Background Asthma is characterized by increased airway narrowing in response to nonspecific stimuli. The disorder is influenced by both environmental and genetic factors. Exosomes are nanosized vesicles of endosomal origin released from inflammatory and epithelial cells that have been implicated in asthma. In this study we characterized the microRNA (miRNA) content of exosomes in healthy control subjects and patients with mild intermittent asthma both at unprovoked baseline and in response to environmental challenge. Objective To investigate alterations in bronchoalveolar lavage fluid (BALF) exosomal miRNA profiles due to asthma, and following subway air exposure. Methods Exosomes were isolated from BALF from healthy control subjects (n = 10) and patients with mild intermittent asthma (n = 10) after subway and control exposures. Exosomal RNA was analyzed by using microarrays containing probes for 894 human miRNAs, and selected findings were validated with quantitative RT-PCR. Results were analyzed by using multivariate modeling. Results The presence of miRNAs was confirmed in exosomes from BALF of both asthmatic patients and healthy control subjects. Significant differences in BALF exosomal miRNA was detected for 24 miRNAs with a subset of 16 miRNAs, including members of the let-7 and miRNA-200 families, providing robust classification of patients with mild nonsymptomatic asthma from healthy subjects with 72% cross-validated predictive power (Q2 = 0.72). In contrast, subway exposure did not cause any significant alterations in miRNA profiles. Conclusion These studies demonstrate substantial differences in exosomal miRNA profiles between healthy subjects and patients with unprovoked, mild, stable asthma. These changes might be important in the inflammatory response leading to bronchial hyperresponsiveness and asthma.

Abstractit was shown that healthy swine confinement workers have an increased number of inBackground -Inhalation of swine dust causes airway inflammation with influx flammatory cells and other signs of an ongoing inflammatory lung reaction. 3 In healthy, preof inflammatory cells, predominantly neutrophils, into the lungs. A study was viously non-exposed subjects it has been established that inhalation of swine dust causes undertaken to determine whether or not exposure to swine dust induces release of bronchial hyperresponsiveness 4 and an intense airway inflammation as assessed by BAL.5 It interleukin 8 (IL-8) into upper and lower airways and how this possible release is seems probable that inhalation of swine dust also causes an inflammatory response in the related to cellular influx. A further aim was to study the relationship between the upper airways although this has not been studied in detail. The cellular reaction to ininflammatory response and swine dust exposure.haled swine dust in healthy subjects is characterised by a recruitment of inflammatory cells Methods -Thirty one healthy, non-smoking, previously unexposed subjects were (predominantly neutrophilic granulocytes) to the alveolar space, 5 and an increase in several exposed to swine dust during three hours work in a swine house. Bronchoalveolar cytokines, such as IL-1 , IL-1 , 6 and other inflammatory mediators in the lavage (BAL) was performed two weeks before and 24 hours after the exposure (n= BAL fluid. The mechanism for the recruitment of neutrophils is not known. There are many 16). Nasal lavage and acoustic rhinometry were carried out 1-2 hours before and chemoattractants which may contribute to the influx of neutrophils into the airways such as seven hours after the start of the exposure (n=31). Exposure measurements were IL-8, 7 ENA-78, 8 LTB 4 , 9 10 and C5a. 11 Since swine dust is a very potent stimulus for neutroperformed with personal sampling equipment.phil attraction to the airways, the aim of the present study was to investigate whether or not Results -The exposure led to 19-fold and 70-fold increases in the neutrophil con-IL-8, one of the probable chemoattractants for neutrophils, is released in the upper and lower centrations in nasal lavage and BAL fluid, respectively (p<0.001). In BAL fluid macro-airways following exposure to swine dust. phages, lymphocytes and eosinophils increased significantly. The IL-8 levels in BAL fluid increased from <31.3 ng/l to 63 Methods (43-109) ng/l (median (25-75th percentile),  p<0.001), and in nasal lavage fluid Thirty one non-smoking healthy subjects (16 the concentrations increased from 144 men) of mean age 31 (range 18-50) years who (97-227) ng/l to 1064 (864-1437) ng/l had not previously been exposed to farm dust (p<0.001). IL-8 levels showed a significant participated in the study. All subjects denied correlation with the increase in neutro-present or former symptoms of allergy and phils in the nasal lavage fluid but not in airway diseases. They had normal lung function the BAL flui...

