Ultrafine Allergic Inflammation Shows Complex Pattern

The journal of allergy and clinical immunology [0091-6749] Alessandrini yr.2006 vol.117 iss.4 pg.824
Effects of ultrafine carbon particle inhalation on allergic inflammation of the lung
Francesca Alessandrini PhDa, c, , , Holger Schulz MDb, c, Shinji Takenaka DVM, PhDb, c, Bernd Lentner BScb, Erwin Karg MScb, c, Heidrun Behrendt MDa, c and Thilo Jakob MDa, d
aFrom the Division of Environmental Dermatology and Allergy, GSF/TUM, ZAUM Center for Allergy and Environment, Neuherberg and Munich
bInstitute of Inhalation Biology
cFocus-Network: Aerosols and Health, GSF National Research Center for Environment and Health, Neuherberg
dDepartment of Dermatology and Allergy Biederstein, Technical University Munich
.
Background
Epidemiologic studies show that exposure to particulate air pollution is associated with asthma exacerbation. Ultrafine particles (diameter <100>adjuvant activity of inhaled elemental carbon ultrafine particles (EC-UFPs) on allergic airway inflammation.
Methods
The effects of ultrafine particle inhalation on allergic airway inflammation was analyzed in ovalbumin-sensitized mice and nonsensitized controls. Particle exposure (526 μg/m3, 24 hours) was performed 24, 96, or 168 hours before or 24 or 72 hours after ovalbumin aerosol challenge. Allergic inflammation was analyzed at different time points after allergen challenge by means of bronchoalveolar lavage cell count and cytokine/total protein assays, lung histology, and airway hyperresponsiveness.
Results
In sensitized mice, inhalation of ultrafine particles 24 hours before allergen challenge caused a significant increase of bronchoalveolar lavage inflammatory cell infiltrate, protein, IL-4, IL-5, and IL-13 compared with relevant controls. These adjuvant effects were dose- and time-dependent and were still present when particle exposure was performed 4 days before allergen challenge. The adjuvant effect of ultrafine particles was also documented by increased mucus production, peribronchiolar and perivascular inflammation, and enhanced airway hyperresponsiveness. In contrast, particle exposure in sensitized mice after allergen challenge caused only moderate effects, such as a delay of inflammatory infiltrate and a reduction of cytokines in bronchoalveolar lavage fluid.
Conclusion
Exposure to ultrafine carbon particles before allergen challenge exerts strong adjuvant effects on the manifestation of allergic airway inflammation. Allergen-sensitized individuals may therefore be more susceptible to detrimental health effects of ultrafine particles.
>>>>>>>>>>>>>>>>>>>
BrooklynDodger(s) comments: Sorting the multiple approaches to ultrafine particle induced respiratory effects in short exposure, acute effect studies will be a task for supporting a framework on chronic exposure. The real life scenario would be continuing exposure to ultrafines with periodic exposure to allegen challenges. The exposure was the previously considered inert carbon at .5 mg/m3, which is a lot compared to environmental references and zilch compared to occupational