骨髓增生异常综合征髓系细胞免疫表型及其临床意义的研究

探讨骨髓增生异常综合征髓系细胞免疫表型的变化及其临床意义，应用一组单克隆抗体，采用免疫酶标法对５１例ＭＤＳ、２１例 再生了阉生贫血、２１例阵发性睡眠性血红蛋白尿症、１０例急性髓系白轿病患者及１５名正常人骨髓细胞膜表面抗原ＣＤ１３、ＣＤ１４、ＣＤ３３和ＣＤ１５进行检测，同时还检测ＭＤＳ患者的骨髓细胞形态、染色体核型及姊妹染色单体分染并按分型进行促分化、促造血和小剂量化疗ＭＤＳ骨髓单个核细胞较正常人表     

铁代谢相关血清学指标在贫血诊断中的应用价值

目的：了解血清维生素B12（VitB12）、叶酸（FA）及血清铁蛋白（SF）、血清转铁蛋白（TF）、总铁结合力（TIBC）、血清铁（SI）4项铁代谢指标检测在贫血的诊断和鉴别诊断中的价值。方法选择该院2013年1～5月贫血患者126例和健康对照组30例,测定其血清中VitB12、FA、SF、TF、TIBC和SI浓度并进行比较,贫血患者同时抽取骨髓标本涂片,经铁染色及形态学检查,检查结果与上述血清学指标测定结果进行临床诊断符合率的比较。结果铁代谢相关的各个指标的血清浓度在贫血患者和健康对照组比较差异有统计学意义（ P＜0．05）,各类贫血均有其较为特异的血清学特征;126例贫血患者的临床诊断符合率,骨髓检查为82．5％,明显高于血清学检查（69．8％）（χ2＝5．600,P＝0．018）;但在骨髓形态学不能明确诊断的23例贫血患者中,82．6％（19/23）血清学指标检测结果符合临床诊断;两种检查方法的不符合率达25．4％（32/126）。结论骨髓检查和血清学检测对贫血诊断的侧重点不同,各有优势,不能相互替代。二者联合应用对缺铁性贫血（IDA）与慢性病贫血伴缺铁（ACD/ID）、MDS与巨幼细胞性贫血（M A ）以及混合细胞性贫血的鉴别诊断上具有一定的临床价值。     

Refractory anemia and the myelodysplastic syndromes.

Refractory anemia is a component of each of the myelodysplastic syndromes (MDSs). MDSs are acquired pluripotent stem cell disorders leading to one or more peripheral blood cytopenias with dysplasia in the peripheral blood and bone marrow. MDS and aplastic anemia are sometimes grouped as bone marrow failure disorders because patients present with similar peripheral blood pictures. The bone marrow in MDS is generally hypercellular, due to ineffective hematopoiesis, in contrast to the hypocellular bone marrow of aplastic anemia. MDS is more common in the elderly, differing from aplastic anemia that affects all ages. The characteristics of each of the subgroups of the MDS using the World Health Organization (WHO) classification are described. Cytogenetic analysis provides a useful part of disease diagnosis in this new classification system. There is no successful treatment for MDS other than hematopoietic stem cell transplantation which is usually recommended for patients under age 50. A prognostic scoring system has been developed to help predict the severity of disease and guide treatment. Approximately 10% to 40% of MDS cases terminate in acute leukemia. Current treatment consists mostly of supportive measures; however several new therapies are being explored.     

