Circulating lipopolysaccharides in the blood from "bioprotein" production workers.
BACKGROUND
Workers producing bacterial single-cell protein (BSCP), "bioprotein," are exposed to organic dust containing high levels of endoxins (lipopolysaccharides, LPS). Workers in this industry have complained of episodes of fever, fatigue, chest tightness, skin dryness and rubor. The aim of the present study was to quantify LPS and inflammatory mediators in plasma among the workers and non-exposed control subjects.


METHODS
We included eight non-smoking production workers, aged 32-51 (median 38), and eight non-smoking, non-exposed controls, aged 30-51 (median 39). Airborne and plasma endotoxin concentrations were measured, as well as plasma hsCRP and different cytokines, chemokines and metalloproteinases.


RESULTS
The workers who did not use personal respiratory protection were exposed to varying airborne levels of endotoxin, 430 (75-15 000) EU/m3 (median, range). The level of plasma LPS was significantly elevated (p = 0.01) among the workers compared to the non-exposed controls. The workers also had elevated levels of MCP-1 (p = 0.02), MIP-1alpha (p = 0.05) and MMP-3 (p = 0.04). IL-6 and hsCRP were also elevated among the exposed group, but not significantly (p = 0.10 and p = 0.07, respectively).


CONCLUSIONS
In this study, we detected LPS in plasma of individuals exposed to high levels of LPS at their workplace. This finding is supported by elevated levels of several inflammatory cytokines among the workers, significantly exceeding that of the non-exposed control group. To the best of our knowledge, this is the first time that plasma LPS, together with increased inflammatory markers in plasma, has been detected in an occupational setting.
Sikkeland
L I B
LI
Centre for Occupational and Environmental Medicine, Rikshospitalet University Hospital, 0027 Oslo, Norway. liv.sikkeland@rikshospitalet.no
Skogstad
M
M
Ovstebø
R
R
Brusletto
B
B
Haug
K B F
KB
Kongerud
J
J
Eduard
W
W
Kierulf
P
P
D000328:Adult; D000395:Air Pollutants, Occupational / Q000097:blood*; D000821:Animal Feed; D001669:Biochemical Phenomena; D001671:Biochemistry; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D002617:Chemical Industry; D016207:Cytokines / Q000097:blood; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000097:blood*; D008171:Lung Diseases / Q000209:etiology; D008297:Male; D045726:Metalloproteases / Q000097:blood; D020619:Methylococcus capsulatus; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology; D016273:Occupational Exposure
D000395:Air Pollutants, Occupational; D015415:Biomarkers; D016207:Cytokines; D008070:Lipopolysaccharides; D002097:C-Reactive Protein; D045726:Metalloproteases