Exposure to farming in early life and development of asthma and allergy: a cross-sectional survey

BACKGROUND

A farming environment protects against development of asthma, hay fever, and atopic sensitisation in children. We aimed to establish whether increased exposure to microbial compounds has to occur early in life to affect maturation of the immune system and thereby reduces risk for development of allergic diseases.

METHODS

We did a cross-sectional survey in rural areas of Austria, Germany, and Switzerland. 2618 (75%) of 3504 parents of 6-13-year-old children completed a standardised questionnaire on asthma, hay fever, and atopic eczema. Children from farming families, and a random sample of non-farmers' children, who gave consent for blood samples to be obtained for measurements of specific serum IgE antibodies to common allergens were invited to participate (n=901).

FINDINGS

Exposure of children younger than 1 year, compared with those aged 1-5 years, to stables and consumption of farm milk was associated with lower frequencies of asthma (1% [3/218] vs 11% [15/138]), hay fever (3% [7] vs 13% [18]), and atopic sensitisation (12% [27] vs 29% [40]). Protection against development of asthma was independent from effect on atopic sensitisation. Continual long-term exposure to stables until age 5 years was associated with the lowest frequencies of asthma (0.8% [1/122]), hay fever (0.8% [1]), and atopic sensitisation (8.2% [10]).

INTERPRETATION

Long-term and early-life exposure to stables and farm milk induces a strong protective effect against development of asthma, hay fever, and atopic sensitisation.

Exposure to endotoxin or other bacterial components might protect against the development of atopy

BACKGROUND

Several recent studies have shown that growing up on a farm confers significant protection against the development of atopy. These findings point particularly towards the importance of exposure to stable dust and farm animals. It has furthermore been reported that endotoxin, an intrinsic part of the outer membrane of gram negative bacteria, is abundant in environments where livestock and poultry is kept. The aim of this study was therefore to measure the level of environmental endotoxin exposure in homes of farmers' children, children with regular contact to livestock and control children with no contact to farm animals.

METHODS

Eighty-four farming and nonfarming families were identified in rural areas in Southern Germany and Switzerland. Samples of settled and airborne dust were collected in stables, and of settled dust indoors from kitchen floors and the children's mattresses. Endotoxin concentrations were determined by a kinetic Limulus assay.

RESULTS

Endotoxin concentrations were highest in stables of farming families, but were also significantly higher indoors in dust from kitchen floors (143 EU/mg vs 39 EU/mg, P < 0.001) and children's mattresses (49479 EU/m2 vs 9383 EU/m2, P < 0.001) as compared to control children from nonfarming families. In addition, endotoxin levels were also significantly higher in mattresses and dust from kitchen floors in households where children had regular contact to farm animals (38.6 EU/mg and 23340 EU/m2, respectively) as compared to control subjects.

CONCLUSION

We propose that the level of environmental exposure to endotoxin and other bacterial wall components is an important protective determinant for the development of atopic diseases in childhood.

Inhaled formoterol dry powder versus ipratropium bromide in chronic obstructive pulmonary disease

We compared the effectiveness of inhaled formoterol with that of ipratropium in the treatment of chronic obstructive pulmonary disease (COPD). After a 2-wk run-in period, 780 patients with COPD were randomized to receive for 12 wk formoterol dry powder 12 or 24 microg twice daily, ipratropium bromide 40 microg four times daily, or placebo in a multicenter, double-blind, parallel-group study. The primary efficacy variable was the area under the curve for forced expiratory volume in 1 s (FEV(1)) measured over 12 h after 12 wk of treatment. Secondary variables included diary symptoms and quality of life. Both doses of formoterol and ipratropium significantly increased the area under the curve for FEV(1) in comparison with placebo (all p < 0.001). Both doses of formoterol were also significantly superior to ipratropium (all p < 0.025). Compared with placebo, both doses of formoterol significantly improved symptoms (all p < or = 0.007) and quality of life (p < 0.01 for total scores) whereas ipratropium did not show significant effects (all p > or = 0.3). All study treatments exhibited a similar safety profile. We conclude that formoterol is more effective than ipratropium bromide in the treatment of COPD, as the efficacy of ipratropium on airflow obstruction does not translate into a clinical benefit that patients can perceive.

