ABSTRACT
BACKGOUND: On-line hemodiafiltration (HDF) is a technique that relies on the re-injection of pyrogen-free substitution fluid obtained by cold filtration of dialysate. Therefore, safety of this therapy depends on the quality of dialysate and, mainly, on the integrity of the ultrafilters employed. Paired hemodiafiltration (PHF) is a new technique where re-infusion takes place inside the dialyzer by means of dialysate backfiltration. METHODS: To assess safety and feasibility, we carried out prospective cross-over trial comparing PHF with hemodialysis (HD) in five stable HD patients RESULTS: All PHF sessions were well tolerated. No pyrogenic reactions were observed during the study period. No significant difference was found in the incidence of intradialytic hypotension. PHF led to significantly higher small and middle molecule clearance than HD. The reduction rates of urea, creatinine and beta2-M were significantly higher in PHF than in HD, while no difference was found for phosphate. The serum beta2-M levels fell progressively from the HD value of 29 mg/L to 17 mg/L at the end of 3 months's PHF treatment. CONCLUSION: In conclusion, PHF is a feasible and safe convective therapy to increase beta2-M removal compared with HD. Long-term, prospective multicenter clinical studies are mandatory to assess the clinical outcome of this new on-line technique of HDF.