title: CD4:8 ratio >5 is associated with a dominant naive T-cell phenotype and impaired physical functioning in CMV-seropositive very elderly people: results from the BELFRAIL study.
abstract: A subset of older people is at increased risk of hospitalization and dependency. Emerging evidence suggests that immunosenescence reflected by an inverted CD4:8 ratio and cytomegalovirus (CMV) seropositivity plays an important role in the pathophysiology of functional decline. Nevertheless, the relation between CD4:8 ratio and functional outcome has rarely been investigated. Here, CD4:8 ratio and T-cell phenotypes of 235 community-dwelling persons aged ≥81.5 years in the BELFRAIL study and 25 younger persons (mean age 28.5 years) were analyzed using polychromatic flow cytometry. In the elderly persons, 7.2% had an inverted CD4:8 ratio, which was associated with CMV seropositivity, less naive, and more late-differentiated CD4+ and CD8+ T cells. However, 32.8% had a CD4:8 ratio >5, a phenotype associated with a higher proportion of naive T cells and absent in young donors. In CMV seropositives, this subgroup had lower proportions of late-differentiated CD4+ and CD8+ T cells and weaker anti-CMV immunoglobulin G reactivity. This novel naive T-cell-dominated phenotype was counterintuitively associated with a higher proportion of those with impaired physical functioning in the very elderly people infected with CMV. This underscores the notion that in very elderly people, not merely CMV infection but also the state of its accompanying immune dysregulation is of crucial importance with regard to physical impairment.
authors.affiliation: Department of General Practice, Katholieke Universiteit Leuven (KUL), Belgium. Institute of Health and Society, Université Catholique de Louvain (UCL), Brussels, Belgium. wim.adriaensen@med.kuleuven.be.
authors.forename: Wim
authors.initials: W
authors.lastname: Adriaensen
authors.affiliation: Department of Internal Medicine II, Centre for Medical Research, University of Tübingen, Germany.
authors.forename: Evelyna
authors.initials: E
authors.lastname: Derhovanessian
authors.affiliation: Department of General Practice, Katholieke Universiteit Leuven (KUL), Belgium. Institute of Health and Society, Université Catholique de Louvain (UCL), Brussels, Belgium.
authors.forename: Bert
authors.initials: B
authors.lastname: Vaes
authors.affiliation: Department of General Practice, Katholieke Universiteit Leuven (KUL), Belgium. Institute of Health and Society, Université Catholique de Louvain (UCL), Brussels, Belgium.
authors.forename: Gijs
authors.initials: G
authors.lastname: Van Pottelbergh
authors.affiliation: Department of General Practice, Katholieke Universiteit Leuven (KUL), Belgium. Institute of Health and Society, Université Catholique de Louvain (UCL), Brussels, Belgium.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Degryse
authors.affiliation: Department of Internal Medicine II, Centre for Medical Research, University of Tübingen, Germany.
authors.forename: Graham
authors.initials: G
authors.lastname: Pawelec
authors.affiliation: Institute of Medical Virology and Epidemiology of Viral Disease, University Hospital, Eberhard-Karls University, Tübingen, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hamprecht
authors.affiliation: Vaccine and Infectious Disease Institute, University of Antwerp, Belgium.
authors.forename: Heidi
authors.initials: H
authors.lastname: Theeten
authors.affiliation: Department of General Practice, Katholieke Universiteit Leuven (KUL), Belgium. Institute of Health and Society, Université Catholique de Louvain (UCL), Brussels, Belgium.
authors.forename: Catharina
authors.initials: C
authors.lastname: Matheï
mesh_terms: D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology; D001530:Belgium; D016516:CD4-CD8 Ratio; D016022:Case-Control Studies; D015331:Cohort Studies; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D016330:Frail Elderly; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D010641:Phenotype; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D007074:Immunoglobulin G
keywords: CD4:8 ratio; Cytomegalovirus.; Physical functioning; T-cell subsets; Very elderly people