@article {6133, title = {Novel gene variants predict serum levels of the cytokines IL-18 and IL-1ra in older adults.}, journal = {Cytokine}, volume = {65}, year = {2014}, month = {2014 Jan}, pages = {10-6}, abstract = {

Activation of inflammatory pathways measured by serum inflammatory markers such as interleukin-18 (IL-18) and interleukin-1 receptor antagonist (IL-1ra) is strongly associated with the progression of chronic disease states in older adults. Given that these serum cytokine levels are in part a heritable trait, genetic variation may predict increased serum levels. Using the Cardiovascular Health Study and InCHIANTI cohorts, a genome-wide association study was performed to identify genetic variants that influence IL-18 and IL-1ra serum levels among older adults. Multiple linear regression models characterized the association between each SNP and log-transformed cytokine values. Tests for multiple independent signals within statistically significant loci were performed using haplotype analysis and regression models conditional on lead SNP in each region. Multiple SNPs were associated with these cytokines with genome-wide significance, including SNPs in the IL-18-BCO gene region of chromosome 2 for IL-18 (top SNP rs2250417, P=1.9{\texttimes}10(-32)) and in the IL-1 gene family region of chromosome 2 for IL-1ra (rs6743376, P=2.3{\texttimes}10(-26)). Haplotype tests and conditional linear regression models showed evidence of multiple independent signals in these regions. Serum IL-18 levels were also associated with a region on chromosome 2 containing the NLRC4 gene (rs12989936, P=2.7{\texttimes}10(-19)). These data characterize multiple robust genetic signals that influence IL-18 and IL-1ra cytokine production. In particular, the signal for serum IL-18 located on chromosome two is novel and potentially important in inflammasome triggered chronic activation of inflammation in older adults. Replication in independent cohorts is an important next step, as well as molecular studies to better understand the role of NLRC4.

}, keywords = {Aged, Aged, 80 and over, Calcium-Binding Proteins, CARD Signaling Adaptor Proteins, Chromosomes, Human, Pair 2, Female, Genetic Variation, Genome-Wide Association Study, Genotype, Haplotypes, Humans, Inflammation, Interleukin 1 Receptor Antagonist Protein, Interleukin-18, Male, Polymorphism, Single Nucleotide}, issn = {1096-0023}, doi = {10.1016/j.cyto.2013.10.002}, author = {Matteini, A M and Li, J and Lange, E M and Tanaka, T and Lange, L A and Tracy, R P and Wang, Y and Biggs, M L and Arking, D E and Fallin, M D and Chakravarti, A and Psaty, B M and Bandinelli, S and Ferrucci, L and Reiner, A P and Walston, J D} } @article {6608, title = {Simple biologically informed inflammatory index of two serum cytokines predicts 10 year all-cause mortality in older adults.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {69}, year = {2014}, month = {2014 Feb}, pages = {165-73}, abstract = {

BACKGROUND: Individual measurements of inflammation have been utilized to assess adverse outcomes risk in older adults with varying degrees of success. This study was designed to identify biologically informed, aggregate measures of inflammation for optimal risk assessment and to inform further biological study of inflammatory pathways.

METHODS: In total, 15 nuclear factor-kappa B-mediated pathway markers of inflammation were first measured in baseline serum samples of 1,155 older participants in the InCHIANTI population. Of these, C-reactive protein, interleukin-1-receptor antagonist, interleukin-6, interleukin-18, and soluble tumor necrosis factor-α receptor-1 were independent predictors of 5-year mortality. These five inflammatory markers were measured in baseline serum samples of 5,600 Cardiovascular Health Study participants. A weighted summary score, the first principal component summary score, and an inflammation index score were developed from these five log-transformed inflammatory markers, and their prediction of 10-year all-cause mortality was evaluated in Cardiovascular Health Study and then validated in InCHIANTI.

RESULTS: The inflammation index score that included interleukin-6 and soluble tumor necrosis factor-α receptor-1 was the best predictor of 10-year all-cause mortality in Cardiovascular Health Study, after adjusting for age, sex, education, race, smoking, and body mass index (hazards ratio = 1.62; 95\% CI: 1.54, 1.70) compared with all other single and combined measures. The inflammation index score was also the best predictor of mortality in the InCHIANTI validation study (hazards ratio 1.33; 95\% CI: 1.17-1.52). Stratification by sex and CVD status further strengthened the association of inflammation index score with mortality.

CONCLUSION: A simple additive index of serum interleukin-6 and soluble tumor necrosis factor-α receptor-1 best captures the effect of chronic inflammation on mortality in older adults among the 15 biomarkers measured.

}, keywords = {Aged, Aged, 80 and over, Biomarkers, C-Reactive Protein, Cohort Studies, Female, Humans, Inflammation, Interleukin 1 Receptor Antagonist Protein, Interleukin-18, Interleukin-6, Longevity, Male, Receptors, Tumor Necrosis Factor, Type I, Risk Factors}, issn = {1758-535X}, doi = {10.1093/gerona/glt023}, author = {Varadhan, Ravi and Yao, Wenliang and Matteini, Amy and Beamer, Brock A and Xue, Qian-Li and Yang, Huanle and Manwani, Bhavish and Reiner, Alexander and Jenny, Nancy and Parekh, Neel and Fallin, M Daniele and Newman, Anne and Bandeen-Roche, Karen and Tracy, Russell and Ferrucci, Luigi and Walston, Jeremy} }