Assessment of eosinophilic airway inflammation as a contribution to the diagnosis of occupational asthma.

BACKGROUND: Ascertaining the presence of asthma through the assessment of nonspecific bronchial hyperresponsiveness (NSBH) is a key step in the diagnosis of occupational asthma (OA). We aimed at investigating whether indices of airway inflammation including fractional exhaled nitric oxide (FeNO) and sputum eosinophils would be useful adjuncts to the measurement of NSBH in diagnosing OA defined as a positive specific inhalation challenge (SIC). METHODS: The study included 240 consecutive subjects with a suspicion of OA who completed a SIC, of whom 133 showed a positive response. The sensitivity, specificity, and predictive values of NSBH, and FeNO, as well as sputum eosinophil counts assessed at baseline of the SIC were determined. RESULTS: A concentration of histamine inducing a 20% decline in FEV1 (PC20 ) ≤16 mg/mL showed a sensitivity of 87% and a specificity of 36%. A FeNO level ≥25 ppb and a sputum eosinophil count ≥2% provided lower sensitivity rates (47% and 39%, respectively) than the PC20 value. Eight of the 17 subjects without baseline NSBH despite a positive SIC showed a sputum eosinophil count ≥2%, a FeNO level ≥25 ppb, or both outcomes. Combining either a PC20 value ≤16 mg/mL or a FeNO ≥25 ppb increased the sensitivity to 91%. Using either a PC20 ≤16 mg/mL or a sputum eosinophil count ≥1% increased the sensitivity to 94%. CONCLUSION: Adding the assessment of FeNO level and sputum eosinophils to NSBH improves the identification of subjects who may have OA and require further objective testing before excluding the possibility of OA.

Occupational asthma caused by an epoxy amine hardener.

We describe a 43-year-old epoxy floor layer who developed work-related asthma while exposed to an epoxy hardener based on isophorone diamine (IPDA). Challenge exposures to the curing of the epoxy resin system and subsequently to the polyfunctional amine hardener containing IPDA both elicited delayed asthmatic reactions. This report further indicates that exposure to epoxy hardeners containing polyfunctional amines should be considered as a potential cause of occupational asthma. Appropriate work hygiene measures should be implemented to minimize airborne exposure to these volatile compounds.

[The motivational week: A new approach in smoking cessation]. / La semaine motivationnelle : une nouvelle approche dans le sevrage tabagique.

INTRODUCTION: Smoking cessation is complex and challenging. The motivational week is a multidisciplinary approach that has been established in order to increase the chances of quitting smoking. The purpose of this study was to determine the rates of abstinence achieved and the predictive factors for quitting. METHODS: Clinical data, smoking status, levels of dependence and motivation as well as rates of continuous abstinence in the short and long-term of all patients who participated in the motivational week were analysed. RESULTS: Two hundred and thirteen patients were included. The mean age was 49.8 years (10.6). The rates of continuous abstinence were 40.4% at 6 months, 29.1% at 12 months and 21.6% at 2 years. Using logistic regression, having depression or a history of depression was associated with reduced likelihood of smoking cessation: OR: 0.32 [95%CI: 0.16-0.76; P=0.003] at 6 months, OR: 0.35 [95%CI: 0.16-0.77; P=0.009] at 12 months and OR: 0.27 [95%CI: 0.11-0.65; P=0.004] at 2 years. CONCLUSIONS: The motivational week seems to be an approach which is effective long-term and could be used in smoking cessation. This study confirms that depression is an unfavourable factor for quitting.

[Asbestosis still exists ]. / L'asbestose existe encore

A diagnosis of asbestosis, lung fibrosis due to asbestos exposure, was proposed in 2003 in a 64-year-old woman on the basis of the history, computed tomography appearances, lung function studies, and biometric data. This diagnosis was confirmed by the pathological examination of a lung lobe resected surgically for bronchial carcinoma in 2010. The diagnosis of asbestosis is now rarely made as a result of a substantial decrease in dust exposure over the past decades and mainly because of the interdiction of asbestos use in western countries. Currently, the most frequent thoracic manifestations of asbestos exposure are benign pleural lesions and mesothelioma. It has also become exceptional to have pathological confirmation of the diagnosis, obtained in this woman thanks to the surgical treatment of another complication of her occupational exposure.

[Occupational physician roles]. / Les rôles du médecin du travail.

