title: Interleukin-6-gene C/G 174 polymorphism in nonagenarian and octogenarian subjects in the BELFAST study. Reciprocal effects on IL-6, soluble IL-6 receptor and for IL-10 in serum and monocyte supernatants.
abstract: In this study, we have assessed any change in the frequency of the GG homozygotes of the 174 IL-6 polymorphism with increasing age, arguing that if IL-6 tracks with functional disability and age-related diseases, then there may be attrition or reduction in the frequency of homozgyous subjects, who produce higher levels of IL-6 in serum, in older survivors in a population. We have tested this hypothesis in a large group of free-living, mentally competent, nonagenarian and octogenarian subjects from the Belfast Elderly Longitudinal Ageing Study-BELFAST study and found that the frequency of GG homozygotes with IL-6-174C/G polymorphism decreases with age by about 10%, compared with young controls. In addition we find that CC homozygotes have higher serum levels of IL-6 levels compared with GG (P=0.055), with reciprocal and significant changes in the anti-inflammatory IL-10 (P=0.05). Both IL-6 and IL-10 were spontaneously produced from separated mononuclear cell monolayers in elderly subjects, with significantly higher levels of secreted IL-10 supernatant levels (P=0.05) at 20 h, for G allele subjects carrying the IL-6-174C/G polymorphism. In conclusion, in the BELFAST study, there appears to be a reduction in the frequency of GG homozygotes in the octo/nonagenarian age group and a higher serum IL-6 level associated with CC homozygotes with reciprocal changes for the anti-inflammatory cytokine IL-10.
authors.affiliation: Department of Geriatric Medicine, Queens University of Belfast, Whitla Medical Building, 97, Lisburn Road, Belfast, UK.
authors.forename: Irene M
authors.initials: IM
authors.lastname: Rea
authors.forename: Owen A
authors.initials: OA
authors.lastname: Ross
authors.forename: Marilyn
authors.initials: M
authors.lastname: Armstrong
authors.forename: Susan
authors.initials: S
authors.lastname: McNerlan
authors.forename: Denis H
authors.initials: DH
authors.lastname: Alexander
authors.forename: Martin D
authors.initials: MD
authors.lastname: Curran
authors.forename: Derek
authors.initials: D
authors.lastname: Middleton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics / Q000276:immunology*; D003470:Culture Media; D005260:Female; D005838:Genotype; D006801:Humans; D016753:Interleukin-10 / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood* / Q000235:genetics*; D008297:Male; D009000:Monocytes / Q000378:metabolism; D009660:Northern Ireland; D011110:Polymorphism, Genetic; D019947:Receptors, Interleukin-6 / Q000235:genetics*; D012995:Solubility
chemical_list: D003470:Culture Media; D015850:Interleukin-6; D019947:Receptors, Interleukin-6; D016753:Interleukin-10