Clinical Significance of Minimal Residual Disease in Pediatric Patients with TCF3/PBX1+ B-cell Acute Lymphoblastic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the consistency of flow cytometry (FCM) method and polymerase chain reaction (PCR) technique in the detection of minimal residual disease (MRD) at different treatment stages in pediatric patients with TCF3/PBX1+ B-cell acute lymphoblastic leukemia (B-ALL) and the correlations between the detection results and prognosis.@*METHODS@#The clinical data of 64 newly diagnosed pediatric patients with TCF3/PBX1+ B-ALL admitted to the Department of Pediatrics of Peking University People's Hospital from January 2005 to December 2017 were retrospectively analyzed. FCM and PCR methods were used to monitor the MRD level in bone marrow samples from 64 children during the same period of treatment on d33 and d90 respectively, and the detection results were analyzed.@*RESULTS@#There were 37 males and 27 females in the 64 patients, with a median age of 8 years(range 0.8 to 16 years). The complete remission (CR) rate after the first cycle of induction chemotherapy was 98.4% (62/63), with overall CR rate of 100%. 12 patients experienced recurrence, with a median recurrence time of 16.9 (5.3-46.3) months. The median follow-up time of the 64 patients was 77.2 (1.0-184.8) months , and the 5-year overall survival (OS) rate and event-free survival (EFS) rate were 82.8%±4.7% and 75.0%±5.4%, respectively. On d90, the concordance rate of the MRD results from the two methods was 98.4%, and the related kappa value was 0.792 (P < 0.001), which were significantly higher than those on d33. After induction chemotherapy (d33), the 5-year EFS rate of MRD-FCM- group (79.3%±5.3%) was significantly better than that of MRD-FCM+ group (40.0%±21.9%) (P =0.028), there were no significant differences in the 5-year OS rate and EFS rate between MRD-PCR+ group and MRD-PCR- group, and the 5-year EFS rate of MRD-FCM-/PCR- group (85.4%±5.5%) was significantly better than that of MRD-FCM+/PCR+ group (40.0 %±21.9%) (P =0.026).@*CONCLUSION@#In children with TCF3/PBX1+ B-ALL, the MRD results detected by FCM and PCR methods show good consistency, especially in consolidation therapy period (d90). The MRD level at the end of induction therapy (d33) is an important factor affecting the long-term prognosis, especially the MRD results detected by FCM method, which is significantly associated with prognosis.

Clinical features and prognosis of childhood B-lineage acute lymphoblastic leukemia expressing the PRAME gene / 中国当代儿科杂志

OBJECTIVES@#To study the clinical and prognostic significance of the preferentially expressed antigen of melanoma (PRAME) gene in the absence of specific fusion gene expression in children with B-lineage acute lymphoblastic leukemia (B-ALL).@*METHODS@#A total of 167 children newly diagnosed with B-ALL were enrolled, among whom 70 were positive for the PRAME gene and 97 were negative. None of the children were positive for MLL-r, BCR/ABL, E2A/PBX1, or ETV6/RUNX1. The PRAME positive and negative groups were analyzed in terms of clinical features, prognosis, and related prognostic factors.@*RESULTS@#Compared with the PRAME negative group, the PRAME positive group had a significantly higher proportion of children with the liver extending >6 cm below the costal margin (P<0.05). There was a significant reduction in the PRAME copy number after induction chemotherapy (P<0.05). In the minimal residual disease (MRD) positive group after induction chemotherapy, the PRAME copy number was not correlated with the MRD level (P>0.05). In the MRD negative group, there was also no correlation between them (P>0.05). The PRAME positive group had a significantly higher 4-year event-free survival rate than the PRAME negative group (87.5%±4.6% vs 73.5%±4.6%, P<0.05), while there was no significant difference between the two groups in the 4-year overall survival rate (88.0%±4.4% vs 85.3%±3.8%, P>0.05). The Cox proportional-hazards regression model analysis showed that positive PRAME expression was a protective factor for event-free survival rate in children with B-ALL (P<0.05).@*CONCLUSIONS@#Although the PRAME gene cannot be monitored as MRD, overexpression of PRAME suggests a good prognosis in B-ALL.