Characterization of N-acetylcysteine and ambroxol in anti-oxidant therapy

Reactive free oxygen radicals are known to play an important role in the pathogenesis of various lung diseases such as idiopathic pulmonary fibrosis (IPF), adult respiratory distress syndrome (ARDS) or cystic fibrosis (CF). They can originate from endogenous processes or can be part of exogenous exposures (e.g. ozone, cigarette smoke, asbestos fibres). Consequently, therapeutic enhancement of anti-oxidant defence mechanisms in these lung disorders seems a rational approach. In this regard, N-acetyl-L-cysteine (NAC) and ambroxol have both been frequently investigated. Because of its SH group, NAC scavenges H2O2 (hydrogen peroxide), .OH (hydroxol radical), and HOCl (hypochlorous acid). Furthermore, NAC can easily be deacetylated to cysteine, an important precursor of cellular glutathione synthesis, and thus stimulate the cellular glutathione system. This is most evident in pulmonary diseases characterized by low glutathione levels and high oxidant production by inflammatory cells (e.g. in IPF and ARDS). NAC is an effective drug in the treatment of paracetamol intoxication and may even be protective against side-effects of mutagenic agents. In addition NAC reduces cellular production of pro-inflammatory mediators (e.g. TNF-alpha, IL-1). Also, ambroxol [trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexane hydrochloride] scavenges oxidants (e.g. .OH, HOCl). Moreover, ambroxol reduces bronchial hyperreactivity, and it is known to stimulate cellular surfactant production. In addition, ambroxol has anti-inflammatory properties owing to its inhibitory effect on the production of cellular cytokines and arachidonic acid metabolites. For both substances effective anti-oxidant and anti-inflammatory function has been validated when used in micromolar concentrations. These levels are attainable in vivo in humans. This paper gives an up-to-date overview about the current knowledge of the hypothesis that oxidant-induced cellular damage underlies the pathogenesis of many human pulmonary diseases, and it discusses the feasibility of anti-oxidant augmentation therapy to the lung by using NAC or ambroxol.

References values for forced spirometry. Group of the European Community Respiratory Health Survey

The European Coal and Steel Community (ECSC) prediction equations exemplify a significant effort carried out approximately 15 yrs ago to provide uniform standards for lung function testing, but this set of equations has not been properly validated as yet. The present study evaluates the ECSC reference values and four other sets of prediction equations, using spirometric data collected in 12,900 nonasthmatic subjects (43% lifetime nonsmokers and 36% active smokers) aged 20-44 yrs from the European Community Respiratory Health Survey (ECRHS). Standardized spirometric measurements were obtained using a common protocol in 34 centres in 14 countries. For each prediction equation, the prediction deviations (i.e. observed minus predicted value) for forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were examined for the whole study population and for each centre. For the age range included, the errors about the ECSC equations showed the most prominent underestimation of both predicted FVC (+355 and +360 mL on average in males and females, respectively) and predicted FEV1 (+211 and +200 mL, respectively) among the five studies examined. As expected, FVC and FEV1 in active smokers from the ECRHS were significantly lower than in lifetime nonsmokers (each p<0.01). We conclude that the present European recommendations on lung function reference values should be reconsidered, but further data for nonsymptomatic subjects above the age of 44 yrs are needed.

The effect of ozone exposure on allergen responsiveness in subjects with asthma or rhinitis

The aim of this study was to determine whether ozone enhances bronchial responsiveness to allergens in subjects with allergic asthma, or facilitates a bronchial response in subjects with allergic rhinitis. Twenty-four subjects with mild stable allergic asthma, 12 subjects with allergic rhinitis without asthma, and 10 healthy subjects participated in the study. Subjects breathed 250 ppb ozone or filtered air (FA) for 3 h of intermittent exercise. Airway responsiveness to methacholine was determined 1 h before and after exposures, and allergen responsiveness 3 h after exposures. We determined the concentration of methacholine (PC20FEV1) and the dose of allergen (PD20FEV1) producing a 20% fall in FEV1. In the subjects with asthma, FEV1 decreased by 12.5 +/- 2.2% (mean +/- SEM; p = 0.0001), PC20FEV1 of methacholine by 0.91 +/- 0.19 doubling concentrations (p = 0.0001) and PD20FEV1 of allergen by 1.74 +/- 0.25 doubling doses (p < 0.0001) after ozone compared with FA. The changes in lung function, methacholine, and allergen responsiveness did not correlate with each other. In the subjects with rhinitis, mean FEV1 decreased by 7.8% and 1.3% when ozone or FA, respectively, were followed by allergen inhalation (p = 0.035). Therefore, our data suggest that short-term exposure to ozone can increase bronchial allergen responsiveness in subjects with mild allergic asthma or rhinitis.

Prevalence of respiratory symptoms, bronchial hyperresponsiveness and atopy among adults: west and east Germany

