title: Association of mismatches for HLA-DR with incidence of posttransplant hip fracture in kidney transplant recipients.
abstract: BACKGROUND
  Bone fractures are a frequent complication after kidney transplantation, for which various predisposing factors have been identified. It has been suggested that human leukocyte antigen (HLA) mismatch increases the risk.
  
  
  METHODS
  Data on hip fractures occurring in the first 5 years posttransplant were analyzed among kidney transplants from deceased donors performed between 1995 and 2008 and reported to the Collaborative Transplant Study.
  
  
  RESULTS
  In the 20,509 patients analyzed, the cumulative rate of hip fracture by year 5 posttransplant was 0.85%. Cox regression analysis identified the following risk factors: female recipients aged 40 to 59 years (hazard ratio [HR] 2.26, P=0.029), female recipients 60 years or older (HR 5.14, P<0.001), male recipients 60 years or older (HR 2.39, P=0.028), and donor age more than or equal to 60 years (HR 1.75, P=0.009). Using the rate of fractures in recipients with zero HLA-DR mismatch as the reference, the risk of hip fracture increased for grafts with one HLA-DR mismatch to HR 1.85 (95% confidence interval [CI] 1.18-2.89, P=0.007) and with two HLA-DR mismatches to HR 2.24 (CI 1.25-4.02, P=0.007). There was a significant association between the number of HLA-DR mismatches and the diagnosis of osteoporosis 5 years after transplantation: one HLA-DR mismatch risk ratio 1.26 (CI 1.12-1.43, P<0.001) and two HLA-DR mismatches risk ratio 1.45 (CI 1.20-1.74, P<0.001).
  
  
  CONCLUSIONS
  The risk of hip fracture after kidney transplantation seems to be markedly exacerbated by HLA-DR mismatching. These findings add to the growing base of evidence that HLA-DR matching influences morbidity after kidney transplantation.
authors: Department of Transplantation Immunology, University of Heidelberg, Heidelberg, Germany.
authors: Gerhard
authors: G
authors: Opelz
authors: Bernd
authors: B
authors: Döhler
mesh_terms: D000305:Adrenal Cortex Hormones / Q000009:adverse effects / Q000627:therapeutic use; D000328:Adult; D001379:Azathioprine / Q000009:adverse effects / Q000627:therapeutic use; D016572:Cyclosporine / Q000009:adverse effects / Q000627:therapeutic use; D003928:Diabetic Nephropathies / Q000276:immunology; D005260:Female; D006084:Graft Rejection / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology*; D006620:Hip Fractures / Q000276:immunology*; D006650:Histocompatibility Testing; D006801:Humans; D007166:Immunosuppressive Agents / Q000009:adverse effects / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009173:Mycophenolic Acid / Q000009:adverse effects / Q000627:therapeutic use; D011183:Postoperative Complications / Q000188:drug therapy / Q000276:immunology; D012189:Retrospective Studies; D016559:Tacrolimus / Q000009:adverse effects / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000305:Adrenal Cortex Hormones; D006684:HLA-DR Antigens; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D009173:Mycophenolic Acid; D001379:Azathioprine; D016559:Tacrolimus