On‐line haemodiafiltration. Remarkable removal of β2‐microglobulin. Long‐term clinical observations

Abstract

In the first part with on-line HDF, starting from HDF 60 ml/min a significantly higher beta2-M reduction ratio and clearance vs HD is noted. In HDF100 (i.e. with 241 replacement volume per 4-h treatment) vs HD, a beta2-M reduction ratio of 72.7% vs 49.7% (P= 0.0000) and a beta2-M clearance of 116.8 vs 63.8 ml/min (P=0.0000) was obtained. Comparing HDF120 with HDF100, there is a significantly higher beta2-M clearance with the former (P<0.005), although the beta2-M reduction ratio was not significantly better. In the HDF120 session the amount of beta2-M in the total dialysate was 292 mg per session. If one adds the known 17% adsorption on the polysulfone membrane, a total of 341.6 mg beta2-M per session is removed, which adds up to 1024.8 mg a week. Concerning the small molecules, our results with HDF100 also show a higher creatinine and especially P clearance vs HD. In the second part with 16 patients with more than 10 years of dialysis treatment (mean 14 years 1 month), the mean time on HDF amounted to 39.5% of the total treatment time. In four patients only biocompatible and highly permeable membranes were used, AN69 and mainly polysulfone, and in four other patients these membranes were used for more than 95% of the treatment time. Therefore, it is not surprising that the prevalence of carpal tunnel syndrome was only 12.5% in the patients after 10 years of dialysis. Twenty-five percent of these patients met the criteria for diagnosis of beta2-M bone-amyloidosis, proposed by van Ypersele de Strihou et al., but without a retrospective X-ray analysis. The mean predialysis beta2-M value was 29.6 mg/l. The mean values for serum albumin, serum total cholesterol, HDL and LDL cholesterol were within normal limits. For the parathyroid hormone a mean of 287.5 pg/ml was found. Subtotal parathyroidectomy was performed in five patients. The mean dose of 43 U erythropoietin/kg per session is comparable with those reported in the literature. Conclusions. Like Canaud, in our renal unit, treatment with on-line HDF with a highly permeable and biocompatible membrane has proven to be an efficient, well-tolerated and safe technique. Furthermore it leads to a low prevalence of dialysis amyloidosis and a superior P clearance. However, continuous attention must be paid to an on-line sterile and apyrogenic dialysate. Although on-line HDF is undoubtedly a more optimal approach of chronic dialytic treatment, it also carries a higher cost, which is currently evaluated to be nearly US$11 per session.

Role of Residual Kidney Function and Convective Volume on Change in β2-Microglobulin Levels in Hemodiafiltration Patients

“…However, most studies were small (10-13) or uncontrolled (14,15) and none of these studies specifically addressed the effect of RKF or convective volume on ␤2M decrease. Relatively large effects of HDF were reported in a randomized study in 42 patients, comparing mid-dilution HDF with exchange volumes of 60 L/treatment with low-flux HD and using ultrapure dialysis fluids.…”

“…Indeed, a relation between the delivered convective volume and ␤2M reduction ratio has been reported during a dialysis session (14,15). In addition, in the Dialysis Outcomes and Practice Patterns Study (DOPPS) a survival benefit was observed only in HDF patients who were treated with high convective volumes (replacement of Ն15 L/treatment) (16).…”

“…In addition, it has been shown that removal of ␤2M is further increased with online hemodiafiltration (HDF) by using excess ultrafiltration to provide increased convective transport. Actually, lower predialysis ␤2M levels have been reported after 3 to 12 mo treatment with HDF, as compared with low-flux or high-flux HD (10)(11)(12)(13)(14)(15). It has been proposed that the improved survival of HDF patients, as reported in few observational studies (16)(17)(18), can be partly attributed to increased removal of ␤2M and other MMW uremic toxins by convective transport.…”

Effect of Online Hemodiafiltration on All-Cause Mortality and Cardiovascular Outcomes

“…With modern online hemodiafiltration equipment, high convection and substitution volumes can be reached safely, 3 resulting in markedly enhanced removal of middle molecular mass substances. [4][5][6][7] Several nonrandomized observational studies suggested a survival benefit in patients who are treated with online hemodiafiltration. [8][9][10][11] However, small randomized studies failed to show a difference between online hemodiafiltration and standard hemodialysis (as summarized by van der Weerd et al 12 ).…”

Pulse Push/Pull Hemodialysis: Convective Renal Replacement Therapy

“…Much evidence shows that HDF delivers better dialysis outcomes than high-flux HD; for example, HDF has been shown to improve middle-to-large size molecular removal, allow better EPO control, reduce oxidative stress and inflammation (Lornoy et al, 2000, Vaslaki et al, 2006, Ward et al, 2000, and even to positively influence patient mortality (Canaud et al, 2006, Jirka et al, 2006. These benefits have been attributed to the higher convective doses permitted during HDF.…”