure to potassium tetrachloroplatinate(II) (K(2)PtCl(4)). He was immediately removed from his workplace and admitted for a medical opinion about 6 months afterwards. Spirometry was normal, but asthma was corroborated by a positive response to methacholine. The results of skin prick testing could not be interpreted due to urticaria factitia. Challenge with K(2)PtCl(4) by a dosimeter method yielded a clear immediate-type reaction with an increase of exhaled nitric oxide from 32 to 156 ppb after 24 h indicating an increased airway inflammation. Pt salts with four halide ligands like K(2)PtCl(4) may cause an allergic immediate-type reaction and occupational asthma. Workers in the production of Pt-containing cytotoxic drugs with exposure to these substances should be included in medical surveillance programs for the prevention of occupational asthma caused by Pt salts.

Comparison of different non-invasive methods for detection of allergic asthma

Non-invasive methods to assess inflammation of lower airways are induced sputum (IS), exhaled nitric oxide (eNO), and exhaled breath condensate (EBC). Here we focused on the assessment of airway inflammation with a panel of non-invasive methods in health care workers (HCWs) with suspected latex allergy with and without current allergic respiratory symptoms about 10 years after the latex ban in German health care facilities. Seventy-seven non-smoking subjects were examined by skin prick test and specific IgE measurements, eNO, IS, and EBC. Sensitivity, specificity, and positive and negative predicted values for relevant biomarkers were calculated using current asthma symptoms as the gold standard. Twenty-nine subjects (38%) reported ongoing asthmatic symptoms (AS). In these subjects the EBC concentrations of nitrogen oxides (NO(x); p=0.027) and leukotriene B(4) (p=0.025) were significantly higher than in subjects without AS. In addition, in the subjects with AS the numbers of eosinophils (p=0.015) and the concentrations of IL-5 (p= 0.021) in IS samples were significantly higher than in the subjects without AS. A good correlation between several inflammatory markers in IS was detected. The maximum Youden Index was reached for IS total eosinophils ≥3.5·10(4) with a test efficiency of 0.72. In conclusion, non-invasive inflammatory monitoring with EBC and IS may assist the diagnosis of allergic asthma. Self-reported current asthmatic symptoms were reflected by eosinophilic inflammation and the best parameter to support the asthma diagnosis is a total number of eosinophils ≥3.5·10(4) in IS.

[Workplace-related respiratory allergies. Current developments]

It is common that the inhalation of occupational allergens induces occupational airway diseases, but the inducers are diverse and complex, and the pathomechanism of the disease is not clear in every case. Only few allergens have been studied in detail (e.g., wheat flour and natural rubber latex), and most of the occupational airway sensitizers have only been documented as case reports. This review describes occupational type I aeroallergens according to their source (plant, animal, microbial, and chemical) and workplace application area. New aspects on the diagnosis and legal preventive regulations for occupational allergic airway diseases are described.

Utility of exhaled breath condensate pH for diagnosing occupational asthma

INTRODUCTION

The current reference standard method for diagnosing occupational asthma (OA) is specific inhalation challenge (SIC) with the suspected agent. The alternative method is serial peak expiratory flow (PEF) monitoring. Nevertheless, PEF does not have optimal sensitivity and specificity for this purpose. The aim of this study was to evaluate the utility of exhaled breath condensate (EBC) pH for the diagnosis of OA.

MATERIAL AND METHODS

A prospective study was performed in 37 subjects with suspected OA. Serial PEF monitoring was carried out for 2 weeks at work and for 2 weeks off work. At the end of each period, the EBC pH and the methacholine concentration resulting in a 20% FEV(1) decrease (PC20) were measured. SIC was subsequently performed. PEF graphs were interpreted visually by 3 experienced independent readers.

RESULTS

Seventeen patients tested positive with SIC. Receiver-operating characteristic curves showed that a decrease in EBC pH greater than 0.4 units during the period at work compared to the off-work period achieved the most satisfactory sensitivity (40%, CI 19.4-66.5) and specificity (90%, CI 66.9-98.2) for diagnosing OA. When EBC pH findings were added to PEF results, the diagnostic yield of PEF generally increased. Other test combinations (e.g. EBC pH plus PC20 or EBC pH plus PC20 plus PEF) did not improve diagnostic performance.

