title: Prospective analysis of human leukocyte functional tests reveals metal sensitivity in patients with hip implant.
abstract: BACKGROUND
  The aim of the study was to examine the reactivity of peripheral human leukocytes to various metal ions prior and following hip replacement in order to investigate implant-induced metal sensitivity.
  
  
  METHODS
  Three patient groups were set up: (1) individuals without implants and no history of metal allergy (7 cases), (2) individuals without implants and known history of metal allergy (7 cases), and (3) patients undergoing cementless hip replacement (40 cases). Blood samples were taken in groups 1 and 2 at three different occasions; in group 3, prior and 3, 6, 12, 24, and 36 months after surgery. Peripheral leukocytes were separated and left either untreated or challenged with Ti, NiCl₂, CoCl₂, CrCl₃, and phytohemagglutinin. Cell proliferation, cytokine release, and leukocyte migration inhibition assays were performed. Metal-induced reactivity was considered when all three assays showed significant change. Skin patch tests were also carried out.
  
  
  RESULTS
  Both skin patch tests and leukocyte functional tests were negative in group 1, and both were positive in group 2. In group 3, after 6 months, 12% of the patients showed reactivity to the tested metals except for NiCl2. Following the 36-month period, 18% of group three became sensitive to metals (including all the earlier 12%). In contrast, patch tests were negative at each time point in group 3.
  
  
  CONCLUSIONS
  Orthopedic implant material may induce metal reactivity after implantation in a manner where susceptibility is yet to be elucidated. Leukocyte triple assay technique might be a useful tool to test implant material-related sensitivity.
authors.affiliation: Department of Orthopedic Surgery, Institute of Musculoskeletal Surgery, University of Pécs Clinical Center, 1 Akác utca, Pécs 7632, Hungary. csabavermes@hotmail.com
authors.forename: Csaba
authors.initials: C
authors.lastname: Vermes
authors.forename: József
authors.initials: J
authors.lastname: Kuzsner
authors.forename: Tamás
authors.initials: T
authors.lastname: Bárdos
authors.forename: Péter
authors.initials: P
authors.lastname: Than
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D054441:Cell Migration Assays, Leukocyte / Q000379:methods; D049109:Cell Proliferation; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000209:etiology* / Q000276:immunology; D007962:Leukocytes / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D008670:Metals / Q000009:adverse effects* / Q000276:immunology; D008875:Middle Aged; D010328:Patch Tests; D011184:Postoperative Period; D011446:Prospective Studies
chemical_list: D016207:Cytokines; D008670:Metals