The Impact of Induction Treatment Response on the Prognosis of Pediatric Core Binding Factor-Acute Myeloid Leukemia Patients / 中国实验血液学杂志

OBJECTIVE@#To explore the impact of induction treatment response on the prognosis of pediatric core binding factor-acute myeloid leukemia (CBF-AML).@*METHODS@#The result of induce reaction and survival data of 157 pediatric CBF-AML patients in our hospital from September 2008 to December 2018 were retrospectively analyzed．The survival rate of the patients with different degrees of morphological remission after induction chemotherapy was comparative analyzed.@*RESULTS@#Among the 157 children with CBF-AML, 113 (72.4%) patients achieved morphologic leukemia-free state (MLFS) after the first course of induction chemotherapy, 153 (98.1%) patients achieved MLFS after the second course of induction chemotherapy. The 5-year event-free survival (EFS) rate and 5-year overall survival (OS) rate of patients with non-remission (NR) status after the first course of induction of chemotherapy was significantly lower than the patients achieved MLFS and the patients achieved partial remission (PR). The 5-year EFS rate and 5-year OS rate of the patients with PR status after the second course of induction chemotherapy were lower than the patients achieved MLFS, but the difference was not statistically significant. Multivariable analyze showed that NR after the first course of induction chemotherapy and myeloid sarcoma were the independent risk factors affecting EFS of the patients. There were six patients with NR status after the first course of induction chemotherapy, in which all of them harbored t(8;21), three of them with sex chromosome deletion, two of them with myeloid sarcoma.@*CONCLUSION@#NR status after the first course of induction chemotherapy was the independent risk factor affecting EFS and OS of CBF-AML patients, it can be taken as an indicator for higher risk stratification. PR status after the first course of induction chemotherapy may not be used as a diagnostic criterion for primary drug resistance.

Influence of dasatinib treatment on body height in children with acute myeloid leukemia / 中国当代儿科杂志

OBJECTIVE@#To study the influence of dasatinib treatment on body height in children with acute myeloid leukemia (AML).@*METHODS@#A retrospective analysis was performed for the clinical data of 86 AML children aged <17 years. According to the treatment regimen, these children were divided into a conventional chemotherapy group and a dasatinib chemotherapy group. The 57 children in the conventional chemotherapy group were given conventional chemotherapy drugs without tyrosine kinase inhibitor, and the 29 children in the dasatinib chemotherapy group were given conventional chemotherapy drugs and dasatinib. The two groups were compared in terms of height standard deviation score (HtSDS) at the beginning of treatment and after treatment, as well as the change in HtSDS after 1 and 2 years of treatment.@*RESULTS@#There was no significant difference in HtSDS between the conventional and dasatinib chemotherapy groups before treatment. Within the first two years of treatment, the dasatinib chemotherapy group had a similar change trend of HtSDS as the conventional chemotherapy group. Four children in the dasatinib chemotherapy group reached the final adult height during follow-up, which was significantly lower than the target height (P=0.044). In the conventional chemotherapy group, there was no significant difference between final adult height and target height. In the dasatinib chemotherapy group, the children in adolescence had a significant change in HtSDS after treatment (P=0.032).@*CONCLUSIONS@#Dasatinib treatment may affect the final height of children with AML, and the use of dasatinib after the beginning of adolescence may lead to growth disorder, but dasatinib treatment has little effect on body height in the short-term treatment.

Clinical characteristics and prognostic analysis of pediatric pro-B cell acute lymphoblastic leukemia / 中国当代儿科杂志

OBJECTIVE@#To explore the clinical-biological characteristics and prognosis of pediatric pro-B cell acute lymphoblastic leukemia (pro-B-ALL).@*METHODS@#A total of 64 patients aged less than 18 years old with pro-BALL were enrolled. Clinical characteristics, therapeutic effect and prognostic factors were retrospectively analyzed.@*RESULTS@#Pro-B-ALL occurred in 6.23% (64/1 028) of pediatric ALL. Among the 64 patients, 35 were male and 29 were female. The median age was 7.0 years (range 0.4-16.0 years) at diagnosis, of which 39% and 6% were ≥ 10 years old and < 1 year old respectively. The median WBC count was 25.5×10@*CONCLUSIONS@#Pediatric pro-B ALL is a heterogeneous disease with clinical and biological diversity. Biological characteristics, such as immunological markers, genetic alterations, and MRD at 3 months after chemotherapy may be important factors for the long-term prognosis.

