Khanduri Uma, Sharma Archna
Department of Haematology, St Stephen's Hospital, Tis Hazari, Delhi, India.
Natl Med J India. 2007 Jul-Aug;20(4):172-5.
Megaloblastic anaemia is not uncommon in India, but data are insufficient regarding its prevalence, and causative and precipitating factors. We did a prospective study to document such data for patients of megaloblastic anaemia.
All patients presenting to our hospital over a period of 6 months with a haemoglobin < 10 g/dl and/or mean corpuscular volume > 95 fL and blood film findings consistent with megaloblastosis were included in the study. Demographic data, diet, drug intake, previous blood transfusion and presenting symptoms were recorded. Clinical findings were obtained from medical records of patients. Complete blood counts, blood film examination, reticulocyte count and cobalamin and folate assays were done. Results of liver function tests and bone marrow slides were available for review.
Megaloblastic anaemia was diagnosed in 175 patients with anaemia. Assays were done on 120 patients (55 were lost to follow up) and results showed cobalamin deficiency in 78 patients (65%), combined cobalamin and folate deficiency in 20 patients (12%) and pure folate deficiency in 8 patients (6%). Fifteen per cent of patients had normal or high values of both vitamins, having received blood or haematinics before the diagnosis was established. The peak incidence of megaloblastic anaemia was in the age group of 10-30 years (48%), with female preponderance (71%). The predominant symptoms were fatigue, anorexia and gastritis, low grade fever, shortness of breath, palpitations and mild jaundice. Twenty-five per cent of patients were on acid-suppressing medication and 15% had previous transfusion for anaemia. Eighty-seven per cent of patients with cobalamin deficiency and 75% with folate deficiency were lactovegetarians. In the combined deficiency cohort, 71% were vegetarians and 29% were occasional non-vegetarians. Physical findings were pallor (85%), glossitis (29%), mild icterus (25%) and hyperpigmentation (18%). Abnormal haematological findings were mean corpuscular volume 77-123 fL (9 patients had iron deficiency), red cell distribution width 16%-44%, pancytopenia in 62% of patients, reticulocyte count > 2% in 42% of patients and typical megaloblastic blood films in all patients. Bone marrow smears available in 22 patients showed moderate-to-severe megaloblastosis. Thirty-two per cent of patients in whom liver function tests were done showed indirect bilirubinaemia with normal enzymes.
Megaloblastic anaemia was diagnosed from complete blood counts, red cell indices, blood film examination and assays of the two vitamins. Bone marrow examination was not essential for diagnosis. Cobalamin deficiency was the major cause of megaloblastosis. Aetiological factors were a diet poor in cobalamin or folate, increased requirements during the growth period and pregnancy, and the use of acid-suppressing medication. Physicians managing these patients need to be aware of the timing of blood sampling for assays, that haematinics and transfusions provide only short term benefits, and that long term follow up and diet counselling is crucial.
巨幼细胞贫血在印度并不罕见，但关于其患病率、病因及诱发因素的数据并不充分。我们开展了一项前瞻性研究，以记录巨幼细胞贫血患者的此类数据。
本研究纳入了在6个月期间前来我院就诊、血红蛋白<10 g/dl和/或平均红细胞体积>95 fL且血涂片检查结果符合巨幼细胞贫血的所有患者。记录人口统计学数据、饮食、药物摄入情况、既往输血史及就诊时症状。临床检查结果来自患者的病历。进行了全血细胞计数、血涂片检查、网织红细胞计数以及钴胺素和叶酸检测。肝功能检查结果及骨髓涂片可供查阅。
175例贫血患者被诊断为巨幼细胞贫血。对120例患者进行了检测（55例失访），结果显示78例患者（65%）存在钴胺素缺乏，20例患者（12%）同时存在钴胺素和叶酸缺乏，8例患者（6%）为单纯叶酸缺乏。15%的患者在确诊前接受过输血或服用过补血剂，两种维生素水平正常或偏高。巨幼细胞贫血的发病高峰年龄在10 - 30岁组（48%），女性占优势（71%）。主要症状为疲劳、厌食、胃炎、低热、气短、心悸及轻度黄疸。25%的患者正在服用抑酸药物，15%的患者既往因贫血接受过输血。87%的钴胺素缺乏患者和75%的叶酸缺乏患者为乳类素食者。在合并缺乏组中，71%为素食者，29%为偶尔非素食者。体格检查发现面色苍白（85%）、舌炎（29%）、轻度黄疸（25%）及色素沉着（18%）。血液学异常表现为平均红细胞体积77 - 123 fL（9例患者存在缺铁），红细胞分布宽度16% - 44%，62%的患者全血细胞减少，42%的患者网织红细胞计数>2%，所有患者均有典型的巨幼细胞血涂片表现。22例患者的骨髓涂片显示中度至重度巨幼细胞变。进行肝功能检查的患者中，32%表现为间接胆红素血症但酶正常。
通过全血细胞计数、红细胞指数、血涂片检查及两种维生素检测可诊断巨幼细胞贫血。骨髓检查对诊断并非必需。钴胺素缺乏是巨幼细胞变的主要原因。病因包括饮食中钴胺素或叶酸缺乏、生长期及孕期需求增加以及使用抑酸药物。诊治这些患者的医生需要了解检测的采血时间，补血剂和输血仅提供短期益处，长期随访及饮食咨询至关重要。