The prevalence of respiratory symptoms, atopic sensitization and bronchial hyperresponsiveness was compared in a random sample of adults, 20-44 yrs of age, in two cities in West and East Germany, Hamburg and Erfurt, respectively. There were much higher levels of outdoor air pollution due to sulphur dioxide and suspended particulates in Erfurt, and major differences in living conditions during the last 40 yrs. Within the European Respiratory Health Survey, a short questionnaire was answered by 3,156 (80% response rate) subjects in Hamburg and 3,272 (74%) in Erfurt. A subset of responders to the short questionnaire completed a long questionnaire, spirometry, methacholine or bronchodilator test, skin test, and total and specific immunoglobulin E (IgE) measurements, with a total number of 1,159 participants in Hamburg and 731 in Erfurt. Six out of 8 questions on respiratory symptoms and diagnoses were answered in the affirmative more frequently in Hamburg than in Erfurt. In Hamburg, mean forced expiratory volume in one second (FEV1)% of predicted was 105 vs 107% in Erfurt (p < 0.0001), and bronchial hyperresponsiveness was more frequently observed in Hamburg than in Erfurt (25 vs 19%; p < 0.05). Atopic sensitization was more prevalent in Hamburg than in Erfurt regarding the results of skin tests against grass pollen (24 vs 19%; p < 0.05), birch pollen (19 vs 8%; p < 0.0005), cat (10 vs 2%; p < 0.0005), and Dermatophagoides pteronyssinus (14 vs 10%; p < 0.05). This was reflected by the prevalences of positive specific IgE values, which were higher in Hamburg than in Erfurt for grass (26 vs 20%; p < 0.05), birch (20 vs 10%; p < 0.0005) and cat (12 vs 8%; p < 0.05). In Hamburg, compared to Erfurt, there was: a lower mean number of siblings (p < 0.005); a higher degree of childhood and current exposure to environmental tobacco smoke (p < 0.005); and a higher frequency of fitted carpets and reported mould or mildew inside the house (p < 0.005). Therefore, these data may support the hypothesis that childhood factors and exposure to indoor allergens and irritants may have been more relevant for the development of asthma and atopy than the potential long-term exposure to high concentrations of sulphur dioxide and particulate matter.

Nanoscale chemical imaging by photoinduced force microscopy

Correlating spatial chemical information with the morphology of closely packed nanostructures remains a challenge for the scientific community. For example, supramolecular self-assembly, which provides a powerful and low-cost way to create nanoscale patterns and engineered nanostructures, is not easily interrogated in real space via existing nondestructive techniques based on optics or electrons. A novel scanning probe technique called infrared photoinduced force microscopy (IR PiFM) directly measures the photoinduced polarizability of the sample in the near field by detecting the time-integrated force between the tip and the sample. By imaging at multiple IR wavelengths corresponding to absorption peaks of different chemical species, PiFM has demonstrated the ability to spatially map nm-scale patterns of the individual chemical components of two different types of self-assembled block copolymer films. With chemical-specific nanometer-scale imaging, PiFM provides a powerful new analytical method for deepening our understanding of nanomaterials.

Comparison of the effects of salmeterol and formoterol on airway tone and responsiveness over 24 hours in bronchial asthma

The recent development of new beta 2-adrenoceptor agonists with a duration of action in excess of 12 h may change strategies in the treatment of bronchial asthma. This study aims at the direct comparison of the main representatives of this new class of drugs, formoterol (F) and salmeterol (S), in asthmatic patients over the course of 24 h. Twelve patients with mild bronchial asthma participated in a double-blind, randomized, placebo-controlled clinical trial. In a dose-finding study we determined the protective and bronchodilating effects of 12 and 24 micrograms F aerosol vs 50 and 100 micrograms S 30 min after inhalation. In a 24-h study we investigated the effects of 12 micrograms F and 50 micrograms S on airway tone and responsiveness. Bronchial responsiveness was assessed as the dose of methacholine necessary to decrease FEV1 by 20%. In the dose-finding study, compared with placebo, all doses of F and S equally increased FEV1 (p < 0.003) and protected against inhaled methacholine (p < 0.0001). In the 24-h study 12 micrograms F and 50 micrograms S increased FEV1 and significantly protected against methacholine-induced bronchoconstriction up to 24 h (p < 0.05), compared with placebo. Phase and amplitude of the circadian variation of FEV1 and airway responsiveness were not affected. Clinically recommended doses of aerosolized F (12 micrograms) and S (50 micrograms) have a duration of action up to 24 h and are equally effective at bronchodilation and protection in acute experiments in patients with mild bronchial asthma.

Increased hydrogen peroxide and thiobarbituric acid-reactive products in expired breath condensate of asthmatic patients

Symptoms of bronchial asthma are a manifestation of airway inflammation. Circulatory leucocytes (predominantly eosinophils, mast cells and neutrophils), release inflammatory mediators, including reactive oxygen species, i.e. superoxide anion which is dismutated to hydrogen peroxide (H2O2). Neutrophils from asthmatics generate greater amounts of these species than those of healthy subjects. Some of the H2O2 and thiobarbituric acid-reactive products (TBARs) can evaporate from alveolar lining fluid, and could be expired from the airways of asthmatics. In this study, therefore, we determined whether asthmatic patients exhale more H2O2 and TBARs than healthy subjects. We examined 10 healthy subjects as a control group and 21 asthmatic subjects. In asthmatic subjects, forced expiratory volume in one second (FEV1), was 68+/-9% of predicted value, peak expiratory flow rate (PEFR) was 65+/-8% pred, and bronchial reversibility was 34+/-5% of prebronchodilated FEV1. The mean H2O2 level measured spectrofluorimetrically in the expired breath condensate of asthmatic subjects was 26 fold higher than that in healthy controls (0.26+/-0.29 vs 0.01+/-0.03 nM; p<0.05). The concentration of TBARs in breath condensate was also higher in asthmatic patients compared with nonasthmatics (0.073+/-0.071 vs 0.004+/-0.009 nM; p<0.05). There was a significant correlation between H2O2 level and concentration of TBARs in asthmatic patients (r=0.74; p<0.01). There was also a strong inverse correlation between H2O2 content of all asthmatics and FEV1% pred (r=-0.63; p<0.005) and PEFR% pred (r=-0.52; p<0.05). We conclude that there are elevated levels of hydrogen peroxide and thiobarbituric acid-reactive products in expired breath condensate of asthmatic patients, and that measurement of these substances in the expired breath condensate could be a simple, noninvasive method that could be used as a biochemical marker of airway inflammation.

