title: Time course of low molecular weight proteins in the early kidney transplantation period--influence of corticosteroids.
abstract: BACKGROUND
  Cystatin C (Cys C) is an established new marker of renal function in patients with various renal diseases and in kidney transplantation. However, few data are available for the early post-transplantation period.
  
  
  METHODS
  Twenty-two patients who underwent renal transplantation (RTx) were evaluated for the kinetics of Cys C from day 0 to 14 in relation to creatinine and beta-2 microglobulin (B2MG). Blood samples were obtained immediately before and after transplantation and on a daily basis thereafter. Serum levels before transplantation (100%) were used to calculate reduction ratios.
  
  
  RESULTS
  The decrease of the analytes differed considerably: immediately after RTx Cys C declined by 27.3% (P < 0.01). However, after 3 days, on average, all patients showed a significant increase in Cys C levels (15+/-2.5%; P < 0.01). B2MG levels fell quickly by 55.4 and 73.8% after days 1 and 7, respectively, and remained stable thereafter. In contrast, creatinine did not decrease immediately after RTx but fell slowly by 67.5% at the end of the study. Prior to rejection, all analytes showed a similar behaviour. Rejection treatment with high-dose methylprednisolone induced a significant increase in Cys C (+22.8+/-7.9%, P < 0.05), while in parallel, creatinine and B2MG decreased (-12.9+/-3.4 and -8.4+/-6.89%).
  
  
  CONCLUSIONS
  Corticosteroid treatment for induction of immunosuppression or rejection therapy significantly induces Cys C, but decreases B2MG. Cys C and B2MG are not helpful in establishing the diagnosis of rejection earlier. Thus, our data indicate that Cys C and B2MG testing does not accurately reflect changes in the glomerular filtration rate early after transplantation.
authors.affiliation: Department of Internal Medicine I, University of Bonn, Germany. u.poege@uni-bonn.de
authors.forename: Uwe
authors.initials: U
authors.lastname: Pöge
authors.forename: Thomas
authors.initials: T
authors.lastname: Gerhardt
authors.forename: Arend
authors.initials: A
authors.lastname: Bökenkamp
authors.forename: Birgit
authors.initials: B
authors.lastname: Stoffel-Wagner
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Klehr
authors.forename: Tilman
authors.initials: T
authors.lastname: Sauerbruch
authors.forename: Rainer P
authors.initials: RP
authors.lastname: Woitas
mesh_terms: D000328:Adult; D003404:Creatinine; D055316:Cystatin C; D015891:Cystatins / Q000097:blood* / Q000493:pharmacokinetics*; D005260:Female; D005919:Glomerular Filtration Rate; D006084:Graft Rejection / Q000097:blood / Q000503:physiopathology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000601:surgery; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D001613:beta 2-Microglobulin; D003404:Creatinine