Tavares João, Baptista Bernardo, Gonçalves Bebiana, Horta Alexandra Bayão
Medicine Department, Hospital da Luz, Lisbon, Portugal.
Eur J Case Rep Intern Med. 2019 Feb 18;6(2):001045. doi: 10.12890/2019_001045. eCollection 2019.
A 49-year-old female patient presented to our hospital with asthenia, odynophagia, low grade fever, worsening symptoms of chronic depression, and symmetric leg paresthesias. Investigations showed macrocytic anaemia, leucopenia, thrombocytopenia, high lactate dehydrogenase levels and a normal Coombs test. Trilineage dysplasia was detected in the bone marrow biopsy specimen. The diagnostic work-up led us to the diagnosis of pernicious anaemia with a spuriously normal value of vitamin B12 and high titres of anti-intrinsic factor autoantibodies. This case highlights the importance of considering vitamin B12 deficiency in the differential diagnosis of myelodysplasia, even when vitamin B12 levels seem to be normal.
Vitamin B12 deficiency is characterized by neuropsychiatric manifestations and bone marrow failure with accompanying dysplastic changes.Spuriously normal vitamin B12 levels can occur in pernicious anaemia due to anti-intrinsic factor autoantibody interference in the laboratory assay.Myelodysplastic syndromes and vitamin B12 deficiency share clinical and laboratory similarities, so a correct differential diagnosis is crucial for adequate treatment.
一名49岁女性患者因乏力、吞咽痛、低热、慢性抑郁症状加重以及双侧腿部感觉异常前来我院就诊。检查显示大细胞性贫血、白细胞减少、血小板减少、乳酸脱氢酶水平升高且库姆斯试验正常。骨髓活检标本中检测到三系发育异常。诊断性检查使我们确诊为恶性贫血，维生素B12值假性正常且抗内因子自身抗体滴度高。该病例强调了在骨髓发育异常的鉴别诊断中考虑维生素B12缺乏的重要性，即使维生素B12水平看似正常。
维生素B12缺乏的特征为神经精神表现和伴有发育异常改变的骨髓衰竭。由于抗内因子自身抗体干扰实验室检测，恶性贫血中可出现假性正常的维生素B12水平。骨髓增生异常综合征和维生素B12缺乏在临床和实验室方面有相似之处，因此正确的鉴别诊断对于恰当治疗至关重要。
