title: A pilot study to evaluate renal hemodynamics in cirrhosis by simultaneous glomerular filtration rate, renal plasma flow, renal resistive indices and biomarkers measurements.
abstract: BACKGROUND
  Renal hemodynamic measurements are complicated to perform in patients with cirrhosis, yet they provide the best measure of risk to predict hepatorenal syndrome (HRS). Currently, there are no established biomarkers of altered renal hemodynamics in cirrhosis validated by measured renal hemodynamics.
  
  
  METHODS
  In this pilot study, simultaneous measurements of glomerular filtration rate (GFR), renal plasma flow (RPF), renal resistive indices and biomarkers were performed to evaluate renal hemodynamic alterations in 10 patients with cirrhosis (3 patients without ascites, 5 with diuretic-sensitive and 2 diuretic-refractory ascites).
  
  
  RESULTS
  Patients with diuretic-refractory ascites had the lowest mean GFR (36.5 ml/min/1.73 m(2)) and RPF (133.6 ml/min/1.73 m(2)) when compared to those without ascites (GFR 82.9 ml/min/1.73 m(2), RPF 229.9 ml/min/1.73 m(2)) and with diuretic-sensitive ascites (GFR 82.3 ml/min/1.73 m(2), RPF 344.1 ml/min/1.73 m(2)). A higher mean filtration fraction (FF) (GFR/RPF 0.36) was noted among those without ascites compared to those with ascites. Higher FF in patients without ascites is most likely secondary to the vasoconstriction in the efferent glomerular arterioles (normal FF ~0.20). In general, renal resistive indices were inversely related to FF. While patients with ascites had lower FF and higher right kidney main and arcuate artery resistive indices, those without ascites had higher FF and lower right kidney main and arcuate artery resistive indices. While cystatin C and β2-microglobulin performed better compared to Cr in estimating RPF, β-trace protein, β2-microglobulin, and SDMA, and (SDMA+ADMA) performed better in estimating right kidney arcuate artery resistive index.
  
  
  CONCLUSIONS
  The results of this pilot study showed that identification of non-invasive biomarkers of reduced RPF and increased renal resistive indices can identify cirrhotics at risk for HRS at a stage more amenable to therapeutic intervention and reduce mortality from kidney failure in cirrhosis.
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hepatology, University of Maryland School of Medicine, Baltimore, Md., USA.
authors.forename: Ayse L
authors.initials: AL
authors.lastname: Mindikoglu
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Dowling
authors.forename: Jade J
authors.initials: JJ
authors.lastname: Wong-You-Cheong
authors.forename: Robert H
authors.initials: RH
authors.lastname: Christenson
authors.forename: Laurence S
authors.initials: LS
authors.lastname: Magder
authors.forename: William R
authors.initials: WR
authors.lastname: Hutson
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Seliger
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Weir
mesh_terms: D000209:Acute-Phase Proteins / Q000652:urine; D000368:Aged; D001201:Ascites / Q000188:drug therapy / Q000209:etiology; D015415:Biomarkers / Q000378:metabolism; D003404:Creatinine / Q000097:blood / Q000652:urine; D055316:Cystatin C / Q000097:blood; D004232:Diuretics / Q000627:therapeutic use; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D000072596:Hepatitis A Virus Cellular Receptor 1; D006530:Hepatorenal Syndrome / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000097:blood; D000071068:Lipocalin-2; D054834:Lipocalins / Q000097:blood / Q000652:urine; D008103:Liver Cirrhosis / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008562:Membrane Glycoproteins / Q000652:urine; D008875:Middle Aged; D010865:Pilot Projects; D011518:Proto-Oncogene Proteins / Q000652:urine; D011991:Receptors, Virus; D012079:Renal Circulation / Q000502:physiology*; D017595:Renal Plasma Flow / Q000502:physiology*; D012720:Severity of Illness Index; D014655:Vascular Resistance / Q000502:physiology*; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D004232:Diuretics; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D011991:Receptors, Virus; D001613:beta 2-Microglobulin; D003404:Creatinine; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase