Objective: To investigate the clinical features and treatment of child patient with chronic myeloid leukemia (CML) and T315I mutation in the ABL1 kinase domain. Methods: The clinical features, diagnosis and treatment of one child CML patient with T315I mutation in ABL1 kinase domain in Fujian Medical University Union Hospital were retrospectively analyzed, and the literature was reviewed. Results: The patient was treated with imatinib and dasatinib. The BCR-ABL^IS value decreased and then increased. The disease progressed to the accelerated phase. At the same time, the T315I mutation was detected in the ABL1 kinase domain, the harringtonine chemotherapy was used, and the condition of patient got better. But eventually the hematopoietic stem cell transplantation could not be performed, the CML progressed to the blast phase and the patient died half a year later. Conclusions The prognosis of children with CML and T315I mutation in ABL1 kinase domain is poor. In the absence of punatinib treatment, hematopoietic stem cell transplantation should be performed as soon as possible after chemotherapy, which may improve the prognosis.

Objective: To investigate the clinical effect and safety of dasatinib combined with Chinese Children's Leukemia Group-acute lymphoblastic leukemia (CCLG-ALL) 2008 protocol in treatment of childhood Philadelphia chromosome-positive (Ph⁺) acute lymphoblastic leukemia (ALL). Methods: The clinical data of 22 patients with Ph⁺ ALL who were newly diagnosed at the age of less than 15 years old in Fujian Medical University Union Hospital from January 2014 to December 2018 were retrospectively analyzed. All patients were treated with dasatinib combined with CCLG-ALL2008 protocol (high-risk group). The patients were assigned to two groups according to different starting times of oral dasatinib: the dasatinib-induced group (starting from day 15 of induction chemotherapy) and the dasatinib-consolidated group (starting with early consolidated chemotherapy). The early treatment response and 5-year event-free survival (EFS) rate were compared between the two groups. Results: The differences of clinical characteristics and early efficacy of chemotherapy before treatment of dasatinib between the two groups were not statistically significant (both P > 0.05). The complete remission (CR) rate on day 33 of induction chemotherapy was higher in the dasatinib-induced group than that in the dasatinib-consolidated group [100% (10/10) vs. 75% (9/12)], but the difference was not statistically significant (χ ²= 2.895, P= 0.221). The rate of minimal residual disease (MRD) turned negative (<0.01%) on day 33 of induction chemotherapy in the dasatinib-induced group was significantly higher than that in the dasatinib-consolidated group [70% (7/10) vs. 17% (2/12)], and the difference was statistically significant (χ ²= 6.418, P= 0.027). The 3-year EFS rate was higher in the dasatinib-induced group than that in the dasatinib-consolidated group (88.9% vs. 63.5%), but the difference was not statistically significant (P= 0.163). The incidence of grade 3-4 infection in the dashatinib-induced group was lower than that in the dasatinib-consolidated group, and the difference was statistically significant [60% (6/10) vs. 100% (12/12), P= 0.029]. the other grade 3-4 adverse reactions related to the chemotherapy drugs mainly included hematological toxicity, diarrhea, abnormal liver function, edema and pleural effusion, but there was no significant difference between the two groups (all P > 0.05). Conclusions Dasatinib combined with CCLG-ALL2008 protocol in the treatment of children with Ph⁺ ALL has good efficacy and safety. Furthermore, the early use of dasatinib on day 15 of induction chemotherapy can enable patients to achieve deeper remission earlier and improve long-term efficacy.

Objective:To investigate the clinical characteristics and efficacy of children with acute lymphoblastic leukemia (ALL) and TP53 mutation, and to explore the relationship between TP53 mutation and the prognosis of children with ALL.Methods:The clinical data of 141 children with newly diagnosed ALL from November 2016 to December 2019 in Fujian Medical University Union Hospital were collected, and the whole-exome gene assay was performed in bone marrow samples of the children by using next-generation sequencing technology. The clinical characteristics of children with TP53 mutation were retrospectively analyzed, and the Kaplan-Meier method was used to compare the overall survival (OS) and event-free survival (EFS) of children with or without TP53 mutation.Results:Among the 141 children with newly diagnosed ALL, TP53 mutations were detected in 5 children (3.5%), all of which were B-precursor acute lymphoblastic leukemia (B-ALL). No TP53 mutation was detected in T-cell acute lymphoblastic leukemia (T-ALL) children, and TP53 mutation accounted for 4.0% (5/126) of B-ALL children. The types of TP53 mutation were all single nucleotide variants. Five ALL children with TP53 mutation were male, with a median age of 60 months (16- 156 months). At the time of onset, all children had anemia and elevated lactate dehydrogenase, and 4 children had subcutaneous hemorrhage and hyperuricemia. The immunophenotypes of all children were precursor B-cell type, and 4 children had myeloid antigen expression. Among 4 ALL children with TP53 mutation who received standard treatment, 2 cases relapsed, and the recurrence time was 8.9 months and 12.1 months, respectively. The expected 15-month EFS rate and OS rate of ALL children with TP53 mutation were lower than those of ALL children without TP53 mutation (37.5% vs. 97.7%, χ2 = 29.90, P < 0.001; 37.5% vs.98.3%, χ2 = 24.90, P < 0.001). Conclusions:ALL children with TP53 mutation are more commonly found in male and B-cell type, with high early recurrence rate and poor efficacy. TP53 mutation may become a necessary supplement for prognostic assessment.

