Canavese C, DeCostanzi E, Branciforte L, Caropreso A, Nonnato A, Pietra R, Fortaner S, Jacono F, Angelini G, Gallieni M, Fop F, Sabbioni E
Department of Internal Medicine, University of Torino, Italy.
J Nephrol. 2001 May-Jun;14(3):169-75.
Since dialysis has brought long-term survival to uremic patients, we can now speculate on more subtle problems derived from imbalance or sub-optimal regulation of some elements such as trace metals. We focused on the rubidium (Rb) status in dialysis patients (HD), as concerns about its possible deficiency have been raised.
Rb in uremic patients was evaluated by: A) serum concentration (graphite furnace atomic absorption spectroscopy) from blood samples of 70 patients on chronic hemodialysis (HD) in comparison with 75 controls; B) tissue concentration (neutron activation analysis) from autopsy or biopsy samples (20) of HD patients in comparison with 21 controls; C) in vivo intradialytic mass balance during standard bicarbonate dialysis in 8 HD patients.
A) Serum Rb concentrations in HD patients significantly were lower than in normal controls (304 +/- 81 micrograms/L versus 350 +/- 74 micrograms/L p < 0.001, log-transformed 5.68 +/- 0.28 versus 5.84 +/- 0.20, p < 0.001). Univariate logistic regression analysis found a significantly higher risk of serum Rb < 250-300 and 350 micrograms/L in uremic patients than in controls (Odd ratios or 12.6, 95% CI 2.77-57.04; 4.0, 95% CI 1.92-8.4; 2.08, 95% CI 1.02-4.25, respectively). B) Rb was significantly lower in tissues of HD patients, including brain (2250 +/- 1520 ng/g versus 5490 +/- 1250 ng/g, p = 0.0002) than normal controls. C) Rb was transferred from the patients' blood to the dialysis bath during a standard bicarbonate dialysis session, giving mean intradialytic Rb removal of 4.0 +/- 1.1 mg/session.
These results confirm that Rb deficiency may arise in uremic patients, and indicate that diffusive dialysis treatments allow Rb removal which, however, with a standard bicarbonate schedule does not seem to be any greater than that expected with normal urine output (20 mg/week). Further studies are needed to clarify the roles of many factors in this Rb deficiency, including the effects of uremia by itself, pre-dialysis factors (diet, impaired renal function and drugs), dialysis procedures (frequency, hours, diffusive/convective components) or other biochemical/clinical parameters (hemoglobin, body mass index, age). The finding of a Rb deficiency in uremia is important as it has a role in neurobehavioural functions, mainly as an antidepressant. As Rb deficiency may be implicated in central nervous system alterations which strongly influence the quality of life, we believe that monitoring serum Rb in uremic patients and clarifying the causal mechanisms of deficiency will facilitate future therapeutic approaches.
自从透析为尿毒症患者带来长期生存以来，我们现在可以推测一些元素（如微量元素）失衡或调节欠佳所引发的更细微问题。我们关注透析患者（血液透析）的铷（Rb）状况，因为人们已经开始担忧其可能存在的缺乏情况。
通过以下方式评估尿毒症患者的Rb：A）对70例慢性血液透析（HD）患者的血样进行血清浓度检测（石墨炉原子吸收光谱法），并与75例对照者进行比较；B）对HD患者的20份尸检或活检样本进行组织浓度检测（中子活化分析），并与21例对照者进行比较；C）对8例HD患者在标准碳酸氢盐透析期间进行体内透析质量平衡检测。
A）HD患者的血清Rb浓度显著低于正常对照者（304±81微克/升对350±74微克/升，p<0.001；经对数转换后为5.68±0.28对5.84±0.20，p<0.001）。单因素逻辑回归分析发现，尿毒症患者血清Rb<250 - 300微克/升和<350微克/升的风险显著高于对照者（比值比分别为12.6，95%置信区间2.77 - 57.04；4.0，95%置信区间1.92 - 8.4；2.08，95%置信区间1.02 - 4.25）。B）HD患者组织中的Rb显著低于正常对照者，包括大脑（2250±1520纳克/克对5490±1250纳克/克，p = 0.0002）。C）在标准碳酸氢盐透析过程中，Rb从患者血液转移至透析液中，每次透析Rb的平均清除量为4.0±1.1毫克。
这些结果证实尿毒症患者可能出现Rb缺乏，并表明弥散性透析治疗会导致Rb清除，然而，采用标准碳酸氢盐透析方案时，其清除量似乎并不比正常尿量（20毫克/周）预期的清除量更大。需要进一步研究以阐明许多因素在这种Rb缺乏中的作用，包括尿毒症本身的影响、透析前因素（饮食、肾功能受损和药物）、透析程序（频率、时长、弥散/对流成分）或其他生化/临床参数（血红蛋白、体重指数、年龄）。尿毒症中发现Rb缺乏很重要，因为它在神经行为功能中起作用，主要作为一种抗抑郁剂。由于Rb缺乏可能与强烈影响生活质量的中枢神经系统改变有关，我们认为监测尿毒症患者的血清Rb并阐明缺乏的因果机制将有助于未来的治疗方法。
