[维生素B12和叶酸缺乏引起的血栓性微血管病（假性TMA）]

摘要(中文译文)

血栓性微血管病（TMA）以微血管病性溶血性贫血、血小板减少和器官损害为特征。作为一种罕见但可逆的病因，维生素B12和叶酸缺乏可表现为血栓性微血管病（假性TMA），伴溶血性尿毒症综合征（HUS）样临床特征，构成重大的诊断挑战。一名56岁女性出现重度大细胞性贫血、血小板减少、急性肾损伤及溶血实验室证据。检查发现显著叶酸缺乏、明显大细胞增多（MCV>120 fL）、结合珠蛋白水平降低及乳酸脱氢酶显著升高。ADAMTS13活性降低，但与经典血栓性血小板减少性紫癜不符，而补体检查显示继发性消耗性激活。感染性、自身免疫性、恶性及药物相关病因均被排除。患者需要短暂连续性肾脏替代治疗、血浆置换及糖皮质激素治疗，随后接受高剂量叶酸和维生素B12补充。维生素替代治疗后，观察到网织红细胞快速反应、溶血消退及完全血液学缓解。本病例突出表明，叶酸和维生素B12缺乏可引起可逆性假性TMA，伴HUS样表现。早期识别和针对性维生素补充至关重要，因其可避免不必要的侵入性或高昂治疗。Orv Hetil. 2026; 167(14): 556-559.

Abstract

Thrombotic microangiopathies (TMA) are characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ damage. As a rare but reversible cause, vitamin B12 and folate deficiency may present as thrombotic microangiopathy (pseudo-TMA) with hemolytic uremic syndrome (HUS)-like clinical features, posing a significant diagnostic challenge. A 56-year-old woman developed severe macrocytic anemia, thrombocytopenia, acute kidney injury, and laboratory signs of hemolysis. Investigations revealed marked folate deficiency, pronounced macrocytosis (MCV>120 fL), low haptoglobin levels, and markedly elevated lactate dehydrogenase. ADAMTS13 activity was reduced but not consistent with classical thrombotic thrombocytopenic purpura, while complement studies demonstrated secondary, consumptive activation. Infectious, autoimmune, malignant, and drug-related causes were excluded. The patient required transient continuous renal replacement therapy, plasma exchange, and corticosteroid treatment, followed by high-dose folate and vitamin B12 supplementation. After vitamin replacement, a rapid reticulocyte response, resolution of hemolysis, and complete hematologic remission were observed. This case highlights that folate and vitamin B12 deficiency can cause reversible pseudo-TMA with HUS-like presentation. Early recognition and targeted vitamin supplementation are essential, as they may prevent unnecessary invasive or costly therapies. Orv Hetil. 2026; 167(14): 556-559.

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