Long-term administration of N-acetylcysteine decreases hydrogen peroxide exhalation in subjects with chronic obstructive pulmonary disease

Patients with chronic obstructive pulmonary disease (COPD) exhale more hydrogen peroxide (H2O2) and lipid peroxidation products than healthy subjects. This may reflect oxidative stress in the airways that plays important role in the development and progression of COPD. N-acetylcysteine (NAC), a mucolytic drug, possesses antioxidant properties as it is a precursor of reduced glutathione that together with glutathione peroxidase may decompose H2O2 and lipid peroxides. We aimed to determine the effect of NAC, 600 mg effervescent tablets (Fluimucil), once a day for 12 months, and placebo on the concentration of H2O2 and thiobarbituric acid reactive substances (TBARs) in expired breath condensate and serum levels of two lipid peroxidation products (TBARs, lipid peroxides) in patients with COPD. The study was performed as a double-blind, double-dummy comparison between active drug and placebo in two parallel groups. Forty-four outpatients with stable COPD (22 in the NAC group and 22 in the placebo group) completed the study. Specimens of expired breath condensate and serum were collected at the randomization visit and then every 3 months over 1 year. The concentration of TBARs and H2O2 in expired breath condensate was measured spectrofluorimetrically by the thiobarbituric acid and homovanillic acid methods, respectively. Serum levels of lipid peroxides were determined spectrophotometrically after extraction with butanol and pyridine. Initially, H2O2 exhalation did not differ between the placebo and NAC groups up to 6 months of treatment. After this the significant differences were observed. After 9 and 12 months of treatment NAC group exhaled 2.3-fold (0.17+/-0.33 microM vs. 041+/-0.26 microM, P<0.04) [median 0.01 microM, quartile range (qr)=0.22 vs. median 0.15 microM, qr =0.43] and 2.6-fold (0.15+/-0.23 microM vs. 0.40+/-0.25 microN, P<0.05) median = 0.00 microM, qr = 0.23 vs. median = 0.36 microM, qr = 0.51] less H2O2 than placebo receivers, respectively. No significant effect of NAC administration on TBARs exhalation and serum levels of TBARs and lipid peroxides were noted over the whole treatment period. Also no significant associations between exhaled H2O2 and concentrations of lipid peroxidation products were noted in both treatment groups at any time-point. These results indicate that long-term oral administration of NAC attenuates H2O2 formation in the airways of COPD subjects and prove anti-oxidant action of drug. However, further studies are necessary to estimate the clinical significance of this finding.

Respiratory symptoms in European animal farmers

Farmers are known to be at high risk for the development of occupational airway disease. The aim of this European study was to determine which airway symptoms predominate in different types of animal farmers (cattle, pigs, poultry, sheep) and to compare the prevalence of symptoms to the general population. A total of 6,156 randomly selected animal farmers in Denmark, Germany (Schleswig-Holstein, Niedersachsen), Switzerland, and Spain completed a questionnaire on respiratory symptoms and farming characteristics in 1995-1997. The prevalence of general respiratory symptoms was compared to the results of the European Community Respiratory Health Survey (ECRHS) obtained in the same regions. Pig farmers were at highest risk for the development of work-related symptoms. A significant dose-response relationship between daily hours worked inside animal houses and symptoms was established for pig and poultry farmers. Additionally, self-reported nasal allergies (odds ratio (95% confidence interval): 3.92 (3.26-4.71)) and nasal irritation during work (3.98 (3.35-4.73)) were shown to be associated with the development of chronic phlegm. The prevalence of wheezing, shortness of breath, asthma and nasal allergies was signficantly lower among all farmers in the age group 20-44 yrs than among the general population. However, the prevalence of usually bringing up phlegm in winter among farmers was significantly higher than in the general population (9.4 (8.3-10.5%) versus 7.5 (6.5-8.5%)). Individual factors have been shown to be related to the prevalence of chronic phlegm among farmers. Additionally, this study could support the hypothesis that farming could be negatively related to allergic diseases.

