Continuous beta-2 microglobulin–based clearance highlights superiority of high-Dose HDF over high-flux HD in predicting outcomes

Abstract

Abstract Recent studies suggest that high-dose hemodiafiltration (HDF) may reduce mortality more effectively than high-flux hemodialysis (HD), though the mechanisms remain unclear. Traditional metrics such as Kt/V and convective volume do not fully capture overall dialysis efficiency. This study proposes a novel approach using circulating beta-2-microglobulin (ß2M) levels to estimate an equivalent Continuous Dialytic Clearance (eCDCß2M), reflecting an equivalent glomerular filtration rate. Using data from the FRENCHIE study, we calculated eCDCß2M and assessed its association with patient outcomes, including all-cause and cardiovascular mortality, in comparison with traditional dialysis dose metrics. Our analysis showed that HDF achieved higher treatment efficiency than high-flux HD, with a mean increase of + 1.5 ml/min in eCDCß2M. Moreover, eCDCß2M demonstrated superior predictive value for mortality risk compared to Kt/V. These findings support eCDCß2M as a meaningful and physiologically relevant measure of dialysis efficiency and adequacy. By better reflecting the continuous function of the native kidney, this approach may improve patient stratification and outcome prediction across all forms of kidney replacement treatment schedule. Further validation in independent patient cohorts is warranted.