骨髓增生异常综合征患者有核红细胞糖原染色的意义

目的 探讨骨髓涂片有核红细胞糖原染色(PAS染色)在骨髓增生异常综合征(MDS)患者骨髓发育异常血细胞形态学判断、诊断、鉴别诊断中的意义.方法 回顾性分析406例MDS、67例巨幼细胞贫血(MegA)、76例缺铁性贫血(IDA)、207例非重型再生障碍性贫血(NSAA)、144例免疫性血小板减少性紫癜(ITP)、50例阵发性睡眠性血红蛋白尿症(PNH)、50例急性红白血病(AEL)患者的骨髓涂片有核红细胞PAS染色结果及MDS患者的其他相关实验室检查结果,并进行统计学分析.结果 MDS组有核红细胞PAS染色阳性检出率(53.0%)与NSAA组(14.5%)、ITP组(27.1%)、PNH组(16.0%)、AEL组(84.0%)比较差异均有统计学意义(P值均为0.000),但与MegA组(46.3%)、IDA组(40.8%)比较差异无统计学意义(P值分别为0.310和0.052).MDS组有核红细胞PAS染色阳性率(中位数,M=1%)及阳性积分(M'=2)低于AEL组(M=8%,M'=17),高于NSAA组(M=0%,M'=0)、ITP组(M=0%,M'=0)、PNH组(M=0%,M'=0)、MegA组(M=0%,M'=0)、IDA组(M=0%,M'=0)(P值均＜0.05).有核红细胞PAS染色阳性率和阳性积分在除AEL外所有对照组中诊断MDS的最佳临界值(cut-off)分别为0.5%和0.5,其诊断敏感性60.8%,特异性74.4%.将MDS患者按有核红细胞PAS染色结果分为PAS阳性组和PAS阴性组,PAS阳性组较阴性组骨髓涂片红系比例(E)高,HGB水平低,平均红细胞体积(MCV)小,平均红细胞血红蛋白含量(MCH)、平均红细胞血红蛋白浓度(MCHC)低(P值均＜0.05).PAS阳性组的骨髓巨核细胞总数、淋巴样小巨核细胞数及小巨核细胞占巨核细胞比例均高于PAS阴性组(P值均＜0.05).外周血中性粒细胞碱性磷酸酶阳性指数(NALP)PAS阳性组低于PAS阴性组(P=0.000).伴异常染色体核型的MDS患者有核红细胞PAS染色阳性检出率、阳性率、阳性积分均高于染色体核型正常MDS患者;IPSS分型较高危险度组(中危-2+高危)MDS患者的PAS染色阳性检出率、阳性率、阳性积分均高于较低危险度组(低危+中危-1).结论 有核红细胞PAS染色阳性提示骨髓红系细胞发育异常,有助于MDS与其他血细胞减少性疾病的鉴别诊断.

Abstract：

Objective To investigate the implications of erythroblasts periodic acid-Schiff (PAS)stain for myelodysplastic syndromes (MDS) dyserythropoiesis, diagnosis and differential diagnosis. Methods PAS stain of bone marrow (BM) erythroblasts in 406 MDS pateints, 207 non-severe aplastic anemia (NSAA), 144 immune thrombocytopenic purpura (ITP), 67 megaloblastic anemia (MegA), 76 iron deficiency anemia (IDA), 50 paroxysmal nocturnal hemoglobinuria (PNH), and 50 acute erythroid leukemia (AEL) as well as some related laboratory parameters in MDS patients were analyzed retrospectively. Results PAS-positive detection rate was significantly higher in MDS (53.0%) than in NSAA (14. 5%), ITP (27.1%) and PNH (16.0%), but was significantly lower in MDS than in AEL (84. 0%) (all P =0.000). There was no significant difference in PAS-positive detection between MDS and MegA (46.3%), or MDS and IDA (40.8 %) (P = 0.310, 0. 052, respectively). Erythroblasts PAS-positive rate (Median, M =1%) and PAS-positive scores (M' =2) was significantly lower in MDS than in AEL (M =8%; M' = 17),and significantly higher than in NSAA(M =0%; M' =0), ITP(M =0%; M' =0), PNH(M =0%; M' =0), MegA (M = 0%; M' = 0), and IDA (M = 0%; M' = 0) (all P ＜ 0.05). The cut-off value of PAS-positive rate and score for distinguishing MDS from the other groups except AEL were 0. 5% and 0. 5, with a sensitivity and specificity of 60.8% and 74.4%, respectively. For MDS patients, the percentage of BM erythroid cells was significantly higher in PAS-positive group than in PAS-negative group (P ＜ 0.05), and so were megakaryocyte count, lymphocyte-like micromegakaryocyte count and percentage of micromegakaryocyte (P =0.002, 0. 000, 0. 000, respectively). HGB、MCV、MCH and MCHC were significantly lower in PASpositive group (all P ＜ 0. 05), and so was the neutrophil alkaling phosphatase (NALP) (P = 0.000). PASpositive detection rate, positive rate and score were higher in MDS patients with abnormal karyotype than with normal karyotype, and were also higher in IPSS high/intermediate-risk 2 group than in low/intermidiate-risk 1group. Conclusion The positive reaction of erythroblasts PAS stain is an indicator of dyserythropoiesis. It is helpful to the diagnosis of MDS patients.     