Increased content of thiobarbituric acid-reactive substances and hydrogen peroxide in the expired breath condensate of patients with stable chronic obstructive pulmonary disease: no significant effect of cigarette smoking

The imbalance between oxidants and antioxidants is known to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Cigarette smoking is the most frequent factor responsible for development of COPD by leading to oxidant overload in the lower airways, due to presence of its own oxidants and to recruitment and activation of pulmonary phagocytes. We aimed to determine whether (1) patients with stable COPD have higher thiobarbituric acid-reactive substances (TBARs, an end-product of lipid peroxidation) and H2O2 levels in expired breath condensate than healthy subjects who have never smoked; (2) COPD subjects who are current smokers exhale more TBARs and H2O2 than COPD ex-smokers and those who have never smoked; and (3) concentration of TBARs correlates with H2O2 levels in the breath condensate of COPD patients. The TBAR and H2O2 content in expired breath condensate of 17 healthy nonsmoking subjects and 44 patients (11 current smokers, 20 ex-smokers and 13 who had never smoked) with stable COPD [forced expiratory volume in 1 s (FEV1) 63.3 +/- 16.3% and FEV1 reversibility 5.2 +/- 4.3% predicted value] was measured spectrofluorimetrically by the thiobarbituric acid and homovanillic acid methods, respectively. The mean concentrations of TBARs and H2O2 in the expired breath condensate of COPD subjects were 12 (0.48-0.86 microM vs. 0.04 +/- 0.14 microM; P < 0.05) and 10 times (0.48 +/- 0.67 microM vs. 0.05 +/- 0.07 microM; P < 0.005) higher than in healthy controls. Current smokers with COPD did not exhale more H2O2 than COPD ex-smokers and those who had never smoked. TBARs levels shared only a tendency to be higher in the breath condensate of smoking COPD subjects than in that of ex-smokers (0.92 +/- 1.49 microM vs. 0.35 +/- 0.44 microM) and of COPD subjects who had never smoked (0.92 +/- 1.49 microM vs. 0.30 +/- 0.53 microM). No correlation was found between TBAR and H2O2 levels in the whole COPD group. These variables did not correlate with cigarette smoking status and the time from smoking cessation. Subjects with stable COPD exhibit increased lipid peroxidation and H2O2 generation in the airways. Current cigarette smoking does not distinguish COPD subjects with respect to TBARs and H2O2 exhalation.

Increased content of hydrogen peroxide in the expired breath of cigarette smokers

Cigarette smoking causes an influx of mononuclear phagocytes and polymorphonuclear leucocytes into the lower airways. These cells have altered oxygen metabolism and release more H2O2 than phagocytes from nonsmokers. In this study, we intended to determine whether asymptomatic cigarette smokers exhale more H2O2 than healthy nonsmokers. The content of H2O2 in the expired condensate of 27 nonsmokers and 33 cigarette smokers was measured spectrofluorimetrically (homovanillic acid method). The mean H2O2 level in the expired breath condensate of all cigarette smokers was about fivefold higher than that found in the whole nonsmoker group (0.24 +/- 0.32 versus 0.05 +/- 0.11 nM). However, only 16 smokers (49%) and 6 nonsmokers (22%) had detectable levels of H2O2 in expired breath that reached values 0.49 +/- 0.28 and 0.23 +/- 0.10 nM, respectively. Although the cigarette smoking status was similar for both male and female smokers, females expired 2.5 fold less H2O2 than males (0.15 +/- 0.24 (n = 21) versus 0.38 +/- 0.39 (n = 12) nM. No correlation was found between expired H2O2 levels and cigarette smoking status expressed as the daily cigarette consumption, cumulative cigarette consumption and urinary cotinine concentration. It is suggested that in some smokers, expressed H2O2 can be a noninvasive marker of oxidant overload in the lower airways related to cigarette smoking.

Exhalation of H2O2 and thiobarbituric acid reactive substances (TBARs) by healthy subjects

Enhanced exhalation of H2O2 and TBARs have been reported in various inflammatory lung diseases. This may reflect activated phagocytes influx and free radical generation in the airways. However, to apply these compounds as markers of oxidative stress it is necessary to understand factors influencing their exhalation in healthy subjects. We investigated the concentration of H2O2 and TBARs in expired breath condensate (EBC) of 58 healthy volunteers. EBC was collected seven times every 4 h during 24 h and three times every 7 d during 2 consecutive weeks. The H2O2 exhalation revealed diurnal variation with two-peak values 0.45 +/- 0.29 microM and 0.43 +/- 0.22 microM at 12:00 and 24:00 h. The lowest concentrations, 0.26 +/- 0.13 microM and 0.25 +/- 0.26 microM, were found at 20:00 and 8:00 h. Cigarette smokers exhaled about 2.4 times more H(2)O(2) than never smoked subjects. Moreover, in contrast to nonsmokers, cigarette smokers' H2O2 exhalation was stable over 2 week observation. The mean H2O2 concentration estimated over the whole 2 week period was higher in subjects above 40 years regardless of smoking habit, and it positively correlated with age in never smoked subjects (p <.004). Smoking of one cigarette caused 1.8-fold rise in H2O2 exhalation (p <.01). The baseline H2O2 levels correlated with cumulative cigarette consumption (p <.05) and MEF 25% of predicted (p <.05). Neither moderate exercise nor one puff of salbutamol nor ipratropium influenced significantly the concentration of H2O2 and TBARs in EBC. Only 4 of 120 EBC specimens from never smoked subjects revealed detectable levels of TBARs. Cigarette smokers exhaled more TBARs (p <.05) than never smoked volunteers. Our results indicate that healthy never smoked subjects exhale H2O2 with diurnal variation and significant changes over 2 week observation. Cigarette smoking enhanced H2O2 generation in the airways. These results could be useful for planning studies with exhaled H2O2 as a marker of airway inflammation. Occasional detection of TBARs in EBC of never smoked persons may be a result of sufficient antioxidant activity in the airways that protects tissues from peroxidative damage.

