title: The immune response after fracture trauma is different in old compared to young patients.
abstract: BACKGROUND
  Despite significant medical progress and improved treatment, surgical procedures of proximal femur fractures in older patients are still associated with a high postoperative complication and mortality rate. Recently, several authors investigated the phenomenon of immunoageing, indicating differences in the ageing immune system. The aim of the present multi-center prospective clinical trial was to analyze differences in the posttraumatic immune response of old patients compared to young patients.
  
  
  METHODS
  Blood was collected from young patients (<50 y, n = 20) with long bone fractures (YF), old patients (>70 y, n = 21) with proximal femur fractures (OF) upon clinical admission and within 6 hours after surgery, and two healthy age matched control groups (YH & OH). Serum TRAIL- and cytokine concentrations were analyzed via cytometric bead array, Fas-Ligand and TNF-Receptor-I via ELISA. CD15(+) magnetic bead-isolated neutrophils (PMN) were TUNEL stained.
  
  
  RESULTS
  IL-6 was significantly increased only in OF after trauma and surgery whereas YF patient exhibited a marked decrease of TNF after trauma. Interestingly, a significant increase of GM-CSF serum levels was observed in YF only, whereas OF exhibited a decrease of systemic IFN-γ concentrations after trauma and after surgery. The healthy controls, old and young, had more or less similar inflammation levels. Moreover, TRAIL serum levels were diminished in OF after trauma and even further after surgery whereas in YF this was only observed after the surgical procedure. Fas-L concentrations were reduced only in YF after surgery or trauma. PMN apoptosis was significantly reduced only in YF, indicating activation of the innate immune system.
  
  
  CONCLUSIONS
  In summary, our data suggest that the posttraumatic immune response is differently regulated in old and young trauma patients. The operative procedure further impacts these differences after trauma. Whether the decreased activation of PMNs and phagocytes along with the observed dysregulation of the posttraumatic inflammatory response contributes to the high perioperative mortality rate of the elderly suffering from a proximal femoral fracture requires further investigation.
authors.affiliation: Department of Trauma Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Helen
authors.initials: H
authors.lastname: Vester
authors.affiliation: Department of Orthopedic Trauma, Hand-, Plastic-, and Reconstructive Surgery, University Hospital Ulm, Ulm, Germany.
authors.forename: Markus S
authors.initials: MS
authors.lastname: Huber-Lang
authors.affiliation: Department of Orthopedic Trauma, Hand-, Plastic-, and Reconstructive Surgery, University Hospital Ulm, Ulm, Germany.
authors.forename: Qerim
authors.initials: Q
authors.lastname: Kida
authors.affiliation: Department of Orthopedic Trauma, Hand-, Plastic-, and Reconstructive Surgery, University Hospital Ulm, Ulm, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Scola
authors.affiliation: Department of Trauma Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany.
authors.forename: Martijn
authors.initials: M
authors.lastname: van Griensven
authors.affiliation: Department of Orthopedic Trauma, Hand-, Plastic-, and Reconstructive Surgery, University Hospital Ulm, Ulm, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Gebhard
authors.affiliation: Siegfried Weller Institute for Trauma Research, BG Trauma Center Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Nüssler
authors.affiliation: Department of Orthopedic Trauma, Hand-, Plastic-, and Reconstructive Surgery, University Hospital Ulm, Ulm, Germany ; BG-Trauma Center Murnau, Prof.-Küntscher-Str. 8, 82418 Murnau, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Perl
keywords: Apoptosis; Immunoageing; Inflammation; Trauma