Coll P, Guttormsen A B, Berstad A
Medisinsk avdeling, Haukeland Sykehus, Bergen.
Tidsskr Nor Laegeforen. 1999 Oct 10;119(24):3577-9.
Elevated plasma homocystein (tHcy) is a marker for functional deficiency of folate and/or cobalamin. Malabsorption of these vitamins occurs in various gastroenterologic diseases. A frequent mutation (C677T) in the gene coding for the enzyme methyltetrahydrofolate reductase (MTHFR) is often associated with elevated values of tHcy. We have investigated 24 patients with tHcy > 40 mumol/l for gastrointestinal disease that can contribute to such elevation. Of these, 19 were homozygous for mutated MTHFR, four were heterozygous and one was normal. We found two cases of probable celiac disease, one case of Crohn's disease and one case of ulcerative colitis. These four were homozygous for the C667T mutation. Furthermore, we found eight persons who were anacidic; four homozygous, three heterozygous and one normal. All had gastritis histologically, six had serum gastrin > 50 pmol/l, and four were already on treatment with cobalamin injections. Helicobacter pylori-infection was found in nine out of 22 persons. Gastrointestinal disease occurs frequently in patients with tHcy > 40 mumol/l, but with the exception of conditions resulting in serious deficiency of cobalamin, these diseases alone do not seem sufficient to cause such high levels. We suggest that a reasonable approach to patients with homocystein values above 40 mumol/l is to exclude cobalamin deficiency, and that further investigations should be based upon thorough anamnesis and symptoms.
血浆同型半胱氨酸（总同型半胱氨酸，tHcy）升高是叶酸和/或钴胺素功能缺乏的一个标志物。这些维生素的吸收不良发生于多种胃肠疾病中。编码亚甲基四氢叶酸还原酶（MTHFR）的基因中一种常见突变（C677T）常与tHcy值升高相关。我们对24例tHcy>40μmol/L的患者进行了调查，以寻找可能导致这种升高的胃肠疾病。其中，19例为MTHFR突变纯合子，4例为杂合子，1例正常。我们发现2例可能的乳糜泻、1例克罗恩病和1例溃疡性结肠炎。这4例均为C667T突变纯合子。此外，我们发现8例胃酸缺乏者；4例纯合子，3例杂合子，1例正常。所有患者组织学检查均有胃炎，6例血清胃泌素>50pmol/L，4例已在接受钴胺素注射治疗。22例中有9例发现幽门螺杆菌感染。tHcy>40μmol/L的患者常发生胃肠疾病，但除导致严重钴胺素缺乏的情况外，这些疾病单独看来似乎不足以导致如此高的水平。我们建议，对于同型半胱氨酸值高于40μmol/L的患者，合理的做法是排除钴胺素缺乏，进一步的检查应基于详尽的病史和症状。
