title: Renal allograft C4d deposition in Chinese: Hong Kong perspective.
abstract: BACKGROUND
  Acute rejection constitutes a significant proportion of renal allograft loss. Peritubular capillary deposition of C4d has been recognized as the footprint of humoral alloimmunity and proven to be a sensitive and specific marker for humoral rejection in the appropriate clinical context. Its presence in indication biopsies is the most important independent risk factor for graft failure. Data are, however, scarce among Chinese subjects.
  
  
  METHODS
  We retrospectively reviewed all renal graft biopsies performed from 1 April 2002 to 31 March 2006 for unexplained acute renal dysfunction or delayed graft function. Renal outcomes were assessed at the time of renal biopsy and at 1 month, 3 months, 6 months and 1 year afterwards. Survival was assessed by Kaplan-Meier analysis. Multivariate analysis was used to determine if C4d positivity is an independent risk factor for poor renal outcome.
  
  
  RESULTS
  Fifty-two biopsies were included, of which 16 were positive for peritubular capillary C4d. Peritubular capillary C4d was associated with lower glomerular filtration rate and higher serum creatinine at 6 and 12 months after renal biopsies. The C4d-positive group fares worse in terms of death-censored graft failure, doubling of serum creatinine and reaching 50% of glomerular filtration rate at the end of the study. Peritubular capillary C4d deposition was the only significant risk factor that predicts graft failure in multivariate analysis.
  
  
  CONCLUSIONS
  Our findings confirmed the independent prognostic value of peritubular capillary C4d staining on renal allograft survival in Chinese.
authors.affiliation: Department of Medicine and Geriatrics, ICU, Caritas Medical Centre, Hong Kong. yuenskit@yahoo.com.hk
authors.forename: Sze K
authors.initials: SK
authors.lastname: Yuen
authors.forename: Yuen F
authors.initials: YF
authors.lastname: Mak
authors.forename: Hon L
authors.initials: HL
authors.lastname: Tang
authors.forename: Sai P
authors.initials: SP
authors.lastname: Yong
authors.forename: Kai M
authors.initials: KM
authors.lastname: Chow
authors.forename: Kwok H
authors.initials: KH
authors.lastname: Chu
authors.forename: Ka S
authors.initials: KS
authors.lastname: Fung
authors.forename: Wai H H
authors.initials: WH
authors.lastname: Chan
authors.forename: Kwok L
authors.initials: KL
authors.lastname: Tong
mesh_terms: D000328:Adult; D000917:Antibody Formation; D044466:Asian People; D015935:Complement C4b / Q000032:analysis*; D003404:Creatinine / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006084:Graft Rejection / Q000276:immunology* / Q000401:mortality / Q000503:physiopathology; D006723:Hong Kong; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000276:immunology* / Q000503:physiopathology / Q000601:surgery; D016030:Kidney Transplantation / Q000401:mortality; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000032:analysis*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014181:Transplantation Immunology; D014184:Transplantation, Homologous
chemical_list: D010446:Peptide Fragments; D015935:Complement C4b; C032261:complement C4d; D003404:Creatinine