ras基因与儿童急性髓细胞性白血病关系研究

目的探讨ras基因在儿童急性髓细胞性白血病（AML）中的表达及其与治疗和预后的相关性。方法用逆转录聚合酶链反应（RT—PCR）半定量方法检测ras基因家族（K—ras,N—ras,H—ras）的表达水平,结合细胞形态学、流式细胞仪免疫分型检测、染色体R带显带核型分析,对36例初诊AML及部分病例进行跟踪。同期采集30例特发性急性血小板减少性紫癜（ITP）患儿骨髓标本作为对照。结果实验组与对照组相比。N-ras、K—ras的平均表达水平明显升高,差异有统计学意义,其中N—ras更具显著意义。AML患儿中ras基因突变多见于M2、M4及M5型。对2例M2患儿进行跟踪检测（1例为不同时期包括初诊和缓解期及复发前的测定,另1例为长期无病生存）,ras基因水平异常活化可见于复发前,也可见于长期缓解患儿。结论初诊儿童AMLras基因表达水平异常增高。ras检测可作为判断儿童AML疗效、预后及随访指标之一。     

Epidemiology of childhood acute myeloid leukemia

Although leukemia is the most common childhood cancer diagnosis, the subtype, acute myeloid leukemia (AML), is less common and fewer etiologic studies exist. This review summarizes the major risk factors for AML. We searched the literature using PubMed for articles on childhood AML and reviewed 180 articles. While few risk factors are definitive, we identified several with consistent evidence of a possible effect. Thorough analysis of genetic and epigenetic factors is missing from this literature and methodological issues are unresolved. Future studies should more closely examine causal mechanisms, improve exposure measurement, and include analysis using genetic and epigenetic factors. Pediatr Blood Cancer 2013; 60: 728–733. © 2013 Wiley Periodicals, Inc.     

急性髓系白血病患儿骨髓细胞中血管内皮生长因子及其受体的变化

目的探讨儿童急性髓系白血病(AML)骨髓细胞中血管内皮生长因子(VEGF)及其受体(VEGFR)的表达差异,分析其与儿童急性髓系白血病临床特征的关系,以及化疗前后的变化。方法采用SP免疫组化方法检测20例AML患儿治疗前后以及对照组骨髓中VEGF/VEGFR(Flt-1和KDR)的表达情况。结果VEGF、Flt-1、KDR在AML患儿骨髓中表达水平高于对照组。化疗后获得完全缓解(CR)14例患儿的VEGF、Flt-1、KDR表达在化疗后比化疗前显著降低;化疗后未获得CR的6例患儿的表达化疗前后差异无统计学意义。AML患儿的VEGF表达与骨髓中幼稚细胞百分比、外周血中幼稚细胞百分比呈正相关。骨髓中VEGF、Flt-1、KDR的表达水平在不同年龄、不同性别、有无髓外浸润差异无统计学意义。高表达的VEGF组缓解率低于低表达组。结论VEGF、Flt-1、KDR在AML患儿中呈高表达,提示可能与儿童急性白血病发生过程与预后有关。     

T-cell acute lymphoblastic leukemia relapsing as acute myelogenous leukemia

We present the unusual case of a 16-year-old girl with T-cell acute lymphoblastic leukemia (ALL) with an early thymocyte immunophenotype without myeloid markers, who after 13 months of complete hematological remission relapsed as acute myelogenous leukemia (AML) with minimal differentiation and died of her disease. Whether the AML represented a relapse with lineage switch of the original immature T-cell clone or a new secondary malignancy, could not be proven due to the absence of molecular or clonal markers. This report suggests that a subset of CD7+ T-cell leukemias without mature T-cell antigens (CD4-, CD8-) are minimally differentiated and can relapse as AML.     

