title: Increased metal allergy in patients with failed metal-on-metal hip arthroplasty and peri-implant T-lymphocytic inflammation.
abstract: BACKGROUND
  In 16 patients with revised metal-on-metal arthroplasty and peri-implant lymphocytic inflammation, we verified the role of metal hypersensitivity by patch testing (PT) and lymphocyte transformation test (LTT).
  
  
  METHODS
  In the 16 patients with lymphocyte dominated periprosthetic inflammation, allergy history was obtained by a questionnaire, specific serum IgE to aeroallergens was measured to assess atopy, PT to standard and metal series was performed and metal sensitivity was further assessed by LTT using blood mononuclear cells.
  
  
  RESULTS
  Revision surgery was performed because of pain (8/16), osteolysis (4/16), dislocation (3/16) and loosening of the stem (1/16). Histological examination showed perivascular infiltrates of T lymphocytes, high endothelial venules, fibrin exudation and accumulation of macrophages with drop-like inclusions. Five patients had a history of cutaneous metal allergy and atopy was found in 25% of the patients. In 13/16 patients (81%), systemic metal sensitivity was found based on PT and/or LTT. Patch test reactions were seen in 11/16 patients (69%; partly multiple reactions/patient): 7/16 to Cobalt (Co), 7/16 to Chromium (Cr), 4/16 to Nickel (Ni), and one each to Molybdenum (Mo) and Manganese (Mn). Ten of 16 patients (62%) showed enhanced LTT reactivity to metals: 7/16 to Ni, 7/16 to Co, 5/16 to Cr, 5/16 to Mo and 4/16 to Mn.
  
  
  CONCLUSIONS
  The lymphocyte dominated peri-implant inflammation may well reflect an allergic hyper-reactivity in these patients, given the high rate of concomitantly found metal allergy. Despite the overall incidence of metal implant allergy being low, allergic reactions should be included as differential diagnosis in failed metal-on-metal arthroplasty.
authors.affiliation: Department of Dermatology and Allergology, Ludwig-Maximilians-University Munich, Frauenlobstr. 9-11, Munich 80337, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Thomas
authors.forename: L R
authors.initials: LR
authors.lastname: Braathen
authors.forename: M
authors.initials: M
authors.lastname: Dörig
authors.forename: J
authors.initials: J
authors.lastname: Auböck
authors.forename: F
authors.initials: F
authors.lastname: Nestle
authors.forename: T
authors.initials: T
authors.lastname: Werfel
authors.forename: H G
authors.initials: HG
authors.lastname: Willert
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000485:Allergens / Q000276:immunology*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D006967:Hypersensitivity / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D007118:Immunoassay; D015994:Incidence; D007249:Inflammation / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology; D008297:Male; D008670:Metals / Q000276:immunology*; D008875:Middle Aged; D010328:Patch Tests; D011475:Prosthesis Failure; D012086:Reoperation; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000485:Allergens; D008670:Metals