Objective:To investigate the clinical characteristics and prognostic factors of TCF3-PBX1 fusion gene-positive childhood B-cell precursor acute lymphoblastic leukemia (B-ALL).Methods:The clinical data of 1 287 newly diagnosed children with B-ALL who were admitted to five hospital in Fujian province (Fujian Medical University Union Hospital, the First Affiliated Hospital of Xiamen University, Zhangzhou Affiliated Hospital of Fujian Medical University, Quanzhou First Hospital Affiliated to Fujian Medical University, Nanping First Hospital of Fujian Province) from April 2011 to December 2020 were retrospectively analyzed. According to the results of TCF3-PBX1 fusion gene testing, all the patients were divided into TCF3-PBX1-positive group and TCF3-PBX1-negative group. The clinical characteristics, early treatment response [minimal residual disease (MRD) at middle stage and end of induction chemotherapy] and long-term efficacy [overall survival (OS) and event-free survival (EFS)] of the patients in both groups were compared. Kaplan-Meier method was used for survival analysis. The prognostic factors of TCF3-PBX1-positive B-ALL were analyzed by using Cox proportional hazards model. Among 83 children with TCF3-PBX1-positive B-ALL, the treatment regimens, risk stratification and efficacy evaluation of 62 cases were performed by using Chinese Children's Leukemia Group (CCLG)-ALL 2008 regimen and 21 cases were performed by using Chinese Children's Cancer Group (CCCG)-ALL 2015 regimen, and the efficacy and incidence of serious adverse events (SAE) between the two groups compared.Results:Among 1 287 B-ALL patients, 83 patients (6.4%) were TCF3-PBX1-positive. The proportion of patients with initial white blood cell count (WBC)≥50×10 9/L in the TCF3-PBX1-positive group was higher than that in the TCF3-PBX1-negative group, while the proportions of patients with MRD ≥1% on induction chemotherapy day 15 or day 19, and MRD ≥0.01% on induction chemotherapy day 33 or day 46 in the TCF3-PBX1-positive group were lower than those in the TCF3-PBX1-negative group (all P < 0.05). Univariate Cox regression analysis showed that MRD ≥1% on induction chemotherapy day 15 or day 19 and TCF3-PBX1 ≥0.01% on induction chemotherapy day 33 or day 46 were risk factors for OS and EFS (all P < 0.05). Multivariate analysis showed that MRD ≥1% on induction chemotherapy day 15 or day 19 was an independent risk factor for OS ( HR = 10.589, 95% CI 1.903-58.933, P = 0.007) and EFS ( HR = 10.218, 95% CI 2.429-42.980, P = 0.002). TCF3-PBX1≥0.01% on induction chemotherapy day 33 or day 46 was an independent risk factor for EFS ( HR = 6.058, 95% CI 1.463-25.087, P = 0.013) but not for OS ( HR = 3.550, 95% CI 0.736-17.121, P = 0.115). The 10-year EFS and OS rates of the TCF3-PBX1-positive group were 84.6% (95% CI 76.9%-93.1%) and 89.1% (95% CI 82.1%-96.6%), and the differences between the two groups were not statistically significant (both P > 0.05). Among 80 children who received standardized treatment, compared with children who were treated with CCLG-ALL 2008 regimen, the incidence of infection-related SAE was lower in children who were treated with CCCG-ALL 2015 regimen [0 (0/21) vs. 20.3% (12/59), χ2 = 5.22, P = 0.022], but there were no statistical differences in treatment-related mortality, relapse rate, EFS and OS between the two groups (all P > 0.05). Conclusions:Children with TCF3-PBX1-positive B-ALL have a good prognosis, and MRD≥1% at middle stage of induction chemotherapy and TCF3-PBX1≥0.01% at the end of induction chemotherapy may be influencing factors for poor prognosis. CCCG-ALL 2015 regimen can reduce infection-related SAE while achieving good efficacy.