Iron deficiency anemia. How to diagnose and correct

The prevalence of iron deficiency anemia has decreased in recent years because of improved dietary habits. Yet, iron deficiency anemia is still the most common anemia. Among mature adults, anemia of chronic disease is probably more common. Mean corpuscular volume and red cell distribution width, along with a peripheral smear examination, can often distinguish iron deficiency anemia from other common microcytic anemias, such as thalassemia minor. A normal serum iron level excludes iron deficiency anemia and indicates other causes for microcytic anemia. Often, a low serum iron level and total iron-binding capacity are due to chronic disease, and measurement of serum ferritin or a bone marrow stain for hemosiderin will be necessary to diagnose iron deficiency. Iron therapy to restore the red cell mass should be continued until iron stores are replenished.     

慢性病贫血患者测定血清转铁蛋白受体的临床意义

目的 :评估血清转铁蛋白受体在慢性病性贫血患者中的价值。方法 :对 4 2例慢性病贫血病人经骨髓可染铁检测分为慢性病贫血伴缺铁 (ACDID)组 ,慢性病贫血不伴缺铁 (ACDNID)组及 30例缺铁性贫血 (IDA)进行血红蛋白 (Hb)、红细胞平均容积 (MCV)、红细胞平均血红蛋白量 (MCH)、红细胞平均血红蛋白浓度 (MCHC)及血清铁蛋白 (SF)、血清转铁蛋白受体 (STfR)的检测及计算STfR/SF、STfR/logSF的比值 ,并对结果进行分析。结果 :4 2例慢性病贫血患者中骨髓可染铁缺乏 2 2例 ,占5 2 % ;缺铁性贫血组与慢性病贫血伴缺铁组SF值比有显著差异 (P <0 .0 1) ,慢性病贫血伴缺铁组与慢性病贫血不伴缺铁组比无显著差异 (P >0 .0 5 )。STfR、STfR/logSF值在IDA、ACDID组均升高 ,与健康对照组相比有显著差异 (P <0 .0 1) ,而ACD NID与健康对照组相比无显著差异 (P >0 .0 5 ) ,慢性病贫血伴缺铁与不伴缺铁两组相比有显著差异 (P <0 .0 1)。STfR与SF呈负相关 (r =- 0 .39P <0 .0 1)。结论 :慢性病贫血患者约有半数合并缺铁。STfR是一种新的反映机体铁贮存状况指标 ,能准确评估慢性病贫血病人体内贮存铁状况 ,STfR、STfR/logSF可作为诊断ACD是否合并缺铁的诊断依据。STfR与SF间在缺铁性贫血中呈负相关。     

Microcytic anemia. Differential diagnosis and management of iron deficiency anemia.

