title: CTLA4 gene polymorphisms influence the incidence of infection after renal transplantation in Chinese recipients.
abstract: BACKGROUND
  Immunosuppressive therapy is usually administered following renal transplantation to protect the graft from rejection. However, this often causes complications such as infections to occur. Single nucleotide polymorphisms (SNPs) within the CTLA4 gene, such as -1772T/C (rs733618), +49A/G (rs231775) and +6230 G/A (rs3087243), can affect graft rejection and the long-term clinical outcome of organ transplantation. The role of CTLA4 SNPs in T cell-mediated immunity in renal transplantation and association with infection after transplantation is unknown.
  
  
  METHODS
  In this study, the risk of infection according to CTLA4 SNPs was investigated in 304 patients who received kidney graft transplants between 2008 and 2012.
  
  
  RESULTS
  The frequency of the rs4553808 GG genotype was significantly higher in recipients with viral infection (14.89%) than in those without infections (3.50%) (Bonferroni-adjusted p = 0.005). A significant difference (p = 0.001) in patients with the rs4553808 GG genotype from those with the AA+AG genotypes was found in the viral cohort using the log-rank test. A significant association was found between the rs4553808 genotype and onset of viral infection in transplant recipients (p = 0.001). The frequencies of the CGTAG and CGCAG haplotypes were significantly higher in the viral infection group (9.6% and 5.3%) than in the non-viral infection group (3.8% and 1.4%) (p = 0.0149 and p = 0.0111). No association between any CTLA4 SNP and bacterial infection was found. Multivariate analyses revealed that one risk factor, the use of antibody induction therapy (p = 0.007), was associated with bacterial infection, and two risk factors, antibody use (p = 0.015) and recipient rs4553808 genotype (p = 0.001), were associated with viral infection.
  
  
  CONCLUSIONS
  The rs4553808 GG genotype may be a risk factor for viral infection in kidney transplantation. The CTLA4 haplotypes CGTAG and CGCAG were partially associated with the development of viral infection in Chinese kidney transplant recipients.
authors.affiliation: Urological Center and Organ Transplantation Center, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yifeng
authors.initials: Y
authors.lastname: Guo
authors.forename: Fang
authors.initials: F
authors.lastname: Guo
authors.forename: Chongyang
authors.initials: C
authors.lastname: Wei
authors.forename: Jianxin
authors.initials: J
authors.lastname: Qiu
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Fang
authors.forename: Junwei
authors.initials: J
authors.lastname: Gao
mesh_terms: D000328:Adult; D001424:Bacterial Infections / Q000453:epidemiology / Q000235:genetics; D060908:CTLA-4 Antigen / Q000235:genetics*; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D007676:Kidney Failure, Chronic / Q000601:surgery; D016030:Kidney Transplantation; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009181:Mycoses / Q000453:epidemiology / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011183:Postoperative Complications / Q000453:epidemiology / Q000235:genetics; D012307:Risk Factors; D014777:Virus Diseases / Q000453:epidemiology / Q000235:genetics*
chemical_list: D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human