Occupational medicine is an important medical discipline in Belgium, with about one thousand of experts. Roles of the occupational physicians must be analyzed on the basis both of legal prescriptions and real practice. The examination of the roles of the occupational physician in various countries shows that regulation are an important legal framework from which he can deploy his practice. A contrario it is also the means which makes it possible to the unions and the management to force him. However the real roles are definitely broader than the regulations let understand, concerning very diverse fields which make this medical discipline a real preventive general medicine. It is less and less a public health discipline and approaches gradually in practice the clinical disciplines, in the sense that the singular colloquium, the knowledge of the particular work places and risks of every worker and the individualization of the action are its bases. On the other hand, fitness for work assessments and its procession of authoritarian medical and administrative acts, heritages of the public health, hardly efficient, should largely disappear from the prescriptions. It will allow for a wider deployment of the activity of the occupational physician towards the industrial organisations, by proposing the necessary adaptations of the work places, the limitations of exposure to harmful effects, the remediation of the psychosocial load, etc, through "preventive prescriptions". Complementarily, the population ageing imposes new solutions to rehabilitate the old workers, and this will be likely to modify, not only the medical approach in work environment, but also already imposes a closer cooperation with the general practitioner, which is likely to improve the action abilities of both medical disciplines.

[Relations between the occupational physician and the general practitioner]. / Les relations entre le médecin du travail et le médecin généraliste.

The occupational physician (OP) and the general practitioner (GP) both aim at maintaining and promoting public health. The attending physician is the physician who has been freely chosen by the patient whilst the occupational physician is assigned by the company. Although synergy between both professions might seem obvious, in reality it is not always so. The focus of the occupational physician's work is on the worker in his work place. Through health monitoring action and knowledge of jobs and positions, the occupational physician aims to contribute to the improvement of well-being at work. Medical examinations result in drafting a form stating the person's ability or inability to occupy his/her assigned job. In line with the required respect for the patient's rights and, hence, with his/her authorization, the GP may transmit the medical information the said GP deems useful to the OP, e.g. back-to-work medical examinations and pre-back-to-work medical consultations are opportunities to establish a contact between both practitioners in view of considering the possibilities of adapting the workplace situation at the time of resumption of work. The GP should know that there exists an appeal opportunity with the Office in charge of Monitoring Well-being at Work (Employment Federal Public Service) against a decision that by which the worker is not allowed to stay in his assigned work task. During the medical examinations the OP may endorse the action of the GP by strengthening the worker/patient's awareness of the fact that his/her health problems must be adequately taken into account and by organizing information sessions about general interest campaigns about, for instance, cardiovascular risk prevention or a campaign about quitting smoking or reducing alcohol consumption to a more sensible and reasonable level. Knowledge of delayed effects of professional exposure should be consolidated in GPs; the possibility of drawing attention to one's suspicions about occupational illnesses to the Fund for Occupational Illnesses must also again brought to mind. In order to establish a follow-up program on the health of patients beyond their professional activity, it is necessary to draft a "liaison document", between the OP and the GP, which identifies the professional risks workers/patients have been exposed to. In sum, it is important to provide GPs with means to identify the patient's OP and consolidate their knowledge of occupational medicine by organizing on-going training modules.

[The missions of the Occupational Diseases Fund. Under-claim and recognition of occupational lung cancer, in particular those related to asbestos]. / Les missions du Fonds des Maladies Professionnelles. La sous-déclaration des cancers respiratoires professionnels, en particulier dus a l'amiante.

The missions of the Occupational Diseases Fund are defined in application of the law regarding the insurance against occupational diseases. The workers covered by this law are granted several rights, such as a financial compensation in case of temporary or permanent disability, a further compensation if they have to be taken away from the risk in the workplace, the reimbursement of health care costs related to the occupational disease, or the payment of an annuity to the widow(er) if death is its ultimate consequence. Among the compensable diseases, we shall focus on lung cancer, and especially the one related to asbestos exposure. This type of cancer is clearly under-registrated in Belgium as in most countries of the European Union, leading to an insufficient number of cases entitled to compensation by our institution. In this instance, the insurance against occupational diseases and all related social advantages are hugely under-exploited in our country. It is our duty to increase doctors' awareness of the problem and spread accurate information to reverse this trend and provide occupational cancer cases with a legitimate compensation, in particular those related to asbestos. A wider knowledge of the occupational history of cancer patients, thanks to occupational physicians, and a better use of mineralogical analyses on lung samples, would improve this situation inacceptable on any level : medical, social or even human.

Sputum eosinophilia: an early marker of bronchial response to occupational agents.

