Korean J Intern Med.  2010 Mar;25(1):77-81. 10.3904/kjim.2010.25.1.77.

Application of Cystatin C Reduction Ratio to High-Flux Hemodialysis as an Alternative Indicator of the Clearance of Middle Molecules

• Park JS
• Kim GH
• Kang CM
• Lee CH

• KMID: 1785658
• DOI: http://doi.org/10.3904/kjim.2010.25.1.77

Abstract

BACKGROUND/AIMS
Although high-flux (HF) dialyzers with enhanced membrane permeability are widely used in current hemodialysis (HD) practice, urea kinetic modeling is still being applied to indicate the adequacy of both low-flux (LF) and HF HD. In comparison with urea (molecular weight, 60 Da) and beta2-microglobulin (beta2MG, 12 kDa), cystatin C (CyC, 13 kDa) is a larger molecule that has attractive features as a marker for assessing solute clearance. We postulated that CyC might be an alternative for indicating the clearance of middle molecules (MMs), especially with HF HD.
METHODS
Eighty-nine patients were divided into LF and HF groups. Using single pool urea kinetic modeling, the urea reduction ratio (URR) and equilibrated Kt/Vurea (eKt/Vurea) were calculated. The serum CyC concentrations were measured using particle-enhanced immunonephelometry. As indices of the middle molecular clearance, the reduction ratios of beta2MG and CyC were calculated.
RESULTS
The beta2MG reduction ratio (beta2MGRR) and CyC reduction ratio (CyCRR) were higher in the HF group compared to the LF group. However, the URR and eKt/Vurea did not differ between the two groups. The CyCRR was significantly correlated with the eKt/Vurea and beta2MGRR (r = 0.47 and 0.69, respectively, both p < 0.0001).
CONCLUSIONS
Compared to the LF dialyzer, the HF dialyzer removed CyC and beta2MG more efficiently. Unlike the beta2MGRR, the CyCRR was correlated with the eKt/Vurea and beta2MGRR. This study suggests a role for the CyCRR as an alternative indicator of the removal of MMs.

Keyword

Dialysis; beta 2-Microglobulin; Cystatin C

MeSH Terms

Adult
Aged
Biological Markers/blood
Case-Control Studies
Cystatin C/*blood
Female
Hemodialysis Solutions
Humans
Kidney Failure, Chronic/*blood/*therapy
Male
Middle Aged
Models, Biological
Nephelometry and Turbidimetry/*methods
Renal Dialysis/*methods
Urea/blood
Uremia/blood/therapy
beta 2-Microglobulin/blood