Background-Exposure to swine dust causes an intense airway inflammation with increased levels of interleukin 8 (IL-8) and predominantly neutrophils in the nasal and bronchoalveolar lavage fluids of healthy human subjects. It is not clear which components in the swine house environment are responsible for the airway reaction. The aim of the present study was to evaluate and compare the eVect in vitro of swine dust components on human alveolar macrophages and bronchial epithelial cells. Methods-Normal human bronchial epithelial cells (NHBE), human pulmonary epithelial carcinoma cell line (A549), and human alveolar macrophages were stimulated with swine dust, lipopolysaccharides (LPS; present in Gram negative bacteria), grain dust (swine feed components), and glucans (a structural component of fungi) in a dose response manner (1-100 µg/ml). Results-Swine dust at a concentration of 100 µg/ml increased IL-8 production 20 fold in NHBE cells, 28 fold in A549 cells, and 15 fold in macrophages. LPS (100 µg/ml) stimulated all three cell types significantly, in macrophages to the same extent as swine dust, but in NHBE and A549 cells swine dust was 5-8 times as potent. Grain dust (100 µg/ml) had no eVect in A549 cells but stimulated NHBE cells and macrophages. Glucans (100 µg/ ml) stimulated A549 cells and macrophages but not NHBE cells. Both glucans and grain dust were weaker stimuli than swine dust and LPS. The LPS content of swine dust solution was 2.16 (0.2) ng/ 100 µg and of grain dust was 0.53 (0.04) ng/ 100 µg. Conclusions-Swine dust is a strong stimulus for IL-8 production in both bronchial epithelial cells and human alveolar macrophages, whereas LPS has diVerent potency in these cells. (Thorax 1998;53:260-264)

Inhalation of swine-house dust may cause an acute airway inflammatory condition (organic dust toxic syndrome). Thirty-eight healthy subjects were exposed to swine dust while weighing swine for 3 h. We studied the correlation between acute health effects and the inhaled bacterial exposure markers peptidoglycan (the main constituent of the cell walls of gram-positive bacteria, but also present in lesser amounts in gram-negative bacteria) and lipopolysaccharides (LPS; present only in gram-negative bacteria). LPS activity in airborne dust was measured with the Limulus amebocyte lysate assay (LPS(LAL)), and the total LPS was estimated from 3-hydroxy fatty acids, which were measured with gas chromatography-mass spectrometry (GC-MS) (LPS(GC-MS)). Peptidoglycan was estimated from muramic acid measured with GC-MS. The median (25th to 75th percentile) concentration of inhalable dust was 21 (16 to 25) mg/m3. LPS(LAL) was 1.2 (0.9 to 1.4) microg/m3; LPS(GC-MS) was 3.9 (2.5 to 4.9) microg/m3; and the peptidoglycan concentration in airborne dust was 6.5 (2.7 to 13) microg/m3. All exposure markers correlated significantly with an increase in serum interleukin-6. LPS(LAL) showed the highest correlation (r2 = 0.29) and total inhaled dust the lowest (r2 = 0.09). LPS(LAL) also correlated with symptoms and with an increase in bronchial responsiveness and decrease in vital capacity (VC). Peptidoglycan, but not LPS(LAL), correlated with an increase in the blood granulocyte concentration and in body temperature. The results suggest that several microbial agents in inhaled swine-house dust may contribute to acute systemic health effects.

Inhalation of swine dust induces airway inflammation and general symptoms, such as fever and malaise. In the present investigation, the presence and time course of changes in tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in serum were studied to evaluate possible mechanisms by which inhalation of swine dust induces general symptoms. A group of 14 previously nonexposed subjects weighed swine for 3 h. The average +/- SD inhalable dust concentration was 22.4 +/- 4.7 mg/m3 and endotoxin, 1.2 +/- 0.4 microgram/m3. TNF-alpha in serum increased from 2.5 (1.8 to 3.1) ng/L (median, interquartile range) before exposure to maximum values 10.0 (4.6 to 15.7) ng/L between 3 and 5 h after the start of exposure. IL-6 increased from less than 1.5 to 21.4 (18.6 to 33.6) ng/L 4 to 11 h after the start of exposure. Maximum IL-6 occurred 1 to 5 h after the maximum TNF-alpha. In many subjects, however, an early rise in IL-6 parallel to the change in TNF-alpha was seen. The results that some of the peripheral reactions to swine dust might be mediated by TNF-alpha and IL-6. The early rise in IL-6 implies multiple origins of the IL-6.

