An elevated pro-inflammatory cytokine profile in multiple chemical sensitivity.
BACKGROUND
Multiple chemical sensitivity (MCS) is a medically unexplained condition characterized by reports of recurrent unspecific symptoms attributed to exposure to low levels of common volatile chemicals. The etiology of MCS is poorly understood, but dysregulation of the immune system has been proposed as part of the pathophysiology.


OBJECTIVE
To compare plasma levels of cytokines in Danish MCS individuals with a healthy, sex- and age-matched control group.


METHODS
Blood samples were obtained from 150 un-exposed MCS individuals and from 148 age- and sex-matched healthy controls. Plasma concentrations of 14 cytokines, chemokines and growth and allergen-specific IgE were measured. All participants completed a questionnaire including questions on MCS, psychological distress, morbidities and medication use at the time of the study.


RESULTS
Plasma levels of interleukin-1β, -2, -4, and -6 were significantly (P<0.001) increased in the MCS group compared with controls, tumor necrosis factor-α was borderline significantly (P=0.05) increased and interleukin-13 was significantly decreased (P<0.001).


CONCLUSIONS
MCS individuals displayed a distinct systemic immune mediator profile with increased levels of pro-inflammatory cytokines and interleukin-2 and inverse regulation of Th2 associated cytokines interleukin-4 and interleukin-13 suggestive of low-grade systemic inflammation, along with a deviating Th2-associated cytokine response not involving IgE-mediated mechanisms.
The Danish Research Centre for Chemical Sensitivities, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, Gentofte, Denmark. Electronic address: thomas.meinertz.dantoft@regionh.dk.
T M
TM
Dantoft
The Danish Research Centre for Chemical Sensitivities, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, Gentofte, Denmark.
J
J
Elberling
Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark, Lyngby, Denmark.
S
S
Brix
Department of Clinical Biochemistry, Copenhagen University Hospital Gentofte, Gentofte, Denmark.
P B
PB
Szecsi
Aleris-Hamlet, Private Hospital, Copenhagen, Denmark.
S
S
Vesterhauge
The Danish Research Centre for Chemical Sensitivities, Department of Dermato-Allergology, Copenhagen University Hospital Gentofte, Gentofte, Denmark.
S
S
Skovbjerg
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015897:Comorbidity; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000150:complications / Q000453:epidemiology; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018777:Multiple Chemical Sensitivity / Q000097:blood* / Q000150:complications / Q000453:epidemiology; D055815:Young Adult
D016207:Cytokines; D018836:Inflammation Mediators
Case–control studies; Cytokines; Immunological regulation; Multiple chemical sensitivity; Sickness behavior