D Talini

Asthma-like symptoms, atopy, and bronchial responsiveness in furniture workers.

OBJECTIVES: To study the role of individual and occupational risk factors for asthma in furniture workers. METHODS: 296 workers were examined (258 men, 38 women) with a questionnaire of respiratory symptoms and diseases, baseline spirometry, bronchial provocative test with methacholine, and skin prick tests. Non-specific bronchial hyperreactivity was defined as when a provocative dose with a fall of 20% in forced expiratory volume in 1 second (PD20FEV1) was < 0.8 mg and atopy in the presence of at least one positive response to skin prick tests. Workers were subdivided into spray painters (exposed to low concentrations of diisocyanates and solvents), woodworkers (exposed to wood dusts), and assemblers (control group). RESULTS: The prevalences of attacks of shortness of breath with wheezing and dyspnoea were higher in spray painters (13.5% and 11.5% respectively) than in woodworkers (7.7% and 6.3%) or in assemblers (1.6% and 1.6%); prevalences of chronic cough, asthma, and rhinitis were also slightly but not significantly higher in spray painters and in woodworkers than in assemblers. The difference in the prevalence of respiratory symptoms among the job titles was due to the atopic subjects, who showed a higher prevalence of chronic cough, wheeze, shortness of breath with wheeze, dyspnoea, and asthma in spray painters than in the other groups. The prevalence of non-specific bronchial hyperreactivity in subjects who performed bronchial provocative tests was 17.7%, with no significant difference among groups. Asthma symptoms were significantly associated with non-specific bronchial hyperreactivity. Asthma-like symptoms plus non-specific bronchial hyperreactivity was found in 4% of assemblers, 10% of woodworkers, and 13.3% of spray painters (chi 2 = 2.6, NS). Multiple logistic analysis taking into account individual (smoke, atopy, age) and occupational (job titles) risk factors confirmed that spray painters had higher prevalence of chronic cough than assemblers, and a trend in increasing the prevalence of shortness of breath with wheeze, dyspnoea, and asthma. CONCLUSIONS: Painters in the furniture industry, particularly atopic subjects, are at higher risk of asthma-like symptoms than other job titles. In these workers asthma-like symptoms are more sensitive than non-specific bronchial hyperreactivity in detecting a negative effect of the occupational exposure.

Chest radiography and high resolution computed tomography in the evaluation of workers exposed to silica dust: relation with functional findings.

OBJECTIVES--To compare the usefulness of high resolution computed tomography (HRCT) with chest radiography (CR) in the diagnosis and assessment of severity of silicosis. METHODS--27 workers exposed to silica underwent CR, HRCT, and pulmonary function tests. Two experienced readers independently evaluated CR by International Labour Office classification, and grouped the results into four categories. HRCT categories of nodule profusion and the extent of emphysema were graded on a four point scale; in 20 subjects the percentage distribution of lung densities were measured by HRCT. RESULTS--Concordance between readers was higher for HRCT than for CR (K statistic = 0.49 and 0.29 respectively). There was poor concordance between CR and HRCT in the early stage of silicosis. No significant difference in pulmonary function tests was found among different CR categories, but forced expiratory volume in one second (FEV1), maximal expiratory flow at 50% and 75% of FVC (MEF50, MEF75), and diffusion capacity significantly decreased with increasing HRCT categories. Subjects with simple silicosis detected by HRCT had a lower FEV1 than subjects without silicosis, whereas subjects with conglomerated silicosis showed higher residual volume and functional residual capacity than subjects with simple silicosis. These relations were not affected by smoking or symptoms of chronic bronchitis. Different grades of emphysema detected by HRCT were significantly different in diffusion capacity. Only the HRCTs of the lowest and the highest categories of profusion of parenchymal opacities were significantly different in their distribution of density classes. CONCLUSION--HRCT is more reproducible and accurate than CR, as suggested by the higher agreement between readers and the better correlation with pulmonary function tests, irrespective of smoking and chronic bronchitis; however, these data do not support the hypothesis that HRCT is more sensitive than CR in the early detection of silicosis.