Physical, psychological, and social features were assessed with standardized methods in 84 early RA patients followed prospectively for 2 years. During this time disease activity decreased, and disability evaluated by HAQ remained small. Psychological distress measured by SCL-90 (Symptom Check List) was in general not very pronounced and fairly stable over time. A high pain level at baseline provided a 4 times higher risk for a high level of psychological distress after 2 years. The prevalence of early retirement was 37% at the end of the study. Physical demanding work and a high initial HAQ score were the best predictors of work disability, increasing the risk of not working 10.7 and 5.5 times, respectively. At least 28% of patients had lower annual income compared to the year before disease onset. The ability to do shopping, home work, leisure time activities and social activities were negatively influenced by the disease in more than half of the patients. The social and economical consequences were thus considerable in the early stages of RA.

Endotoxin exposure is associated with wheeze and asthma morbidity, while early life exposure may reduce risk of allergy and asthma. Unfortunately, it is difficult to compare endotoxin results from different laboratories and environments. We undertook this study to determine if lipopolysaccharide (LPS) extraction efficiency could account for differences among laboratories. We generated and collected aerosols from chicken and swine barns, and corn processing. We randomly allocated side-by-side filter samples to five laboratories for Limulus assay of endotoxin. Lyophilized aliquots of filter extracts were analyzed for 3-hydroxy fatty acids (3-OHFAs) as a marker of LPS using gas chromatography-mass spectrometry. There were significant differences in endotoxin assay and GC-MS (LPS) results between laboratories for all dust types (p < 0.01). Patterns of differences between labs varied by dust type. Relationships between assay and GC/MS results also depended on dust type. The percentages of individual 3-OHFA chain lengths varied across labs (p < 0.0001) suggesting that each lab recovered a different fraction of the LPS available. The presence of large amounts of particle associated LPS and absence of a freezing thawing cycle were associated with lower correlations between LPS and bioactivity, consistent with an absence of Limulus response to cell-bound endotoxin. These data suggest that extraction methods affect endotoxin measurements. The LAL methods may be most suitable when comparing exposures within similar environments; GC-MS offers additional information helpful in optimizing sample treatment and extraction. GC-MS may be of use when comparing across heterogeneous environments and should be considered for inclusion in future studies of human health outcomes.

Background-Acute exposure of healthy subjects to swine house dust causes increased bronchial responsiveness to methacholine but no acute bronchoconstriction. The role of cysteinyl leukotrienes and mast cells in increased bronchial responsiveness is unclear. Methods-Ten non-asthmatic subjects were exposed to swine dust for three hours while weighing pigs in a piggery. Urine was collected prior to and for up to 12 hours after entering the piggery and at the same times five days before and the day after exposure. As indices of whole body leukotriene production and mast cell activation, urinary levels of leukotriene E 4 (LTE 4 ) and 9 ,11 -PGF 2 , the earliest appearing urinary metabolite of prostaglandin D 2 (PGD 2 ), were measured. Bronchial responsiveness to methacholine was determined five days before and the day after the exposure. Results-Methacholine PD 20 FEV 1 decreased from 1.32 mg (95% CI 0.22 to 10.25) before exposure to 0.38 mg (95% CI 0.11 to 1.3) after exposure (p<0.01). Associated with the increase in bronchial responsiveness there was a significant mean diVerence between post-and prechallenge levels of LTE 4 (diVerence 38.5 ng/mmol creatinine (95% CI 17.2 to 59.8); p<0.01) and 9 ,11 -PGF 2 (diVerence 69 ng/mmol creatinine (95% CI 3.7 to 134.3); p<0.05) on the day of exposure to swine dust. Swine dust exposure induced a 24-fold increase in the total cell number and a 12-fold increase in IL-8 levels in the nasal lavage fluid. The levels of LTB 4 and LTE 4 in nasal lavage fluid following exposure also increased 5.5-fold and 2-fold, respectively. Conclusions-The findings of this study indicate that cysteinyl leukotrienes and other mast cell mediators contribute to the development of increased bronchial responsiveness following inhalation of organic swine dust.