title: Risk factors and prognosis of late acute rejection in Chinese kidney transplant recipients.
abstract: OBJECTIVE
  Accumulating literature indicates that late acute rejection (LAR) after kidney transplantation portends an unfavourable prognosis. There are no data on the incidence of LAR in Asian subjects, or its risk factors and associated clinical outcomes.
  
  
  METHODS
  We conducted a retrospective single-centre case-+control study to investigate the incidence, risk factors and prognosis of LAR in Chinese kidney transplant recipients. Subjects with or without LAR were matched for age, gender, era of transplantation, allograft type, and maintenance immunosuppression regimen.
  
  
  RESULTS
  Thirty-two episodes of LAR occurred within an observation period of 12 years giving an incidence rate of 0.46 episodes per 1000 patient-years. Acute rejection within the first year after transplantation was associated with an increased risk of LAR (OR 3.59, P = 0.041). In patients receiving maintenance immunosuppression regimen with steroid, cyclosporin A (CsA) and mycophenolate or an m-TOR inhibitor, patients with LAR showed lower trough CsA levels prior to and at the time of rejection compared to Controls (86.0 ± 26.1 vs. 105.6 ± 13.3 μg/L, P = 0.049; and 75.7 ± 35.7 vs. 106.0 ± 20.5 μg/L, P = 0.032, respectively). Trough CsA level below 80 μg/L was associated with the development of LAR (OR 10.82, P = 0.032). Patients with LAR showed an inferior allograft survival (P < 0.001) while patient survival rates were similar (P = 0.122).
  
  
  CONCLUSIONS
  Late acute rejection is uncommon in Chinese kidney transplant recipients but is associated with reduced allograft survival. Risk factors include acute rejection in the first post-transplant year and trough CsA level below 80 μg/L in patients on CsA-based maintenance immunosuppression. Minimization of immunosuppression in apparently stable kidney transplant recipients must be exercised with caution.
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Maggie Ming Yee
authors: MMY
authors: Mok
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Maggie Kam Man
authors: MKM
authors: Ma
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Desmond Yat Hin
authors: DYH
authors: Yap
authors: Division of Anatomical Pathology, Department of Pathology & Clinical Biochemistry, Queen Mary Hospital, University of Hong Kong.
authors: Gavin Sheung Wai
authors: GSW
authors: Chan
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Man Fai
authors: MF
authors: Lam
authors: Division of Transplantation & Immunogenetics, Department of Pathology & Clinical Biochemistry, Queen Mary Hospital, University of Hong Kong.
authors: Janette Siu Yin
authors: JSY
authors: Kwok
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Lorraine Pui Yuen
authors: LPY
authors: Kwan
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Gary Chi Wang
authors: GCW
authors: Chan
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Cindy Bo Ying
authors: CBY
authors: Choy
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Sydney Chi Wai
authors: SCW
authors: Tang
authors: Division of Nephrology, Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors: Tak Mao
authors: TM
authors: Chan
mesh_terms: D000208:Acute Disease; D000328:Adult; D005260:Female; D006084:Graft Rejection / Q000209:etiology*; D006085:Graft Survival; D006801:Humans; D016030:Kidney Transplantation / Q000009:adverse effects* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012307:Risk Factors
keywords: allograft; immunosuppressive agents; kidney transplantation; prognosis; risk factors