Cost of illness of atopic asthma and seasonal allergic rhinitis in Germany: 1-yr retrospective study

The purpose of this study was to evaluate the cost of illness of moderate-to-severe atopic asthma and/or seasonal allergic rhinitis (SAR) in Germany from the perspective of third-party payers (TPP) and patients. Five-hundred patients (276 children/adolescents) with moderate-to-severe asthma and/or SAR were included in this cross-sectional study. Information was collected using a specific patient questionnaire and the abstraction of patient records. Overall, annual costs per patient increased with the severity of atopic asthma and if it was associated with SAR. The average annual cost of SAR was Euro1,089 per child/adolescent and Euro1,543 per adult. Annual costs of severe asthma plus SAR increased to Euro7,928 per child/adolescent and to Euro9,287 per adult. For TPPs, the main cost drivers were medication, hospitalisation, and rehabilitation. The most significant costs for patients were household modifications. For children/adolescents, 60-78% of the expenditures were direct costs, while in adults, 58% of expenditures were indirect costs. It was also observed that patients with moderate and severe asthma used inhaled corticosteroids less frequently than recommended by treatment guidelines. In summary, the total cost for patients increases with the severity of atopic asthma and/or seasonal allergic rhinitis and indirect costs represent a large proportion of the total cost.

Comprehensive mutational analysis of primary and relapse acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by differentiation block at the promyelocyte stage. Besides the presence of chromosomal rearrangement t(15;17), leading to the formation of PML-RARA (promyelocytic leukemia-retinoic acid receptor alpha) fusion, other genetic alterations have also been implicated in APL. Here, we performed comprehensive mutational analysis of primary and relapse APL to identify somatic alterations, which cooperate with PML-RARA in the pathogenesis of APL. We explored the mutational landscape using whole-exome (n=12) and subsequent targeted sequencing of 398 genes in 153 primary and 69 relapse APL. Both primary and relapse APL harbored an average of eight non-silent somatic mutations per exome. We observed recurrent alterations of FLT3, WT1, NRAS and KRAS in the newly diagnosed APL, whereas mutations in other genes commonly mutated in myeloid leukemia were rarely detected. The molecular signature of APL relapse was characterized by emergence of frequent mutations in PML and RARA genes. Our sequencing data also demonstrates incidence of loss-of-function mutations in previously unidentified genes, ARID1B and ARID1A, both of which encode for key components of the SWI/SNF complex. We show that knockdown of ARID1B in APL cell line, NB4, results in large-scale activation of gene expression and reduced in vitro differentiation potential.

Association between exposure to farming, allergies and genetic variation in CARD4/NOD1

BACKGROUND

Caspase recruitment domain protein (CARD) 4 has been recently identified as an intracellular pattern recognition receptor that interacts with muropeptides found in common Gram-negative bacteria. We therefore aimed to explore whether the previously observed inverse association between exposure to microbial products and asthma and allergies in childhood is modified by genetic variation in CARD4.

METHODS

We genotyped 668 children [mean age 9.3 (SD 1.5) years] enrolled in the cross-sectional ALEX study for seven haplotype tagging single nucleotide polymorphisms in CARD4. We studied the association of asthma, hay fever and allergen-specific serum immunoglobulin E with exposure to a farming environment and with levels of endotoxin and muramic acid measured in house dust samples. We tested whether these associations differed between the genotypes of the polymorphisms under study.

RESULTS

A strong protective effect of a farming environment on allergies was only found in children homozygous for the T allele in CARD4/-21596, but not in children carrying the minor allele (C). Among the former, farmers' children had a significantly lower frequency of sensitization against pollen (5.8%), hay fever (1.7%) and atopic asthma symptoms (1.7%) compared with children not living on a farm (19.4%, 13.0% and 7.6%, P<0.01, <0.01 and <0.05, respectively). Conversely, no significant difference in prevalence of these phenotypes by farming status was found among children with a C allele in CARD4/-21596 (14.3%, 7.1% and 8.0%vs 16.5%, 9.0% and 5.7%, respectively).

CONCLUSION

Polymorphisms in CARD4 significantly modify the protective effect of exposure to a farming environment.