BACKGROUND: False-negative responses to specific inhalation challenge (SIC) with occupational agents may occur. We explored whether assessing changes in sputum cell counts would help improve the identification of bronchial reactivity to occupational agents during SICs. METHODS: The predictive value of the changes in sputum cell counts after a negative FEV(1) response to a first challenge exposure to an occupational agent was determined using the changes in airway calibre observed during repeated challenges as the 'gold standard'. The study included 68 subjects investigated for work-related asthma in a tertiary centre. After a control day, the subjects were challenged with the suspected occupational agent(s) for up to 2 h. All subjects who did not show an asthmatic reaction were re-challenged on the following day. Additional challenges were proposed to those who demonstrated a > or = 2% increase in sputum eosinophils or an increase in nonspecific bronchial hyperresponsiveness to histamine after the second challenge day. RESULTS: Six of the 35 subjects without changes in FEV(1) on the first challenge developed an asthmatic reaction on subsequent challenges. ROC analysis revealed that a >3% increase in sputum eosinophils at the end of the first challenge day was the most accurate parameter for predicting the development of an asthmatic response on subsequent challenges with a sensitivity of 67% and a specificity of 97%. CONCLUSIONS: An increase in sputum eosinophils is an early marker of specific bronchial reactivity to occupational agents, which may help to identify subjects who will develop an asthmatic reaction only after repeated exposure.

Latex-induced occupational asthma: time trend in incidence and relationship with hospital glove policies.

BACKGROUND: Natural rubber latex (NRL) has become as a major cause of occupational asthma (OA) in workers using NRL gloves. Few population-based studies have assessed the impact of changes in the patterns of glove usage on the incidence of NRL-induced OA. OBJECTIVE: To characterize the time trends in incident cases of NRL-induced OA in Belgium and examine whether incidence rates were related to the types of gloves used in hospitals. METHODS: Incident cases of NRL-induced OA were identified through a retrospective review of all claims submitted to the Workers' Compensation Board up to December 2004. Based on the results of diagnostic procedures, the diagnosis of NRL-induced OA was categorized as definite, probable, unlikely, or indeterminate. The patterns of glove usage were characterized through a questionnaire survey of Belgian hospitals. RESULTS: A total of 298 claims for NRL-induced OA were identified, including 127 subjects with definite OA and 68 with probable OA. Categorized by the year of asthma onset, the incident cases of definite and probable NRL-induced OA markedly decreased from 1999 onwards. The use of powdered NRL gloves fell from 80.9% in 1989 to 17.9% in 2004. Powdered NRL gloves were predominantly substituted with NRL-free gloves, especially in the case of non-sterile procedures. CONCLUSION: These national compensation-based data confirm that a persistent decline in the incidence of NRL-induced OA has occurred since late 1990s. This downward trend has temporally been associated with a decreasing usage of powdered NRL, further supporting a beneficial role of changes in glove policies.

Trends in asbestos body counts in bronchoalveolar lavage fluid over two decades.

As in most western countries, the use of asbestos has decreased in Belgium since the mid 1970's. Successive regulations have lowered the permissible levels of exposure and prohibited the use of various asbestos products. In order to assess the impact of these prevention measures on the pulmonary fibre burden of asbestos-exposed patients, the bronchoalveolar lavage fluid (BALF) asbestos body (AB) analysis database of the authors' laboratory was reviewed for the period 1983-2000. A total of 4,772 cases were considered, of which 95% were males. AB concentration exceeded 1 AB x mL BALF(-1) in 36.1%. There was essentially no change in the mean concentration of AB over the period evaluated. However, the concentrations in individuals with very high levels decreased over time. This was associated with a shift in exposure categories from primary asbestos workers to those exposed during handling of asbestos-containing materials or to asbestos in place in buildings or industrial sites. This is consistent with epidemiological data indicating that the number of severe cases of asbestosis caused by very high cumulated doses decreases but that benign pleural diseases and mesothelioma remain the most frequent asbestos-related diseases. Past prevention measures are not expected to have a measurable influence on the incidence of mesothelioma in the near future.

Occupational asthma in symptomatic workers exposed to natural rubber latex: evaluation of diagnostic procedures.

