title: Interleukin-9 in stable liver transplant recipients.
abstract: BACKGROUND
  Interleukin-9 (IL-9) has recently been described to be involved in the maintenance of a tolerant environment, but there is no evidence of its role in human liver transplantation. The aim of our study was to measure the serum levels of IL-9 in stable liver transplant recipients and examine their influence on immunosuppressant load.
  
  
  METHODS
  Serum IL-9 levels were determined in 34 healthy subjects and 30 stable liver transplant recipients who were free of rejection episodes for at least 8 years. The results were analyzed according to the blood levels of calcineurin inhibitors (CNIs) at the time of the study: 13 patients showed high concentrations of either cyclosporine or tacrolimus (high CNI: cyclosporine > 80 ng/mL or tacrolimus > 5 ng/mL) and another 17 patients showed low CNI levels.
  
  
  RESULTS
  The concentrations of IL-9 were significantly higher among liver transplant recipients compared with healthy subjects. In addition, patients with low CNI blood levels showed higher serum levels of IL-9, an effect that was greater with tacrolimus, albeit not significantly.
  
  
  CONCLUSIONS
  These preliminary results indicated that increased serum IL-9 concentrations accompanied a lower immunosuppressive load. It remains to be established whether this relates to induction of tolerance in liver transplantation.
authors: Gastroenterology and Hepatology Unit, Faculty of Medicine, University Hospital Marqués de Valdecilla, Santander, Spain.
authors: E
authors: E
authors: Fábrega
authors: M
authors: M
authors: López-Hoyos
authors: D
authors: D
authors: San Segundo
authors: F
authors: F
authors: Casafont
authors: I
authors: I
authors: Moraleja
authors: B
authors: B
authors: Sampedro
authors: F
authors: F
authors: Pons-Romero
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D016903:Drug Monitoring; D005260:Female; D006084:Graft Rejection / Q000276:immunology / Q000517:prevention & control; D006085:Graft Survival / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000627:therapeutic use; D016906:Interleukin-9 / Q000097:blood*; D016031:Liver Transplantation / Q000009:adverse effects / Q000276:immunology; D008297:Male; D008875:Middle Aged; D013030:Spain; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; C508607:IL9 protein, human; D007166:Immunosuppressive Agents; D016906:Interleukin-9