T细胞受体双基因标志检测对ALL患儿化疗效应评价初探

目的     

Sequential acquisition of IgH and TCR rearrangements during the preleukemic phase of acute lymphoblastic leukemia in an adolescent patient

Acute lymphoblastic leukemia (ALL) can be preceded by a prodromal phase of bone marrow failure. In serial trephine biopsies in a girl with acquired bone marrow hypoplasia, we have identified a monoclonal B‐cell precursor population characterized by a clone‐specific IgH‐FR3 gene rearrangement. Progression to ALL more than 4 months later was accompanied by acquisition of an additional T‐cell receptor rearrangement. Thus, hypoplastic pre‐ and overt leukemia share a common clonal origin. Prospective biobanking and extended molecular analysis can help to better understand the nature and sequence of genetic events during progression of a covert (pre)leukemic clone. Pediatr Blood Cancer 2011;56:301–303. © 2010 Wiley‐Liss, Inc.     

小儿急性淋巴细胞白血病IgH和Vδ_2Dδ_3基因重排的研究

目的 探讨IgH和Vδ2Dδ3基因重排在初诊儿童急性淋巴细胞白血病(ALL)中的分布频率及其在中枢神经系统白血病(CNSL)早期诊断与脑脊液(CSF)微量残留病(MRD)监测中的意义。方法 对初诊ALL患者的骨髓标本及不同病期CSF标本采用聚合酶链反应(PCR)检测IgH基因重排和巢式聚合酶链反应(Nested-PCR)检测Vδ2Dδ3基因重排。结果 32份ALL患者骨髓标本中有23份存在克隆特异性IgH基因重排和／或Vδ2Dδ3基因重排。在骨髓标本存在异常基因重排的诱导缓解治疗期患儿的23份CSF中,9份检出Vδ2Dδ3基因重排,4份检出IgH基因重排。而完全缓解期患儿的37份CSF中,3份检出IsH基因重排,7份检出Vδ2Dδ3基因重排。结论 在所检初诊ALL患者的骨髓标本中,IgH重排片段的阳性检出率为47％,Vδ2Dδ3基因的阳性检出率为38％;ALL患者脑脊液中ISH和Vδ2Dδ3基因重排的PCR动态监测较CSF常规、生化及细胞学检测更灵敏,更有助于CNSL的早期诊断,对CNSL的预防及预后的判断有指导意义。     

T‐cell‐rich HLA‐haploidentical hematopoietic stem cell transplantation for relapsed/refractory pediatric Philadelphia chromosome‐positive acute lymphoblastic leukemia without posttransplant tyrosine kinase inhibitor therapy

Intensive chemotherapy with tyrosine kinase inhibitor (TKI) improves the prognosis of patients with Philadelphia chromosome‐positive acute lymphoblastic leukemia (Ph‐ALL). However, the prognosis of cases of relapsed or refractory Ph‐ALL remains poor. Here, we aimed to assess the efficacy of T‐cell‐rich HLA‐haploidentical hematopoietic stem cell transplantation (TCR‐haplo‐HSCT) in eight patients with relapsed or refractory pediatric Ph‐ALL. Transplant‐related mortality was observed in two patients. All patients discontinued TKI after receiving TCR‐haplo‐HSCT. The 3‐year probability of overall survival and event‐free survival was 75.0 and 62.5%, respectively. These results indicate the efficacy of TCR‐haplo‐HSCT for relapsed/refractory pediatric Ph‐ALL.     

Origins of STIL‐TAL1 fusion genes in children who later developed paediatric T‐cell acute lymphoblastic leukaemia: An investigation of neonatal blood spots

SCL/TAL1 interrupting locus (STIL)‐T‐cell acute leukaemia (TAL1) fusion genes are present in approximately 11‐27% of children with paediatric T‐cell acute lymphoblastic leukaemia (T‐ALL), but the developmental timing of the rearrangement is still unknown. To investigate whether the fusion gene can be detected in neonatal blood spots (NBSs) from paediatric patients diagnosed with T‐cell ALL, we analysed DNA from 38 paediatric patients with T‐ALL by nested polymerase chain reaction and electrophoresis. The STIL‐TAL1 fusion gene was not detected in NBSs from any of the 38 patients with T‐ALL, suggesting that STIL‐TAL1 fusion genes are most probably postnatal events in paediatric T‐ALL.     

