title: Characterization of urinary CD4⁺ and CD8⁺ T cells in kidney transplantation patients with polyomavirus BK infection and allograft rejection.
abstract: OBJECTIVE
  The objective of this study was to characterize CD4(+) and CD8(+) T-cell populations in blood and urine of renal transplant patients with BK virus (BKV) infection or allograft rejection.
  
  
  METHODS
  Percentages and absolute numbers of CD4(+) and CD8(+) effector memory T-cell subtype (TEM ) and terminal differentiated T cells (TTD ) in renal transplant patients with BKV infection (n = 14), with an episode of allograft rejection (n = 9), and in uncomplicated renal transplant patients with a stable kidney function (n = 12) were measured and compared using 4-color fluorescence-activated cell sorting. Results were correlated with the number of CD4(+) and CD8(+) T cells in renal biopsies.
  
  
  RESULTS
  In patients with allograft rejection, the number of urinary CD4(+) TEM and CD8(+) TEM cells was significantly increased compared to patients with BKV infection or patients without complications. Positive correlation was found between the number of CD4(+) and CD8(+) cells in the renal biopsies and the number of CD4(+) and CD8(+) cells in urine. In patients with rejection, after 2 months of immunosuppressive therapy, a reduction in urinary CD8(+) TEM cells was found.
  
  
  CONCLUSIONS
  CD4(+) TEM and CD8(+) TEM cells in urine could be a marker to distinguish allograft rejection from BKV-associated nephropathy and to monitor therapy effectiveness in renal transplant patients with allograft rejection.
authors.affiliation: Department of Internal Medicine, Division of Nephrology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: W B
authors.initials: WB
authors.lastname: van Doesum
authors.forename: W H
authors.initials: WH
authors.lastname: Abdulahad
authors.forename: M C R F
authors.initials: MC
authors.lastname: van Dijk
authors.forename: S
authors.initials: S
authors.lastname: Dolff
authors.forename: W J
authors.initials: WJ
authors.lastname: van Son
authors.forename: C A
authors.initials: CA
authors.lastname: Stegeman
authors.forename: J S F
authors.initials: JS
authors.lastname: Sanders
mesh_terms: D000328:Adult; D000368:Aged; D064591:Allografts / Q000276:immunology; D001739:BK Virus; D001706:Biopsy; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D005260:Female; D006084:Graft Rejection / Q000097:blood / Q000276:immunology / Q000652:urine*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007668:Kidney / Q000473:pathology*; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D027601:Polyomavirus Infections / Q000097:blood / Q000276:immunology / Q000652:urine*; D016176:T-Lymphocyte Subsets; D014412:Tumor Virus Infections / Q000097:blood / Q000276:immunology / Q000652:urine*; D014556:Urine / Q000166:cytology; D055815:Young Adult
chemical_list: D007166:Immunosuppressive Agents
keywords: BK nephropathy; BK virus; CD4+ T cells; CD8+ T cells; FACS; Urine; allograft rejection; renal transplantation; virology