title: Effect of on-line hemodiafiltration with endogenous reinfusion (HFR) on the calcium-phosphorus metabolism: medium-term effects.
abstract: OBJECTIVE
  The purpose of the study was to examine the effect of hemodiafiltration with endogenous reinfusion (HFR) compared to hemodialysis (HD) on 28 uremic patients with secondary hyperparathyroidism (2HPT) but positively selected for good and stable control of phosphatemia in order to evaluate the independent effects of dialysis treatments on bone turnover metabolism.
  
  
  METHODS
  The study was divided into 3 periods of observation: a) HD for three months; b) HFR for three months; c) HFR for a further 3 months. We analysed the trend of: whole PTH, 1-84 PTH, 7-84 PTH, alkaline phosphatase and its bone isoenzyme, total and ionised calcium, phosphatemia, dose of phosphate binder agents, beta2-microglobulin, CRP. All the variations found were evaluated through mean values +/- SD, t-tests, multivariate analysis.
  
  
  RESULTS
  We observed a deceleration in bone turnover characterized by a reduction of the total and bone alkaline phosphatase (IU/mL) from 92.3 +/- 82.8 and 35.8 +/- 49.8 at the end of HD to 63.4 +/- 23.9 and 16.0 +/- 8.7 at the end of HFR, respectively, and 1-84 PTH from 317.5 +/- 264.6 pg/mL at the end of HD to 287.5 +/- 258.9 pg/mL at the end of the 3rd month of HFR. Beta2-microglobulin was reduced from 32.9 +/- 16.1 mg/L at the end of HD to 26.4 +/- 8.1 mg/L already at the end of the first three months of HFR. CRP was reduced from 2.5 +/- 2.6 mg/dL at the beginning of the study to 1.3 +/- 1.7 mg/dL at the end of HFR. There were no differences with regard to: dialytic efficiency, nutritional status, calcemia, phosphatemia (maintained in the K-DOQI range for the entire duration of the study), also thanks to more careful use of phosphate chelating agents.
  
  
  CONCLUSIONS
  We are of the opinion that HFR - essentially thanks to the use of ultrapure endogenous infusate - induces a deceleration in bone turnover due to 2PHT. In addition, phosphate subtraction in HFR is better compared to HD, thanks to the improvement of the anti-inflammatory conditions by removing the cytokines harmful to bone metabolism and excluding a priori the negative effects related to hyperphosphatemia.
authors.affiliation: Territorial Nephrology and Dialysis Unit, Azienda USL n. 8, Cagliari, Italy. dialisiterritorio@tiscali.it
authors.forename: P G
authors.initials: PG
authors.lastname: Bolasco
authors.forename: P M
authors.initials: PM
authors.lastname: Ghezzi
authors.forename: R
authors.initials: R
authors.lastname: Ferrara
authors.forename: M
authors.initials: M
authors.lastname: Maxia
authors.forename: M
authors.initials: M
authors.lastname: Pinna
authors.forename: F
authors.initials: F
authors.lastname: Logias
authors.forename: G
authors.initials: G
authors.lastname: Cogoni
authors.forename: F
authors.initials: F
authors.lastname: Cadinu
authors.forename: T
authors.initials: T
authors.lastname: Ghisu
authors.forename: B
authors.initials: B
authors.lastname: Contu
authors.forename: D
authors.initials: D
authors.lastname: Casu
authors.forename: M
authors.initials: M
authors.lastname: Passaghe
authors.forename: A
authors.initials: A
authors.lastname: Pilloni
authors.forename: M
authors.initials: M
authors.lastname: Ganadu
authors.forename: L
authors.initials: L
authors.lastname: Gazzanelli
mesh_terms: D000368:Aged; D000469:Alkaline Phosphatase / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000378:metabolism; D005260:Female; D017583:Hemodiafiltration / Q000379:methods*; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009752:Nutritional Status; D009862:Online Systems; D010758:Phosphorus / Q000378:metabolism*; D016896:Treatment Outcome; D014511:Uremia / Q000378:metabolism* / Q000628:therapy*; D001613:beta 2-Microglobulin / Q000378:metabolism
chemical_list: D001613:beta 2-Microglobulin; D010758:Phosphorus; D002097:C-Reactive Protein; D000469:Alkaline Phosphatase; D002118:Calcium