RQ-PCR检测Ig/TCR基因重排监测急性淋巴细胞白血病患儿治疗过程微小残留白血病

目的 研究RQ-PCR检测急性淋巴细胞白血病（ALL）患儿Ig/TCR基因重排在微小残留白血病（MRD）监测中的作用。方法 以2009年3月至2011年3月在广州市妇女儿童医疗中心血液肿瘤科确诊和治疗的ALL患儿为研究对象,PCR检测初诊ALL患儿的Ig/TCR基因重排;基因扫描分析初诊患儿Ig/TCR基因重排的克隆特性;对ALL患儿的单克隆性Ig/TCR基因重排进行测序,RQ-PCR检测不同治疗阶段Ig/TCR基因重排的表达量。结果 86例ALL患儿进入分析,男52例,女34例;年龄1~13（4.3±3.0）岁,随访时间1~26（14.3±7.0）个月。①83例（96.5%）检出1种或以上Ig/TCR基因重排,共检出209个Ig/TCR基因重排;②91.8%（56/61例）检出1种或以上单克隆性Ig/TCR基因重排;61例172个Ig/TCR基因重排中,单克隆性、寡克隆性和多克隆性Ig/TCR基因重排的检出率分别为58.1%（100个）、30.8%（52个）和11.0%（19个）,差异有统计学意义（P=0.000）;③26例完成连续3次随访,其中22例持续完全缓解患儿的Ig/TCR基因重排平均相对表达量持续下降,在维持治疗前均为MRD阴性（≤1.0×10-4）;4例复发患儿在诱导缓解治疗后至复发前各检测时点Ig/TCR基因重排表达量均＞1.0×10-4,并在复发前已有回升,从开始回升至临床复发的平均时间为3.75（2～8）个月。结论 Ig/TCR基因重排相对表达量可反映MRD水平,可作为判断预后、监测复发和指导治疗的有效手段。     

T‐cell large granular lymphocyte leukemia in a child with anemia and Crohn's disease

T‐LGL leukemia has been rarely reported in children. We report a child with T‐LGL leukemia who presented with anemia and went on to develop Crohn's disease. Although prednisolone treatment proved effective in the treatment of anemia, large granular lymphocyte counts increased as the doses were tapered. T‐cell rearrangement studies revealed a clonal rearrangement of the TCR Vβ/jβ2 gene. Concurrently, the patient developed severe diarrhea. Inflammatory changes across the upper and lower intestines led to the diagnosis of Crohn's disease. This case highlights that T‐LGL leukemia could be occurred in children. Flow cytometry and/or T‐cell gene rearrangement studies are recommend in patients of anemia and various kind of autoimmune diseases including Crohn's disease, even in children.     

应用半重叠TCR γ特异性引物的PCR方法检测淋巴细胞白血病

采用更加敏感的半重叠式TCRγ特异性引物的PCR方法，对28例ALL初治、CR及BMT患儿进行检测，并用消化煮沸及酚抽提法分别对所有骨髓标本进行DNA提取，将PCR结果进行比较。结果表明：消化煮沸法用于微量标本的DNA提取优于酚抽提法，28例ALL患儿中16例检出TCRγ特异性条带，MRD组18例，阳性检出12例，其中免疫分型标记为B细胞型的4例，占25％，免疫标记为T细胞型者全部出现TCRγ阳性条带。并对该引物的语系特异性及双克隆重排问题进行了理论探讨。     

Bone marrow minimal disseminated disease (MDD) and minimal residual disease (MRD) in childhood T‐cell lymphoblastic lymphoma stage III,detected by flow cytometry (FC) and real‐time quantitative polymerase chain reaction (RQ‐PCR)

Background

Despite overlapping features of T‐cell lymphoblastic lymphoma (T‐LLy) and T‐cell acute lymphoblastic leukemia (T‐ALL), which respond favorably to T‐ALL treatment, clinical and biological differences exist. We retrospectively assessed the prevalence of submicroscopic bone marrow (BM) minimal disseminated disease (MDD) at diagnosis and the early response to treatment (minimal residual disease—MRD) and their prognostic significance in 17 children with stage III T‐LLy treated according to Berlin‐Frankfurt‐Munster (BFM) non‐Hodgkin lymphoma protocols.

