title: Clinical outcomes and C2 cyclosporin monitoring in maintenance renal transplant recipients: 1 year follow-up study.
abstract: BACKGROUND
  Cyclosporin A (CsA) concentration monitoring with 2 h post-dosing levels (C2) correlates with the incidence of rejection and graft outcome in de novo renal transplant patients. The advantages of this policy beyond the first 12 months remain a matter of debate. The purpose of the present work was to evaluate the C2 target ranges on CsA monitoring after the first year in stable kidney transplant patients.
  
  
  METHODS
  We studied 142 patients, 94 on CsA-steroids and 48 on triple therapy (CsA-azathioprin-steroids), transplanted for 104+/-42 months and with a serum creatinine of 1.53+/-0.52 mg/dl. C2 and C0 measurements were performed at baseline and at least twice more during the year of follow-up.
  
  
  RESULTS
  The mean annual C2 blood levels in double therapy patients showed C2 in 23 (24.5%) of <600 ng/ml; in 53 (56.4%) of between 600 and 850 ng/ml; and in 18 patients (19.1%) of >850 ng/ml. In the triple therapy group, C2 in 12 (25%) was <500 ng/ml, in 24 (50%) between 500 and 700 ng/ml and in 12 patients (25%) >700 ng/ml. In both groups, higher C2 levels were associated with a better absorption of the drug measured by the ratio C2/C0 and C2/dose. There were no differences in incidence of infections, need for hospitalization and the presence of hypertension, hyperuricaemia, hypercholesterolaemia or diabetes between patients with low and high C2 blood levels. However, serum creatinine was higher in triple therapy patients with lower C0 levels (P = 0.004). In 135 patients (90 on double and 45 on triple therapy), renal function remained stable during follow-up and 120 of them (89%) had C2 values under the recommended ranges.
  
  
  CONCLUSIONS
  C2 monitoring in maintenance patients enabled us to identify overexposure to CsA. Target levels of C2 should be adjusted according to the immunosuppressive regime. C2 levels between 600 and 800 ng/ml in double therapy patients and between 500 and 700 ng/ml in triple therapy patients are sufficient to give an adequate immunosuppression. The superiority of C2 with respect to C0 levels could not be demonstrated.
authors.affiliation: Department of Nephrology, Hospital Ramón y Cajal, Universidad de Alcalá de Henares, Madrid, Spain. rmarcen.hrc@salud.madrid.org
authors.forename: Roberto
authors.initials: R
authors.lastname: Marcén
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Villafruela
authors.forename: Julio
authors.initials: J
authors.lastname: Pascual
authors.forename: José Luis
authors.initials: JL
authors.lastname: Teruel
authors.forename: Javier
authors.initials: J
authors.lastname: Ocaña
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Tenorio
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Burgos
authors.forename: Joaquín
authors.initials: J
authors.lastname: Ortuño
mesh_terms: D000328:Adult; D000368:Aged; D016572:Cyclosporine / Q000008:administration & dosage*; D016903:Drug Monitoring; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D016030:Kidney Transplantation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D007166:Immunosuppressive Agents; D016572:Cyclosporine