title: Impact of sepsis on levels of plasma cystatin C in AKI and non-AKI patients.
abstract: BACKGROUND
  Cystatin C is a marker of acute kidney injury (AKI). However, systemic inflammation associated with sepsis, a common AKI-trigger, may affect cystatin C. We studied the impact of sepsis on cystatin C levels in plasma. Furthermore, we investigated whether the presence of sepsis affects the predictive properties of cystatin C.
  
  
  METHODS
  Three hundred and twenty-seven intensive care unit (ICU) patients were categorized as having: neither AKI nor sepsis (n = 151), sepsis without AKI (n = 80), AKI without sepsis (n = 24) or AKI and sepsis (n = 72) during their first week in the ICU. Changes in cystatin C and creatinine over time in patients with and without sepsis or AKI were analysed using repeated measures analysis of variance. The performance of cystatin C on admission to predict sustained AKI, worsened AKI or death was assessed from the area under the receiver-operating characteristic curve (AUC-ROC) in septic and non-septic patients separately.
  
  
  RESULTS
  In non-AKI patients, cystatin C increased and creatinine decreased significantly over the first week. The change in cystatin C or creatinine did not differ significantly between septic and non-septic patients without AKI. Even in AKI patients, the cystatin C change did not differ significantly between septic and non-septic patients. The AUC-ROCs for prediction of the composite outcome were 0.80 and 0.78 in patients with and without sepsis, respectively, and did not differ significantly (P = 0.76).
  
  
  CONCLUSIONS
  The inflammatory response induced by sepsis has no impact on the levels of cystatin C in plasma during the first week in the ICU.
authors.affiliation: Department of Physiology and Pharmacology, Section of Anaesthesia and Intensive Care Medicine, Karolinska Institutet, Stockholm, Sweden. johan.martensson@karolinska.se
authors.forename: Johan
authors.initials: J
authors.lastname: Mårtensson
authors.forename: Claes-Roland
authors.initials: CR
authors.lastname: Martling
authors.forename: Anders
authors.initials: A
authors.lastname: Oldner
authors.forename: Max
authors.initials: M
authors.lastname: Bell
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood* / Q000175:diagnosis / Q000401:mortality; D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood*; D003422:Critical Care / Q000379:methods; D016638:Critical Illness / Q000401:mortality / Q000628:therapy; D055316:Cystatin C / Q000097:blood*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood* / Q000175:diagnosis / Q000401:mortality; D015996:Survival Rate; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D002097:C-Reactive Protein; D003404:Creatinine