Expanded Hemodialysis with Theranova Dialyzer and Residual Kidney Function in Incident Hemodialysis Patients.

Background: Expanded hemodialysis (HD) using a medium cut-off dialyzer improves the clearance of middle-molecular toxins compared to conventional HD. This study evaluated the effect of expanded HD on preserving residual kidney function in incident HD patients.

Methods: Patients who initiated HD were randomized to receive dialysis with either a Theranova 400 (Baxter) or a high-flux dialyzer with a similar surface area over 12 months. The primary outcome was a change in glomerular filtration rate (GFR) over 12 months, as determined by the mean of urea and creatinine clearance. The secondary outcome was a change in 24-hour urine volume, middle molecules, and kidney injury markers.

Results: A total of 80 HD patients (mean age [SD]: 63 [12] years; male: 52 [65%]) underwent randomization. Over 12 months, the Theranova group demonstrated a significantly smaller decrease in GFR than the high-flux group (least-squares mean difference of change [95% confidence interval]: -1.4 [-2.4, -0.5] mL/min/1.73 m2). Theranova maintained greater 24-hour urine volume until 9 months, not at 12 months, compared to the high-flux dialyzer. The reduction ratio for κ/λ free light chains, TNF-α, and GDF-15 was higher in the Theranova group than in the high-flux group. The increase in the kidney injury marker, IGFBP7, was attenuated in the Theranova group. Hospitalization rate and mortality did not differ between the two groups.

Conclusions: This trial suggests that expanded HD using the Theranova dialyzer may slow decline in residual kidney function compared with a high-flux dialyzer in incident HD patients.