BACKGROUND: Natural rubber latex (NRL) has been increasingly identified as a cause of occupational asthma (OA). OBJECTIVE: We sought to examine the accuracy of the clinical history, immunologic tests, and assessment of nonspecific bronchial hyperresponsiveness in diagnosing OA caused by latex compared with that of the specific inhalation challenge (SIC). METHODS: Forty-five consecutive patients referred for investigation of possible OA caused by latex underwent a diagnostic protocol, including an open medical questionnaire, skin prick testing against latex, measurement of bronchial responsiveness to histamine, and inhalation challenge with latex gloves. Recorded clinical history was judged retrospectively by 4 physicians who were blinded for the results of other objective tests. RESULTS: The clinical history, skin prick testing against NRL, and assessment of nonspecific bronchial hyperresponsiveness showed a high sensitivity (87%, 100%, and 90%, respectively) but a low specificity (14%, 21%, and 7%, respectively) when compared with the results of the SIC. Logistic regression analysis showed that combining the results of skin prick tests against latex with the clinical history enhanced the negative predictive value from 50% to 71%, whereas the positive predictive value remained virtually unchanged (75% vs 76%). CONCLUSION: The clinical history and immunologic tests were the most useful procedures in diagnosing NRL-induced asthma, although combining the 2 procedures remained less accurate than SIC. Further examination of the predictive values of available tests is warranted to recommend diagnostic strategies that are specific to the various agents causing OA.

Combined fractional excretion of sodium and urea better predicts response to saline in hyponatremia than do usual clinical and biochemical parameters.

BACKGROUND: The treatment of hyponatremic patients requires physicians to make a therapeutic choice between saline infusion and water restriction. Therefore, they need readily available and reliable parameters to facilitate making that choice. This study was designed to determine whether the use of clearance ratios can help clinicians recognize saline-responding hyponatremic patients. PATIENTS AND METHODS: Thirty-five nonedematous, hospitalized, hyponatremic patients were classified according to their history and saline response into four groups: diuretic-taking patients, polydipsic patients, saline responders, and saline nonresponders. Within these four groups, clinical and biochemical volume-related parameters, including clearance ratios, were prospectively evaluated before infusion of 2 L isotonic saline. Clearance ratios as well as usual clinical and biochemical parameters were tested for their accuracy in predicting saline responsiveness. RESULTS: Both positive (70%) and negative (54.5%) predictive values for hypovolemia were unsatisfactory; clinical prediction of hypovolemia was also characterized by low sensitivity (41.1%), but acceptable specificity (80%). In the polydipsia and saline-nonresponder groups, plasma urea and uric acid values tended to be lower than in the diuretic and saline-responder groups. However, the usefulness of these parameters was limited by too large an overlap among the different groups. In both polydipsic patients and saline responders, urinary sodium concentration was low. The combined amount of urinary sodium and potassium in relation to plasma sodium did not discriminate among the different groups. Most helpful in distinguishing among the groups was a combination of several clearance ratios (fractional excretions of sodium, potassium, urea, and uric acid), since the predictive use of each parameter on its own was restricted. The best indicator of saline responsiveness was a low fractional excretion of filtered sodium (< 0.5%) combined with a low fractional excretion of urea (< 55%). CONCLUSION: The accuracy of clinical evaluation for predicting the state of extracellular fluid volume in hyponatremia is low. The combination of low fractional sodium excretion (< 0.5%) and low fractional urea excretion (< 55%) is the best biochemical way to predict saline response, whereas high fractional potassium excretion (> 20%) indicates diuretic intake.

Bone marrow scintigraphy in lung carcinomas using nanosized colloids: when is it useful and how useful is it?

Bone marrow scintigrams (MS) combined with single photon emission computed tomographic investigation of the liver (liver SPECT) were obtained using 99Tcm-labelled human serum albumin nanosized colloids in 52 patients with histologically proven lung carcinomas (adenocarcinomas = 17, squamous cell = 16, small cell = 14, large cell = 5, 31 generalized cases at the time of the first MS investigation among whom 13 patients had proven skeletal metastases). They were compared with conventional bone scintigrams (BS) as well as clinical, biological, radiological and follow-up data obtained for the same patients. In the present series, MS appeared as sensitive as BS in diagnosing skeletal metastases (77%) if all abnormal MS and BS presentations are considered as diagnostic, but more sensitive (77% versus 54%) if more restrictive analytical criteria are applied. The two investigations yielded the same specificities whatever the analytical criteria applied. These preliminary conclusions have, however, to be confirmed on larger populations than the present series. The most striking differences between BS and MS were observed in the case of small-cell lung carcinomas, with more lesions detected by MS than by BS. Liver SPECT also made it possible to diagnose seven and to suspect one out of the ten situations of hepatic metastases. The combination of liver spect and MS in the framework of a single injection of 99Tcm-labelled nanosized colloids thus allowed us to diagnose 80% of the patients with osseous and/or hepatic metastasis or 40% of all generalized cases.