Objective:To investigate the clinical features and prognosis of B-cell acute lymphoblastic leukemia (B-ALL) children with intrachromosomal amplification of chromosome 21 (iAMP21).Methods:The data of 233 children diagnosed with B-ALL who received chemotherapy according to Chinese Children Cancer Group (CCCG) - acute lymphoblastic leukemia -2015 (CCCG-ALL-2015) protocol in the Affiliated Union Hospital of Fujian Medical University from January 2019 to December 2020 were retrospectively analyzed. These patients were divided into iAMP21 group and non-iAMP21 group according to whether iAMP21 was positive in the bone marrow fluid of children before chemotherapy based on ETV6-RUNX1 probe fluorescence in situ hybridization. Children in iAMP21 group received CCCG-ALL-2015 intermediate-risk group regimen induction chemotherapy, while children in non-iAMP21 group received different intensities of chemotherapy according to the clinical risk classification. The clinicopathological characteristics of patients were compared in both groups, the therapeutic efficacy and prognosis of B-ALL children with iAMP21 was analyzed.Results:iAMP21 was found in 5 (2.1%) of 233 B-ALL children. The median hemoglobin concentration in iAMP21 group was higher than that in non-iAMP21 group [99 g/L (71-148 g/L) vs. 74 g/L (30-156 g/L); U = 268.50, P = 0.043]; there were 4 cases (80%) with bone pain in iAMP21 group (5 cases) and 53 cases (23.2%) with bone pain in non-iAMP21 group (228 cases),and the difference in the osteoarticular pain incidence of both groups was statistically significant ( χ2 = 8.53, P = 0.017). There were no significant differences in the proportion of patients with different gender, age, white blood cell counts, platelet counts, hepatosplenomegaly between the two groups (all P > 0.05). Among 5 children with iAMP21, 1 patient was detected with high CRLF2 expression and 1 patient with IKZF1 1-8 exon loss of heterozygosity. The above mentioned two children with iAMP21, whose minimal residual disease (MRD) were still positive after consolidation therapy, and then they received chimeric antigen receptor T-cell treatment and hematopoietic stem cell transplantation. MRD of the other 3 children with iAMP21 turned negative after induction therapy. Up to the last follow-up in October 2021, 5 patients with iAMP21 had disease-free survival. Conclusions:The incidence of B-ALL children with iAMP21 is about 2%. These patients are prone to osteoarticular pain and have relatively mild anemia. The curative effect of some children is still poor after active treatment,which needs to be further clarified with more samples.

Objective:To investigate the clinical characteristics and prognosis of IL3-IGH fusion gene-positive pediatric acute lymphoblastic leukemia (ALL) with hypereosinophilia as the first presentation.Methods:The clinical data of 1 pediatric IL3-IGH fusion gene-positive ALL patient with hypereosinophilia as the first presentation in January 2021 in Fujian Medical University Union Hospital was retrospectively analyzed and relevant literature was reviewed.Results:This 11-year-old male patient underwent bone marrow examination, and results showed that the proportion of eosinophils was increased; immunophenotyping disclosed that there were about 49.4% abnormal naive B lymphocytes in bone marrow; 43 leukemia fusion genes showed all negative; the whole transcriptome sequencing showed IL3-IGH fusion gene-positive. The patient was finally diagnosed as B-ALL with IL3-IGH fusion gene. According to the Chinese Children Cancer Group (CCCG)-ALL 2020 regimen, eosinophils returned to normal after induction therapy. Bone marrow examination on day 19 of induction showed that the proportion of promyelocytes was 0.005, the proportion of eosinophils was 0.05, and the minimal residual disease (MRD) was 23.02%. Bone marrow examination on day 46 of induction showed remission, and MRD was 0.18%. Consolidation chemotherapy used CAT (cyclophosphamide 1 g/m 2 once; cytarabine 50 mg/m 2, 12 h once, 7 days in total; mercaptopurine 40 mg/m 2, once per night, 7 days in total) regimen. Then the patient was added with lusotinib (75 mg 12 h once) orally and continued to receive high-dose methotrexate (5 g/m 2) regimen chemotherapy for 2 courses, the MRD was 0.20%. Chimeric antigen receptor T-cell (CAR-T) regimen was administered, followed by negative MRD. Conclusions:IL3-IGH fusion gene ALL is more frequently found in males, and more common in older children and young adults. It is prone to organ infiltration damage, and it has a high rate of induction failure and recurrence as well as poor prognosis.

