Influence of socioeconomic status trajectories on innate immune responsiveness in children.
OBJECTIVE
Lower socioeconomic status (SES) is consistently associated with poor health, yet little is known about the biological mechanisms underlying this inequality. In children, we examined the impact of early-life SES trajectories on the intensity of global innate immune activation, recognizing that excessive activation can be a precursor to inflammation and chronic disease.


METHODS
Stimulated interleukin-6 production, a measure of immune responsiveness, was analyzed ex vivo for 267 Canadian schoolchildren from a 1995 birth cohort in Manitoba, Canada. Childhood SES trajectories were determined from parent-reported housing data using a longitudinal latent-class modeling technique. Multivariate regression was conducted with adjustment for potential confounders.


RESULTS
SES was inversely associated with innate immune responsiveness (p=0.003), with persistently low-SES children exhibiting responses more than twice as intense as their high-SES counterparts. Despite initially lower SES, responses from children experiencing increasing SES trajectories throughout childhood were indistinguishable from high-SES children. Low-SES effects were strongest among overweight children (p<0.01). Independent of SES trajectories, immune responsiveness was increased in First Nations children (p<0.05) and urban children with atopic asthma (p<0.01).


CONCLUSIONS
These results implicate differential immune activation in the association between SES and clinical outcomes, and broadly imply that SES interventions during childhood could limit or reverse the damaging biological effects of exposure to poverty during the preschool years.
Women and Children's Health Research Institute, Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada.
Meghan B
MB
Azad
Yuri
Y
Lissitsyn
Gregory E
GE
Miller
Allan B
AB
Becker
Kent T
KT
HayGlass
Anita L
AL
Kozyrskyj
D001249:Asthma / Q000097:blood / Q000276:immunology*; D002478:Cells, Cultured; D002648:Child; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D015850:Interleukin-6 / Q000276:immunology* / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D016014:Linear Models; D008297:Male; D008350:Manitoba; D015999:Multivariate Analysis; D012923:Social Class; D012959:Socioeconomic Factors
D015850:Interleukin-6