Microcytic anemia is defined as the presence of small, often hypochromic, red blood cells in a peripheral blood smear and is usually characterized by a low MCV (less than 83 micron 3). Iron deficiency is the most common cause of microcytic anemia. The absence of iron stores in the bone marrow remains the most definitive test for differentiating iron deficiency from the other microcytic states, ie, anemia of chronic disease, thalassemia, and sideroblastic anemia. However, measurement of serum ferritin, iron concentration, transferrin saturation and iron-binding capacity, and, more recently, serum transferrin receptors may obviate proceeding to bone marrow evaluation. The human body maintains iron homeostasis by recycling the majority of its stores. Disruptions in this balance are commonly seen during menstruation, pregnancy, and gastrointestinal bleeding. Although the iron-absorptive capacity is able to increase upon feedback regarding total body iron stores or erythropoietic activity, this physiologic response is minimal. Significant iron loss requires replacement with iron supplements. The vast majority of patients respond effectively to inexpensive and usually well-tolerated oral iron preparations. In the rare circumstances of malabsorption, losses exceeding maximal oral replacement, or true intolerance, parenteral iron dextran is effective. In either form of treatment, it is necessary to replete iron stores in addition to correcting the anemia.     

Bone marrow amyloidosis with erythropoietin-resistant anemia in a patient undergoing chronic hemodialysis treatment

The resistance to erythropoietin, which is used to treat normochromic, normocytic anemia in chronic renal failure, can develop in patients with conditions such as iron deficiency, aluminum toxicity, hyperparathyroidism, chronic inflammatory diseases, and primary hematological disorders. We found amyloidosis in the bone marrow of a woman without any other etiology for erythropoietin resistance who was undergoing chronic hemodialysis. Her anemia did not improve, despite 6 months of erythropoietin therapy. Bone marrow amyloidosis was found to be the reason for erythropoietin-resistant anemia in our patient with chronic renal failure and renal anemia. We present the case of bone marrow amyloidosis because it is a very rare cause of erythropoietin resistance.     

Iron overload‐related heart failure in a patient with transfusion‐dependent myelodysplastic syndrome reversed by intensive combined chelation therapy

Patients with transfusion‐dependent myelodysplastic syndromes (MDS) have an increased risk of cardiac events, due to both chronic anemia and iron overload. Here, we report the recovery of cardiac function after an intensive iron chelation therapy in a MDS patient who had developed heart failure due to iron overload.     

骨髓单个核细胞Coomb's试验在淋巴瘤合并贫血患者诊断中的意义

目的探讨ML(淋巴瘤)合并贫血(外周血红细胞悬液Coomb,s试验阴性)患者对骨髓的单个核细胞进行Coomb,s试验的临床价值。方法抽取我院自2008年11月至2011年11月以来,于我科治疗的血液病患者临床资料进行回顾性分析,其中A组AIHA(自身免疫性的溶血性贫血)患者10例(阳性对照组),均系外周血红细胞悬液Coomb's试验呈阳性者;B组4名正常人与46例各类型(再障,PNH,IDA等)贫血患者共50例(阴性对照组),均已明确诊断;C组ML合并贫血患者100例(实验组)均系外周血红细胞悬液Coomb,s试验呈阴性者;对3组患者骨髓的单个核细胞进行Coomb,s试验,并予以对比分析。结果对A组骨髓的单个核细胞进行Coomb,s试验,10例均提示为阳性,而B组中50例均提示为阴性,C组23例结果呈阳性,而67例结果呈阴性,A组患者骨髓单个核细胞Coomb,s试验阳性率为100.0%(10/10),C组患者阳性率为23.0%(23/100),两组差异呈显著性(P<0.05)。结论 ML合并贫血(外周血红细胞悬液Coomb,s试验阴性)患者对骨髓的单个核细胞进行Coomb,s试验检查,能够对其诊断以及鉴别诊断均提供有效的实验依据,从而避免误诊情况的发生,同时也能够对患者进行有效并且及时的治疗,应予推广。     