Chimeric antigen receptors T cells for treatment of 48 relapsed or refractory acute lymphoblastic leukemia children: long term follow-up outcomes / 中华血液学杂志

Objective: To evaluate the safety and efficacy of chimeric antigen receptors T cells (CAR-T) in childhood acute B lymphoblastic leukemia (B-ALL) to probe the prognosis-related factors. Methods: Forty-eight children, 29 boys and 19 girls, aged 3-17years old (median age was 8 years old) , with recurrent or refractory CD19 positive B-ALL, were treated by the CD19 specific CAR-T cells. A total of 48 cases received 61 infusions. Flow cytometry or real-time quantitative polymerase chain reaction method were used to monitor micro residual disease (MRD) . The follow-up period was from 16 to 1 259 days with the median follow-up of 406 days. SPSS software was used to statistical analysis. Results: No adverse reaction was observed during 61 infusions. The most common adverse reaction after CAR-T cell infusions was cytokine-release syndrome (CRS) . Only 2 cases experienced level 3 CRS performance, including continuous high fever, convulsions, delirium, serous cavity effusion, and decreasing of blood pressure. Tocilizumab was given to release CRS performance. No treatment-related death occurred. Thirty-seven patients showed response during 7 to 28 days after infusions. The early response rate was 77.1%, with MRD before infusion less than 5% group higher than the MRD more than 5% group (87.1% vs 58.8%, χ2=4.968, P=0.036) . For the 37 patients who showed response to CAR-T cell infusions, univariate analysis identified that age, disease status at the time of treatment, MRD before infusion affected 2-year OS rate (P<0.05) . Multivariate prognostic analysis for EFS disclosed that the MRD before infusion more than 5% (RR=3.433, 95% CI 1.333-8.844, P=0.011) and not bridge to HSCT (RR=4.996, 95% CI 1.852-13.474, P=0.001) were the independent risk factors. Conclusion: The fourth generation CAR-T cells directed against CD19 could effectively and safely treat relapsed and refractory B-ALL, which implicated that CAR-T therapy as a novel therapeutic approach could be useful for patients with relapsed or refractory B-ALL who have failed all other treatment options. Reducing MRD as far as possible by effective pretreatment chemotherapy was in favor of increasing the response rate. Bridging HSCT after CAR-T cell treatment might be a better therapeutic strategy for the patient with refractory or molecular relapsed B-ALL.

Study of clinical outcome and prognosis in pediatric core binding factor-acute myeloid leukemia / 中华血液学杂志

Objective: To analyze the clinical outcome and the prognostic factor in pediatric patients with core binding factor-acute myeloid leukemia (CBF-AML). Methods: A total of 121 newly diagnosed pediatric CBF-AML patients enrolled from Aug. 2005 to Sep. 2017 were retrospectively reviewed. Cumulative incidence of relapse (CIR), event-free survival (EFS) and overall survival (OS) rates were estimated by Kaplan-Meier method and prognostic factors were evaluated by Cox regression with SPSS. Results: Of the 121 patients, 120 patients were assessed for bone marrow remission after induction chemotherapy. 100 cases (83.3%) achieved complete remission (CR) after the first course of chemotherapy. 119 cases (99.2%) achieved CR after the second course of chemotherapy. Of the 121 patients, 13 patients (10.7%) had recurrence with the median interval of recurrence as 13.8 months (3.7 to 58.8 months). 17 patients (14.0%) died. The CIR, EFS and OS at 3 years were 12.7%, 77.5% and 82.8%, respectively. The factors including age at diagnosis, sex, initial WBC count, presence of extramedullary leukemia, C-KIT expression, additional chromosomal abnormalities, and CR after the first course of chemotherapy were analyzed by multivariate regression analysis of Cox. Multivariate analysis identified that additional chromosomal abnormalities was the only independent risk factor affecting OS (HR=4.289, 95%CI 1.070-17.183, P=0.040). Conclusions: Pediatric CBF-AML was a unique setting of prognostic subtypes. Chemotherapy produced good responses. Additional chromosomal abnormalities was the only independent risk factor for OS in pediatric CBF-AML.

