Comparison of the effects of pre-dilution and post-dilution online hemodiafiltration on the levels of inflammatory markers, lymphocytes, and platelets.

Online hemodiafiltration (OL-HDF) is a blood purification therapy based on diffusion and ultrafiltration and is classified into two types according to the mode of addition of the substitution fluid: pre-dilution OL-HDF (pre-HDF) and post-dilution OL-HDF (post-HDF); we previously reported that pre-HDF is more biocompatible. However, we used lower blood and substitution flow rates in that study and may not have accurately simulated the treatment conditions used in Europe. In this study, we compared the biocompatibilities of the treatment conditions of pre-HDF, commonly used in Japan, and post-HDF, commonly used in Europe, to determine the most biocompatible treatment conditions. We compared the biocompatibilities of pre-HDF and post-HDF using high blood flow rates and high substitution fluid volumes, and also compared the results with those of our previous study. We enrolled six stable patients undergoing maintenance dialysis at our clinic for this study. After the patients underwent hemodialysis (HD), post-HDF, and pre-HDF treatment, the biocompatibilities (based on the serum levels of high-sensitivity C-reactive protein, interleukin-6, pentraxin-3, ß-thromboglobulin, and soluble P-selectin, and the results of the lymphocyte blastogenesis test using phytohemagglutinin and concanavalin A as mitogens) and removal performances (removal performance for urea, creatinine, ß2-microglubulin [MG], and α1-MG, and albumin leakage) were determined. There were no significant differences in the biocompatibility parameters evaluated among the three treatment modes. Post-HDF was associated with significantly higher removal rates of ß2-MG than HD. Post-HDF was associated with significantly higher removal rate of α1-MG, and also significantly higher albumin leakage, than HD and pre-HDF.

Therapeutic effect of high-efficiency online hemodiafiltration for recurrent restless legs syndrome in dialysis patients.

Two dialysis patients developed recurrent restless legs syndrome. The clinical courses and the association between the α1-microglobulin removal rate and the therapeutic effects of hemodiafiltration were analyzed. Case 1: a middle-aged woman was switched from predilution online hemodiafiltration to hemodialysis, following which the α1-microglobulin removal rate decreased from 39.1 to 29.9%. A month later, the severe restless legs syndrome occurred. The treatment was then switched to high-efficiency hemodiafiltration and 2 weeks later, these symptoms were resolved. The α1-microglobulin removal rate increased to 41.9%. Her symptoms recurred 5 years later with severity; thus, the hemodiafiltration treatment conditions were changed. Under revised conditions, the α1-microglobulin removal rate was 42.6%, and her symptoms were alleviated. Continuation of high-efficiency hemodiafiltration led to the resolution of the syndrome at 1 month after recurrence. Case 2: a middle-aged man on hemodialysis developed the restless legs syndrome in the second year of treatment. The α1-microglobulin removal rate was 23.8%. After switching to a month-long high-efficiency hemodiafiltration with a removal rate of ≥ 40%, his symptoms were resolved. However, the syndrome recurred after a year with severity. The symptoms were alleviated using various measures. The hemodiafilters were changed, and hemodiafiltration with an α1-microglobulin removal rate of ≥ 40% was continued; 2 months later, his symptoms resolved. High-efficiency online hemodiafiltration is an effective therapeutic strategy for restless legs syndrome in dialysis patients. We found, for the first time, that target removal efficiency is an α1-microglobulin removal rate of 40% or higher.

Evaluation of low-volume post-dilution online hemodiafiltration with Japanese high-performance hemodiafilters.

PURPOSE: To assess the removal performance of low-volume post-hemodiafiltration (HDF) with Japanese hemodiafilters and the removal performance with 20 % reduction in the total dialysate flow rate (Qdtotal). METHODS: Subjects were 8 patients undergoing pre-HDF. Study 1: Post-HDF was performed at a blood flow rate (Qb) of 250 mL/min and a total volume of substitution fluid (Vs) of 12 L/session(s) for 4 hrs using Fineflux-210Seco (FIX), ABH-21PA (ABH), and NVF-21H (NVF). We assessed removal efficiency of small molecular solutes, low-molecular-weight-proteins and the amount of albumin loss. Study 2: Post-HDF was performed at Vs of 12 L/s under G-1, Qdtotal of 500 and Qb of 250 mL/min; G-2, Qdtotal of 400 and Qb of 250 mL/min; and G-3, Qdtotal of 400 and Qb of 300 mL/min. Removal efficiency was compared and analyzed between these conditions. RESULTS: Study 1: The results using FIX, ABH and NVF are shown in order. The Kt/V were 1.8, 1.9 and 1.8. The ß2-Microglobulin (MG) removal rate (RR) (%) were 81.2, 83.1 and 82.8, and the α1-MG RR were 37.4, 40.2 and 38.5, respectively. Study 2: The results in G-1, 2 and 3 are shown in order. The Kt/V and the RR of small solutes, were significantly higher in G-3. The ß2-MG RR (%) were 81.2, 80.1 and 81.0, and the α1-MG RR were 37.4, 37.5 and 38.0, respectively. CONCLUSIONS: Low-volume post-HDF performed at Qb of 250 mL/min with Japanese high-performance hemodiafilters exhibited favorable removal efficiency for all solutes. Even with 20 % reduction in Qdtotal, the removal performance was also favorable.

Comparison of the effects of predilution and postdilution hemodiafiltration on neutrophils, lymphocytes and platelets.

Numerous studies have been carried out to investigate the solute removal efficiency of hemodiafiltration (HDF). However, the effect of the dilution mode on blood cell damage during HDF has not yet been examined in detail. Here, we compared predilution and postdilution HDF with respect to their effects on blood cells. Five patients were allocated to one session each of predilution HDF and postdilution HDF. Concentrations of interleukin (IL)-6, intercellular adhesion molecule (ICAM)-1, and platelet-derived microparticles (PDMP), and the phagocytotic and sterilizing functions of neutrophils before and after the HDF sessions were evaluated. Lymphocyte blastoid transformation induced by mitogens was also evaluated by measurement of the [(3)H]-thymidine uptake. The IL-6 and ICAM-1 concentrations decreased after predilution HDF, and increased after postdilution HDF. Lymphocyte blastoid transformation was more pronounced after predilution HDF than after postdilution HDF. There was no significant difference in PDMP between the dilution modes. We conclude that predilution HDF could be more favorable for dialysis patients than postdilution HDF from the point of view of the effects on the blood cells, especially neutrophils and lymphocytes.