title: Cystatin C can be affected by nonrenal factors: a preliminary study on leukemia.
abstract: OBJECTIVE
  The aim of this study was to evaluate the influence of malignancy and the impact of nephrotoxic drugs used in bone marrow transplantation (BMT) on the circulating levels of cystatin C in leukemia.
  
  
  METHODS
  We studied nineteen patients (eleven men and eight women; mean age 30.1 +/- 11.2, 27.9 +/- 7.1 years) with acute lymphoblastic leukemia, acute myeloid leukemia and chronic myeloid leukemia. Cystatin C, urea, creatinine and creatinine clearance (CrCl) were measured 24 h before BMT, 1 week after BMT, 2 weeks after BMT and 3 weeks after BMT. The control group consisted of twenty healthy adults, and the mean age was 29.1 +/- 8.9.
  
  
  RESULTS
  At the pretransplantation period, values of cystatin C were significantly higher than in the control group (P < 0.05). Urea, creatinine and CrCl values were not statistically different from the controls. One week after BMT, the level of cystatin C was significantly low as compared to the levels measured 24 h before BMT, but was still significantly higher than the controls (P < 0.05), whereas the levels of urea, creatinine and CrCl were in accordance with the levels of the controls. Two and three weeks after BMT, cystatin C values maintained the significant increase (P < 0.05), whereas the values of urea, creatinine and CrCl still corresponded with those of the controls in both group.
  
  
  CONCLUSIONS
  Our preliminary data expose that cystatin C is not a reliable GFR marker in patients during leukemia or for monitoring nephrotoxic drugs used in BMT, but we can not reach definitive conclusion due to no gold standard for comparing the diagnostic accuracy of cystatin C. Further study is needed to elucidate the precise mechanism underlying this observation.
authors.affiliation: University of Ufuk, Faculty of Medicine, Department of Biochemistry, Ankara, Turkey.
authors.forename: Selda
authors.initials: S
authors.lastname: Demirtaş
authors.forename: Ozay
authors.initials: O
authors.lastname: Akan
authors.forename: Murat
authors.initials: M
authors.lastname: Can
authors.forename: Esra
authors.initials: E
authors.lastname: Elmali
authors.forename: Hamdi
authors.initials: H
authors.lastname: Akan
mesh_terms: D000212:Acyclovir / Q000627:therapeutic use; D000328:Adult; D000583:Amikacin / Q000627:therapeutic use; D000666:Amphotericin B / Q000627:therapeutic use; D015415:Biomarkers / Q000097:blood; D016026:Bone Marrow Transplantation; D003404:Creatinine / Q000097:blood; D016572:Cyclosporine / Q000627:therapeutic use; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007938:Leukemia / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008657:Metabolic Clearance Rate
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D000666:Amphotericin B; D016572:Cyclosporine; D000583:Amikacin; D003404:Creatinine; D000212:Acyclovir