TY - JOUR
T1 - Variability of serum levels of tumor necrosis factor-alpha, interleukin 6, and soluble interleukin 6 receptor over 2 years in young women
AU - Ho, Gloria Y.F.
AU - Xue, Xiao Nan
AU - Burk, Robert D.
AU - Kaplan, Robert C.
AU - Cornell, Elaine
AU - Cushman, Mary
N1 - Funding Information:
This research was supported by National Institute of Health grants R01CA64247 and R01 AI31055. We thank Dr. Mimi Kim for her advice in statistical analyses.
PY - 2005/4/7
Y1 - 2005/4/7
N2 - Serum levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and soluble interleukin 6 receptor (sIL-6R) have been studied as risk factors of cardiovascular disease in longitudinal studies. However, it is unknown about their long-term intra-individual variations and whether single measurements of these cytokines and receptor are reliable biomarkers in epidemiological studies. In this study, serum levels of TNF-α, IL-6, and sIL-6R were assayed by ELISAs in 36 young, healthy women from whom three blood samples were collected at 12-month intervals over 2 years, and the intraclass correlation coefficients (ICC) were estimated. The ICC of 0.73 (95% CI = 0.49-0.79) for TNF-α was comparable to those of other commonly used biomarkers, justifying its use in epidemiological studies. The ICC of 0.48 (95% CI = 0.25-0.58) for IL-6 was not optimal. However, IL-6 has been demonstrated as a consistent risk factor for cardiovascular disease, suggesting it could still be a useful biomarker if its disease association is substantial. The ICC of 0.36 (95% CI = 0.10-0.47) for sIL-6R was relatively low, and multiple samples would need to be collected in prospective studies for this receptor.
AB - Serum levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and soluble interleukin 6 receptor (sIL-6R) have been studied as risk factors of cardiovascular disease in longitudinal studies. However, it is unknown about their long-term intra-individual variations and whether single measurements of these cytokines and receptor are reliable biomarkers in epidemiological studies. In this study, serum levels of TNF-α, IL-6, and sIL-6R were assayed by ELISAs in 36 young, healthy women from whom three blood samples were collected at 12-month intervals over 2 years, and the intraclass correlation coefficients (ICC) were estimated. The ICC of 0.73 (95% CI = 0.49-0.79) for TNF-α was comparable to those of other commonly used biomarkers, justifying its use in epidemiological studies. The ICC of 0.48 (95% CI = 0.25-0.58) for IL-6 was not optimal. However, IL-6 has been demonstrated as a consistent risk factor for cardiovascular disease, suggesting it could still be a useful biomarker if its disease association is substantial. The ICC of 0.36 (95% CI = 0.10-0.47) for sIL-6R was relatively low, and multiple samples would need to be collected in prospective studies for this receptor.
KW - Interleukin 6
KW - Soluble interleukin 6 receptor
KW - Tumor necrosis factor-alpha
KW - Variability
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U2 - 10.1016/j.cyto.2004.08.008
DO - 10.1016/j.cyto.2004.08.008
M3 - Article
C2 - 15784406
AN - SCOPUS:15244347218
SN - 1043-4666
VL - 30
SP - 1
EP - 6
JO - Cytokine
JF - Cytokine
IS - 1
ER -