中国北方人群获得性骨髓衰竭综合征患者端粒酶基因突变的研究

目的 研究中国北方人群骨髓衰竭综合征(BMF)患者端粒酶复合体基因突变发生的频率.方法 收集北方地区4家综合医院诊断明确的BMF患者90例(包括再生障碍性贫血、骨髓增生异常综合征、阵发性睡眠性血红蛋白尿症),正常对照45名.提取患者外周血DNA.PCR方法扩增TERC基因及TERT基因第一、二外显子,双脱氧核酸终止法测序.结果 90例BMF患者中发现2例TERC基因突变和2例TERT突变.TERC突变为n37 A→G和n 66G→C.TERT基因突变为n1870 G→T,造成氨基酸缺失E/*和n1780 G→T,造成氨基酸替换S/I.除TREC n37 A→G突变外,均为首次报道.其中1例TERT突变患者最终诊断为先天性角化不良(DKC),而非获得性BMF.90例患者最终确诊获得性BMF患者共89例,其中发现3例突变.中国北方BMF人群中端粒酶基因突变发生率为3.4%.结论 首次报道了我国BMF患者端粒酶基因的3种突变.中国北方人群中获得性BMF患者端粒酶复合体基因突变发生率为3.4%.端粒酶基因突变可引起端粒的缩短,可能是疾病发生的原因之一.     

Iron assessment tests: transferrin receptor vis-à-vis zinc protoporphyrin

OBJECTIVES: To review and compare the biochemical, analytical, and clinical features of two relatively new tests for assessing iron status and diagnosing iron disorders, namely, the serum transferrin receptor concentration (sTfR) and the erythrocyte zinc protoporphyrin/heme ratio (ZnPP/H). To consider the merits of each test for the diagnosis of iron disorders with emphasis on iron-deficient erythropoiesis, especially in the clinically important preanemia stage of iron depletion. CONCLUSIONS: Although the basic biochemical mechanisms underlying the two tests are very different, both of these tests are noteworthy because they are considered to reflect iron status in the bone marrow. The principal advantage to serum transferrin receptor is the lack of a response to anemia of chronic disease (ACD), which affects other iron status indicators, for example, ferritin and transferrin saturation. The principal advantage to erythrocyte zinc protoporphyrin is low cost, but point-of-care testing and simplicity can also be advantages. Both serum transferrin receptor and erythrocyte zinc protoporphyrin have been demonstrated to be useful in a variety of clinical situations. Serum transferrin receptor can be best used in diagnosing iron disorders, especially for patients with pathologies that may affect iron metabolism. Erythrocyte zinc protoporphyrin can be best used as a primary screening test for assessing iron status, especially in patients likely to have uncomplicated iron deficiency. While these applications are primary, both tests are more broadly useful, for example, in monitoring iron therapy.     

Anemia in the elderly

Anemia should not be accepted as an inevitable consequence of aging. A cause is found in approximately 80 percent of elderly patients. The most common causes of anemia in the elderly are chronic disease and iron deficiency. Vitamin B12 deficiency, folate deficiency, gastrointestinal bleeding and myelodysplastic syndrome are among other causes of anemia in the elderly. Serum ferritin is the most useful test to differentiate iron deficiency anemia from anemia of chronic disease. Not all cases of vitamin B12 deficiency can be identified by low serum levels. The serum methylmalonic acid level may be useful for diagnosis of vitamin B12 deficiency. Vitamin B12 deficiency is effectively treated with oral vitamin B12 supplementation. Folate deficiency is treated with 1 mg of folic acid daily.     

