[Bronchial and alveolar NO parameters in smokers]. / Stickstoffmonoxid in verschiedenen Kompartimenten des Atemtrakts - Vergleich der Daten von Nichtrauchern und Rauchern.

Our aim was to determine by means of five exhaled flow rates differential parameters of FeNO and the relations between them in smokers and non-smokers. 34 smokers (without respiratory symptoms and medication) were examined. Compared to 43 healthy non-smokers, FeNO was significantly lower. The analysis of the differential NO parameters by means of the two-compartment model of NO production revealed a significant decrease in the bronchial NO concentration, but no significant changes of NO in alveolar fraction by smokers. The relations between differential parameters in non-smokers confirm the theoretical expectations of the two-compartment model. Conversely, smokers exhibit an abnormal remarkable correlation, namely, a high correlation between the reduced C(aw) und FeNO at all five flow rates. It may be assumed that the alveolar NO fraction in smokers is to some extent of bronchial origin. Such a preposition is in line with significantly decreases of FEV(1), FEF(50) and FEF(75) in smokers, which are associated with turbulences, flow inhomogeneity and a varied delay of expiration time from the peripheral airways. We hypothesize that the decreased NO concentration in the bronchial wall of smokers plays a pathophysiological role in the genesis of small airways disease.

[Occupational challenges in hairdressers with regard to FENO measurements]. / Arbeitsplatzbezogene Expositionstestungen von Friseuren mit besonderer Berücksichtigung des exhalierten Stickstoffmonoxids (FENO).

A clear diagnosis of occupational asthma in hairdressers usually is difficult since standardized tests are lacking. We investigated the potential role of F (E)NO measurements for complementary diagnostic and pathophysiological assertions. Only a few of the work-related respiratory complaints of fifteen examined hairdressers were associated with a significant bronchial obstruction at rest, a non-specific hyperreactivity, a broncho-obstructive reaction in the specific provocation test and/or a type I allergy to work-related agents. In a total of 53 %, at least one of these parameters was pathological and multiple deviations were exceptional. It is remarkable that atopical subjects were underrepresented in the whole group, but represented the majority of those hairdressers who had developed the occupational disease no. 4302. The results of F (E)NO measurements performed for the first time with a group of hairdressers (we found in only 3 subjects increased baseline values, in only 1 subject increased F (E)NO after the exposure test) which diagnostically proved to be helpful to detect allergic and isocyanate asthma are also inconsistent with a substantial airway allergy due to work-related substances. On the other hand, the few atopical hairdressers show a significantly higher disease risk. Hairdressers' respiratory complaints obviously occur mainly due to chemical-irritative stimuli on the bronchial mucosa, especially in atopical subjects. In contrast to our results, by acknowledgment of an occupational disease mostly (in about 66 %) allergizing effects according to occupational disease no. 4301 are accepted.

Increase in exhaled nitric oxide (eNO) after work-related isocyanate exposure.

UNLABELLED: The objective of this study was to evaluate the role of eNO changes post inhalative isocyanate challenge tests (DeltaeNO) with regard to specific asthmatic reactions and unspecific bronchial hyperresponsiveness (BHR) to predict clinical and subclinical responses of isocyanate workers. METHODS: 55 workers with isocyanate-related respiratory complaints (29 with BHR and 25 without BHR) underwent occupational-type challenge tests. We determined eNO before, during and up to 22 h after diagnostic isocyanate challenge. RESULTS: The 12 asthmatic responders (22%) in the isocyanate-challenge test showed the highest eNO changes 22 h after challenge as well as a significant association between these changes and BHR. There was a positive association between an eNO increase of > 50% and an asthmatic response when compared to nonresponders with an odds ratio of 6.1; 95% CI 1.4-26.3; P = 0.02. More than half of the employees with BHR (52%) but only 20% of those without BHR developed an eNO rise of > 50% after 22 h. Furthermore, a significant positive association was found between the combination of BHR plus eNO increase of 50% after 22 h and the maximum sRaw change (% of baseline value) during the period 0-22 h after isocyanate exposure. The combination of BHR and eNO increase of > 50% was also associated with clinical symptoms during specific challenge tests (cough, shortness of breath, and/or rhinitis). DISCUSSION AND CONCLUSIONS: An eNO increase 22 h post isocyanate challenge occurred in two-thirds of responders and in approximately half of nonresponders with BHR but only rarely in those without BHR. The combination of BHR and eNO increase in nonresponders may offer a new diagnostic tool to register subjects with an increased risk of developing occupational asthma. However, a large study group to perform follow-up investigations into this topic would be helpful to emphasize the importance of this finding.