Skin reactivity and specific IgE levels in the evaluation of allergic sensitivity to common allergens for epidemiological purposes

An investigation was conducted to test the validity of the skin‐prick test (SPT) with eleven common allergens (Lofarma series proposed by Italian National Research Council for epidemiological studies) as a method for predicting the presence of specific antibodies in serum. The relationship between SPT, evaluated by two different methods (MWD = mean weal diameter, AHWR = allergen histamine weal ratio), and specific IgE levels (RAST) has been investigated in 101 patients tested consecutively for suspected allergic disease. Sensitivity, specificity and overall efficiency were assessed for different criteria of SPT positivity (≥4 mm or ≥5 mm using MWD; ++ or +++ using AHWR). For pollens and moulds, a weal diameter ≥5 mm gave better results than 4 mm, whereas for mites a MWD ≥4 mm showed a better sensitivity and overall efficiency than 5 mm. Danders showed low sensitivity when either 5 or 4 mm criterion was considered. AHWR evaluation gave no better results, except for animal danders. Correlation coefficients between weal size and RAST class showed a good relationship for mites and pollens using both methods of SPT evaluation; a moderate relationship was observed with MWD criterion for moulds and with AHWR for danders.

Pattern of airway response to allergen extract of Phleum pratensis in asthmatic patients during and outside the pollen season.

In order to evaluate the pattern of airway response to a specific bronchial provocative test (sBPT) with an extract of Phleum pratensis standardized in biological units (BU), we studied 27 patients with seasonal asthma due to grass pollen by means of allergologic evaluations, methacholine inhalation test and sBPT, outside the pollen season in all patients and, in 10 of them, also during the pollen season. We used a DeVilbiss 646 nebulizer with a dosimeter, giving increasing doses (0.01-2.5 BU) of the allergen solution and we monitored FEV1 to assess early (EAR) and late (LAR) airway responses. Outside the pollen season sBPT elicited an isolated EAR in 16 and a dual asthmatic response (DAR) in 11 patients. We observed no significant difference between EAR and DAR patients as regards the provocative dose causing a 15% fall in FEV1 (PD15FEV1) methacholine, EAR (expressed by PD15FEV1 allergen) or allergologic data. There was a significant relationship between PD15FEV1 allergen and PD15FEV1 methacholine (r = 0.43, p less than 0.05). The reproducibility of sBPT was assessed in 11 patients outside the pollen season. The correlation coefficients between the two tests were: r = 0.91, p less than 0.001 for the total delivered dose of allergen during sBPT; r = 0.79, p less than 0.01 for PD15FEV1 allergen; r = 0.95, p less than 0.001 for the maximum percent fall in FEV1 during LAR. Ten patients repeated all tests during the grass pollen season. PD15FEV1 methacholine and baseline FEV1 decreased significantly during the pollen season, but PD15FEV1 allergen did not change significantly during the season.(ABSTRACT TRUNCATED AT 250 WORDS)

Sputum eosinophilia is a determinant of FEV1 decline in occupational asthma: results of an observational study

Objective To evaluate the potential determinants of forced expiratory volume in 1 s (FEV1) decline in workers with occupational asthma (OA) still exposed to the causative agent. We hypothesised that sputum eosinophilia might be a predictor of poor asthma outcome after diagnosis. Setting, design and participants In a specialistic clinical centre of the University Hospital of Pisa, we studied 39 participants (28 M, 11 F) diagnosed as having OA, routinely followed up between 1990 and 2009. They were a subgroup of 94 participants diagnosed as affected by OA in that period: 9 had been removed from work at the diagnosis, 21 were excluded for having ceased occupational exposure after few months from diagnosis, and 25 were lost at the follow-up or had no acceptable sputum measurements at the diagnosis. Estimates of the decline in FEV1 were obtained by means of simple regression analysis during the period of occupational exposure after diagnosis. Logistic regression was used to analyse the effects of factors (baseline FEV1 and sputum inflammatory cells, duration and type of exposure) that may potentially influence FEV1 decline. Results At follow-up (5.7+3.7 years), most participants were still symptomatic despite inhaled corticosteroids (ICS) treatment and had their occupational exposure reduced. Participants with higher sputum eosinophils (>3%) at baseline had a significantly greater decline of FEV1 (–52.5 vs −18.6 mL/year, p=0.012). Logistic regression showed that persistent exposure and sputum eosinophilia were significantly associated with a greater decline in FEV1 (OR 11.5, 95% CI 1.8 to 71.4, p=0.009 and OR 6.7, 95% CI 1.1 to 41.7, p= 0.042, respectively). Conclusions Sputum eosinophilia at diagnosis, together with the persistence of occupational exposure during follow-up, may contribute to a greater decline in FEV1 in patients with OA still at work. Further long-term studies are required as to whether intensive ICS treatment may be beneficial for patients with OA and increase ad eosinophilic inflammation.

Salbutamol plus beclomethasone dipropionate, but not salbutamol alone, completely prevent early and late asthmatic responses to allergen

The effect of a week treatment with inhaled salbutamol plus placebo (S+P) vs. salbutamol combined with beclomethasone dipropionate (S+BDP) on early and late asthmatic responses to inhaled allergen was studied in ten atopic patients in a randomized, double-blind, cross-over study. All patients had previously shown a dual type response to the specific bronchial provocative test (sBPT). Each patient performed two periods of treatment for a week, with a 15 day interval between them: (a) salbutamol 0.3 mg, tid + placebo; (b) salbutamol 0.3 mg+BDP 0.2 mg, tid; at the end of each treatment period, sBPT was performed and the last treatments were given 1.5-2 h before and 3-4 h after allergen challenge. S + BDP completely prevented both early and late responses to allergen, while S + P reduced but did not completely inhibit early and late responses. The difference between the two treatments was significant for early and late asthmatic responses. Non-specific bronchial hyperresponsiveness to methacholine was performed before each treatment period, after 6 days of treatment before sBPT and the day after sBPT at the end of the treatment period; there was only a mild increase in PD15FEV1 methacholine after 6 days of treatment with S + BDP in comparison with S + P treatment. These results suggest that salbutamol plus beclomethasone may be used effectively in the prophylaxis of early and late asthmatic reactions induced by allergen in sensitized subjects.

Specific bronchial reactivity to toluene diisocyanate: relationship with baseline clinical findings.

One hundred and fourteen subjects with asthma induced by toluene diisocyanate were identified and the pattern of their bronchial responses to challenge with toluene diisocyanate was studied. An occupational type specific bronchial provocation test with toluene diisocyanate (10-25 parts per thousand million for 10-15 minutes) elicited an immediate response in 24, a late response in 50, and a dual response in 40 patients. Subjects with a dual response showed at diagnosis a longer duration of symptoms and a greater prevalence of airway obstruction; in these subjects FEV1 (percentage of predicted value) was lower than in subjects with immediate or late reactions to toluene diisocyanate. The percentage of current smokers and ex-smokers was significantly lower in subjects with a late response (26%) than in subjects with immediate or dual responses (56% and 57% respectively). In 27 of the 114 subjects a non-specific challenge test with methacholine was performed and subjects with dual responses showed greater non-specific bronchial hyperresponsiveness than the other groups. These results suggest that a dual response to specific challenge in bronchial asthma related to toluene diisocyanate may be associated with more severe disease than other types of response, as assessed by duration of symptoms, baseline airway obstruction, and non-specific bronchial hyperresponsiveness. The high prevalence of non-smokers and low prevalence of smokers in the group with a late response to specific challenge is so far unexplained.