Measurements of serum ferritin used to predict concentrations of iron in bone marrow in anemia of chronic disease

We determined serum ferritin, C-reactive protein (CRP), fibrinogen, and the erythrocyte sedimentation rate (ESR) in 73 patients with anemia of chronic disease. Nomograms of CRP, ESR, or fibrinogen vs ferritin concentrations were constructed and used to estimate the iron store in bone marrow. Iron stores estimated from the nomograms were compared with the results of staining cytological bone marrow smears for iron, the reference method for evaluating iron in bone marrow. In contrast to the results of Witte et al. (Clin Chem 1985;31:1011; Am J Clin Pathol 1986;85:202-6 and 1988;90:85-7), we observed that nomograms of CRP, fibrinogen, or ESR (i.e., acute-phase reactants not influenced by changes in iron metabolism) vs ferritin are not suitable to correct for the acute-phase component of changes in ferritin concentrations. For ferritin concentrations less than 70 micrograms/L, we found that iron deficiency, as judged from bone marrow iron stain, apparently was always present.     

在不同类型骨髓增生异常综合征Id4基因甲基化差异的初步研究

本研究探讨Id4基因在不同类型骨髓增生异常综合症（MDS）患者中的甲基化情况差异。采用甲基化特异性聚合酶链反应（MS—PCR）对50例不同类型MDS患者骨髓进行Id4基因启动子区甲基化状况检测,并以缺铁性贫血患者骨髓作为对照。结果发现：Id4基因在对照组骨髓中呈完全非甲基化状态,在MDS各种类型中,甲基化状态有差异：6例RA、2例RARS和4例MDS—U患者骨髓Id4基因均呈非甲基化状态,而18例RCMD中有2例。12例RAEBI和8例RAEBII中各有3例为Id4基因甲基化。骨髓原始细胞比例分别低于和高于5％的两组患者中,Id4甲基化分别有2例和6例,各占每组的6．7％和30％,差异有显著性意义。初步结论是：骨髓原始细胞比例高的MDS患者有可能发现Id4基因甲基化。     

骨髓增生异常综合征的早期诊断研究

目的：联合应用四种克隆性分析法对骨髓增生异常综合征（MDS）的早期诊断进行研究。方法：对临床上怀疑为MDS的50例患者应用常规染色体核型分析，姐妹染色单体分化（SCD）染色，荧光原位杂交（FISH）和聚合酶链反应－单链构象多态性分析（PCR－SSCP）等技术分别检测染色体畸形，细胞周期时间，8三体（＋8）和N-ras突变。结果：45例符合FAB诊断标准；5例不符合FAB标准，其中2例患者只有红系病态造血改变，形态学诊断均为可疑RA，另3例患者无涉及三系的病态造血改变，形态学诊断分别为增生性贫血（1例），慢性再生障碍性贫血（2例），在这5例患者中，当色体核型分析发现4例具有克隆性当色体异常；SCD检测证实2例细胞周期时间延迟；FISH检测发现3例存在＋8异常；PCR－SSCP发现1例存在N－ras外显子1突变，证实它们实际上均为RA患者。结论：联合应用染色体核型分析，SCD、FISH和PCR－SSCP等方法可对形态学检查无病态造血或仅有一系病造血改变的不典型MDS患者有效进行早期诊断。     

Management of thrombocytopenia in bone marrow failure: a review

The clinical course of many neoplastic and primary bone marrow diseases will result in cytopenias secondary to bone marrow failure or infiltration. Acute and chronic leukemias, the myelodysplastic syndromes (MDS), aplastic anemia, breast and prostate cancer, as well as other hematologic and solid tumors, all may lead to chronic, severe cytopenias. Management of anemia and neutropenia are well described in the medical literature. Less well detailed are management approaches for patients with chronic thrombocytopenia, with or without active bleeding. Severe thrombocytopenia presents many difficult management choices for caregivers, patients and their families, especially near the end of life. The use of platelet transfusions in this patient population presents complex issues; platelets are logistically more difficult to transfuse than red cells and carry risks including acute febrile episodes, alloimmunization, and infection. In this review, we discuss the association of chronic thrombocytopenia to serious bleeding and the role of various prophylactic and therapeutic interventions available to palliative care and hospice providers. Specifically, this review examines the following issues: What is the morbidity and mortality from chronic thrombocytopenia in the setting of cancer or other bone marrow failure states? Is there a role for prophylactic platelet transfusions in the palliative care setting, and if so, with what frequency of monitoring, and at what transfusion threshold? What is the impact of alloimmunization and how can it be minimized? What treatments are available besides, or in addition to, platelet transfusions for acute bleeding episodes?     

