title: Association of arginine vasopressin surrogate marker urinary copeptin with severity of autosomal dominant polycystic kidney disease (ADPKD).
abstract: BACKGROUND
  Experimental studies suggest a detrimental role for cyclic adenosine monophosphate (cAMP) and vasopressin in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD). It is unknown, however, whether urinary cAMP and copeptin concentration are associated with disease severity in patients with ADPKD.
  
  
  METHODS
  Urinary cAMP (u-cAMP) and copeptin concentration (u-copeptin) were measured by immunoassay in ADPKD patients with CKD stage ≤4. We compared our measurements with clinical parameters including estimated glomerular filtration rate (eGFR), total kidney volume (TKV), and height-adjusted TKV (htTKV). Logarithmic transformation of all variables was performed to fulfill the requirement of equal distribution of the residuals.
  
  
  RESULTS
  We included 50 patients in this study (24 females and 26 males; mean age: 49.3 years). The median eGFR and TKV were 53.2 ml/min/1.73 m(2) (interquartile range: IQR; 29.4-68.45) and 1138.1 ml (IQR; 814.7-2065.0), respectively. The median u-copeptin level was 12.19 (IQR; 6.91-22.32) ng/ml. Although u-cAMP/u-Cr was not significantly correlated with TKV (R = -0.006, p = 0.967) and eGFR (R = 0.077, p = 0.602), urinary copeptin/u-Cr was statistically associated with the various markers of disease severity in ADPKD [positively with TKV (R = 0.351, p = 0.014), htTKV (R = 0.383, p = 0.008) and negatively with eGFR (R = -0.304, p = 0.036)].
  
  
  CONCLUSIONS
  In ADPKD subjects, a higher u-copeptin is associated with disease progression, suggesting that u-copeptin may be a new surrogate marker to predict renal prognosis in ADPKD.
authors.affiliation: Department of Urology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-Ku, Tokyo, 173-8605, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Nakajima
authors.affiliation: Department of Urology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-Ku, Tokyo, 173-8605, Japan.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Urology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Kawano
authors.affiliation: Department of Urology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Horie
authors.affiliation: Department of Urology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi-Ku, Tokyo, 173-8605, Japan. muto@med.teikyo-u.ac.jp.
authors.forename: Satoru
authors.initials: S
authors.lastname: Muto
mesh_terms: D000328:Adult; D000368:Aged; D001127:Arginine Vasopressin / Q000378:metabolism*; D015415:Biomarkers; D015992:Body Mass Index; D000242:Cyclic AMP / Q000652:urine; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006020:Glycopeptides / Q000652:urine*; D006801:Humans; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016891:Polycystic Kidney, Autosomal Dominant / Q000378:metabolism* / Q000652:urine; D051436:Renal Insufficiency, Chronic / Q000378:metabolism / Q000652:urine; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D006020:Glycopeptides; C048197:copeptins; D001127:Arginine Vasopressin; D000242:Cyclic AMP
keywords: Autosomal dominant polycystic kidney disease; Copeptin; GFR; Marker; Total kidney volume; Vasopressin