Hvas A-M, Nexo E
Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus C, Denmark.
J Intern Med. 2005 Mar;257(3):289-98. doi: 10.1111/j.1365-2796.2004.01437.x.
The performance of holotranscobalamin (holoTC) was compared with the other markers of vitamin B12 deficiency, and the influence of age, renal function, and thyroid status was examined.
We examined 937 individuals not treated with vitamin B12 but in whom vitamin B12 deficiency was suspected because of a plasma methylmalonic acid (MMA) above 0.28 micromol L(-1) within the past 4 years. Besides laboratory tests, a structured interview and a neurological examination were performed amongst 534 individuals. Amongst these, 140 individuals qualified for a randomized trial (MMA 0.40-2.00 micromol L(-1)). They were randomized to injections with vitamin B12 or placebo and re-examined after 3 months.
One university hospital in Aarhus, Denmark.
The ROC curves indicate that holoTC (AUC: 0.90) compared favourable with plasma vitamin B12 (AUC: 0.85) for identifying individuals likely to have vitamin B12 deficiency (MMA > or =0.75 micromol L(-1) and plasma total homocysteine (tHcy) > or =15 micromol L(-1)), and further that holoTC (AUC: 0.91) might replace combined testing with plasma vitamin B12 and the metabolites. No association was observed between the biochemical markers and symptoms and signs possibly related to vitamin B12 deficiency. HoloTC, TC saturation, plasma vitamin B12, MMA, and tHcy were significantly associated with plasma creatinine (all with P <0.001). Only tHcy was significantly associated with thyroid stimulating hormone (P=0.02).
HoloTC shows promise as first-line tests for diagnosing early vitamin B12 deficiency.
比较全反钴胺素（holoTC）与维生素B12缺乏的其他标志物，并研究年龄、肾功能和甲状腺状态的影响。
我们检查了937名未接受维生素B12治疗但因过去4年内血浆甲基丙二酸（MMA）高于0.28微摩尔/升而疑似维生素B12缺乏的个体。除实验室检查外，还对534名个体进行了结构化访谈和神经学检查。其中，140名个体符合随机试验条件（MMA为0.40 - 2.00微摩尔/升）。他们被随机分为接受维生素B12注射或安慰剂注射，并在3个月后重新检查。
丹麦奥胡斯的一家大学医院。
ROC曲线表明，在识别可能存在维生素B12缺乏的个体（MMA≥0.75微摩尔/升且血浆总同型半胱氨酸（tHcy）≥15微摩尔/升）方面，holoTC（曲线下面积：0.90）比血浆维生素B12（曲线下面积：0.85）表现更优，并且进一步表明holoTC（曲线下面积：0.91）可能替代血浆维生素B12及其代谢产物的联合检测。未观察到生化标志物与可能与维生素B12缺乏相关的症状和体征之间存在关联。HoloTC、转钴胺素饱和度、血浆维生素B12、MMA和tHcy均与血浆肌酐显著相关（均P<0.001）。只有tHcy与促甲状腺激素显著相关（P = 0.02）。
HoloTC有望作为诊断早期维生素B12缺乏的一线检测方法。
