Expanded Hemodialysis with Theranova Dialyzer and Residual Kidney Function in Patients Starting Long-Term Hemodialysis: A Randomized Controlled Trial.

KEY POINTS: This randomized controlled trial evaluated the effect of expanded hemodialysis on preserving residual kidney function in patients starting treatment with long-term hemodialysis. The expanded hemodialysis group with Theranova dialyzer showed smaller decrease in GFR than the high-flux group over 12 months. The Theranova group had a larger reduction in middle molecules and inflammatory cytokines and smaller increases in kidney injury markers. BACKGROUND: Expanded hemodialysis using a medium cutoff dialyzer improves the clearance of middle-molecular toxins compared with conventional hemodialysis. This study evaluated the effect of expanded hemodialysis on preserving residual kidney function in patients starting treatment with long-term hemodialysis. METHODS: Patients who initiated long-term hemodialysis 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 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 patients on hemodialysis (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 to −0.5] ml/min per 1.73 m(2)). Theranova maintained greater 24-hour urine volume until 9 months, not at 12 months, compared with the high-flux dialyzer. The reduction ratio for κ/λ free light chains, TNF-α, and growth differentiation factor-15 was higher in the Theranova group than in the high-flux group. The increase in the kidney injury marker, IGF-binding protein 7, was attenuated in the Theranova group. Hospitalization rate and mortality did not differ between the two groups. CONCLUSIONS: This trial suggests that expanded hemodialysis using the Theranova dialyzer slowed decline in residual kidney function compared with a high-flux dialyzer in patients starting treatment with long-term hemodialysis. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Theranova versus High-flux Dialyzer on Preservation of Residual Renal Function, NCT04211571.