Non-invasive assessment of airway inflammation in ship-engine workers.

Smoking is harmful for respiratory function. In young to middle-aged men the damage is insidious and difficult to demonstrate. The respiratory impairment could increase under specific stressful conditions in the professional environment. On the hypothesis that exhaled markers are useful for assessing airway susceptibility to inhaled irritants, we measured exhaled markers and lung function in smoking and non-smoking engine-driver military coastguards before and after a patrol at sea. Eighteen men, mean age 39 yrs (range 23-58 yrs), 8 smokers, underwent spirometry, exhaled and nasal nitric oxide (eNO, nNO), exhaled carbon monoxide (CO) and exhaled breath condensate (EBC) for measures of hydrogen peroxide (H2O2), leukotriene B4 (LTB4), proteins (Prots), 8-isoprostanes (8-IsoPs), nitrite (NO2-) and nitrosothiols (RS-NOs) at baseline and after an 8-hour patrol navigation on board small, high-speed diesel-powered ships. At baseline, the smokers showed higher middle flows and CO levels, lower eNO and nNO than non-smokers, but similar levels of EBC markers; geometric means (95% confidence interval), CO: 23.6 (14.5 to 38.3) vs. 3.5 (2.5 to 5.3) ppm; eNO: 7.9 (4.8 to 12.9) vs. 26.7 (15.7 to 45.5) ppb, p=0.000. After navigation, Prots, 8-IsoPs and RS-NOs (but not lung function variables or other markers) significantly increased only in smokers; baseline vs post-navigation RS-NOs: 0.27 (0.11 to 0.65) vs. 1.30 (0.58 to 2.89) micromol, p=0.012. The respiratory consequences of a stressing environment in engine-driver military coastguards who actively smoke are better assessed by measuring EBC markers than by eNO, nNO or lung function. By increasing airway inflammation from oxidative-stress, tobacco smoking appears to interact with other chemical or physical factors elicited during sea navigation. Precisely what these factors are deserves further investigation.

Immediate skin reactivity to histamine and to allergens in cohorts of 9-year-old schoolchildren studied 16 years apart.

BACKGROUND: Differing or increasing prevalence of positive allergen skin-prick tests observed in Europe could at least in part be explained by population changes in histamine skin reactivity. These changes would also alter the relationship between positive allergen skin-prick tests and serum IgE. OBJECTIVE: To assess changes in histamine reactivity, allergen skin-prick tests and serum IgE in our geographical setting. METHODS: We compared the outcome of two epidemiological surveys conducted 16 years apart in unselected 9-year-old schoolchildren (170 in 1983 and 176 in 1999) from a semi-rural region in central Italy. Outcome measures were skin-prick tests with two histamine concentrations (10 and 1 mg/mL) and 11 locally relevant allergens; serum total and specific IgE for positive allergens. RESULTS: The two histamine concentrations induced significantly larger mean weal diameters in 1999 than in 1983 (10 mg/mL: 5.28+/-0.82 mm vs. 3.25+/-0.97 mm; P<0.001). Whereas the prevalence of subjects with at least one positive allergen-induced weal reaction (>or=3 mm) increased over the 16 years (from 15.3% in 1983 to 25.6% in 1999), the prevalence of positive skin-prick tests, expressed as the allergen/ histamine weal ratio, remained almost unchanged. A given allergen weal diameter yielded less total (P<0.05 by Student's t-test for cumulative weals <8 mm) and specific (P<0.01 by Student's t-test for weals <3 mm, P<0.05 by Kruskal-Wallis test) serum IgE in 1999 than in 1983. CONCLUSIONS: Although the causes and mechanisms remain unclear, the increased histamine skin reactivity over time is associated with an increase in positive allergen skin-prick tests. In the presence of increased tissue and organ susceptibility to histamine, minute amounts of specific IgE could have important biological consequences.