Mutation of CTLA-4 causes primary immunodeficiency disease: One case report / 中国免疫学杂志

The main biological function of cytotoxic T cell-associated protein 4 (CTLA-4) is to suppress the T cell response and suppress the immune response, and its mutation will cause a series of immune related abnormalities. This case reports a rare case of onset of lymphocytosis, immune hemolysis, repeated infection, and other similar symptoms of autoimmune lymphoproliferative syndrome which caused by CTLA4 Exon2 c. 151 C＞T mutation. Sequencing validation was performed to clarify the source of gene mutation. We review the pathogenesis of CTLA4 and new progress in treatment in this case, and the follow-up treatment for the patient was prospected.

Prognostic factors of pediatric patients with Ph-positive acute lymphoblastic leukemia / 中华血液学杂志

Objective: To explore the clinical features and prognostic factors of Ph-positive and/or BCR-ABL positive acute lymphoblastic leukemia (Ph+ ALL) in children. Methods: The clinical data of 68 Ph+ ALL children who were treated at Peking University People's Hospital from December 2006 to December 2016 was retrospectively reviewed. Survival analysis were estimated by Kaplan-Meier method. Univariate analysis was estimated by Log-rank test and Chi-square, and multivariate analysis was estimated by Cox proportional hazards regression model. Results: In the 68 cases, the proportion of male to female was 2.1∶1, with a median age of 8 (1-16) years, and the median overall survival (OS) and disease free survival (DFS) were 16.8 months and 13.5 months, respectively. The early response rate to treatment was 43.9%, with myeloid-antigens-expression group lower than the non-expression group (29.6% vs 61.3%, χ2=5.814, P=0.020); The complete remission (CR) rate after one-course induction therapy was 86.2% (56/65), with good-response group higher than the poor-response group (100.0% vs 74.2%, χ2=6.680, P=0.003);The CR rate after induction in patients receiving imatinib plus chemotherapy was higher than the patients receiving chemotherapy only (94.9% vs 73.1%, χ2=5.185, P=0.024). The 2-and 5-year OS were (61.4±7.0)% and (50.8±8.1)%, respectively. The 2-and 5-year DFS were (54.6±6.8)% and (48.6±7.3)%, respectively. Univariate analysis showed that the initial WBC, LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year OS rate (all P<0.05). LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year DFS rate (all P<0.05). Multivariate prognostic analysis for OS (RR=45.7, 95% CI 1.4-1 528.2, P=0.033) and DFS (RR=52.3, 95% CI 1.6-1 725.9, P=0.026) showed that the spleen ≥ 3 cm was the independent risk factor. Conclusions: Pediatric Ph+ ALL is a special condition with unique clinical and biological features. The early response to treatment was poor in patients with myeloid-antigens-expression, which resulted in a low CR rate after one-course induction and the administration of imatinib can remarkably improve the CR rate. Initial spleen ≥ 3 cm is an independent prognostic factor. The efficacy of chemotherapy alone is poor, and imatinib combined with chemotherapy is applauded in the aim of improving outcomes.

Clinical characteristics and prognostic analysis of children and adolescents over 10 years of age with acute lymphoblastic leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the clinical characteristics and prognosis of children and adolescents over 10 years of age with acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>A total of 86 newly diagnosed ALL children and adolescents over 10 years of age (62 cases of B-ALL and 24 cases of T-ALL) were enrolled. Clinical characteristics, therapeutic effect and prognostic factors were retrospectively analyzed. Event-free survival (EFS) and overall survival (OS) rates were estimated by the Kaplan-Meier method. Prognostic factors were evaluated by COX regression analysis.</p><p><b>RESULTS</b>Of 86 patients, 62 were in medium risk, and 24 in high risk. At diagnosis, 53 patients (62%) had hepatomegaly, 50 patients (58%) had splenomegaly, and 46 patients (54%) had lymphoadenopathy. Twenty-nine patients (34%) showed high leukocyte counts (≥50×10/L) at diagnosis. The karyotype analysis was performed on 78 patients. The percentage of hyperdiploidy was 19% (15 cases), and that of hypodiploidy was 5% (4 cases). Eleven patients (14%) had abnormalities of chromosome structure. Of them, one patient was Philadelphia chromosome-positive, and another patient had the t (1; 19) chromosomal translocation. Three patients (4%) were positive for TEL/AML1, 3 (4%) were positive for E2A/PBX1, 6 were positive for BCR/ABL (7%), and 4 (5%) were positive for SIL/TAL1. During 4 weeks of induction therapy, 85 patients (99%) achieved complete remission (CR). In 86 patients, the 5-year anticipated EFS and OS were (64±6)% and (75±5)% respectively. The 5-year EFS and OS in the medium risk group were significantly higher than those in the high risk group (P<0.05). The 5-year EFS in B-ALL patients was significantly higher than that in T-ALL patients (P<0.05). COX multivariate analysis showed that white blood counts at diagnosis and minimal residual disease (MRD) after induction therapy were independent prognostic factors.</p><p><b>CONCLUSIONS</b>Children and adolescents with ALL over 10 years of age often have clinical characteristics of unfavorable prognosis. White blood counts at diagnosis and MRD after induction therapy may be important factors for the long-term prognosis.</p>