CONCLUSIONS

Acidification of EBC pH at work and adding the EBC pH measurement to PEF monitoring during periods at work and off work may be useful for improving the diagnosis of OA.

Metal-induced asthma and chest X-ray changes in welders

OBJECTIVES

The aim of this study was to evaluate the coexisting factors and usefulness of diagnostic methods in metal-induced asthma in Polish welders.

MATERIALS AND METHODS

Examination of 50 welders occupationally exposed to metals and with suspicion of metal-induced asthma (group A), 100 welders occupationally exposed to metals but without suspicion of metal-induced asthma (group B), and two control groups (10 patients with atopic asthma and 10 healthy subjects) was carried out. Questionnaire survey, clinical examination, skin prick tests to common aeroallergens and metal salts, rest spirometry tests, X-ray, metacholine challenge and a single-blind, placebo controlled specific inhalation challenge tests with metals (or work-like conditions challenge tests) were performed.

RESULTS

In group A--in 9 cases we obtained positive results of specific inhalation challenge tests with metals (in 3 cases with nickel, in 4 cases with chromium, in 1 case with cobalt and in 1 case with manganese). Nine cases of metal-induced occupational asthma were recognized. In group B--only in one case we obtained positive results of work-like conditions challenge test (clinical and spirometry changes, eosinophil influx in induced sputum), which confirmed the diagnosis of occupational asthma. In most of examined welders (62%), pulmonary changes in chest X-ray images were noted. The statistical analysis revealed that working as a welder for more than 10 years is the coexisting factor of presence of chest X-ray changes (p- or q-type nodular changes or interstitial changes). Positive results of skin prick tests with metal salts were the coexisting factors of occupational asthma due to metals among examined group of welders.

CONCLUSIONS

Specific inhalation challenge plays the key role in diagnostics of metal-induced asthma in welders. Pulmonary changes in chest X-ray were found in a significant percentage of examined welders.

[Respiratory allergens and asthma exacerbation]

INTRODUCTION

Asthma exacerbations are characterized by a progressive aggravation of respiratory symptoms such as dyspnea, cough, wheezing or chest tightness.

BACKGROUND

The relationship between allergy and asthma exacerbations has been evaluated by epidemiological studies based on various criteria such as oral corticosteroid requirement, emergency room visits and hospital admission for asthma. Many studies have observed that deteriorating asthma can be related to increased exposure to allergens, particularly allergens from house dust mite, cockroach, cat, rodent, mold or pollen. Several studies have demonstrated that sensitization to respiratory allergens and allergen exposure increases the risk of exacerbation of asthma. When asthma exacerbations are work-related, occupational allergens may be implicated.

CONCLUSIONS AND PERSPECTIVES

Most studies provide evidence that allergen exposure contributes to the risk of asthma exacerbations, but other precipitating factors, such as viruses, can interact and increase the risk.

Occupational asthma: new low-molecular-weight causal agents, 2000-2010

Background. More than 400 agents have been documented as causing occupational asthma (OA). The list of low-molecular-weight (LMW) agents that have been identified as potential causes of OA is constantly expanding, emphasizing the need to continually update our knowledge by reviewing the literature. Objective. The objective of this paper was to identify all new LMW agents causing occupational asthma reported during the period 2000-2010. Methods. A Medline search was performed using the keywords occupational asthma, new allergens, new causes, and low-molecular-weight agents. Results. We found 39 publications describing 41 new LMW causal agents, which belonged to the following categories: drugs (n = 12), wood dust (n = 11), chemicals (n = 8), metals (n = 4), biocides (n = 3), and miscellaneous (n = 3). The diagnosis of OA was confirmed through SIC for 35 of 41 agents, peak expiratory flow monitoring for three (3) agents, and the clinical history alone for three (3) agents. Immunological tests provided evidence supporting an IgE-mediated mechanism for eight (8) (20%) of the newly described agents. Conclusion. This paper highlights the importance of being alert to the occurrence of new LMW sensitizers, which can elicit OA. The immunological mechanism is explained by a type I hypersensitivity reaction in 20% of all newly described LMW agents.