Fatigue in survivors of childhood acute lymphoblastic and myeloid leukemia in Japan

Background: Fatigue in cancer survivors is a serious problem in pediatric oncology, but reports on this issue are limited, especially in Asian countries. Methods: Sixty‐three patients with acute lymphoblastic leukemia and 18 patients with acute myeloid leukemia who attended a follow‐up outpatient clinic were enrolled. Participants were required to be >8 years of age, in remission, and without any cancer treatment for at least the previous 1 year. A control group consisted of 243 subjects whose age and gender were matched with the patient group. A questionnaire consisting of 12 items was devised for fatigue measurement. Results: Principal factor analysis identified three dimensions, defined as physical fatigue, decreased function, and altered mood. The mean total and the three fatigue dimension scores tended to be higher in the control group, but significant differences between the scores were seen only in the total and physical fatigue scores. Multiple regression analysis indicated an association of present older age or shorter duration after completion of treatment with total and physical fatigue, and an association of presence of total body irradiation with decreased function. Conclusion: Pediatric leukemia survivors in Japan experience equal or less fatigue compared with that of controls in different fatigue dimensions. Elucidation of underlying mechanisms of cancer‐related fatigue including the differences of cultural background among different countries is necessary for future study of this issue.     

儿童急性髓系白血病治疗进展

急性髓系白血病(AML)是由于造血干细胞分化障碍及增殖过度所致异常骨髓造血前体细胞聚集的恶性克隆性疾病。近年来随着危险度分层的合理应用、靶向药物的不断研发、支持治疗的进步、造血干细胞移植技术的日渐成熟,儿童AML的生存率已经较前有明显提高。文章综述儿童AML的治疗进展。     

Immunohistochemical nuclear positivity for WT1 in childhood acute myeloid leukemia

Several studies have reported previously that acute myeloid leukemia (AML) may express WT1 detected by RT-PCR and/or Northern blotting. The diagnostic utility of WT1 expression in AML using immunohistochemistry has not been reported previously. Paraffin-embedded tissue sections from 55 AML, 12 acute lymphoblastic leukemia (ALL), and 10 normal bone marrow specimens were immunostained for WT1 (anti-N terminus antibody). 22/55 AML cases (40%) demonstrated nuclear immunopositivity for WT1, including 20/47 bone marrow trephines and 2/4 granulocytic sarcomas. All the ALL and normal bone marrow specimens were negative. A significant proportion of AML expresses nuclear immunostaining for WT1, a finding that has only been described previously in Wilms' tumor and desmoplastic small round cell tumor. This finding is important for the correct interpretation of immunohistochemical findings in the diagnosis of “small round cell” tumors of childhood, especially in cases of extramedullary deposits of AML, in which traditional myeloid markers may be negative.     

Clinical significance of central nervous system involvement at diagnosis of childhood T-cell acute lymphoblastic leukemia

BACKGROUND: Patients with T-cell acute lymphoblastic leukemia (T-ALL) frequently present with unfavorable features at diagnosis. Therefore, they are considered to have a higher risk to relapse. We sought to correlate initial central nervous system (CNS) disease at diagnosis with shortened survival in childhood T-ALL. PROCEDURE: A retrospective analysis of 48 children with T-ALL was performed. The group consisted of 32 boys and 16 girls whose median age was 8 years. Their CNS status was classified as CNS-1 (no blast cells in cerebrospinal fluid (CSF); n = 44), CNS-2 (<5 WBC/microl of CSF with blast cells; n = 0), or CNS-3 (> or =5 WBC/microl of CSF with blast cells or signs of CNS involvement; n = 4). For univariate prognostic analyses, we used the log-rank test to determine the influence of patient characteristics (age, sex, lymphomatous presentations, initial leukocyte count, CNS disease, and newer therapeutic strategies) on each point. RESULTS: Complete remission was induced in 87.5% of patients. Median survival was 37 months, and 5-year overall survival and disease-free survival rates were 49.5% +/- 8.1% and 47.1% +/- 8.2%, respectively. Patients without initial CNS involvement seemed to have a trend toward longer overall survival (P = 0.036). Disease-free survival was not influenced by age, leukocyte count, or other factors analyzed. CONCLUSIONS: Patients who present with initial CNS involvement have a prognosis worse than that of patients without CNS disease. The introduction of early and effective CNS-directed therapy might no longer portend a poor prognosis for CNS leukemia.     

