Haurani F I, Hall C A, Rubin R
J Clin Invest. 1979 Nov;64(5):1253-9. doi: 10.1172/JCI109580.
A 34-year-old Black woman had severe megaloblastic anemia in childhood. Initially, and over the years, she responded well to massive doses of parenteral cobalamin (Cbl) or oral folic acid. Metabolic reactions involving Cbl and folate enzymes were normal during both relapse and remission except for the absence of thymidylate synthetase in relapse. Amino acid analyses of urine and plasma showed no significant abnormalities. Neither cystathionine, homocystine, formiminoglutamic acid, nor methylmalonic acid was detected in the urine. The serum Cbl level was repeatedly elevated even when the patient was receiving only folic acid therapy. The elevation of the vitamin in the serum was found to be a result of markedly increased levels of transcobalamin II (TC II), as identified by several physicochemical techniques. The patient's TC II-Cbl shared immunologic properties with normal TC II but did not facilitate or impede the uptake of Cbl or Cbl bound to normal TC II, respectively, by human cells.
一名34岁的黑人女性童年时患有严重的巨幼细胞贫血。最初以及多年来，她对大剂量的肠外钴胺素（Cbl）或口服叶酸反应良好。除复发时胸苷酸合成酶缺乏外，复发和缓解期间涉及Cbl和叶酸酶的代谢反应均正常。尿液和血浆的氨基酸分析未显示明显异常。尿液中未检测到胱硫醚、同型胱氨酸、亚胺甲基谷氨酸或甲基丙二酸。即使患者仅接受叶酸治疗，血清Cbl水平也反复升高。通过多种物理化学技术鉴定，发现血清中维生素升高是由于转钴胺素II（TC II）水平显著增加所致。患者的TC II-Cbl与正常TC II具有免疫特性，但分别不促进或阻碍人体细胞对Cbl或与正常TC II结合的Cbl的摄取。
