The change in nasal inflammatory markers after intranasal challenges with particulate chitin and lipopolysaccharide: a randomized, double-blind, placebo-controlled, crossover study with a positive control

Respiratory diseases and allergy in farmers working with livestock: a EAACI position paper

Farmers constitute a large professional group worldwide. In developed countries farms tend to become larger, with a concentration of farm operations. Animal farming has been associated with negative respiratory effects such as work-related asthma and rhinitis. However, being born and raised or working on a farm reduces the risk of atopic asthma and rhinitis later in life. A risk of chronic bronchitis and bronchial obstruction/COPD has been reported in confinement buildings and livestock farmers. This position paper reviews the literature linking exposure information to intensive animal farming and the risk of work-related respiratory diseases and focuses on prevention. Animal farming is associated with exposure to organic dust containing allergens and microbial matter including alive microorganisms and viruses, endotoxins and other factors like irritant gases such as ammonia and disinfectants. These exposures have been identified as specific agents/risk factors of asthma, rhinitis, chronic bronchitis, COPD and reduced FEV₁. Published studies on dust and endotoxin exposure in livestock farmers do not show a downward trend in exposure over the last 30 years, suggesting that the workforce in these industries is still overexposed and at risk of developing respiratory disease. In cases of occupational asthma and rhinitis, avoidance of further exposure to causal agents is recommended, but it may not be obtainable in agriculture, mainly due to socio-economic considerations. Hence, there is an urgent need for focus on farming exposure in order to protect farmers and others at work in these and related industries from developing respiratory diseases and allergy.

Mucosal Vaccine Approaches for Prevention of HIV and SIV Transmission

Optimal protective immunity to HIV will likely require that plasma cells, memory B cells and memory T cells be stationed in mucosal tissues at portals of viral entry. Mucosal vaccine administration is more effective than parenteral vaccine delivery for this purpose. The challenge has been to achieve efficient vaccine uptake at mucosal surfaces, and to identify safe and effective adjuvants, especially for mucosally administered HIV envelope protein immunogens. Here, we discuss strategies used to deliver potential HIV vaccine candidates in the intestine, respiratory tract, and male and female genital tract of humans and nonhuman primates. We also review mucosal adjuvants, including Toll-like receptor agonists, which may adjuvant both mucosal humoral and cellular immune responses to HIV protein immunogens.

Adaptation to Occupational Exposure to Moderate Endotoxin Concentrations: A Study in Sewage Treatment Plants in Germany

Acute or chronic inhalation of endotoxin may lead to changes of lung function and inflammatory markers in the airways. Adaptation to workplace exposure may be possible. In this study, we investigated the possible difference in inflammatory markers assessed in nasal lavage fluid (NALF) in chronical exposure compared to voluntary subjects exposed acutely to endotoxin. We sought to define the variability of inflammatory markers in NALF and the dose-related changes after moderate exposure in naïve subjects. Endotoxin exposure (4-1039 EU/m³) resulted from routine work during one shift in sewage treatment plants. Subjects were matched to pairs (8 workers escorted by 10 students). Inflammatory markers were investigated before, directly after, and 16 h after the shift end. Additional NALF samples were collected in students without any specific exposure after 3 days. In NALF, total cell count, and interleukin (IL)-8 and IL-1β concentrations were significantly higher in workers than in students at all times pointing to workplace-related long-lasting exposure resulting in adaptation. However, concentration of inflammatory markers without specific exposure in students showed a great variability, covering the whole range of values recorded in the workers. The findings of this study make us to recommend a repeated assessment of inflammatory markers in healthy volunteers before the investigation of exposure-related changes and a sample size adequate for statistical analysis.

Chemical Exposure-Induced Changes in the Expression of Neurotrophins and Their Receptors in the Main Olfactory System of Mice Lacking TRPM5-Expressing Microvillous Cells

Functional maintenance of the mammalian main olfactory epithelium (MOE) is challenging because of its direct exposure to a wide spectrum of environmental chemicals. We previously reported that transient receptor potential channel M5-expressing microvillous cells (TRPM5-MCs) in the MOE play an important role in olfactory maintenance. To investigate the underpinning mechanisms, we exposed transcription factor Skn-1a knockout (Skn-1a-/-) mice lacking TRPM5-MCs, and TRPM5-GFP mice to either vehicle (water) or a mixture of odorous chemicals and chitin for two weeks and analyzed the expression of olfactory signaling proteins using immunolabeling and neurotrophin (NT) and NT receptor (NTR) gene transcripts using real-time quantitative PCR. The chemical exposure did not significantly attenuate the immunolabeling of olfactory signaling proteins. Vehicle-exposed Skn-1a-/- and TRPM5-GFP mice expressed similar levels of NT and NTR gene transcripts in the MOE and olfactory bulb. Chemical exposure significantly increased MOE expression of p75NTR in Skn-1a-/- mice, while p75NTR expression was reduced in TRPM5-GFP mice, as compared to vehicle-exposed mice. Additionally, our RNA in situ hybridization analysis and immunolabeling confirmed MOE expression of most NTs and NTRs. Together, these results indicate that TRPM5-MCs and chemical exposure influence expression of some NTs and NTRs in the MOE and olfactory bulb (OB).

Pulmonary illness as a consequence of occupational exposure to shrimp shell powder

OBJECTIVES

An employee with no prior history of allergy or asthma, experienced respiratory and flu-like symptoms during production of shrimp shell powder in a seafood savory factory in Norway. We aimed to clarify the diagnosis and to identify the cause of the symptoms by specific inhalation challenge (SIC) and by characterizing the powder's biocontaminants, particle size fractions and inflammatory potential.

METHODS

Respiratory and immunological responses were measured the day before and after each of four challenges with 20-150g shrimp shell powder during three consecutive days. The powder was analyzed for endotoxin, microorganisms and particle size fractions by standardized laboratory methods. Total inflammatory potential was quantified by reactive oxygen species (ROS) production in a granulocyte assay.

RESULTS

The patient had elevated IgG, but not IgE, towards shrimp shell powder. 20min challenge with 150g shrimp shell powder induced 15% decrease in FVC, 23% decrease in FEV1 and increased unspecific bronchial reactivity by methacholine. Neutrophils and monocytes increased 84% and 59%, respectively, and the patient experienced temperature increase and flu-like symptoms. The shrimp shell powder contained 1118 endotoxin units/g and bacteria including Bacillus cereus, and 57% respirable size fraction when aerosolized. The ROS production was higher for shrimp shell powder than for endotoxin alone.

CONCLUSIONS

Endotoxin and other bacterial components combined with a high fraction of respirable dust might be the cause of the symptoms. The patient's characteristics and response to SIC were best compatible with occupational asthma and organic dust toxic syndrome, while hypersensitivity pneumonitis could not be excluded.