Latex allergen exposure increases exhaled nitric oxide in symptomatic healthcare workers.

The objective of this study was to investigate the clinical and diagnostic impact of baseline exhaled nitric oxide (eNO) levels and latex allergen-induced eNO changes in different healthcare worker groups. Healthcare workers, 31 latex-sensitised and 14 nonsensitised, underwent occupational-type challenge tests with powdered allergenic latex gloves. Sensitised as well as nonsensitised healthcare workers developed a significant eNO increase 1 h after challenge. Conversely, only latex-sensitised employees showed a significant eNO increase 22 h after challenge, which showed a significant relationship with bronchial obstruction (specific airway resistance changes). However, there was no difference in either baseline eNO level or eNO increase after 22 h between asthmatic (n = 13) and rhinitic only (n = 20) responders. The specificity and sensitivity of a 50% eNO increase after 22 h in responders were 100 and 56%, respectively. These results support the assumption that the whole respiratory tract is involved in a combined allergic rhinitis and asthma syndrome. Smoking healthcare workers showed reduced baseline exhaled nitric oxide levels, but, as shown for the first time, an allergen-induced exhaled nitric oxide increase comparable to that of nonsmokers. Corticosteroid therapy inhibited the allergen-induced exhaled nitric oxide change but not the clinical response in the challenge test. These findings suggest that cigarette smoke and corticosteroids initiate distinct molecular mechanisms influencing nitric oxide concentrations in the airways.

Challenge from methacholine, natural rubber latex, or 4,4-diphenylmethane diisocyanate in workers with suspected sensitization affects exhaled nitric oxide [change in exhaled NO levels after allergen challenges].

OBJECTIVE: Nitric oxide (NO) levels in the exhaled air of asthmatic patients have been shown to be increased. This observation has also been reported in workers who are allergic to laboratory animals. To determine if a challenge test with natural rubber latex (NRL) or 4,4'-diphenylmethane diisocyanate (MDI) would also produce an increase of NO exhalation in sensitized patients, we carried out this study. METHODS: Nine subjects with suspected occupational asthma were exposed to MDI, and 18 took part in a challenge test with gloves powdered with NRL. Nineteen subjects underwent a challenge test with methacholine (MCh). Exhaled NO was measured by a modified chemiluminescence analyzer according to the European Respiratory Society guidelines. RESULTS: We found that there was a decrease in exhaled NO concentrations 16-18 h after MCh challenge testing and subsequent bronchodilation with salbutamol, in three subjects. Three of nine participants had a significant immediate bronchial obstruction after exposure to MDI, of those three, two had MDI-specific IgE antibodies. After 22 h, their levels of exhaled NO had increased > 10 parts per billion (ppb). Eight of the 18 subjects participating in the NRL challenge test displayed an NO concentration increase of at least 10 ppb after 22 h (seven had NRL-specific IgE antibodies). A significant decrease in the one-second forced expiratory volume (FEV1) was documented in four of those eight participants after NRL challenge. CONCLUSIONS: There was no clear relationship between bronchial response, substance-specific IgE antibodies and an increase in exhaled NO levels. However, there was a tendency for subjects with substance-specific IgE antibodies and bronchial reaction to develop an increase in exhaled NO concentration. Further studies are needed to determine if analysis of NO from the lower respiratory tract can become a useful non-invasive tool for detecting lower airway inflammatory response even before clinical symptoms occur.