High serum cobalamin levels in the clinical setting - clinical associations and holo-transcobalamin changes
High serum cobalamin levels in the clinical setting - clinical associations and holo-transcobalamin changes
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DOI：
10.1046/j.1365-2257.2001.00134.x
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发表时间：
2001-12-01
期刊：
影响因子：
--
通讯作者：
George, K
中科院分区：
文献类型：
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作者：
Carmel, R;Vasireddy, H;George, K
虽然低钴胺素水平已被深入研究，但关于高水平的系统信息，特别是在临床环境中，是稀缺的。因此，在21/2个月的时间内，对60名钴胺素水平高的患者和75名钴胺素水平正常的患者进行了前瞻性比较。与临床疾病和实验室检查结果的关联进行了检查。测定了转钴胺素（TC）I和II，特别是用微细二氧化硅粉末分级分离的全蛋白（携带循环内源性钴胺素的TC）。在670次连续的临床要求检测中，有94次（14%）出现了高钴胺素水平（> 664 pmol/l; > 900 ng/l）。与高钴胺素水平唯一独立显著相关的是临床疾病中的肾衰竭（P = 0.01），实验室检查中的血清肌酐升高（P = 0.0001）和白蛋白降低（P = 0.0002）。肾功能衰竭时，holo-TC I和holo-TC II水平均升高（P = 0.0001），但holo-TC II的升高幅度相对较大。结果表明，在临床实践中，高钴胺素水平比低钴胺素水平更常见，并且似乎经常与肾功能衰竭有关。Holo-TC II和Holo-TC I的升高表明有几种机制在起作用。holo-TC II的蓄积表明，肾脏中丰富的TC II受体对钴胺素的细胞摄取可能受损。众所周知，高钴胺素水平与白细胞疾病之间的联系是罕见的，与肝脏疾病之间没有联系。
Whereas low cobalamin levels have been studied intensively, systematic information about high levels, especially in the clinical setting, is scarce. Therefore, a prospective comparison was done of 60 patients with high cobalamin levels and 75 with normal levels obtained by a hospital laboratory over a 21/2 month period. Associations with clinical disorders and laboratory test results were examined. Transcobalamin (TC) I and II were measured, especially the holoproteins (TC carrying circulating endogenous cobalamin) which were fractionated with microfine silica powder. High cobalamin levels (> 664 pmol/l; > 900 ng/l) occurred in 94 of 670 consecutive clinically requested assays (14%). The only independently significant associations with a high cobalamin level were renal failure among the clinical disorders (P = 0.01), elevated serum creatinine (P = 0.0001) and diminished albumin (P = 0.0002) levels among laboratory tests. Both holo-TC I and holo-TC II levels were increased in renal failure (P = 0.0001) but the increase was relatively greater in holo-TC II. The results indicate that high cobalamin levels area more frequent than low ones in clinical practice and appear to be associated often with renal failure. The elevation of both holo-TC II and holo-TC I suggests that several mechanisms are operative. The accumulation of holo-TC II suggests that cellular uptake of cobalamin by the abundant TC II receptors in the kidney may be impaired. The much better known association of high cobalamin levels with leucocytic disorders is rare, and no association was seen with liver disease.