Department of Internal Medicine & Pediatrics, Ghent University, Ghent, Belgium.
Department of Data Analysis, Faculty of Psychology and Pedagogy, Ghent University, Ghent, Belgium.
Nephrol Dial Transplant. 2020 Apr 1;35(4):648-656. doi: 10.1093/ndt/gfz132.
Haemodiafiltration (HDF) is accepted to effectively lower plasma levels of middle molecules in the long term, while data are conflicting with respect to the additive effect of convection on lowering protein-bound uraemic toxins (PBUTs). Here we compared pre-dialysis β2-microglobulin (β2M) and PBUT levels and the percentage of protein binding (%PB) in children on post-dilution HDF versus conventional high- (hf) or low-flux (lf) haemodialysis (HD) over 12 months of treatment.
In a prospective multicentre, non-randomized parallel-arm intervention study, pre-dialysis levels of six PBUTs and β2M were measured in children (5-20 years) on post-HDF (n = 37), hf-HD (n = 42) and lf-HD (n = 18) at baseline and after 12 months. Analysis of variance was used to compare levels and %PB in post-HDF versus conventional hf-HD and lf-HD cross-sectionally at 12 months and longitudinal from baseline to 12 months.
For none of the PBUTs, no difference was found in either total and free plasma levels or %PB between post-HDF versus the hf-HD and lf-HD groups. Children treated with post-HDF had lower pre-dialysis β2M levels [median 23.2 (21.5; 26.6) mg/dL] after 12 months versus children on hf-HD [P<0.01; 35.2 (29.3; 41.2) mg/dL] and children on lf-HD [P<0.001; 47.2 (34.3; 53.0) mg/dL]. While β2M levels remained steady in the hf-HD and lf-HD group, a decrease in β2M was demonstrated for children on post-HDF (P<0.01).
While post-HDF successfully decreased β2M, no additive effect on PBUT over 12 months of treatment was found. PBUT removal is complex and hampered by several factors. In children, these factors might be different from adults and should be explored in future research.
血液透析滤过（HDF）被认为可长期有效降低血浆中中分子水平，而对流在降低蛋白结合尿毒症毒素（PBUT）方面的附加作用的数据存在争议。在此，我们比较了在接受后稀释 HDF 治疗 12 个月后，儿童的透析前β2-微球蛋白（β2M）和 PBUT 水平以及蛋白结合百分比（%PB）与常规高通量（hf）或低通量（lf）血液透析（HD）之间的差异。
在一项前瞻性、多中心、非随机平行臂干预研究中，我们在基线和 12 个月时，分别测量了接受 HDF（n=37）、hf-HD（n=42）和 lf-HD（n=18）治疗的儿童（5-20 岁）的透析前 6 种 PBUT 和β2M 水平。方差分析用于比较 12 个月时后稀释 HDF 与常规 hf-HD 和 lf-HD 之间的水平和%PB 的横断面差异，以及从基线到 12 个月的纵向差异。
对于所有 PBUT 来说，在总血浆水平、游离血浆水平和%PB 方面，后稀释 HDF 与 hf-HD 和 lf-HD 之间均无差异。与 hf-HD 组[35.2（29.3；41.2）mg/dL]和 lf-HD 组[47.2（34.3；53.0）mg/dL]相比，接受后稀释 HDF 治疗的儿童在 12 个月时的透析前β2M 水平[中位数 23.2（21.5；26.6）mg/dL]较低（P<0.01）。而在 hf-HD 和 lf-HD 组中，β2M 水平保持稳定，而在后稀释 HDF 组中，β2M 水平下降（P<0.01）。
虽然后稀释 HDF 成功降低了β2M，但在 12 个月的治疗期间，对 PBUT 没有发现附加作用。PBUT 的清除较为复杂，并受到多种因素的阻碍。在儿童中，这些因素可能与成人不同，应在未来的研究中进行探索。
