title: Immune biomarkers predictive of respiratory viral infection in elderly nursing home residents.
abstract: OBJECTIVE
  To determine if immune phenotypes associated with immunosenescence predict risk of respiratory viral infection in elderly nursing home residents.
  
  
  METHODS
  Residents ≥ 65 years from 32 nursing homes in 4 Canadian cities were enrolled in Fall 2009, 2010 and 2011, and followed for one influenza season. Following influenza vaccination, peripheral blood mononuclear cells (PBMCs) were obtained and analysed by flow cytometry for T-regs, CD4+ and CD8+ T-cell subsets (CCR7+CD45RA+, CCR7-CD45RA+ and CD28-CD57+) and CMV-reactive CD4+ and CD8+ T-cells. Nasopharyngeal swabs were obtained and tested for viruses in symptomatic residents. A Cox proportional hazards model adjusted for age, sex and frailty, determined the relationship between immune phenotypes and time to viral infection.
  
  
  RESULTS
  1072 residents were enrolled; median age 86 years and 72% female. 269 swabs were obtained, 87 were positive for virus: influenza (24%), RSV (14%), coronavirus (32%), rhinovirus (17%), human metapneumovirus (9%) and parainfluenza (5%). In multivariable analysis, high T-reg% (HR 0.41, 95% CI 0.20-0.81) and high CMV-reactive CD4+ T-cell% (HR 1.69, 95% CI 1.03-2.78) were predictive of respiratory viral infection.
  
  
  CONCLUSIONS
  In elderly nursing home residents, high CMV-reactive CD4+ T-cells were associated with an increased risk and high T-regs were associated with a reduced risk of respiratory viral infection.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jennie
authors.initials: J
authors.lastname: Johnstone
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Robin
authors.initials: R
authors.lastname: Parsons
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Fernando
authors.initials: F
authors.lastname: Botelho
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jamie
authors.initials: J
authors.lastname: Millar
authors.affiliation: Canadian Center for Vaccinology, IWK Health Centre and Capital Health, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Shelly
authors.initials: S
authors.lastname: McNeil
authors.affiliation: Department of Medicine, Geriatrics Division, Research Center on Aging, University of Sherbrooke, Sherbrooke, Quebec, Canada.
authors.forename: Tamas
authors.initials: T
authors.lastname: Fulop
authors.affiliation: Department of Medicine, Northern Ontario School of Medicine, Sudbury, Ontario, Canada.
authors.forename: Janet
authors.initials: J
authors.lastname: McElhaney
authors.affiliation: Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Melissa K
authors.initials: MK
authors.lastname: Andrew
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Walter
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada; Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: P J
authors.initials: PJ
authors.lastname: Devereaux
authors.affiliation: Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Mehrnoush
authors.initials: M
authors.lastname: Malekesmaeili
authors.affiliation: Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada; Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Brinkman
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada; Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Mahony
authors.affiliation: McMaster Immunology Research Centre, McMaster University, Hamilton, Ontario, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada; Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bramson
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada; Department of Medicine, McMaster University, Hamilton, Ontario, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada; Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mark
authors.initials: M
authors.lastname: Loeb
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism*; D002170:Canada; D015331:Cohort Studies; D003587:Cytomegalovirus / Q000276:immunology; D003586:Cytomegalovirus Infections / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D009735:Nursing Homes; D010641:Phenotype; D012141:Respiratory Tract Infections / Q000276:immunology* / Q000821:virology*; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D015415:Biomarkers