Comparison between Airway Responses to High versus Low Molecular Weight Compounds in Occupational Asthma

Occupational asthma (OA) is a heterogeneous disease, and the characteristics of the sensitizer responsible for OA may induce different clinical, functional, and biological manifestations. We examined the characteristics of 74 patients with OA induced by low molecular weight compounds (LMWC) or by high molecular weight compounds (HMWC) and diagnosed by specific inhalation challenge (SIC). Patients with OA induced by LMWC had a longer occupational exposure before the beginning of symptoms, a lower sputum eosinophilia, and a higher prevalence of late airway response (LAR), in comparison with patients with OA induced by HMWC. Pulmonary function tended to be poorer and atopy tended to be less frequent in LMWC-induced OA than in HMWC-induced OA. These data confirm and extend previous observations showing that the characteristics of the specific sensitizer inducing OA may determine different clinical, functional, and biological features, probably related to the difference pathogenetic mechanisms underlying these different types of OA.

May the Reduction of Exposure to Specific Sensitizers Be an Alternative to Work Cessation in Occupational Asthma? Results from a Follow-Up Study

Background: Few data are reported on the effects of a reduction of exposure to specific sensitizers in occupational asthma (OA). The objective of this study was to evaluate the clinical outcome of subjects with OA, comparing the effect of a reduction with that of the persistence or cessation of occupational exposure to the specific sensitizer. Subjects and Methods: Forty-one subjects with OA due to different sensitizers were diagnosed via a specific inhalation challenge. After a follow-up interval of 3.5 years, subjects were reexamined by clinical assessment, bronchial hyperresponsiveness (BH) and induced sputum. Results: At follow-up, subjects who had reduced occupational exposure (n = 22) showed a significant improvement in BH and a nonsignificant improvement in sputum eosinophilia (from 5.3 to 1.1%, n.s.), while subjects still exposed (n = 10) showed a significant decrease in FEV1. Subjects who ceased work (n = 9) showed a trend of improvement in BH and sputum eosinophilia. Logistic analysis showed that the major determinant of improvement in BH at follow-up was the severity of BH at diagnosis, with a minimal contribution from the duration of exposure and treatment with inhaled corticosteroids during follow-up; reduction of work exposure did not enter into any model. Conclusion: The reduction of occupational exposure could not be considered to be as effective as work cessation, which remained the best treatment for OA. However, it was not associated with a deterioration of FEV1 as observed in subjects with persistent exposure.

Mild Improvement in Symptoms and Pulmonary Function in a Long-Term Follow-Up of Patients with Toluene Diisocyanate-Induced Asthma

Background: Long-term follow-up of diisocyanate-induced occupational asthma has been occasionally reported. Methods: We studied the outcome of toluene diisocyanate (TDI)-induced asthma in 46 patients at diagnosis and after a follow-up of 11 ± 3.6 years. Symptoms, anti-asthma therapy, forced expiratory volume in 1 s (FEV1) and bronchial hyperresponsiveness to methacholine were assessed. Results: A significant improvement in FEV1 (% predicted) and PD20FEV1 methacholine was observed at follow-up in comparison with diagnosis. Anti-asthma treatment was performed by 42% of patients at diagnosis and by 70% at follow-up. At the time of follow-up, 32 subjects had been removed from exposure for 6.0 ± 6.9 years, whereas 14 subjects continued to work with reduced exposure to TDI. There was a significant reduction in the prevalence of attacks of shortness of breath and dyspnoea at follow-up, but only in unexposed patients. PD20FEV1 was significantly improved only in patients with a lower FEV1 at diagnosis and in those who have ceased work. Logistic regression analysis, using different models with some independent variables, showed that there were no significant determinants of improvement in FEV1 at follow-up, while a shorter duration of symptoms before diagnosis was a significant predictor of improvement in PD20FEV1 at follow-up. Conclusions: Asthma-like symptoms, bronchial hyperresponsiveness and airway obstruction improved, but did not normalize, after a long-term follow-up with cessation or reduction in TDI exposure, mainly in subjects with an early diagnosis of occupational asthma and in patients with a lower baseline FEV1 no longer exposed to TDI.