��ͯ������ϸ����Ѫ�������½�չ

??Acute myeloid leukemia??AML?? accounts for about 20% of childhood leukemia with the cure rate of more than 65%. Although dramatic improvement in treatment of childhood AML has been achieved based on the optimization of risk classification??risk-based therapeutic regimen??monitoring and supportive care??currently??the prognosis of pediatric AML has reached plateau due to the heterogeneity of AML. Targeted therapy based on the precise genotyping and comprehensive treatment will improve the cure rate and quality of life of children with AML.     

The prognostic value of serum lysozyme activity in acute myelogenous leukemia

Serum lysozyme activity was measured in samples from adult patients with acute leukemia, malignant tumors, and in normal adults. Twenty-eight adult patients with acute myelogenous leukemia (AML) had significantly elevated levels of lysozyme at diagnosis, and none of the adults fell within the normal range. Thirty-two patients with AML in complete remission had lysozyme levels comparable to normal adults, whereas patients with AML in relapse (eight cases) also had abnormally high levels of lysozyme activity. Ten patients with AML in remission and off therapy also had normal lysozyme levels. Three patients with acute lymphatic leukemia had normal lysozyme levels, while one child with monomyelocytic leukemia had substantially elevated lysozyme levels before treatment. It seems that in patients in remission and with normal blood values, the serum lysozyme activity is valuable for monitoring the remission.     

p73基因在儿童急性淋巴细胞白血病的表达

目的探讨p73基因在儿童急性淋巴细胞白血病(ALL)的表达及其与临床特征、疗效的关系。方法采用逆转录—聚合酶链反应,对31例ALL、10例ALL缓解(CR)患儿骨髓单个核细胞进行p73 mRNA检测,并进行p73表达与临床特征的相关分析;10例非肿瘤患儿为对照组。结果31例初发ALL p73 mRNA表达阳性率为64.5%,强度为0.316;10例ALL-CR组阳性率90.0%,强度0.641;10例对照组患儿均表达p73 mRNA,强度0.685。CR组和对照组阳性表达率和相对表达强度均明显高于ALL组(P0.05),CR组和对照组的表达差异无统计学意义(P0.05)。p73阴性表达与高危年龄(≥10岁)、外周血高白细胞数(≥50×109/L)、T细胞型、高危临床分型、早期诱导缓解治疗反应差等临床特征相关(P0.05),与性别、FAB分型无关(P0.05)。结论儿童ALL患者p73 mRNA的表达率较低,p73 mRNA的阴性表达可能与儿童ALL的发生发展有关;儿童ALL p73基因阴性表达者可能预后不良;p73基因检测对儿童ALL临床治疗、估计预后有意义。     

血管内皮生长因子在儿童急性白血病发病中的作用

目的研究血管内皮生长因子(VEGF)与儿童急性白血病的发生与预后的关系。方法采用RT_PCR方法检测41例不同疾病阶段急性白血病患儿及5例健康儿童骨髓单个核细胞VEGF基因。应用ELISA技术检测55例儿童急性白血病和20例健康儿童血浆VEGF蛋白(sVEGF)表达水平。结果VEGF基因表达在21例初发及复发未治组患儿为90.5%(19/21例);20例缓解期患儿为30.0%(6/20例);5例健康儿童均未检测到表达。29例初发组sVEGF水平明显高于20例缓解组及正常对照组(P均<0.001);6例复发和难治组sVEGF水平明显高于初发组(P<0.05)、缓解组及正常对照组(P均<0.001);缓解组与正常对照组相比差异无显著性(P>0.05)。患儿的sVEGF水平与下列预后影响因素呈正相关或有统计学意义:①诱导化疗达缓解时间的长短(P<0.01);②初诊时外周血白细胞数高低(P<0.01);③诊断时有无髓外浸润(P<0.05);④发病时血浆LDH水平(P<0.05)与其他临床指标无相关性(P>0.05)。结论VEGF与儿童急性白血病发生与预后密切相关,VEGF基因表达及sVEGF含量可能可以作为儿童急性白血病的危险因素之一,并有助于判断预后。