title: Outcome after kidney transplantation in children with thrombotic risk factors.
abstract: BACKGROUND
  According to the data from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS), vascular thrombosis accounts for 11.6% of graft losses in pediatric renal transplantation. In adults, inherited and acquired thrombophilic risk factors, e.g. factor V Leiden mutation, have been associated with early graft loss and increased rejection episodes. Data on the impact of these factors on the outcome of children after renal transplantation are rare.
  
  
  METHODS
  Sixty-six pediatric patients awaiting renal transplantation (mean age 10.1 yr) were screened for inherited and acquired risk factors for hypercoagulable disorders (protein C, S, and antithrombin III deficiency, antiphospholipid antibodies, factor V Leiden, prothrombin, and MTHFR mutation) in order to intensify anticoagulation in those with an increased risk for thrombophilia: intravenous heparin was administered with a partial prothrombin time (PTT) prolongation of 50 s for 14 days and switched to low-molecular-weight heparin for another 8 wk before aspirin was introduced for the first year. Patients without hypercoagulable risk factors were treated with heparin without PTT prolongation for 14 days and switched to aspirin immediately afterwards. The results on graft survival, incidence of acute rejection episodes, and long-term renal graft function were analyzed between recipients with and without hypercoagulable risk factors.
  
  
  RESULTS
  Thrombophilic risk factors were identified in 27.3% of our patients. No thrombosis occurred. One serious bleeding complication led to a second surgical intervention. The rate of acute rejection episodes was not increased in patients with and without thrombotic risk factors after 90 days (16.7 vs. 25%), 1 yr (22.2 vs. 33.3%), and 3 yr (38.9 vs. 41.7%) of follow-up, respectively (p = n.s.). After a mean follow-up of 3 yr the kidney function was comparable in both groups, with 63.1 in recipients with and 69.8 mL/min/1.73 m(2) in recipients without hypercoagulable risk (p = n.s.). At latest follow-up, three graft losses were found not to be attributed to thrombotic risk factors.
  
  
  CONCLUSIONS
  Children with thrombophilic risk factors were identified and treated with an intensified anticoagulation regimen after renal transplantation. An increased risk for graft failure, acute rejection episodes, or impaired renal function for pediatric renal transplant recipients with hypercoagulable status was not found.
authors.affiliation: Clinic of Pediatric Nephrology, University Clinic Essen, Essen, Germany. birgitta.kranz@uni-essen.de
authors.forename: Birgitta
authors.initials: B
authors.lastname: Kranz
authors.forename: Udo
authors.initials: U
authors.lastname: Vester
authors.forename: Silvio
authors.initials: S
authors.lastname: Nadalin
authors.forename: Andreas
authors.initials: A
authors.lastname: Paul
authors.forename: Christoph E
authors.initials: CE
authors.lastname: Broelsch
authors.forename: Peter F
authors.initials: PF
authors.lastname: Hoyer
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D001706:Biopsy; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006084:Graft Rejection / Q000150:complications / Q000453:epidemiology / Q000473:pathology; D006085:Graft Survival; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000150:complications / Q000601:surgery*; D016030:Kidney Transplantation; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood / Q000150:complications* / Q000517:prevention & control; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants