title: The usefulness of neutrophil CD64 expression for diagnosing infection after orthopaedic surgery in dialysis patients.
abstract: BACKGROUND
  Dialysis patients undergoing orthopaedic surgery are at high risk for postoperative infection. Diagnosis of postoperative infection is difficult in dialysis patients due to presentation of signs and symptoms similar to infection, such as fever and elevated inflammatory marker levels. Neutrophil CD64 expression (CD64), a marker of infection, is upregulated by microbial wall components and several cytokines (interferon-γ and tumor necrosis factor-α). The purpose of this study is to evaluate the usefulness of CD64 for diagnosing postoperative infection in dialysis patients post orthopaedic surgery.
  
  
  METHODS
  Between 2013 and 2014, we prospectively studied 36 dialysis patients (18 men, 18 women; mean age 65.9 years; 49 to 83) who underwent orthopaedic surgery. Dialysis patients were classified into three groups according to their postoperative course as follows; non-infected patients, infection suspected patients, and infected patients. Inflammatory markers such as white blood cell count (WBC), C-reactive protein (CRP) and CD64 were measured before operation and one week after surgery. Using the receiver-operating characteristic (ROC) curve and Akaike's Information Criterion (AIC), the cutoff value of CD64 and CRP was calculated leading to a determination of which inflammatory marker is best accurate for detecting postoperative infection.
  
  
  RESULTS
  We found that postoperative CD64 and CRP levels presented a statistically significant difference between infected patients and non-infected patients (p < 0.05). Furthermore, comparison of the ROC curve and AIC value between postoperative CD64 and CRP levels exhibited that CD64 was more accurate infectious marker than CRP.
  
  
  CONCLUSIONS
  CD64 is a useful marker for detecting postoperative infection after orthopaedic surgery in dialysis patients.
authors.affiliation: Department of Spine and Orthopaedic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan; Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. Electronic address: tooru_doi@yahoo.co.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Doi
authors.affiliation: Hakucho, Geriatric Health Care Facility for the Elderly, Tokyo, Japan.
authors.forename: Tokuhide
authors.initials: T
authors.lastname: Doi
authors.affiliation: Department of Spine and Orthopaedic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Kawamura
authors.affiliation: Department of Rheumatology, Sagamihara National Hospital, National Hospital Organization, Kanagawa, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Matsui
authors.affiliation: Department of Clinical Laboratory, Sagamihara National Hospital, National Hospital Organization, Kanagawa, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Komiya
authors.affiliation: Department of Spine and Orthopaedic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Zaika
authors.initials: Z
authors.lastname: Tei
authors.affiliation: Department of Spine and Orthopaedic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Gaku
authors.initials: G
authors.lastname: Niitsuma
authors.affiliation: Department of Spine and Orthopaedic Surgery, Japanese Red Cross Medical Center, Tokyo, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Kunogi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000009:adverse effects*; D011237:Predictive Value of Tests; D012372:ROC Curve; D017452:Receptors, IgG / Q000097:blood*; D006435:Renal Dialysis; D051437:Renal Insufficiency / Q000150:complications / Q000628:therapy; D013530:Surgical Wound Infection / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology
chemical_list: D017452:Receptors, IgG; D002097:C-Reactive Protein