Gerdemann A, Lemke H D, Nothdurft A, Heidland A, Münch G, Bahner U, Schinzel R
Physiologische Chemie I, Biozentrum, Würzburg, Germany.
Clin Nephrol. 2000 Oct;54(4):276-83.
Patients with end-stage renal disease (ESRD) display very high levels of advanced glycation end products (AGEs). These compounds are suspected to play a pathophysiological role in diabetic nephropathy and late diabetic cardiovascular complications. We investigated to what extent AGE levels can be reduced by high-flux dialysis.
Ten ESRD patients were treated three times each with DIAPES and HF60, two different synthetic, high-flux hemodialysis membranes. The kinetics of AGE removal was studied by fluorescence spectroscopy (excitation 370 nm/ emission 440 nm) and by ELISA of serum samples and the removal of beta2-m was studied by immunonephelometry of plasma samples. Samples were taken during dialysis sessions at t = 0, 30 and 180 min. In addition, molecular weight distribution of AGE products in serum of three patients was analyzed by gel filtration and fluorescence detection.
A significant difference could be found when AGE levels in serum of controls (n = 10) were compared with serum AGE levels of ESRD patients (p < 0.01/fluorescence; p < 0.0001/ ELISA). After 3 h of dialysis AGE-related fluorescence in serum decreased by 25.5 +/- 6.8% for HF60 (p < 0.0001) and 24.3 +/- 6.9% tor DIAPES (p < 0.0001). The corresponding decline measured by ELISA was 23.3 +/- 8.9% for HF60 (p < 0.0001) and 26.1 +/- 7.0% for DIAPES (p < 0.0001). Both methods showed no significant differences for both types of dialysis membranes. Gel filtration revealed that the decrease of fluorescence can be attributed to the removal of AGE peptides with a molecular mass < 12 kDa, only. In the high molecular range (> 12 kDa) no removal but hemoconcentration was observed independent of the dialyzer type used. The reduction of beta2-m during 3 hours of dialysis was 61.8 +/- 6.9% for HF60 (p < 0.0001) and 161.7 +/- 7.0% for DIAPES (p < 0.0001).
Both high-flux dialyzers were equally effective to remove low-molecular AGE products, while AGE-modified proteins of higher molecular weight were only marginally affected. On the basis of our data we suggest the study of molecular mass-dependent uremic toxicity of AGEs and the examination of the influence of other treatment modalities on the level of high-molecular AGEs.
终末期肾病（ESRD）患者体内晚期糖基化终产物（AGEs）水平极高。这些化合物被怀疑在糖尿病肾病及晚期糖尿病心血管并发症中发挥病理生理作用。我们研究了高通量透析能在多大程度上降低AGE水平。
10例ESRD患者分别使用两种不同的合成高通量血液透析膜DIAPES和HF60进行三次治疗。通过荧光光谱法（激发波长370nm/发射波长440nm）、血清样本酶联免疫吸附测定（ELISA）研究AGE清除动力学，通过血浆样本免疫比浊法研究β2 -微球蛋白（β2 -m）的清除情况。在透析过程中t = 0、30和180分钟时采集样本。此外，通过凝胶过滤和荧光检测分析了3例患者血清中AGE产物的分子量分布。
将对照组（n = 10）血清中的AGE水平与ESRD患者血清中的AGE水平进行比较时，发现有显著差异（荧光法：p < 0.01；ELISA法：p < 0.0001）。透析3小时后，HF60组血清中与AGE相关的荧光下降了25.5 +/- 6.8%（p < 0.0001），DIAPES组下降了24.3 +/- 6.9%（p < 0.0001）。ELISA法测得的相应下降幅度，HF60组为23.3 +/- 8.9%（p < 0.0001），DIAPES组为26.1 +/- 7.0%（p < 0.0001）。两种方法对两种透析膜均未显示出显著差异。凝胶过滤显示，荧光的下降仅归因于分子量< 12kDa的AGE肽的清除。在高分子量范围（> 12kDa）内，无论使用何种透析器类型，均未观察到清除现象，反而出现了血液浓缩现象，但β2 -m在透析3小时后的清除率，HF60组为61.8 +/- （p < 0.0001），DIAPES组为161.7 +/- 7.0%（p < 0.0001）。
两种高通量透析器在清除低分子AGE产物方面同样有效，而高分子量的AGE修饰蛋白仅受到轻微影响。基于我们的数据，我们建议研究AGEs分子量依赖性的尿毒症毒性，并考察其他治疗方式对高分子量AGE水平的影响。
