Objective:To analyze the clinical features and prognosis of acute B lymphoblastic leukemia (B-ALL) children carrying a TCF3: : PBX1 fusion gene and to evaluate the prognostic value of this gene.Methods:Retrospective cohort study.A total of 2 164 B-ALL children aged 0-18 years diagnosed and treated at 19 pediatric centers from October 2016 to June 2022 were enrolled.They were divided into the positive group and the negative group according to whether they carried a TCF3: : PBX1 fusion gene.The clinical characteristics, treatment response, adverse reactions, and prognosis of the 2 groups of patients were analyzed.The rank sum and Kruskal-Wallis tests were used to compare two and more than two groups of numerical variables, respectively.Fisher′s exact test was used to compare categorical variables.Results:Among the 2 164 patients, 116 (5.4%) were TCF3: : PBX1 positive, of which 70 patients were female, accounting for 60.3%.There were 840 female patients in the TCF3: : PBX1-negative group, accounting for 41.0%.There was a significant difference in the ratio of females between the TCF3: : PBX1-positive and TCF3: : PBX1-negative groups ( P<0.001).No significant difference was observed in age of onset between the two groups( P>0.05).The proportion of bone marrow naive cells [54.00 (14.00, 76.50)% vs.29.00 (3.00, 68.00)%], white blood cell counts [25.30 (10.46, 60.94)×10 9/L vs.9.03 (4.38, 30.73)×10 9/L] and hemoglobin counts [82.00(63.00, 101.00) g/L vs.74.00(60.00, 90.00) g/L] in the TCF3: : PBX1-positive group were significantly higher than those in the negative group at the onset (all P<0.05).In terms of treatment response, the proportion of peripheral blood naive cells on Day 8 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group [2.00 (0, 9.00)% vs.0 (0, 2.00)%, P<0.001].The proportion of minimal residual disease <0.1% on Day 15 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group ( P=0.038).There were no significant differences in cumulative recurrence rate, treatment-related mortality (TRM), and overall survival (OS) between the TCF3: : PBX1-positive group and TCF3: : PBX1-negative group (all P>0.05).The cumulative recurrence risk of TCF3: : PBX1-positive patients was 9.646 times higher than that of ETV6: : RUNX1-positive patients with better prognosis( HR=9.646, 95% CI: 1.026-90.700, P=0.047).There were no significant differences in TRM and OS between TCF3: : PBX1-positive and ETV6: : RUNX1-positive patients (all P>0.05).A significant enrichment of PAX5 mutations was detected in TCF3: : PBX1-positive patients.Among the 7 high-risk TCF3: : PBX1-positive patients in a single center, 4 patients had PAX5 mutations, and this proportion was significantly higher than that in other patients ( P<0.001). Conclusions:B-ALL children carrying a TCF3: : PBX1 fusion gene have a high remission rate and good long-term prognosis after intensive chemotherapy.It is suggesting that TCF3: : PBX1-positive B-ALL patients should be rated at intermediate risk to receive intensive chemotherapy.

Objective:To analyze the clinical features and prognosis of acute B lymphoblastic leukemia (B-ALL) children carrying a TCF3: : PBX1 fusion gene and to evaluate the prognostic value of this gene.Methods:Retrospective cohort study.A total of 2 164 B-ALL children aged 0-18 years diagnosed and treated at 19 pediatric centers from October 2016 to June 2022 were enrolled.They were divided into the positive group and the negative group according to whether they carried a TCF3: : PBX1 fusion gene.The clinical characteristics, treatment response, adverse reactions, and prognosis of the 2 groups of patients were analyzed.The rank sum and Kruskal-Wallis tests were used to compare two and more than two groups of numerical variables, respectively.Fisher′s exact test was used to compare categorical variables.Results:Among the 2 164 patients, 116 (5.4%) were TCF3: : PBX1 positive, of which 70 patients were female, accounting for 60.3%.There were 840 female patients in the TCF3: : PBX1-negative group, accounting for 41.0%.There was a significant difference in the ratio of females between the TCF3: : PBX1-positive and TCF3: : PBX1-negative groups ( P<0.001).No significant difference was observed in age of onset between the two groups( P>0.05).The proportion of bone marrow naive cells [54.00 (14.00, 76.50)% vs.29.00 (3.00, 68.00)%], white blood cell counts [25.30 (10.46, 60.94)×10 9/L vs.9.03 (4.38, 30.73)×10 9/L] and hemoglobin counts [82.00(63.00, 101.00) g/L vs.74.00(60.00, 90.00) g/L] in the TCF3: : PBX1-positive group were significantly higher than those in the negative group at the onset (all P<0.05).In terms of treatment response, the proportion of peripheral blood naive cells on Day 8 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group [2.00 (0, 9.00)% vs.0 (0, 2.00)%, P<0.001].The proportion of minimal residual disease <0.1% on Day 15 in the TCF3: : PBX1-positive group was significantly higher than that in the negative group ( P=0.038).There were no significant differences in cumulative recurrence rate, treatment-related mortality (TRM), and overall survival (OS) between the TCF3: : PBX1-positive group and TCF3: : PBX1-negative group (all P>0.05).The cumulative recurrence risk of TCF3: : PBX1-positive patients was 9.646 times higher than that of ETV6: : RUNX1-positive patients with better prognosis( HR=9.646, 95% CI: 1.026-90.700, P=0.047).There were no significant differences in TRM and OS between TCF3: : PBX1-positive and ETV6: : RUNX1-positive patients (all P>0.05).A significant enrichment of PAX5 mutations was detected in TCF3: : PBX1-positive patients.Among the 7 high-risk TCF3: : PBX1-positive patients in a single center, 4 patients had PAX5 mutations, and this proportion was significantly higher than that in other patients ( P<0.001). Conclusions:B-ALL children carrying a TCF3: : PBX1 fusion gene have a high remission rate and good long-term prognosis after intensive chemotherapy.It is suggesting that TCF3: : PBX1-positive B-ALL patients should be rated at intermediate risk to receive intensive chemotherapy.

Objective:To investigate the clinical characteristics and possible causes of transient spontaneous remission of childhood acute leukemia.Methods:The data of 3 children with acute leukemia who had transient spontaneous remission before standardized chemotherapy in Sun Yat-sen Memorial Hospital of Sun Yat-sen University in July 2018, May 2019 and October 2020 were collected. Moreover, the related influencing factors of spontaneous remission in leukemia were discussed by review of the literature.Results:All 3 children had fever at the onset of the disease, and they achieved transient spontaneous remission after anti-infection therapy. Case 1 obtained partial remission after the initial diagnosis of acute B lymphocytic leukemia (B-ALL), leukemia gene test showed E2A-PBX1 fusion, and relapsed after 12 days. Case 2 obtained spontaneous remission after the initial diagnosis of B-ALL, leukemia gene test showed p16 gene deletion and NRAS and EP300 genes mutation, and relapsed after 20 days. Case 3 obtained spontaneous remission after the initial diagnosis of acute monocytic leukemia, leukemia gene test showed MLL-ENL fusion and NRAS gene mutation, and relapsed after 30 days. A review of the literature showed that the main influencing factors of spontaneous remission in leukemia were Down syndrome, infection and blood transfusion. Other influencing factors included leukemia-related genes, termination of pregnancy and application of drugs.Conclusions:Transient spontaneous remission of childhood acute leukemia is rare in clinical practice, and the possible mechanism is related to infection-induced immune abnormalities. It is recommended that leukemia patients with spontaneous remission should be closely monitored for minimal residual disease.

Objective: To study the diagnostic strategy of β-thalassemia through retrospective analysis of 3 cases of β-thalassemia. Methods: Three patients were admitted to the Department of Pediatrics, Sun Yat-sen Memorial Hospital of Sun Yat-sen University from January 2014 to June 2015. The clinical manifestations, hemoglobin electrophoresis and gene detection of these patients and their parents were analyzed, diagnostic ideas and key points were discussed when beta thalassemia gene detection did not explain clinical manifestations or hemoglobin electrophoresis. Results: Case 1, boy, 5 years old, was diagnosed as compound heterozygotes of β41-42 and IVS-Ⅱ-654 with hereditary persistence of fetal hemoglobin(HPFH) according to the clinical manifestations of mild anemia, normal size of liver and spleen, 92.8% fetal hemoglobin (HbF) and gene analysis. Case 2, girl, 3 years old, was confirmed the diagnosis of thalassemia intermedia with β41-42 heterozygote compound and ααα^anti3.7 heterozygote in accordance with the manifestations of severe anemia, hepatosplenomegaly, 8.6% HbF, 4.1% hemoglobin A₂(HbA₂) and gene analysis. Case 3, girl, 3 years old, with severe anemia, hepatosplenomegaly, 51.2% HbF and 3.7% HbA₂, was diagnosed as thalassemia major with compound heterozygotes of PolyA (T→C) and β17 by DNA sequencing. Conclusion The diagnosis of β-thalassemia should be confirmed by clinical manifestations of hemolytic anemia, hemoglobin electrophoresis, gene diagnosis and family survey.

Objective To explore the bone marrow stromal cells,anti-late antigen-4 (VLA-4) antibody (aVLA-4),cytarabine (Ara-C) on the proliferation and apoptosis of leukemia HL-60 cells.Methods The experiment was divided into five groups:HL-60 cells were cultured alone (control group),HL-60 cells and stromal cells group (stromal cells group),HL-60 cells + stromal cells + aVLA-4 (antibody group),HL-60 cells + stromal cells + Ara-C group (drug group),HL-60 cells + stromal cells + aVLA-4 + Ara-C group (antibody +drug group).Cell proliferation or inhibition rate was detected by CCK-8 method,the HL-60 cells apoptosis was detected by flow cytometry.The expression of anti-apoptotic gene bcl-2 in HL-60 cells was determined by Western blot.Results After 24 h and 48 h,treatment,the number of the stromal cells group HL-60 cells were higher than that of the control group with significant difference cultured [(7.2±0.3)×1O5/ml vs (5.3±0.4)×105/ml,(8.4±0.2)×105/ml vs (6.8±0.3)×105/m1,P ＜ 0.001],while the HL-60 cell proliferation inhibition rate [(24.3±2.1) ％,(37.0±2.6) ％,(65.6±3.8) ％] and apoptosis rate [(5.7±0.6) ％,(8.0±0.5) ％,(10.4±0.9) ％,(16.5±0.7) ％] of antibody group,drug group,antibody + drug group were higher than the control group with a difference of statistically significant (P ＜ 0.05),and the increase of antibody + drug group was most obvious.With the decreasing of the bcl-2 protein expression,which was most the decrease of antibody + drug group was most obvious.Conclusion Bone marrow stromal cells can stimulate the proliferation of leukemia cells,aVLA-4 interference the interaction between stromal cells and leukemia cells can enhance the chemosensitivity of leukemia cells to Ara-C.