Procedure

Four‐color flow cytometry (FC) was used for lymphoma associated immunophenotype and real‐time quantitative polymerase chain reaction (RQ‐PCR) for T‐cell receptor (TCR β/δ/γ) gene rearrangements with at least 0.01% sensitivity.

Results

Two markers per patient were identified in all cases using FC and in 80% using RQ‐PCR. BM MDD at diagnosis of ≥0.01% was detected by FC and RQ‐PCR in 88% and 80% of patients, respectively, and by at least one of the methods in all patients. A significant correlation was achieved between the methods by Pearson correlation analysis (P = 0.004). MRD levels significantly decreased to very low levels on day 33 in 9 out of 10 patients studied. The only patient that remained positive relapsed.

Conclusions

MDD was prevalent in stage III T‐LLy, for which we could not prove a prognostic significance in the context of ALL‐like treatment. This study shows that both FC and RQ‐PCR methods are efficient for MDD and MRD analyses in T‐LLy. Pediatr Blood Cancer 2009;52:20–25. © 2008 Wiley‐Liss, Inc.     

急性淋巴细胞白血病患儿化疗结束后T淋巴细胞克隆谱系分析

目的了解急性淋巴细胞白血病(ALL)患儿化疗结束后T淋巴细胞免疫重建情况。方法逆转录-聚合酶链反应(RT-PCR)高压变性聚丙烯酰胺凝胶电泳法检测8例正常对照及44例化疗结束后的ALL患儿外周血T细胞受体(TCR)β链可变区(BV)第三互补决定区(CDR3)的克隆谱系。结果白血病化疗结束至48个月TCRBV家族仍可见表达增高或降低(P均0.05)。化疗结束后TCRBVCDR3谱型多态性基本恢复,但寡克隆增生情况仍明显高于正常对照组(P均0.05),小于6个月组差异最明显(P均0.05)。16例普通B细胞急淋(c-ALL)BV8、BV5.1、BV5.2和BV12发生克隆性增生的频率较高,9例前B细胞急淋(pre-B)BV6家族发生克隆性增生较多。结论白血病患儿化疗结束至48个月T细胞免疫尚未完全恢复;T细胞克隆谱系异常以寡克隆增生为主。     

Absence of biallelic TCRγ deletion predicts induction failure and poorer outcomes in childhood T-cell acute lymphoblastic leukemia

Background

The absence of biallelic TCRγ deletion (ABD) is a characteristic of early thymocyte precursors before V(D)J recombination. The ABD was reported to predict early treatment failure in T‐cell acute lymphoblastic leukemia (ALL). This study aimed to investigate its prognostic value in Taiwanese patients with T‐cell ALL.

Procedure

Forty‐five children with T‐cell ALL were enrolled from six medical centers in Taiwan. Quantitative DNA polymerase chain reaction (Q‐PCR) was performed to check the status of TCRγ deletion. The threshold for homozygous deletions by Q‐PCR was defined as a fold‐change <0.35.

Results

ABD was found in 20 patients [20:45] who had higher incidences of induction failure than those without ABD (P = 0.03; hazard ratio [HR] = 8.13; 95% confidence interval [95% CI] = 1.23–53.77) after multivariate regression analysis. Patents with ABD also had inferior EFS and OS (P = 0.071 and 0.0196, respectively). Multivariate Cox analysis indicated that the association between ABD and overall survival was independent of age and leukocyte count on presentation (P = 0.036; HR = 4.25; 95% CI = 1.10–16.42).

