title: T-regulatory cells in chronic rejection versus stable grafts.
abstract: OBJECTIVE
  Studying regulatory T cells in kidney allograft acceptance versus chronic rejection may help in the understanding of more mechanisms of immune tolerance and, in the future, may enable clinicians to induce immune tolerance and decrease the use of immunosuppressive drugs. The aim of the current study was to evaluate regulatory T cells in kidney transplant patients with stable graft versus transplant with biopsy-proven chronic rejection.
  
  
  METHODS
  The 3 groups that were studied included: kidney transplanted patients with no rejection episodes (n = 43); transplanted patients with biopsy-proven renal rejection (n = 27); and healthy age-matched nontransplanted individuals as controls (n = 42).The percentage of regulatory T cells (CD4+CD25+Foxp3+) in blood was determined by flow cytometry.
  
  
  RESULTS
  The regulatory T cell percentage was significantly lower in chronic rejection patients than control or stable graft groups. No significant difference was observed in regulatory T cell percentage between the stable graft and control groups. In the stable graft group, patients on rapamycin had a significantly higher regulatory T cell percentage than patients on cyclosporine. No effect of donor type, infection, or duration after transplant was observed on regulatory T cell percentage.
  
  
  CONCLUSIONS
  The results of the current study are consistent with previous studies addressing the function of regulatory T cells in inducing immunotolerance after kidney transplant. Considering the established role of regulatory T cells in graft maintenance and our observation of high regulatory T cell percentage in patients receiving rapamycin than cyclosporine, we recommend including rapamycin when possible in immunosuppressive protocols. The findings from the current study on the chronic rejection group support ongoing research of having treatment with regulatory T cells, which may constitute a novel, efficient antirejection therapy in the future.
authors.affiliation: From the Department of Microbiology and Immunology, College of Medicine, Arabian Gulf University; and the Department of Pathology, Salmaniya Medical Complex, Manama, Kingdom of Bahrain.
authors.forename: Fatima
authors.initials: F
authors.lastname: Al-Wedaie
authors.forename: Eman
authors.initials: E
authors.lastname: Farid
authors.forename: Khaled
authors.initials: K
authors.lastname: Tabbara
authors.forename: Amgad E
authors.initials: AE
authors.lastname: El-Agroudy
authors.forename: Sumaya M
authors.initials: SM
authors.lastname: Al-Ghareeb
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D065095:Calcineurin Inhibitors / Q000627:therapeutic use; D016022:Case-Control Studies; D002908:Chronic Disease; D016572:Cyclosporine / Q000627:therapeutic use; D005260:Female; D006084:Graft Rejection / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D006085:Graft Survival; D006801:Humans; D007111:Immunity, Cellular / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000187:drug effects / Q000276:immunology* / Q000473:pathology / Q000601:surgery*; D016030:Kidney Transplantation / Q000009:adverse effects*; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D020123:Sirolimus / Q000627:therapeutic use; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology*; D023001:Transplantation Tolerance; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D065095:Calcineurin Inhibitors; D007166:Immunosuppressive Agents; D016572:Cyclosporine; D020123:Sirolimus