title: Serum levels of beta-trace protein and its association to diuresis in haemodialysis patients.
abstract: BACKGROUND
  Beta-trace protein (BTP) has been proposed as an alternative endogenous marker of the glomerular filtration rate. However, possible determinants of BTP in ESRD patients undergoing regular renal replacement therapy have not been evaluated.
  
  
  METHODS
  Serum levels of BTP, beta-2-microglobulin, creatinine and urea were analysed before and after dialysis treatment in 73 patients [haemodialysis (HD) n=52; haemodiafiltration (HDF) n=21]. Patients were categorized into four groups with residual diuresis (RD)<0.5 l/day (group 1; n=24), 0.5-1 l/day (group 2; n=18), 1.1-1.5 l/day (group 3; n=12) and >1.5 l/day (group 4; n=19). Subsequently RD was compared to pre-treatment levels of BTP.
  
  
  RESULTS
  HD treatment did not affect BTP serum levels [pre-treatment 8.1+/-4.1 mg/l (mean+SD) vs post-treatment 7.7+/-4.1 mg/l; -0.6 +/- 16.1%; ns]. However, in 6 out of 21 patients undergoing HDF BTP levels were reduced by more than 20%. Overall, the resulting decrease in serum concentration was minuscule (9.6+/-6.2 vs 8.3+/-4.9 mg/l; -14+/-21.9%; P=0.03). BTP serum levels were tightly associated to RD of the four groups. Comparison of BTP levels showed significant differences between patients of groups 1 vs 3 and 4 as well as 2 vs 4.
  
  
  CONCLUSIONS
  BTP serum levels may serve as a surrogate marker for residual renal function since HD and HDF do not exert clinical relevant alterations on them. Furthermore, BTP serum concentrations appear strongly associated to RD.
authors: Department of Internal Medicine I, University Hospital, Bonn, Germany. thomas.gerhardt@ukb.uni-bonn.de
authors: Thomas
authors: T
authors: Gerhardt
authors: Uwe
authors: U
authors: Pöge
authors: Birgit
authors: B
authors: Stoffel-Wagner
authors: Burkhard
authors: B
authors: Klein
authors: Hans-Ulrich
authors: HU
authors: Klehr
authors: Tilman
authors: T
authors: Sauerbruch
authors: Rainer P
authors: RP
authors: Woitas
mesh_terms: D004231:Diuresis; D005260:Female; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000097:blood*; D054834:Lipocalins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis
chemical_list: D054834:Lipocalins; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase