Objective: To describe the gene mutation profile of newly diagnosed pediatric B-acute lymphoblastic leukemia (B-ALL) and analyze its effect on minimal residual disease (MRD). Methods: A total of 506 newly diagnosed B-ALL children treated in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences from September 2018 to July 2021 were enrolled in this retrospective cohort study. The enrolled children were divided into MRD ≥1.00% group and <1.00% group according to MRD results on the 19th day since chemotherapy, and MRD ≥0.01% group and <0.01% group according to MRD results on the 46th day. Clinical characteristics and gene mutations of two groups were compared. Comparisons between groups were performed with chi-square test or Fisher's exact test. Independent risk factors of MRD results on the 19th day and the 46th day were analyzed by Logistic regression model. Results: Among all 506 patients, there were 318 males and 188 females. On the 19th day, there were 114 patients in the MRD ≥1.00% group and 392 patients in the MRD <1.00% group. On the 46th day, there were 76 patients in the MRD ≥0.01% group and 430 patients in the MRD <0.01% group. A total of 187 gene mutations were detected in 487 (96.2%) of 506 children. The most common gene mutations were signal transduction-related KRAS gene mutations in 111 cases (22.8%) and NRAS gene mutations in 99 cases (20.3%). Multivariate analysis showed that PTPN11 (OR=1.92, 95%CI 1.00-3.63), KMT2A (OR=3.51, 95%CI 1.07-11.50) gene mutations and TEL-AML1 (OR=0.48, 95%CI 0.27-0.87), BCR-ABL1 (OR=0.27, 95%CI 0.08-0.92) fusion genes and age >10 years (OR=1.91, 95%CI 1.12-3.24) were independent influencing factors for MRD ≥1.00% on the 19th day. BCORL1 (OR=2.96, 95%CI 1.18-7.44), JAK2 (OR=2.99, 95%CI 1.07-8.42) and JAK3 (OR=4.83, 95%CI 1.50-15.60) gene mutations and TEL-AML1 (OR=0.43, 95%CI 0.21-0.87) fusion gene were independent influencing factors for MRD ≥0.01% on the 46th day. Conclusions: Children with B-ALL are prone to genetic mutations, with abnormalities in the RAS signaling pathway being the most common. Signal transduction related PTPN11, JAK2 and JAK3 gene mutations, epigenetic related KMT2A gene mutation and transcription factor related BCORL1 gene mutation are independent risk factors for MRD.
Child ; Female ; Male ; Humans ; High-Throughput Nucleotide Sequencing ; Neoplasm, Residual/genetics* ; Retrospective Studies ; Genomics ; Precursor Cell Lymphoblastic Leukemia-Lymphoma

Objective: To investigate the effects of PM_2.5 exposure at different stages of early life on the prefrontal cortex of offspring rats. Methods: Twelve pregnant SD rats were randomly divided into four groups: Control group (CG), Maternal pregnancy exposure group (MG), Early postnatal exposure group (EP) and Perinatal period exposure group (PP), 3 rats in each group. The pregnant and offspring rats were exposed to clean air or 8-fold concentrated PM_2.5. MG was exposed from gestational day (GD) 1 to GD21. EP was exposed from postnatal day (PND) 1 to PND21, and PP was exposed from GD1 to PND21. After exposure, the prefrontal cortex of 6 offspring rats in each group was analyzed. HE staining was used to observe the pathological damage in the prefrontal cortex. ELISA was employed to detect neuroinflammatory factors, and HPLC/MSC was applied to determine neurotransmitter content. Western blot and colorimetry were applied for detecting astrocyte markers and oxidative stress markers, respectively. Results: Compared with MG and CG, the pathological changes of prefrontal cortex in PP and EP were more obvious. Compared with MG and CG, the neuroinflammatory factors (IL-1, IL-6, TNF-α) in PP and EP were increased significantly (P＜0.01), the level of MT were decreased significantly (P＜0.05), and the level of oxytocin (OT) showed a downward trend; the level of neurotransmitter ACh was also increased significantly (P＜0.01). Compared with MG and CG, the GFAP level of PP and EP showed an upward trend, the level of oxidative stress index SOD in PP and EP was decreased significantly (P＜0.01), and the level of ROS was increased significantly (P＜0.01). Compared with the offspring rats of CG and MG, the CAT level of PP was decreased significantly (P＜0.01, P＜0.05). Compared with the offspring rats of CG, the CAT level of EP was decreased significantly (P＜0.05). There was no significant difference in IL-1, IL-6, TNF-α, MT, OT, ACh, GFAP, SOD, ROS and CAT levels between PP and EP, or MG and CG. Conclusion: PM_2.5 exposure in early life has adverse effects on the prefrontal cortex of offspring male rats, and early birth exposure may be more sensitive.
Animals ; Female ; Interleukin-1/pharmacology* ; Interleukin-6 ; Male ; Neurotransmitter Agents ; Particulate Matter/toxicity* ; Prefrontal Cortex ; Pregnancy ; Rats ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; Superoxide Dismutase ; Tumor Necrosis Factor-alpha/pharmacology*

OBJECTIVE: To investigate the consistency between FCM and PCR on the detecting of MRD in TCF3-PBX1 METHODS: 55 cases of paediatric TCF3-PBX1 RESULTS: Among the 55 children with TCF3-PBX1 CONCLUSION The detection result of MRD in TCF3-PBX1 detect by FCM and PCR shows better consistency. MRD positivity detected by FCM at the end of induction therapy (day 33) predicts a high risk of relapse in TCF3-PBX1 ALL patients.
Adolescent ; Bone Marrow ; Child ; Child, Preschool ; Female ; Humans ; Male ; Neoplasm, Residual ; Oncogene Proteins, Fusion/genetics* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prognosis ; Recurrence

OBJECTIVE: To study the association of platelet level at diagnosis with prognosis in children with acute lymphoblastic leukemia (ALL). METHODS: A total of 892 children with ALL who underwent chemotherapy with the CCLG-ALL 2008 regimen were enrolled. According to the platelet count at diagnosis, these children were divided into normal platelet count group (platelet count ≥100×109/L; n=263) and thrombocytopenia group (platelet count <100×10/L; n=629). The thrombocytopenia group was further divided into (50- <100)×10/L (n=243), (20- <50)×10/L (n=263), and <20×10/L (n=123) subgroups. The association of clinical features (sex, age, immunophenotype, and molecular biology) with event-free survival (EFS) and overall survival (OS) was analyzed. RESULTS: Compared with the thrombocytopenia group, the normal platelet count group had significantly lower positive rate of MLL gene rearrangement and recurrence rate (P<0.05), as well as a significantly higher 10-year EFS rate (P<0.05). There was no significant difference in 10-year OS between the two groups (P>0.05). The normal platelet count group still had a significantly higher 10-year EFS rate than the thrombocytopenia group after the children with MLL gene rearrangement were excluded (P<0.05), and there was still no significant difference in 10-year OS between the two groups (P>0.05). The <20×10/L subgroup had significantly lower 10-year EFS and OS rates than the normal platelet count group, the (50- <100)×10/L subgroup, and the (20- <50)×10/L subgroup (P<0.05). After the children with MLL gene rearrangement were excluded, the <20×10/L subgroup still had significantly lower 10-year EFS and OS rates than the normal platelet count group, the (50-<100)×10/L subgroup, and the (20- <50)×10/L subgroup (P<0.05). CONCLUSIONS ALL children with MLL gene rearrangement often have the clinical manifestation of thrombocytopenia. Platelet level at diagnosis is associated with the prognosis of ALL children. The children with normal platelet count have a low recurrence rate and good prognosis, and those with a platelet count of <20×10/L have the worst prognosis.
Child ; Disease-Free Survival ; Humans ; Immunophenotyping ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prognosis ; Recurrence

Child ; Correlation of Data ; Flow Cytometry ; Humans ; Immunophenotyping ; Neoplasm, Residual ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Prognosis

OBJECTIVETo investigate the application of multiplex ligation-dependent probe amplification (MLPA) in the detection of copy number variations (CNVs) in pediatric ETV6/RUNX1-positive acute lymphoblastic leukemia (ALL), to compare this method with conventional karyotype analysis and fluorescence in situ hybridization (FISH), and to evaluate the value of MLPA.

METHODSThe clinical data of 95 children with ETV6/RUNX1-positive ALL who were treated from January 2006 to November 2012 were analyzed retrospectively, including clinical features, results of karyotype analysis, and results of FISH. CNVs were detected with MLPA.

RESULTSCNVs were detected in 73 (77%), and the median number of CNVs was 1 (range 0-6). The CNVs of EBF1, CDKN2A/2B, PAX5, ETV6, RB1, and BTG1 were detected in more than 10% of all the patients. The changes in the chromosome segments carrying the genes with CNVs detected by MLPA were not detected by conventional karyotype analysis. The coincidence rate between the CNVs in ETV6 gene detected by FISH and those detected by MLPA was 66%.

CONCLUSIONSMLPA is an efficient and convenient method to detect CNVs in children with ETV6/RUNX1-positive ALL.

Adolescent ; Child ; Child, Preschool ; Core Binding Factor Alpha 2 Subunit ; analysis ; DNA Copy Number Variations ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Infant ; Male ; Multiplex Polymerase Chain Reaction ; methods ; Oncogene Proteins, Fusion ; analysis ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; genetics

OBJECTIVETo identify the incidence of PAX5 deletion in childhood B-lineage acute lymphoblastic leukemia (B-ALL) without reproducible chromosomal abnormalities and to investigate the association between PAX5 abnormalities and prognosis of ALL.

METHODSMultiplex ligation-dependent probe amplification was used to determine the copy numbers of PAX5 gene in children newly diagnosed with B-ALL without reproducible chromosomal abnormalities between April 2008 and April 2013 and controls (children with non-hematologic diseases or tumors). The patients were classifiied into deletion group and non-deletion group based on the presence of PAX5 deletion.

RESULTSEighteen (21%) out of 86 children with B-ALL had PAX5 deletion. The deletion group had a significantly higher total white blood cell count at diagnosis than the non-deletion group (P=0.001). The Kaplan-Meier analysis demonstrated that the deletion group had a significantly lower disease-free survival (DFS) rate than the non-deletion group (0.69±0.12 vs 0.90±0.04; P=0.017), but there was no significant difference in the overall survival rate between the two groups (P=0.128). The Cox analysis showed that PAX5 deletion was a risk factor for DFS (P=0.03).

CONCLUSIONSPAX5 deletion is an independent risk factor for DFS in B-ALL children without reproducible chromosomal abnormalities.

Acute Disease ; Adolescent ; Cell Lineage ; Child ; Child, Preschool ; Chromosome Aberrations ; Disease-Free Survival ; Female ; Gene Deletion ; Humans ; Infant ; Male ; PAX5 Transcription Factor ; genetics ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; mortality

OBJECTIVETo study the efficacy and safety of Chinese Childhood Leukemia Group ALL 2008 (CCLG-ALL2008) protocol combined with tyrosine kinase inhibitor (TKI, imatinib) for the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in children.

METHODSThe clinical data of 53 patients aged less than 15 years when first diagnosed with Ph+ ALL between October 2008 and December 2013 were retrospectively analyzed. The patients were assigned to two groups: HR (n=26) and HR+TKI (n=27). The HR group was treated with CCLG-ALL2008 protocol (for high-risk patients). The HR+TKI group was treated with imatinib in combination with CCLG-ALL2008 protocol (for high-risk patients).

RESULTSThe complete remission rate and chemotherapy induction-related mortality rate in the TKI+HR and HR groups were 100% vs 75% and 0 vs 15%, respectively. The 3-year event-free survival (EFS) rate in the HR group was (6±5)%; the 5-year EFS rate of the TKI+HR group was (52±11)%. Compared with the HR group, the TKI+HR group had no increase in the toxic responses to chemotherapy and had a decrease in the infection rate during the induction period.

CONCLUSIONSApplication of imatinib significantly improves the clinical efficacy in children with Ph+ ALL and has good safety.

Adolescent ; Antineoplastic Agents ; therapeutic use ; Child ; Child, Preschool ; Female ; Humans ; Imatinib Mesylate ; adverse effects ; therapeutic use ; Male ; Philadelphia Chromosome ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; genetics ; mortality ; Protein Kinase Inhibitors ; therapeutic use

OBJECTIVETo identify IKZF1 gene copy number abnormalities in BCR/ABL-negative B-lineage acute lymphoblastic leukemia (B-ALL) in children, and to investigate the association between such abnormalities and prognosis.

METHODSMultiplex ligation-dependent probe amplification (MLPA) was applied to detect IKZF1 gene copy number abnormalities in 180 children diagnosed with BCR/ABL-negative B-ALL. These children were classified into IKZF1 deletion group and IKZF1 normal group according to the presence or absence of IKZF1 gene deletion. The association between IKZF1 copy number abnormalities and prognosis of children with BCR/ABL-negative B-ALL was analyzed retrospectively.

RESULTSAmong 180 children, 27 (15.0%) had IKZF1 deletion; among the 27 children, 4 had complete deletions of 8 exons of IKZF1 gene, 17 had deletion of exon 1, 3 had deletions of exons 4-7, and 3 children had deletions of exons 2-7. Compared with those in the IKZF1 normal group, children in the IKZF1 deletion group had higher white blood cell (WBC) count and percentage of individuals with high risk of minimal residual disease at the first visit. IKZF1 deletions often occurred in BCR/ABL-negative children with no special fusion gene abnormalities. They were frequently accompanied by abnormalities in chromosomes 11, 8, 5, 7, and 21. The analysis with Kaplan-Meier method showed that disease-free survival (DFS) in the IKZF1 deletion group was significantly lower than that in the IKZF1 normal group (0.740 ± 0.096 vs 0.905 ± 0.034; P=0.002). Cox analysis showed that after exclusion of sex, age, initial WBC count, cerebrospinal fluid state at the first visit, prednisone response, and chromosome karyotype, IKZF1 deletion still affected the children's DFS (P<0.05).

CONCLUSIONSSome children with BCR/ABL-negative B-ALL have IKZF1 deletion, and IKZF1 deletion is an independent risk factor for DFS in children with BCR/ABL-negative B-ALL.

Adolescent ; Child ; Child, Preschool ; Female ; Fusion Proteins, bcr-abl ; analysis ; Gene Dosage ; Humans ; Ikaros Transcription Factor ; genetics ; Infant ; Male ; Multiplex Polymerase Chain Reaction ; Precursor B-Cell Lymphoblastic Leukemia-Lymphoma ; genetics ; mortality ; Prognosis

OBJECTIVETo study the clinical features of children with relapsed acute lymphoblastic leukemia (ALL) treated with the CCLG-ALL2008 protocol.

METHODSThe data of 591 children who were newly diagnosed with ALL and were treated with the CCLG-ALL 2008 protocol between April 2008 and June 2013 were collected, and the clinical features of 80 children with relapsed ALL were retrospectively analyzed.

RESULTSAfter treatment with the CCLG-ALL2008 protocol, the recurrence rate in the standard-risk, intermediate-risk and the high-risk groups were 7.0%, 10.7% and 28.7% respectively (P<0.05). The recurrence rate in patients with TEL/AML1-positive ALL was 8.0%, and the 5-year overall survival (OS) of the relapsed patients was 37.04%. The recurrence rates in patients with MLL-positive and BCR/ABL-positive ALL were 35.0% and 24.2% respectively, and none of the relapsed patients had long-term survival. The recurrence mainly occurred at the very early stage (53%), and none of patients with recurrence at the very early stage had long-term survival. The recurrence occurred at early stage and late stage accounted for 34% and 14% respectively, and the 5-year OS rates of patients with recurrence at early stage and late stage were 11.44% and 60.00% respectively. The sites of recurrence were mainly bone marrow alone (83%), and the 5-year OS of patients with recurrence at bone marrow alone was 9.23%. The recurrence in bone marrow and outside bone marrow accounted for 11%, and the 5-year OS of patients with recurrence in both bone marrow and outside bone marrow was 25.00%. The recurrence only outside bone marrow accounted for 6%, and the 5-year OS of patients with recurrence only outside bone marrow was 100%. The recurrence rate in patients with T-cell ALL was 9.5%, and none of the relapsed patients had long-term survival. The recurrence rate in patients with B-cell ALL was 14.3%, and the 5-year OS of the relapsed patients was 15.52%.

CONCLUSIONSAfter treatment with the CCLG-ALL2008 protocol, a relatively high recurrence rate is observed in children with high-risk ALL. Positive MLL and positive BCR/ABL are high-risk factors for recurrence. The recurrence rate is not significantly correlated with immunophenotype. A very low survival rate is seen in children whose recurrence have the following features: at early stage, only in bone marrow, T-cell ALL, and abnormal BCR/ABL and MLL.

Adolescent ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; mortality ; Prognosis ; Recurrence ; Retrospective Studies