EAACI consensus statement for investigation of work-related asthma in non-specialized centres

Work-related asthma (WRA) is a relevant problem in several countries, is cause of disability and socioeconomic consequences for both the patient and the society and is probably still underdiagnosed. A correct diagnosis is extremely important to reduce or limit the consequences of the disease. This consensus document was prepared by a EAACI Task Force consisting of an expert panel of allergologists, pneumologists and occupational physicians from different European countries. This document is not intended to address in detail the full diagnostic work-up of WRA, nor to be a formal evidence-based guideline. It is written to provide an operative protocol to allergologists and physicians dealing with asthma useful for identifying the subjects suspected of having WRA to address them to in-depth investigations in a specialized centre. No evidence-based system could be used because of the low grade of evidence of published studies in this area, and instead, 'key messages' or 'suggestions' are provided based on consensus of the expert panel members.

Definitions and classification of work-related asthma

The workplace can trigger or induce asthma and cause the onset of different types of work-related asthma (WRA). Based on current knowledge of clinical features, pathophysiologic mechanisms, and evidence supporting a causal relationship, the following conditions should be distinguished in the spectrum of WRA: (1) immunologic occupational asthma (OA), (2) nonimmunologic OA, (3) work-exacerbated asthma, and (4) variant syndromes, including eosinophilic bronchitis, potroom asthma, and asthmalike disorders caused by organic dusts. The rationale, issues, and controversies relating to this approach are critically reviewed to stimulate the development of a consensus on operational definitions of the various phenotypes of WRA.

Clinical assessment of occupational asthma and its differential diagnosis

Occupational asthma (OA) is defined as asthma caused by sources and conditions attributable to a particular occupational environment and not to stimuli encountered outside the workplace. Two types of OA are distinguished based on their appearance after a latency period or not. The most frequent type appears after a latency period leading to sensitization; the clinical assessment of this type of OA is the topic of this review. The differential diagnosis of OA is also reviewed, including work-exacerbated asthma, eosinophilic bronchitis, hyperventilation syndrome, vocal cord dysfunction, bronchiolitis, and other causes of dyspnea or cough.

Diagnostic utility of exhaled breath condensate analysis in conjunction with specific inhalation challenge in individuals with suspected work-related asthma

BACKGROUND

Establishing the role of exhaled breath condensate (EBC) analysis in work-related asthma (WRA), and more specifically, in conjunction with specific inhalation challenge (SIC), is difficult.

OBJECTIVE

To measure EBC pH, and nitrite/nitrate concentrations before and after SIC in individuals with suspected WRA exposed to either high-molecular-weight (HMW) or low-molecular-weight (LMW) agents and evaluate whether these changes are useful to distinguish between occupational asthma (OA) and work-exacerbated asthma (WEA).

METHODS

One hundred twenty-five consecutive workers undergoing SIC were enrolled. Exhaled breath condensate was collected at the end of the baseline day and 24 hours after exposure to the offending agent. In all EBC samples, pH was measured, and nitrite and nitrate concentrations were determined.

RESULTS

Specific inhalation challenge was positive in 66 individuals, who were then diagnosed with OA. Work-exacerbated asthma was diagnosed in 14, and in 45 patients establishing a direct relationship between the symptoms and work exposure was not possible. In patients with WEA, EBC pH values after SIC were significantly lower than those before SIC (P = .0047). Using the receiver operating characteristic (ROC) curve, we found that an EBC pH decrease of greater than 0.4 units after SIC achieved the most satisfactory sensitivity 79% (confidence interval [CI]: 49-94) and specificity of 100% (CI: 68-100), considering only patients with asthma and without OA. A decrease in EBC pH of 0.4 or more common in those exposed to HMW agents (8/19, 42%) than in those exposed to LMW agents (7/47, 15%).

CONCLUSIONS

Exhaled breath condensate pH in conjunction with SIC may be useful for diagnosing WEA.

Changes in exhaled nitric oxide levels after bronchial allergen challenge

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a marker of inflammation of the airways accompanying changes in the clinical condition of asthma. Allergen exposure has been associated with a delayed elevation of FeNO. The aim of this study was to assess airway inflammation with FeNO measurements during bronchial allergen challenge (BAC), and to determine the diagnostic performance of FeNO changes.

METHODS

Thirty-four patients with asthma and sensitization to inhalant allergens were studied. BAC with common or high-molecular-weight occupational aeroallergens was performed. FeNO was measured before and 24 h after BAC. Receiver operating characteristics curve was built to assess the sensitivity and specificity of increase in FeNO levels associated with BAC outcome.

RESULTS

In 21 patients (61.76%) a positive asthmatic reaction (responders) was observed. A significant increase in postchallenge FeNO was observed in this group of patients compared to the group of nonresponders. A median increase (FeNO postchallenge-FeNO prechallenge) of 14.0 ppb was observed in the group of responders, whereas a -1.0 ppb change was attained in the nonresponder group (P < 0.001). The cutoff point providing maximal sensitivity and specificity for %ΔFeNO after BAC was 12%. This change in FeNO levels has a sensitivity of 0.81 and a specificity of 0.92 for predicting a positive outcome in the BAC.

CONCLUSION

FeNO measurements can be used as a surrogate of airway inflammation accompanying the asthmatic reaction induced by BAC. FeNO measurements may be a useful and reliable tool in the monitoring and interpreting specific bronchial challenge test with allergens.

Induced sputum evaluation in restorers and conservators of cultural heritage

The objective of this study was to examine induced sputum (IS) cells profile from restorers/conservators of cultural heritage (restorers) with no lower airway symptoms and normal ventilatory lung function. The study involved 22 restorers and 48 control workers. Medical interview, physical examination, spirometry, skin prick testing to inhalatory allergens, and IS collection were performed. Compared with control workers, restorers demonstrated higher percentage of neutrophils (34% vs 15.5%; p = .004). This pattern was found only in male workers. They had almost 9 times greater chance to have increased proportion of sputum neutrophils than male controls (odds ratio [OR] 8.98, 95% confidence interval [CI] 1.98-40.7). The mobilization of eosinophils or macrophages into the airways was not established regardless of workers sex. Additional gender difference in sputum cells distribution was found for occupationally unexposed subjects, with higher proportion of sputum neutrophils in women.

Impact of different welding techniques on biological effect markers in exhaled breath condensate of 58 mild steel welders

Total mass and composition of welding fumes are predominantly dependent on the welding technique and welding wire applied. The objective of this study was to investigate the impact of welding techniques on biological effect markers in exhaled breath condensate (EBC) of 58 healthy welders. The welding techniques applied were gas metal arc welding with solid wire (GMAW) (n=29) or flux cored wire (FCAW) (n=29). Welding fume particles were collected with personal samplers in the breathing zone inside the helmets. Levels of leukotriene B(4) (LTB(4)), prostaglandin E(2) (PGE(2)), and 8-isoprostane (8-iso-PGF(2α)) were measured with immunoassay kits and the EBC pH was measured after deaeration. Significantly higher 8-iso-PGF(2α) concentrations and a less acid pH were detected in EBC of welders using the FCAW than in EBC of welders using the GMAW technique. The lowest LTB(4) concentrations were measured in nonsmoking welders applying a solid wire. No significant influences were found in EBC concentrations of PGE(2) based upon smoking status or type of welding technique. This study suggests an enhanced irritative effect in the lower airways of mild steel welders due to the application of FCAW compared to GMAW, most likely associated with a higher emission of welding fumes.

Interest of exhaled biomarkers in occupational asthma to latex: a case report

New methods for exploring pulmonary inflammation might be useful: measurements of exhaled nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) in exhaled breath condensate (EBC). The authors describe the application and utility of these methods in a case report of pediatric nurse presenting an occupational asthma to latex. Despite compliance with avoidance measures, respiratory discomfort had worsened during work. Classical tests (spirometry, monitoring of peak expiratory flow) were not contributing to objectify the discomfort. Exhaled NO and H(2)O(2) in EBC increased immediately after work periods, compared with rest periods. Application of these new methods, at the same time, in workplace appears useful in the objective demonstration of a temporal relation between work and respiratory problems. The results allowed the occupational physician to transfer the patient to a new work station more appropriate for her respiratory health status.

Occupational exposure to toluene diisocyanate and neutrophilic bronchitis without asthma

CONTEXT

Isocyanates represent a leading cause of occupational asthma, and sputum neutrophilia or eosinophilia has been described in subjects with isocyanate-induced occupational asthma after exposure to these chemicals. One case of non-asthmatic eosinophilic bronchitis due to methylene diphenil isocyanates has been reported, but a similar condition in the instance of neutrophilic bronchial inflammation has never been described.