Label-free electrochemical impedance biosensor to detect human interleukin-8 in serum with sub-pg/ml sensitivity

Biosensors with high sensitivity and short time-to-result that are capable of detecting biomarkers in body fluids such as serum are an important prerequisite for early diagnostics in modern healthcare provision. Here, we report the development of an electrochemical impedance-based sensor for the detection in serum of human interleukin-8 (IL-8), a pro-angiogenic chemokine implicated in a wide range of inflammatory diseases. The sensor employs a small and robust synthetic non-antibody capture protein based on a cystatin scaffold that displays high affinity for human IL-8 with a K_D of 35±10 nM and excellent ligand specificity. The change in the phase of the electrochemical impedance from the serum baseline, ∆θ(ƒ), measured at 0.1 Hz, was used as the measure for quantifying IL-8 concentration in the fluid. Optimal sensor signal was observed after 15 min incubation, and the sensor exhibited a linear response versus logarithm of IL-8 concentration from 900 fg/ml to 900 ng/ml. A detection limit of around 90 fg/ml, which is significantly lower than the basal clinical levels of 5–10 pg/ml, was observed. Our results are significant for the development of point-of-care and early diagnostics where high sensitivity and short time-to-results are essential.

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A label-free electrochemical impedance-based sensor for the detection of human interleukin-8 (IL-8) in full serum was developed.

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Detection limit of 90 fg/ml and time-to-result of 15 min was found.

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A large dynamic range of the sensor was observed, with sensor response linear vs logarithm of IL-8 concentration from 900 fg/ml to 900 ng/ml.

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The sensor employs a small and robust synthetic non-antibody capture protein, with high stability and excellent ligand specificity.

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Findings are particularly relevant for the development of point-of-care and early diagnosis sensors where high sensitivity and short time-to-results are essential.

Exposure to pets, and the association with hay fever, asthma, and atopic sensitization in rural children

BACKGROUND

An increasing number of studies report pet exposure to be associated with lower risk of asthma and allergies. This 'protective pet effect' has been suggested to result from a modified T-helper (Th)2-cell response, or because of increased microbial load in homes where pets are kept. We examined the associations between pet contact and the occurrence of asthma and allergies in children of the rural Allergy and Endotoxin (ALEX) population, taking farm animal contact, endotoxin and cat allergen levels in mattress dust into account.

METHODS

Information about contact with pets and farm animals, asthma and allergy were collected for 812 children by a standardized parents' questionnaire and an interview. Mattress dust endotoxin and cat allergen levels as well as specific IgE and IgG4 antibodies to Fel d1 were determined.

RESULTS

Current contact with dogs was inversely associated with diagnosed hay fever (OR 0.26, 95% CI 0.11-0.57), diagnosed asthma (OR 0.29, 95% CI 0.12-0.71), sensitization to cat allergen (OR 0.48, 95% CI 0.23-0.99) and to grass pollen (OR 0.55, 95% CI 0.33-0.94), but not with increased IgG4 levels. Early and current contact with cats were associated with reduced risk of wheezing (OR 0.48, 95% CI 0.23-1.00, and OR 0.49, 95% CI 0.26-0.92, respectively) and grass pollen sensitization. Adjustment for farm animal contact but not for endotoxin and cat allergen exposure attenuated these associations and the effect of pet was stronger among farmers' children.

CONCLUSION

Although pet exposure was very frequent in this rural population, the inverse relation between current dog contact, asthma and allergy was mostly explained by simultaneously occurring exposure to stable animals or was restricted to farm children. In addition, a subtle form of pet avoidance may contribute to the protective effect of pet.

[Multimorbidity and successful aging: the population-based KORA-Age study]

BACKGROUND

The objective of the KORA-Age research consortium is to assess the determinants and consequences of multimorbidity in the elderly and to look into reasons for successful aging in the general public.

PATIENTS AND METHODS

In the KORA-Age cohort study 9,197 persons were included who where born in the year 1943 or before and participants of previous KORA cohort studies conducted between 1984 and 2001 (KORA: Cooperative Health Research in the Region of Augsburg). The randomized intervention study KORINNA (Coronary infarct follow-up treatment in the elderly) tested a nurse-based case management program with 338 patients with myocardial infarct and included an evaluation in health economics.

RESULTS

A total of 2,734 deaths were registered, 4,565 participants submitted a postal health status questionnaire and 4,127 participants were interviewed by telephone (response 76.2% and 68.9% respectively). A gender and age-stratified random sample of the cohort consisting of 1,079 persons took part in a physical examination (response 53.8%).

CONCLUSION

The KORA-Age consortium was able to collect data in a large population-based sample and is contributing to the understanding of multimorbidity and successful aging.