Prognostic impact of loss of sex chromosomes in children with acute myeloid leukemia subtype M2 / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the relationship between loss of sex chromosomes and prognosis in children with acute myeloid leukemia (AML) M2 subtype.</p><p><b>METHODS</b>According to cytogenetic characteristics, 106 children with AML were divided into three groups: patients with normal karyotype (Group A, n=26), patients with abnormal karyotype who had no loss of sex chromosomes (Group B, n=52), and patients with abnormal karyotype who had loss of sex chromosomes (Group C, n=28). Prognosis was compared between the three groups.</p><p><b>RESULTS</b>The 5-year event-free survival (EFS) rates of Groups A, B, and C were (38.9±11.2)%, (59.3±7.3)%, and (66.5±10.5)%, respectively; the EFS of Group C was significantly higher than that of Group A (P=0.035). The 5-year overall survival (OS) rates of Groups A, B, and C were (54.3±13.5)%, (68.1±7.7)%, and (77.9±9.8)%, respectively (P>0.05). The 5-year EFS of 58 patients with t(8;21) was (63.3±7.3)%, significantly higher than that of patients with normal karyotype (P=0.015). All the 28 cases in Group C had t(8;21), and their 5-year EFS was not significantly different from that of patients with t(8;21) in Group B (P>0.05).</p><p><b>CONCLUSIONS</b>Loss of sex chromosomes is a favorable karyotype in children with AML M2 subtype and the patients in this group mostly have t(8;21). Why loss of sex chromosomes indicates a favorable prognosis is probably because it is accompanied by t(8;21) in the patients.</p>

A comparison of minimal residual disease in children with acute lymphoblastic leukemia of different genetic abnormalities / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the changes of minimal residual disease (MRD) in children with B cell acute lymphoblastic leukemia (B-ALL) of different genetic abnormalities.</p><p><b>METHODS</b>Between February 2004 and April 2013, 271 newly diagnosed B-ALL pediatric patients who had finished the induction chemotherapy were enrolled in the study. The characteristics of changes in MRD in patients with different genetic abnormalities on the 15th day and at the end of the induction therapy were analyzed.</p><p><b>RESULTS</b>On the 15th day of the induction chemotherapy, the MRD positive proportion in patients with hyperdiploid was higher on all the three cut-off levels of MRD≥0.1%, 1% and 10% compared to patients without hyperdiploid (P<0.05), but there was no significant difference in the MRD positive proportion on the three levels of MRD between the TEL-AML1-positive and TEL-AML1-negative groups (P>0.05). On the end of induction chemotherapy, there was no significant difference in the MRD positive proportion on the three levels of MRD between the patients with and without hyperdiploid (P>0.05), neither between the BCR-ABL-positive and negative groups. The MRD positive proportion in TEL-AML1-negative patients was significantly higher than in TEL-AML1-positive patients on all three levels of MRD (P<0.05). The MRD positive proportion on two levels of MRD≥0.01% and 0.1% in E2A-PBX1-negative patients was significantly higher than in E2A-PBX1-positive patients (P<0.05).</p><p><b>CONCLUSIONS</b>Children with B-ALL of different genetic abnormalities have different MRD levels during, and at the end of, induction therapy. The prognostic significance of MRD may be related to the genetic abnormalities.</p>