CASE DETAILS

We report a 34-year-old woman, who, 18 months after beginning work in a plastic industry, reported the onset of dry cough at work. Spirometry was normal, reversibility and methacholine challenge tests were negative. A specific inhalation challenge with toluene diisocyanate elicited dry cough without significant changes in respiratory function. Sputum induction showed a post-challenge neutrophil increase.

DISCUSSION

The results of our case suggest that the occurrence of a neutrophilic bronchial inflammation without the functional characteristics of occupational asthma as a consequence of exposure to toluene diisocyanate may also be considered, suggesting a diagnosis of occupational non-asthmatic neutrophilic bronchitis.

New causes of occupational asthma

PURPOSE OF REVIEW

This review focuses on new causative agents of occupational asthma published in 2009 and 2010. The recent developments in the diagnostic tools employed in occupational asthma caused by new agents are summarized.

RECENT FINDINGS

Work exposures are a significant contributor to the burden of asthma and, therefore, there is great scientific interest in work-related asthma. Although the majority of cases probably represent work-aggravated asthma, in a relevant proportion of cases asthma is actually caused by one or more agents present in the workplace. The list of causative agents of immunologically mediated occupational asthma is continuously growing, and new agents and professions are described each year. New insights gained in occupational asthma include routine evaluation of airway inflammation and identification of allergenic triggers using molecular diagnosis.

SUMMARY

A variety of novel high and low-molecular-weight agents have been shown to induce occupational asthma. Apart from the identification of the allergenic sources implicated, molecular diagnosis and detailed characterization of the culprit allergens contributes to increase our knowledge into the pathogenic mechanisms of this disorder. Assessment of airway inflammation helps to confirm the diagnosis and to better understand the physiopathology of the different types of occupational asthma.

The use of fractional exhaled nitric oxide in investigation of work-related cough in a hairdresser

BACKGROUND

Occupational and environmental factors may be a cause of nonasthmatic eosinophilic bronchitis (NAEB). The diagnosis of occupational NAEB requires evidence of sputum eosinophilia. Nevertheless, a minority of patients are not able to produce suitable sputum specimens.

METHODS

This case report describes a 25-year-old woman, working as a hairdresser since the age of 20 years and handling ammonium persulfate, who came under our observation for work-related rhinitis and cough.

RESULTS

A specific inhalation challenge with ammonium persulfate elicited dry cough, without any significant change in forced expiratory volume in 1 s (FEV(1) ). Sputum induction was unsuccessful both pre- and after specific inhalation challenge. Fractional exhaled nitric oxide (FeNO) values significantly increased after specific inhalation challenge, suggesting a diagnosis of occupational NAEB due to ammonium persulfate.

CONCLUSIONS

From this observation we suggest that FeNO measurement should be added to the investigation of work-related cough during specific inhalation challenge, and may be considered as an alternative to induced sputum to evaluate bronchial inflammation when sputum collection is unavailable or unsuccessful.

Occupational rhinitis: consensus on diagnosis and medicolegal implications

PURPOSE OF REVIEW

Work-related rhinitis is a common disease in many working groups, frequently associated with asthma. The purpose of this review is to summarize the specific literature published within the past 12 months, to discuss the diagnostic workup and to illustrate the medicolegal aspects pertaining to this disease.

RECENT FINDINGS

Recently, there has been a growing scientific interest in work-related rhinitis, which includes both occupational rhinitis and work-exacerbated rhinitis. The epidemiological relevance and the relationships to asthma have been evaluated. New etiologic agents and populations at risk have been identified. A new definition and classification, and a diagnostic algorithm, have been proposed.

SUMMARY

In consideration of the epidemiological relevance and of the medicolegal implications, occupational rhinitis should be considered in daily clinical practice by all physicians. In adults with late-onset rhinitis, occupational causes should be queried and patients in whom an occupational association is suspected should be referred for specific assessments.

