Osteocalcin and myoglobin removal in on-line hemodiafiltration versus low- and high-flux hemodialysis.
BACKGROUND
Removal of medium and large solutes is poor with low-flux (LF-HD) and limited with high-flux hemodialysis (HF-HD) and on-line hemodiafiltration (OL-HDF). In clinical practice, there are few in vivo solute markers. Osteocalcin is a protein with a molecular mass of 5,800 daltons, and myoglobin is a large molecule with a molecular mass of 17,200 daltons. The aim of this study was to evaluate the impact of OL-HDF on in vivo removal of a wide spectrum of solutes (urea, creatinine, osteocalcin, beta2-microglobulin, and myoglobin) in comparison to LF-HD and HF-HD.


METHODS
Twenty-three patients (15 men, 8 women) were studied. Every patient underwent three dialysis sessions with routine HD parameters. We compared 1.8-m2 polysulfone LF-HD and 1.8-m2 polysulfone HF-HD versus OL-HDF. Predialysis and postdialysis solute concentrations were measured. The percentage of reduction ratio for each solute was calculated.


RESULTS
Mean values for predialysis osteocalcin, beta2-microglobulin, and myoglobin were 16.3 +/- 21 ng/mL, 27.4 +/- 5 mg/L, and 239 +/- 162 ng/mL in LF-HD, respectively. Urea and creatinine reduction ratios were similar in LF-HD and HF-HD and only 1.2% higher in OL-HDF. Osteocalcin, beta2-microglobulin, and myoglobin reduction ratios for LF-HD were negligible. Mean osteocalcin reduction rates were 54.2% +/- 12% for HF-HD versus 63.5% +/- 9% for OL-HDF (reinfusion volume, 26.8 +/- 5 L/session; P < 0.01). Mean beta2-microglobulin reduction rates were 60.1% +/- 9% for HF-HD versus 75.4% +/- 9% for OL-HDF (P < 0.01). Mean myoglobin reduction rates were 24.5% +/- 6% and 62.7% +/- 9% for HF-HD and OL-HDF, respectively (P < 0.01).


CONCLUSIONS
LF-HD does not seem to remove solutes with a molecular weight greater than 5,800 daltons. OL-HDF provides marked enhancement of convection volume and enables a significant increase in osteocalcin and beta2-microglobulin removal. Myoglobin extraction is nil with LF-HD, very low with HF-HD, and only adequate with OL-HDF.
Department of Nephrology, Hospital General de Castellón, Spain. fmaduellc@senefro.org
Francisco
F
Maduell
Victor
V
Navarro
Ma Carmen
MC
Cruz
Eduardo
E
Torregrosa
Daniel
D
Garcia
Victoria
V
Simon
Jose Antonio
JA
Ferrero
D000328:Adult; D000368:Aged; D003928:Diabetic Nephropathies / Q000097:blood / Q000628:therapy; D005260:Female; D005921:Glomerulonephritis / Q000097:blood / Q000628:therapy; D017583:Hemodiafiltration / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D008181:Lupus Nephritis / Q000097:blood / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009211:Myoglobin / Q000097:blood* / Q000378:metabolism; D009395:Nephritis, Interstitial / Q000097:blood / Q000628:therapy; D009400:Nephrosclerosis / Q000097:blood / Q000628:therapy; D009862:Online Systems / Q000295:instrumentation; D015675:Osteocalcin / Q000097:blood* / Q000378:metabolism; D007690:Polycystic Kidney Diseases / Q000097:blood / Q000628:therapy; D011446:Prospective Studies; D006435:Renal Dialysis / Q000295:instrumentation / Q000379:methods
D009211:Myoglobin; D015675:Osteocalcin