Analysis of life-threatening central never system complications of acute leukemia in 26 children / 中华实用儿科临床杂志

Objective To investigate the clinical characteristics and risk factors of childhood acute leukemia (AL) with severe neurologic complications.Methods From Jun.1991 to Mar.2011,26 AL patients with severe neurologic complications in Peking University People's Hospital were enrolled.The incidence,clinical features,and risk factors for severe neurologic complications were retrospectively analyzed.Results There 26 patients included 8 cases of acute lymphoblastic leukemia,17 cases of acute myeloid leukemia(AML) and 1 case of acute mixed lineage leukemia.There were 20 patients taking CT scan and 17 patients were confirmed with intracranial hemorrhage.Six cases of AML without CT scan were dead.The patients suffering from intracranial hemorrhage all had intraparenchymal hemorrhage.The AML-M5 with intracranial hemorrhage had higher white blood cell count and higher level of L-lactate dehydrogenase than those without intracranial hemorrhage.These were 5 cases(31.25％) of AML with platelet count ＜ 20 × 109/L,12 cases(70.58％) of AML with prolonged prothrombin time,7 cases(41.17％) of AML with prolonged activated partial thromboplastin time,and 8 cases(47.06％) of AML with low fibrinogen when the severe neurologic complication occurred.Conclusions The most common type of severe neurologic complications of childhood AL is intracranial hemorrhage.The patients with AML are prone to occur intracranial hemorrhage.Intensive blood production transfusion may be beneficial to reduce the probability of intracranial hemorrhage in these patients.

Therapeutic effect of clofarabine in children with relapsed or refractory acute lymphoblastic leukemia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the efficacy and adverse effects of clofarabine for relapsed/refractory acute lymphoblastic leukemia in children.</p><p><b>METHODS</b>Twenty-six pediatric patients with relapsed/refractory acute lymphoblastic leukemia were treated with clofarabine. There were 22 males and 4 females, with a mean age of 9.5 years (ranging from 4 to 17 years). They received clofarabine 52 mg/m2 intravenously over 2 hours daily for 5 days. Thirteen patients received two cycles and one patient received three cycles.</p><p><b>RESULTS</b>In the first cycle of clofarabine, complete remission was obtained in 11 children (42%) and partial remission was obtained in 7 children (27%). Eight children (31%) were considered unresponsive. In the second cycle, 11 (85%) of the 13 children obtained complete remission, 1 (8%) partial remission and 1 (8%) was unresponsive. One child received three cycles and obtained complete remission in each cycle. The common adverse events were myelosuppression, infection, liver dysfunction and gastrointestinal adverse reactions. There were no chemotherapy-related deaths.</p><p><b>CONCLUSIONS</b>Clofarabine is effective in the treatment of children with relapsed/refractory acute lymphoblastic leukemia and its adverse effects can be tolerated. Clofarabine could be a promising new treatment for relapsed/refractory acute lymphoblastic leukemia.</p>

Clinical significance of the Wilms' tumor 1 mRNA expression in childhood myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of the Wilms' tumor 1 (WT1) mRNA in childhood myelodysplastic syndrome (MDS), and to evaluate WT1 as a tool to differentiate MDS from aplastic anemia(AA).</p><p><b>METHODS</b>The quantitative expression of WT1 transcript by using real-time quantitative polymerase chain reaction (RQ-PCR) was performed in the bone marrow samples of 36 childhood MDS and 49 childhood AA, the samples were collected from September 2008 to December 2011.</p><p><b>RESULTS</b>(1) The positive rate of WT1 in severe AA (SAA) was 0, 14.3% in chronic AA (CAA), 58.6% in refractory cytopenia (RC), 100% in refractory anemia with excessive blast (RAEB) and 97.5% in acute myeloid leukemia (AML). The mean level of WT1 in SAA, CAA, RC, RAEB and AML was 0.041%, 0.357%, 7.037%, 12.680% and 24.210%, respectively. The positive rate of WT1 in RC patients was higher than that of SAA (P = 0.000) and CAA (P = 0.001). (2) The positive rate of WT1 in patients with hypoplastic MDS was 66.7% and was higher than that of SAA (P = 0.000) and CAA (P = 0.001). The mean level of WT1 in patients with hypoplastic MDS was (3.022 ± 5.040)% and higher than that of SAA \[(0.041 ± 0.047)%, P = 0.000\] and CAA\[(0.351 ± 0.479)%, P = 0.002\].</p><p><b>CONCLUSIONS</b>The level of WT1 in childhood MDS was higher than that of childhood AA. The degree of WT1 expression in MDS increased during disease progression. WT1 is a useful tool for differentiating the childhood hypoplastic MDS from AA.</p>

Clinical features and etiological spectrum in children with pancytopenia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the clinical features and etiological spectrum of pancytopenia in children.</p><p><b>METHODS</b>The clinical data of 174 children with pancytopenia between September 2003 and January 2010 were retrospectively reviewed.</p><p><b>RESULTS</b>Pale face was the most common clinical manifestation (147 cases, 84.5%), followed by bleeding (87 cases, 50.0%) and fever (41 cases, 23.6%). Mild to moderate anemia, severe thrombocytopenia and mild leucopenia were common in complete blood count. Of the 174 children, pancytopenia was attributed to hematopoietic system diseases in 155 cases (89.1%) and non-hematopoietic system diseases (virus infections, systemic lupus erythematosus, hypersplenism and neuroblastoma) in 6 cases (3.4%). Aplastic anemia (91 cases, 52.3%) was the most common cause of pancytopenia, followed by myelodysplastic syndrome (37 cases, 21.3%), acute leukemia and other hematological tumours (11 cases, 6.3%) and hemophagocytic syndrome (6 cases, 3.4%). The cause of pancytopenia was not identified in 13 cases (7.5%).</p><p><b>CONCLUSIONS</b>Anemia, bleeding and fever are the main clinical manifestations of pancytopenia in children. Pancytopenia is mostly caused by aplastic anemia in children. Myelodysplastic syndrome, hematological tumours and hemophagocytic syndrome are also the common causes.</p>

Clinical features and prognosis of t (8; 21)/AML1-ETO-positive childhood acute myeloid leukemia / 中国当代儿科杂志

<p><b>UNLABELLED</b>OBJECTIVE To study the clinical and biological characteristics and prognosis of t(8;21)/AML1-ETO-positive childhood acute myeloid leukemia (AML).</p><p><b>METHODS</b>The clinical data of 55 children who were diagnosed as t (8; 21)/AML1-ETO-positive AML were retrospectively studied. Event-free survival (EFS), disease-free survival (DFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method. Prognostic factors were evaluated by COX regression analysis software.</p><p><b>RESULTS</b>Of the 55 patients, 4 patients gave up treatment after the diagnosis was confirmed and 4 patients were lost to follow-up after the first chemotherapy course. The remaining 47 patients received a double-induction therapy. The total complete remission (CR) rate was 71% and 94% after the first and second chemotherapy course, respectively. The disease was relapsed in 10 patients (21%). The 5-year EFS, DFS and OS rates were (56.1 ± 7.9)%, (59.8 ± 8.1)%, and (72.0 ± 8.1)%, respectively. Multivariate analysis showed that age was an independent risk factor for the long-term prognosis. The older children had a greater risk of experiencing an accident or death (P<0.05). The 5-year OS rate in 27 patients with regular consolidation chemotherapy was significantly higher than 13 patients with irregular chemotherapy after CRz [(47.5 ± 17.1)% vs (38.9 ± 17.3)%; P<0.01].</p><p><b>CONCLUSIONS</b>Childhood t(8;21)/AML1-ETO-positive AML is a highly heterogeneous disease, with a high CR rate and a good long-term prognosis. Age is one of the important factors affecting the long-term therapeutic effect. Regular consolidation chemotherapy applied after CR usually is helpful.</p>

Clinical characteristics of children with B cell type acute lymphoblastic leukemia carrying different fusion gene / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate whether there were differences in the clinical characteristics, cytogenetic characteristics, immunophenotype and prognosis in children with B cell type acute lymphoblastic leukemia (B-ALL) carrying different fusion genes.</p><p><b>METHODS</b>The research included 80 children with B-ALL from Peking University People's Hospital between March 2006 and December 2008. Eighteen children were positive for TEL/AML1, 14 for E2A/PBX1, 11 for BCR/ABL,and 2 cases for MLL/AF4, and 35 cases were negative for all of the 4 fusion genes. Data including clinical characteristics, morphology, immunophenotype and cytogenetic characteristics were collected, and the disease-free survival (DFS) was evaluated. The children were followed up until April 2009.</p><p><b>RESULTS</b>In the 18 children with TEL/AML1+B-ALL, 66.7% were younger than 5 years old. They had low tumor load. FAB-L2 morphology was commonly observed, but t(12;21) was often absence in these children. Up to now,17 children who survived were disease-free. In the 14 children with E2A/PBX1+B-ALL, the majority were female. Thirteen children showed FAB-L1 morphology. Twelve children showed pre-B-ALL immunophenotype. The EFS was close to 80%. In the 11 children with BCR/ABL+B-ALL, 10 children showed common B type immunophenotype. FAB-L1 and FAB-L2 morphology was found in 4 children respectively. The DFS was less than 20%. Two children with MLL/AF4 positive B-ALL had high tumor load. Their morphologic diagnosis was FAB-L1. Both showed the Pro-B-ALL immunophenotype. One child discontinued treatment at the early stage of chemotherapy, and the other child survived disease-free until now.</p><p><b>CONCLUSIONS</b>The B-ALL children with different fusion genes have different clinical characteristics, immunophenotypes and prognosis.</p>

Identification of gene rearrangements in childhood leukemia by using a multiplex polymerase chain reaction-microarray approach / 中国实验血液学杂志

The aim of study was to investigate the application of a novel microarray approach for the eight most common leukemia translocations in children for routine molecular diagnostic hematopathology practice. Bone marrow samples from 84 children with leukemia were analyzed by multiplex nested RT-PCR combined with oligonucleotide microarray. The results showed that out of 84 leukemic samples, 31 (36. 90%) carried 8 types of fusion genes including tel/aml1, e2a/pbx1, bcr/ablp190, bcr/ablp210, mll/af4, aml1/eto, pml/raralpha, cbfbeta/myh11. The sensitivity and specificity of the assay is comparable with the RT-PCR technique. In conclusion, this multiplex nested RT-PCR could quickly screen 8 types of chromosome structural aberrations at the same time. It can provide reliable and helpful information for risk stratification, therapy evaluation and prognosis prediction in childhood leukemia. There are both advantages and disadvantages in applying this new method. The microarray-based assay will be an effective and reliable tool in the clinical screening of leukemia patients for the presence of specific gene rearrangements with important diagnostic and prognostic implications.

Detection of fusion genes in childhood acute lymphoblastic leukemia by using oligonucleotide microarrays approach / 中华儿科杂志

<p><b>OBJECTIVE</b>To evaluate the possibility of applying oligonucleotide microarrays for detection of the fusion genes in childhood acute lymphoblastic leukemia (ALL).</p><p><b>METHODS</b>To detect five types of fusion genes emerging frequently in childhood ALL including TEL/AML1, E2A/PBX1, BCR/ABLp190, BCR/ABLp210, MLL/AF4, probes were designed, synthesized and spotted on the chemical-material-coated-glass plates in array. The total RNAs were extracted from patients' bone marrow or peripheral blood cells at the beginning of diagnosis, analyzed by multiplex nested reverse-transcription-polymerase chain reaction (RT-PCR), and labeled by fluorescein. The products of RT-PCR were hybridized with microarray in order to detect specific types of fusion genes in leukemia cells.</p><p><b>RESULTS</b>Distinctive hybridization signals were obtained for internal positive control and specific types of fusion genes. TEL/AML1 gene was found positive in 2 of the 36 cases, E2A/PBX1 gene in 3, BCR/ABLp190 gene in 2, BCR/ ABLp210 gene in one, and MLL/ AF4 gene in one. The results of the microarray and RT-PCR were consistent.</p><p><b>CONCLUSION</b>The microarray-based assay could screen 5 types of chromosome structural aberrations and the splice variants at the same time. It can provide reliable and helpful information for patient stratification, evaluation of therapeutic effects and prediction of prognosis in childhood ALL, although there are both advantages and disadvantages in applying this new method.</p>