Conclusions

The absence of TCRγ deletion is a predictor of a poor response to induction chemotherapy for pediatric patients with T‐cell ALL in Taiwan. Providing patients with T‐cell ALL and ABD with alternative regimens may be worthwhile to test in future clinical trials. Pediatr Blood Cancer 2012; 58: 846–851. © 2011 Wiley Periodicals, Inc.     

Haploidentical stem cell transplantation with posttransplant cyclophosphamide for refractory systemic juvenile xanthogranuloma

Juvenile xanthogranuloma (JXG) is a generally benign, self‐limited histiocytic disorder, which belongs to non‐Langerhans cell histiocytoses (non‐LCH). However, systemic JXG can be fatal in rare cases. We present the case of an 11‐year‐old female with systemic JXG, who experienced repeated vertebral compression fractures and did not fully respond to systemic chemotherapy. Based on its reported efficacy in LCH, the patient underwent human leukocyte antigen‐haploidentical hematopoietic stem cell transplantation (HSCT) with posttransplant cyclophosphamide. The patient did not suffer major complications and has not experienced relapse for 13 months since HSCT. HSCT may be a potential treatment option for patients with refractory non‐LCH.     

Early T‐Cell Precursor Acute Lymphoblastic Leukemia in an Infant With an NRAS Q61R Mutation and Clinical Features of Juvenile Myelomonocytic Leukemia

Early T‐cell precursor acute lymphoblastic leukemia (ETP‐ALL) is a subtype of T‐acute lymphoblastic leukemia (T‐ALL) arising from a primitive precursor. We present a unique case of an infant with ETP‐ALL with a missense NRAS mutation in codon 61 (c.182A>G, p.Q61R). The patient also had a minor population of non‐ETP T‐ALL blasts and clinical features typically associated with juvenile myelomonocytic leukemia (JMML), namely, absolute monocytosis, splenomegaly, and elevated hemoglobin F. The treatment was initiated with chemotherapy, followed by cord blood transplantation. The patient achieved remission, but unfortunately died from transplant‐related complications. This case highlights an NRAS mutation in ETP‐ALL with JMML‐like phenotype.     

Lineage Switch in MLL‐Rearranged Infant Leukemia Following CD19‐Directed Therapy

Rearrangements of the mixed lineage leukemia (MLL) gene occur frequently in infants with both acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Conversions of leukemia cell lineage are rare, but occur most commonly in the setting of MLL‐rearrangement. Blinatumomab is a bidirectional antibody targeting CD19 with significant activity in relapsed B‐precursor ALL. We report an infant with ALL with t(4;11)(q21;q23) refractory to cytotoxic chemotherapy who was treated with blinatumomab. Following rapid initial clearance of peripheral lymphoblasts, bone marrow evaluation demonstrated a leukemic lineage switch to CD19‐negative monoblastic AML. Complete remission was achieved with myeloid‐directed chemotherapy.     

Clinical applications of the study of immunoglobulin and T-cell receptor gene rearrangements in acute leukemia and non-Hodgkin's lymphoma in children

In addition to conventional morphological, histological and immunological marker studies, cells from 150 children with leukemia or non Hodgkin's lymphoma were analysed using the Southern blot hybridization technique to examine immunoglobulin- (Ig) and T-cell receptor (TCR) gene rearrangements. Patients with B-lineage leukemia or NHL demonstrated in 90% an Ig heavy chain gene rearrangement, 6% with an additional light chain kappa gene rearrangement. Combined Ig- with TCR-beta-gene rearrangements were mainly found in patients with common ALL: 19% at first presentation, and 33% in relapse. Moreover, 6 c-ALL patients showed rearrangements in all 3 gene loci (JH-, Ck- and TCR). Based on the developmental hierarchy of Ig- and TCR gene rearrangements it was possible to further subclassify c-ALL into different stages of B cell development. No correlation could be established between the different constellations of gene rearrangements, the number of rearranged fragments and the course of illness. All patients with T-lineage leukemia or NHL demonstrated TCR rearrangements of the beta-, g- and delta-gene loci, two with an additional Ig gene rearrangement. These data confirm recent reports indicating that immunoglobulin heavy chain gene rearrangements are not restricted to B-lineage neoplasms. Furthermore, non-germline configuration was found in tumor cells of every patient with AUL, O-ALL and AHL, permitting a classification to B- or T-cell lineage. Noteworthy is that every AML patient with Ig- and/or TCR gene rearrangements showed a poor or non-response towards therapy. Specimens of individual patients with differently involved tissues at diagnosis always showed an identical rearrangement. The intensity depended on the number of infiltrating blast cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Spontaneous tumor lysis syndrome in a child with T‐cell acute lymphoblastic leukemia

We report a 5‐year‐old female who presented with unexplained acute renal failure (ARF) and hyperuricemia and who was subsequently diagnosed of T‐cell acute lymphoblastic leukemia (ALL). Peripheral smear was initially unremarkable. She required hemodialysis. Two weeks later, peripheral smear showed 40% blasts and bone marrow demonstrated T‐cell ALL. Our case was the fifth and the youngest case of ALL with spontaneous tumor lysis syndrome. However, in contrast to previous reports in ALL or acute myeloid leukemia, our patient did not have blasts noted on periphereal blood smear and her white blood cell count and serum lactate dehydrogenase level were normal on admission, a time when dialysis‐dependent ARF and severe hyperuricemia were present. Occult hematologic malignancy should be considered in cases of ARF and hyperuricemia of unknown etiology even when peripheral hematologic findings are not informative. Pediatr Blood Cancer 2010;54:773–775. © 2009 Wiley‐Liss, Inc.     

Myeloid lineage switch following chimeric antigen receptor T‐cell therapy in a patient with TCF3‐ZNF384 fusion‐positive B‐lymphoblastic leukemia

A pediatric patient diagnosed initially with B‐lymphoblastic leukemia (B‐ALL) relapsed with lineage switch to acute myeloid leukemia (AML) after chimeric antigen receptor T‐cell (CAR‐T) therapy and hematopoietic stem cell transplant. A TCF3‐ZNF384 fusion was identified at diagnosis, persisted through B‐ALL relapse, and was also present in the AML relapse cell population. ZNF384‐rearrangements define a molecular subtype of B‐ALL characterized by a pro‐B‐cell immunophenotype; furthermore, ZNF384‐rearrangements are prevalent in mixed‐phenotype acute leukemias. Lineage switch following CAR‐T therapy has been described in patients with KMT2A (mixed lineage leukemia) rearrangements, but not previously in any patient with ZNF384 fusion.     

Next‐generation sequencing of PTEN mutations for monitoring minimal residual disease in T‐cell acute lymphoblastic leukemia

Minimal residual disease (MRD) analysis has become a powerful indicator to refine therapy in acute lymphoblastic leukemia (ALL). Here, we present an MRD detection based on the next‐generation sequencing of PTEN exon 7 mutations (NGS‐PTEN) in 30 pediatric T‐cell ALL patients. By comparing the NGS‐PTEN results with current quantitative PCR of antigen receptor gene rearrangements (qPCR‐Ig/TR), an overall concordance of 80% was found between the two methods. However, the NGS‐PTEN qualified a lower number of high‐risk patients than qPCR‐Ig/TR. These findings suggest that NGS‐PTEN is a promising tool that could potentially be used to support current MRD methodologies for T‐ALL patients.     

DEEP JUVENILE XANTHOGRANULOMA: An Unusual Presentation

Juvenile xanthogranuloma (JXG) is a disorder of histiocytes usually associated with cutaneous lesions. It may present a diagnostic dilemma in the absence of cutaneous lesions and when deeply located. Differentiation of JXG from other childhood histiocytosis syndromes, especially Langerhans' cell histiocytosis (LCH), is important. We describe an unusual case of deep JXG in a 27-month-old girl with multiple omental and peritoneal nodules presenting with ascites. Although a diagnosis of LCH was suspected clinically, the absence of Birbeck granules and S-100 protein and T6 antigen negativity, together with CD68 and factor XIIIa positivity, led us to a diagnosis of JXG. Physicians should be aware of the widening spectrum of manifestations of juvenile xanthogranuloma.