title: Monitoring of CD4+CD25highIL-7Rαhigh activated T cells in kidney transplant recipients.
abstract: OBJECTIVE
  In humans, circulating CD4(+)CD25(high) T cells contain mainly regulatory T cells (Treg; FoxP3(+)IL-7Rα(low)), but a small subset is represented by activated effector T cells (Tact; FoxP3(-)IL-7Rα(high)). The balance between Tact and Treg may be important after transplantation. The aim of this study was first to analyze and correlate CD4(+)CD25(high) Tact and Treg with the clinical status of kidney transplant recipients and second to study prospectively the effect of two immunosuppressive regimens on Tact/Treg during the first year after transplantation.
  
  
  METHODS
  CD4(+)CD25(high) Tact and Treg were analyzed by flow cytometry, either retrospectively in 90 patients greater than 1 year after kidney transplantation (cross-sectional analysis) or prospectively in 35 patients receiving two immunosuppressive regimens after kidney transplantation (prospective analysis).
  
  
  RESULTS
  A higher proportion of Tact and a lower proportion of Treg were found in the majority of kidney recipients. In chronic humoral rejection, a strikingly higher proportion of Tact was present. A subgroup of stable recipients receiving calcineurin inhibitor-free immunosuppression (mycophenolate mofetil, azathioprine, or sirolimus) had Tact values that were similar to healthy individuals. In the prospective analysis, the proportion of Tact significantly increased in both immunosuppression groups during the first year after transplantation.
  
  
  CONCLUSIONS
  These data highlight distinct patterns in the proportion of circulating Tact depending on the clinical status of kidney recipients. Moreover, the prospective analysis demonstrated an increase in the proportion of Tact, regardless of the immunosuppressive regimen. The measurement of Tact, in addition to Treg, may become a useful immune monitoring tool after kidney transplantation.
authors.affiliation: Service of Transplantation, Centre Hospitalier Universitaire Vaudois, Rue du Bugnon 46, 1011 Lausanne, Switzerland.
authors.forename: Laure
authors.initials: L
authors.lastname: Vallotton
authors.forename: Karine
authors.initials: K
authors.lastname: Hadaya
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Venetz
authors.forename: Leo H
authors.initials: LH
authors.lastname: Buehler
authors.forename: Donatella
authors.initials: D
authors.lastname: Ciuffreda
authors.forename: Ghaleb
authors.initials: G
authors.lastname: Nseir
authors.forename: Laura
authors.initials: L
authors.lastname: Codarri
authors.forename: Jean
authors.initials: J
authors.lastname: Villard
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Pantaleo
authors.forename: Manuel
authors.initials: M
authors.lastname: Pascual
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D005260:Female; D005434:Flow Cytometry; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control; D006085:Graft Survival; D006801:Humans; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D016130:Immunophenotyping; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood*; D016030:Kidney Transplantation / Q000276:immunology*; D008213:Lymphocyte Activation / Q000187:drug effects; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D015166:Monitoring, Immunologic / Q000379:methods; D011446:Prospective Studies; D020395:Receptors, Interleukin-7 / Q000097:blood*; D012189:Retrospective Studies; D013557:Switzerland; D050378:T-Lymphocytes, Regulatory / Q000276:immunology; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508017:IL2RA protein, human; D007166:Immunosuppressive Agents; D053645:Interleukin-2 Receptor alpha Subunit; D020395:Receptors, Interleukin-7; C415350:interleukin-7 receptor, alpha chain