Three-lineage hemopoietic precursor cells and effectiveness of recombinant human erythropoietin in patients with myelodysplastic syndromes.

Four-stem-cell assays, which evaluate megakaryocytic (CFU-Meg), immature and mature erythropoietic (BFU-E, CFU-E), and granulocyte-macrophage (CFU-GM) colony formation, were performed in nine patients with myelodysplastic syndromes (MDS). The CFU-Meg, BFU-E, and CFU-E colony growths were disturbed more often than the CFU-GM colony formation. A CFU-E increase was not recognized in most MDS patients, but a dose-dependent increase of bone marrow CFU-Es in response to erythropoietin (EPO) was recognized only in two refractory anemia (RA) patients whose CFU-Es were more than one tenth of normal controls. One patient with RA and the other with chronic myelomonocytic leukemia (CMML), both of whose bone marrow CFU-Es did not increase at the higher dose of EPO in vitro, were treated with recombinant human EPO (rHuEPO), resulting in no effects. The responsiveness of patients with MDS to various recombinant hemopoietic factors might be predicted by both the residual degree of bone marrow hematopoietic precursor cells and the response of stem cells to the higher doses of each hemopoietic factor.     

4项联合检测对骨髓增生异常综合征与巨幼细胞贫血鉴别诊断的临床意义

目的探讨铁蛋白(SF)、平均红细胞体积(MCV)、乳酸脱氢酶(LDH)及铁染色联合检测对骨髓增生异常综合征(MDS)与巨幼细胞贫血(MeA)鉴别诊断的临床意义。方法选取临床确诊的39例MeA和32例MDS的初诊患者;35例骨髓象大致正常者为健康对照组。严格按照番禺区中心医院的标准操作规程进行操作,测定血清LDH、血清SF、全血MCV值及骨髓铁染色。两组之间比较采用t检验;多组间比较采用方差分析,两两比较采用q检验。结果 MDS组和MeA组的SF、MCV、LDH及内外铁和健康对照组差异均有统计学意义(P<0.05);MDS组环形铁粒幼细胞明显增高。结论联合检测SF、MCV、LDH及铁染色对鉴别诊断MDS和MeA具有重要的临床意义。     

Iron deficiency anemia

The prevalence of iron deficiency anemia is 2 percent in adult men, 9 to 12 percent in non-Hispanic white women, and nearly 20 percent in black and Mexican-American women. Nine percent of patients older than 65 years with iron deficiency anemia have a gastrointestinal cancer when evaluated. The U.S. Preventive Services Task Force currently recommends screening for iron deficiency anemia in pregnant women but not in other groups. Routine iron supplementation is recommended for high-risk infants six to 12 months of age. Iron deficiency anemia is classically described as a microcytic anemia. The differential diagnosis includes thalassemia, sideroblastic anemias, some types of anemia of chronic disease, and lead poisoning. Serum ferritin is the preferred initial diagnostic test. Total iron-binding capacity, transferrin saturation, serum iron, and serum transferrin receptor levels may be helpful if the ferritin level is between 46 and 99 ng per mL (46 and 99 mcg per L); bone marrow biopsy may be necessary in these patients for a definitive diagnosis. In children, adolescents, and women of reproductive age, a trial of iron is a reasonable approach if the review of symptoms, history, and physical examination are negative; however, the hemoglobin should be checked at one month. If there is not a 1 to 2 g per dL (10 to 20 g per L) increase in the hemoglobin level in that time, possibilities include malabsorption of oral iron, continued bleeding, or unknown lesion. For other patients, an endoscopic evaluation is recommended beginning with colonoscopy if the patient is older than 50.