Molecular alterations in bone marrow mesenchymal stromal cells derived from acute myeloid leukemia patients

The contribution of molecular alterations in bone marrow mesenchymal stromal cells (BM-MSC) to the pathogenesis of acute myeloid leukemia (AML) is poorly understood. Thus we assessed genome-wide genetic, transcriptional and epigenetic alterations in BM-MSC derived from AML patients (AML BM-MSC). Whole-exome sequencing (WES) of AML BM-MSC samples from 21 patients revealed a non-specific pattern of genetic alterations in the stromal compartment. The only mutation present in AML BM-MSC at serial time points of diagnosis, complete remission and relapse was a mutation in the PLEC gene encoding for cytoskeleton key player Plectin in one AML patient. Healthy donor controls did not carry genetic alterations as determined by WES. Transcriptional profiling using RNA sequencing revealed deregulation of proteoglycans and adhesion molecules as well as cytokines in AML BM-MSC. Moreover, KEGG pathway enrichment analysis unravelled deregulated metabolic pathways and endocytosis in both transcriptional and DNA methylation signatures in AML BM-MSC. Taken together, we report molecular alterations in AML BM-MSC suggesting global changes in the AML BM microenvironment. Extended investigations of these altered niche components may contribute to the design of niche-directed therapies in AML.

Determinants of endotoxin levels in living environments of farmers' children and their peers from rural areas

BACKGROUND

Lower frequencies of asthma and hayfever have been observed in children with contact to livestock. At school age, the amount of endotoxin measured in the dust of children's mattresses is inversely related to the occurrence of atopic asthma, hayfever and atopic sensitization both in children from farming and non-farming households.

OBJECTIVE

The aim of the present study was to investigate which home and lifestyle characteristics of farm and non-farm families contribute to endotoxin levels measured in different indoor home environments.

METHODS

In the framework of the Allergy and Endotoxin (ALEX) Study, endotoxin was measured in dust samples from the living room floor and the child's mattress of 319 farmers' families and 493 non-farming families, and in settled dust from stables. Endotoxin content of all dust samples was determined by a kinetic Limulus assay (Limulus-Amebocyte-Lysate test). Information about the child's activities on farms, home characteristics and cleaning behaviours was obtained from parental questionnaires.

RESULTS

Endotoxin levels in stables did not predict the amount of endotoxin measured in floors or mattresses. However, a dose-dependent association between the child's activity on the farm and indoor home endotoxin levels was observed, both in farm and non-farm children. In non-farm children pet keeping and the frequency of floor cleaning were additionally associated with endotoxin levels, whereas in farm children parental farm activities, study area, time since last cleaning, the mattress type as well as younger age of the children contributed to increased microbial exposure.

CONCLUSION

These results demonstrate that regular contact to farm animals increases indoor home endotoxin concentrations, both in farm and non-farm children, and might thus explain the protective effect of contact to livestock on atopic outcomes. To assess children's individual exposure to a microbial environment, measures of mattress dust exposure are needed as stable endotoxin concentrations were not associated with indoor home levels.

Comparison of hydrogen peroxide generation and the content of lipid peroxidation products in lung cancer tissue and pulmonary parenchyma

Lipid peroxidation, as a well-known index of reactive oxygen species activity, not only in lung biochemistry, is an oxidative process associated with membrane lipid destruction. Also, the oxidative modification of nucleic acids by reactive oxygen species is of remarkable biological importance as it may contribute to malignant conversion, but its exact role in lung cancer biology is still not clear. Our study aimed to investigate the level of lipid peroxidation ex vivo in tumour tissue and lung parenchyma obtained from patients with lung cancer. Forty-two patients with lung cancer were enrolled into the study. During a surgical resection, tumour tissue and lung parenchyma were obtained and concentration of lipid peroxidation products, thiobarbituric acid-reactive substances and Schiff bases, and spontaneous generation of hydrogen peroxide, were measured. The concentration of thiobarbituric acid-reactive substances (P<0.001) in the tumour tissue was higher than that in lung parenchyma. In small cell lung cancer as well as in squamous cell carcinoma patients, a positive correlation between spontaneous generation of hydrogen peroxide in tumour tissue and clinical stage (r = 0.43; r = 0.46; respectively) was found. Our results prove enhanced lipid peroxidation in cancer tissue as compared with matched-lung parenchyma. In small cell lung cancer and squamous cell carcinoma patients, the high level of oxidative stress, expressed as a spontaneous generation of hydrogen peroxide in tumour tissue, was associated with clinical progression of tumour's stage.

Needlestick injuries during medical training

Medical students are at risk of acquiring infections caused by needlestick injuries, although it is unknown when needlestick injuries are most likely to occur during medical training. The aim of this study was to define high-risk periods over the course of medical training. A cross-sectional study was conducted among medical students in the first, third, fourth and fifth years of training at two medical schools in Munich. Overall, 1317 (85%) students returned a questionnaire on demographic data, vaccination status against hepatitis B, lifetime prevalence of needlestick injuries, level of knowledge about measures after such accidents, and transmission risks. Lifetime prevalence of needlestick injuries was 23%, ranging from 12% in first year students to 41% in fourth year students. These accidents happened most commonly during medical internships, especially during blood-taking practices; an activity that usually starts during the third year of training. The frequency of respondents not vaccinated against hepatitis B also varied between first (21%) and fourth (6.6%) year students. Needlestick injuries occur frequently and early on in medical training. In order to decrease the risk of preventable infections, complete coverage of vaccination against hepatitis B should be achieved early in medical training.