title: Older Patients Are Immunocompromised by Cytokine Depletion and Loss of Innate Immune Function After HIP Fracture Surgery.
abstract: OBJECTIVE
  We have examined the immune status of elderly patients who underwent surgery for a hip fracture, an injury associated with poor postoperative outcomes, to identify specific immune defects.
  
  
  METHODS
  In a cohort observational study, 16 patients undergoing surgery for hip fractures had immune function evaluation prior to surgery, and then at 3 and 7 days postoperatively, using flow cytometry for phenotype and for monocyte and granulocyte phagocytic function and respiratory burst. Serum samples were stored and batch analyzed using a human cytokine 25-plex panel.
  
  
  RESULTS
  We report significant loss of innate immune function, related specifically to reduced granulocyte numbers by day 7 (P < .0001, flow cytometry; P < .05 white blood cells), and although granulocyte ability to take up opsonized Escherichia coli was increased (P < .05), the ability of those cells to generate a respiratory burst was reduced at days 3 and 7 (P < .05). Monocyte respiratory burst was also significantly reduced (P < .05). Serum cytokine levels indicated very poor T-cell function.
  
  
  CONCLUSIONS
  We have demonstrated that the antimicrobial immune response is profoundly reduced after surgery in elderly patients with hip fractures. The effect was sustained up to 7 days postoperatively, identifying these patients as particularly vulnerable to bacterial infections.
authors.affiliation: Deakin University Medical School, Warrnambool Clinical School, Victoria, Australia.
authors.forename: Alasdair G
authors.initials: AG
authors.lastname: Sutherland
authors.affiliation: Section of Immunology and Infection, University of Aberdeen, Foresterhill, United Kingdom.
authors.forename: Alistair
authors.initials: A
authors.lastname: Cook
authors.affiliation: Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, United Kingdom.
authors.forename: Clare
authors.initials: C
authors.lastname: Miller
authors.affiliation: Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, United Kingdom.
authors.forename: Linda
authors.initials: L
authors.lastname: Duncan
authors.affiliation: Division of Applied Medicine, School of Medicine and Dentistry, Iain Fraser Cytometry Centre, University of Aberdeen, Foresterhill, United Kingdom.
authors.forename: Raif
authors.initials: R
authors.lastname: Yuecel
authors.affiliation: Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, United Kingdom.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Heys
authors.affiliation: Division of Applied Medicine, School of Medicine and Dentistry, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, United Kingdom.
authors.forename: James D
authors.initials: JD
authors.lastname: Hutchison
authors.affiliation: Section of Immunology and Infection, University of Aberdeen, Foresterhill, United Kingdom.
authors.forename: Janet
authors.initials: J
authors.lastname: Liversidge
keywords: T cells; cellular immunology; cytokines; innate immunity; monocytes