Nasal responses to organic dust
from swine confinement buildings are unlinked from pulmonary and systemic
responses
Department
of Pulmonary Medicine,
Background:
Exposure to organic dust at the workplace constitutes a health hazard. Swine
farming is a major industry in
Aim:
We evaluated the impact on the inflammatory and immune system of a short term
three hour exposure in a swine confinement building on 16 persons previously
exposed to this type of work. Here we report on the nasal response to exposure.
Methods:
Participants were selected from a cohort of farm worker apprentices. They were
investigated at baseline, exposed and monitored for up to two weeks after
exposure. Nasal lavage was obtained at five time
points. Cells were counted and typed by differential staining. Cytokines were
evaluated with the CBA kit. As lavage cytokine levels
typically are below 20 pg/ml, the detection threshold
as well as the time dependence and of the kit was explored. The assay was also
compared to ELISA for one solute.
Results:
The CBA assay can be used to determine cytokine concentrations in NAL. It
correlates well with ELISA. There is significant time drift in the CBA signal.
Exposure to swine dust increased cell numbers and cytokine levels in all
participants. IL-1b, IL-6 and IL-8 could be detected, whereas TNF, IL-10 and
IL-12 were below detection threshold. There was no correlation between NAL and
BAL cytokine concentrations, or between NAL cytokines and cells. There was
strong correlation between inhalable endotoxin and total cell number and neutrophil
number. There was no correlation between cytokine concentration and exposure
levels.
Conclusion: There is a significant difference in the
cytokine profiles in the nose, the lung and blood in response to an inflammatory
stimulus. All three organs react to the inflammatory stimulus, but with
different kinetics. There is no united airways, but a
loosely connected conglomerate of tissues, each with its own alarm system.