Irritative effects of vapours and aerosols of bitumen on the airways assessed by non-invasive methods

Irritative effects caused by vapours and aerosols of bitumen were assessed by non-invasive methods including spirometry, nasal lavage fluid (NALF) and induced sputum (IS) in a cross-shift study comparing 320 bitumen-exposed workers with 118 road construction workers as the reference group. Lung function parameters, forced vital capacity (FVC) and forced expiratory volume in one second (FEV(1)) were within normal ranges in both the reference and the bitumen-exposed groups pre- and post-shift with marginally lower values in smokers of both groups. During the shift, a slight decline in FEV(1) and FVC was observed in the bitumen-exposed group independent of their smoking habits, whereas in the non-smoking reference group, the decline in FEV(1) was not observed. No significant differences between bitumen-exposed workers and the reference group and no significant shift effect were observed on the upper airways using NALF analysis. The IS concentrations of interleukin (IL)-8, total protein and matrix metalloproteinase-9 were significantly higher in bitumen-exposed workers than in the reference group. However, the concentration of these three biomarkers in the IS samples, which are indicators of inflammatory effects on the lower airways of bitumen-exposed workers, was already higher in exposed workers before shift and did not show an increase during the shift. Therefore, the key finding of this aspect of the Human Bitumen Study is the detection of potentially (sub-) chronic irritative inflammatory effects in the lower airways of bitumen-exposed workers.

Risk factors, predictors, and markers for work-related asthma and rhinitis

The burden of asthma attributable to occupational exposures is significant. A better evaluation of markers of asthma and rhinitis in occupational settings may help reduce the frequency of occupational asthma (OA) and rhinitis (OR). This publication reviews articles published in 2008 and 2009 to provide an update on aspects related to markers of asthma and rhinitis. Markers derived from occupational exposure assessment, questionnaires, clinical data, and noninvasive tests such as functional tests or measures of serum antibodies are used to develop prediction models for the likelihood of OA and OR development. Findings from prospective studies highlight the course of preclinical signs and markers of airway inflammation in the natural history of OA and OR. Airway inflammation, evaluated by quantification of cells and mediators in induced sputum or nasal lavage and by exhaled nitric oxide, is associated with OA and OR; however, the sensitivity and specificity of these means, especially exhaled nitric oxide, have not been sufficiently assessed.

Exhaled breath condensates in asthma: diagnostic and therapeutic implications

Exhaled breath condensate (EBC) collection and analysis offers a unique non-invasive method to sample the airway lining fluid. It enables classification and quantification of airway inflammation associated with various pulmonary diseases such as asthma. Over the last decade, innumerable efforts have been made to identify biomarkers in EBC for diagnosis and management of asthma. The aim of this review is to consolidate information available to date, summarize findings from studies and identify potential biomarkers which need further refinement through translational research prior to application in clinical practice.

Association of bronchial reactivity to occupational agents with methacholine reactivity, sputum cells and immunoglobulin E-mediated reactivity

BACKGROUND

Bronchial responsiveness and IgE-mediated reactivity are associated with specific bronchial reactivity to allergens.

OBJECTIVE

Our aim was to examine whether airway inflammation also plays a role.

METHODS

Retrospective analysis of all subjects who underwent specific inhalation challenges in the investigation of occupational asthma (OA) since 2000. Responsiveness to methacholine (PC(20) ) and levels of eosinophils and neutrophils in induced sputum on the control day were associated with the presence of OA (positive-specific inhalation challenge). In a sample of subjects exposed to wheat flour, we also examined the role of specific IgE- mediated reactivity (skin reactivity, specific IgE).

RESULTS

PC(20) level was significantly more often normal in subjects with OA (35 of 129, 27% instances) by comparison with non-OA (15 of 189, 8% instances), but the positive predictive value of responsiveness to methacholine for OA was low (35%). Coupling information on the level of eosinophils to responsiveness to methacholine increased positive predictive values for OA from 39% to 69% depending on the thresholds used. The best balance of positive (69%) and negative (60%) predictive values was obtained in the case of normal PC(20) and eosinophils ≥3%. In a multivariate analysis carried out in 34 subjects exposed to wheat flour, responsiveness to methacholine, sputum eosinophils, skin weal size and levels of specific IgE were all significantly associated with OA to wheat flour.

CONCLUSION AND CLINICAL RELEVANCE

Information on the level of sputum eosinophils in addition to PC(20) provides a better association with OA vs. non-OA when PC(20) is normal. Levels of sputum eosinophils in addition to PC(20) and IgE-mediated reactivity increase the likelihood of OA due to wheat flour.