Objective To investigate the clinical features,diagnosis,treatment and prognosis of disseminated aspergillosis in children with leukemia after chemotherapy.Methods The clinical features and treatment of 3 leukemia children after chemotherapy complicated with disseminated aspergillosis were retrospectively analyzed.Results The underlying diseases of all recruited cases were leukemia,which occurred many high-risk predisposing factors for invasive fungal diseases.The major clinical features of disseminated aspergillosis in children with leukemia were prolonged and antibiotics uncontrollable fever,subcutaneous solid nodules,nodules or cavities in pulmonary CT,spread low density lesions in hepatosplenic and kidney in abdominal MR(T2 weighted)and positive serum aspergillus galactomannan(GM).The diagnosis of invasive fungal disease was proven by histopathologic examination.Amphotericin B lipid complex was selected in antifungal therapy for 2 patients and the course of treatment was more than 4 weeks.Moreover,chemotherapy was advised for the 2 patients when clinical manifestations of disseminated aspergillosis improved significantly,neutrophil counts recovered and images did not deteriorate.The patients received voriconazole treatment with follow-up from 6 months to 12 months,and then disseminated aspergillosis was cured up to the standard.1 case received complete remission and was still alive until follow-up period,1 case was died of leukemia relapse because of suspension demand from the family members,and the other 1 case was died of no response or serious adverse drug reactions,uncontrolled infection,and leukemia relapse because of long-term chemotherapy suspension.Conclusions Patients with leukemia after chemotherapy may present with the following manifestations,including fever,subcutaneous solid nodules,pulmonary nodules or cavities,spread low density lesions in hepatosplenic and kidney and serum aspergillus GM antigen positive,which may indicate disseminated aspergillosis.The improvement of prognosis depends on effective and adequate antifungal treatment and chemotherapy for leukemia at the right time.

Objective:To investigate the efficacy and safety of reduced-intensity chemotherapy in treatment of children with Down syndrome-related myeloid leukemia (ML-DS).Methods:The clinical data of 3 hospitalized children with ML-DS who were diagnosed and treated by Children Oncology Group Trial A2971 chemotherapy regimen in Fujian Medical University Union Hospital from January 2016 to June 2019 were retrospectively analyzed, and the clinical characteristics, efficacy and safety were summarized.Results:The ages of 3 children were 1 year and 6 months, 2 years and 6 months, and 1 year and 10 months. Two cases were acute monocytic leukemia, and 1 case was acute megakaryoblastic leukemia. Two cases were positive for EVI1 gene and 1 case had ASXL1 gene mutation, and all 3 cases had complex karyotype. After one course of induction chemotherapy, all 3 cases achieved complete remission, and the minimal residual disease turned negative. During the induction chemotherapy, all 3 cases had severe myelosuppression, and 2 cases of them suffered from severe pneumonia and 1 case of them suffered from intestinal infection and septic shock.Conclusion:The efficacy of reduced-intensity chemotherapy in children with ML-DS is favorable, but the severe complications such as myelosuppression and infection need to be taken seriously.

Objective To summarize the long-term outcomes and safety of childhood Hodgkin lymphoma (HL) with protocol ABVD. Methods The clinical data of 20 children with HL admitted to the Union Hospital of Fujian Medical University from July 2010 to June 2017 were retrospectively analyzed. Among the 20 children with HL, 15 were male and 5 were female. The median age of initial diagnosis was 6.5 years old (3-12 years old). The pathological types were as follow: 1 case was nodular lymphocyte-predominant HL (NLPHL) and 19 cases were classical HL (cHL), including 9 cases of mixed cell type, 9 cases of nodular sclerosis type and 1 case of lymphocyte rich type. Basing on Ann Arbor staging system, 1 patient was evaluated as stage Ⅰ, 4 patients were stage Ⅱ, 10 patients were stage Ⅲ, and 5 patients were stage Ⅳ. There were 3 patients in the low-risk group, 7 patients in the intermediate-risk group, and 10 patients in the high-risk group. There were 9 patients with B symptoms. All patients were treated with the ABVD regimen. Results All the 20 patients completed all chemotherapy courses. After 2 courses, the effective rate was 100％(20/20), including 12 cases of complete remission (CR) and 8 cases of partial remission (PR). After the treatment, 19 cases achieved CR, and at the end of the 6 courses, the evaluation showed that 1 case had residual lesions. Follow-up to February 2018, clinical symptoms of 18 cases achieved CR, 2 cases relapsed (all high-risk group); the median follow-up time was 42 months (10.1-87.9 months), the overall survival rate was 100 ％ (20/20), the estimated 5-year rate of freedom from treatment failure (FFTF) was (89.1 ±7.3) ％.Conclusions According to the risk stratification, ABVD regimen has good safety and long-term efficacy for children with cHL. Even the patients in low-risk or intermediate-risk group do not achieve CR after 2 courses and do not receive radiotherapy, the prognosis of them is still good.