[Clinical characteristics and prognostic analysis of pediatric pro-B cell acute lymphoblastic leukemia]

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 25.5×10⁹/L[range (0.4-831.9)×10⁹/L], of which 35.9% were ≥ 50×10⁹/L. MLL-r positivity was the most frequent genetic alteration in pro-B ALL, occurring in 34% of patients, with lower frequency of CD22 and CD13 expression and higher frequency of CD7 expression, while lower frequency of CD33 expression was found in patients with MLL-AF4 positivity. At a median follow-up of 60.0 months (range 4.9-165.3 months), the estimated 5-year overall survival (OS) and event-free survival (EFS) in the 64 patients were (85±5)% and (78±5)% respectively. Cox proportional hazards regression analysis identified MRD ≥ 0.1% at 3 months after chemotherapy as an independent adverse prognostic factor for both 5-year OS and EFS.

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.

[Pharmacokinetics and pharmacodynamics of pegylated recombinant human granulocyte colony-stimulating factor in children with acute lymphoblastic leukemia: a prospective control trial]

OBJECTIVE

To study the pharmacokinetic characteristics, clinical effect, and safety of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in children with acute lymphoblastic leukemia (ALL).

METHODS

A prospective study was performed on children with ALL who cyclophosphamide, cytarabine, and 6-mercaptopurine were used for consolidation therapy. PEG-rhG-CSF (PEG-rhG-CSF group) or rhG-CSF (rhG-CSF group) was injected after chemotherapy. The plasma concentration of PEG-rhG-CSF was measured, and clinical outcome and safety were observed for both groups.

RESULTS

A total of 17 children with ALL were enrolled, with 9 children in the PEG-rhG-CSF group and 8 children in the rhG-CSF group. In the PEG-rhG-CSF group, the peak concentration of PEG-rhG-CSF was 348.2 ng/mL (range 114.7-552.0 ng/mL), the time to peak was 48 hours (range 12-72 hours), and the half life was 14.1 hours (range 11.1-18.1 hours). The plasma concentration curve of PEG-rhG-CSF was consistent with the mechanism of neutrophil-mediated clearance. Compared with the rhG-CSF group, the PEG-rhG-CSF group had a significantly shorter median time to absolute neutrophil count (ANC) recovery (P<0.05). There were no significant differences between the two groups in ANC nadir, incidence rate of febrile neutropenia, duration of grade IV neutropenia, incidence rate of infection, and length of hospital stay. No bone pain or muscle soreness was observed in either group (P>0.05).

CONCLUSIONS

The pharmacokinetic characteristics of PEG-rhG-CSF in children with ALL receiving consolidation chemotherapy are consistent with the mechanism of neutrophil-mediated clearance, with a short half life and fast recovery of ANC, and there are no significant differences in safety between PEG-rhG-CSF and rhG-CSF.

[Serious adverse events associated with chemotherapy in children with acute lymphoblastic leukemia]

OBJECTIVE

To study the occurrence of serious adverse events (SAEs) related to chemotherapy with CCCG-ALL-2015 regimen in children with acute lymphoblastic leukemia (ALL) and the risk factors for death after the SAEs.

METHODS

A retrospective analysis was performed on the medical data of 734 children with ALL. They were treated with CCCG-ALL-2015 regimen from January 2015 to June 2019. The occurrence of SAEs during the treatment was investigated. The children with SAEs were divided into a death group with 25 children and a survival group with 31 children. A multivariate logistic regression analysis was used to analyze the risk factors for death after the SAEs.

RESULTS

Among the 734 children with ALL, 56 (7.6%) experienced SAEs (66 cases) after chemotherapy, among which 41 cases occurred in the stage of remission induction therapy. Of all 66 cases of SAEs, 46 (70%) were infection-related SAEs, including 25 cases of septic shock (38%), 20 cases of severe pneumonia (30%), and 1 case of severe chickenpox (2%), and 87% of the children with infection-related SAEs had neutrophil deficiency. The most common infection sites were blood and the lungs. The most common pathogens were Gram-negative bacteria, viruses, fungi, and Gram-positive bacteria. There were 16 cases (24%) of hemorrhage-related SAEs, with 11 cases of gastrointestinal bleeding (17%), 4 cases of pulmonary bleeding (6%), and 1 case of intracranial bleeding (2%). Of all 734 children with ALL, 66 (9.0%) died, among whom 25 died due to SAEs. The treatment-related mortality rate was 3.4%, and infection (72%) and bleeding (24%) were the main causes of death. Severe pneumonia was an independent risk factor for treatment-related death in ALL children (OR=4.087, 95%CI: 1.161-14.384, P=0.028).

CONCLUSIONS

SAEs often occur in the stage of remission induction therapy, and infection-related SAEs are more common in ALL children accepting chemotherapy with CCCG-ALL-2015 regimen. The development of severe pneumonia suggests an increased risk for death in these children.

[CD20 is not a poor prognostic factor for childhood B-lineage acute lymphoblastic leukemia with high white blood cell count]

OBJECTIVE

To study the significance of CD20 combined with white blood cell (WBC) count at diagnosis in the prognosis assessment in children with B-lineage acute lymphoblastic leukemia (ALL).

METHODS

A retrospective analysis was performed on the medical data of 821 B-ALL children who were treated with CCLG-ALL2008 regimen from April 2008 to April 2015. Their survival status was followed up.

RESULTS

Among the 821 children, 547 (66.6%) were negative, while 274 (33.4%) were positive for CD20 expression. Among 694 children with WBC<50×10⁹/L (lower WBC count), the 5-year EFS rates were 65.9%±3.2% and 77.3%±2.0% for CD20 positive and negative patients respectively (P=0.001); the 5-year OS rates were 78.3%±2.9% and 87.5%±1.6% for CD20 positive and negative patients respectively (P=0.005); CD20 positive expression was an independent risk factor for EFS (HR=1.634, P=0.001) and OS (HR=1.761, P=0.005). Among 127 children with WBC>50×10⁹/L (higher WBC count), the 5-year EFS rates was 64.3%±7.7% and 53.7%±5.5% for CD20 positive and negative patients respectively (P=0.135); the 5-year OS rate was 81.4%±6.4% and 58.6%±5.6% for CD20 positive and negative patients respectively (P=0.022); CD20 positive expression was an independent protective factor for OS (HR=0.367, P=0.016).

CONCLUSIONS

In children with B-ALL who are treated with CCLG-ALL2008 regimen, those with CD20 positive expression in lower WBC count at diagnosis have a poor prognosis; however, those with CD20 positive expression in higher WBC count at diagnosis have a better long-time survival.

[CD20 is not a poor prognostic factor for childhood B-lineage acute lymphoblastic leukemia with high white blood cell count]

OBJECTIVE

To study the significance of CD20 combined with white blood cell (WBC) count at diagnosis in the prognosis assessment in children with B-lineage acute lymphoblastic leukemia (ALL).

METHODS

A retrospective analysis was performed on the medical data of 821 B-ALL children who were treated with CCLG-ALL2008 regimen from April 2008 to April 2015. Their survival status was followed up.

RESULTS

Among the 821 children, 547 (66.6%) were negative, while 274 (33.4%) were positive for CD20 expression. Among 694 children with WBC<50×109/L (lower WBC count), the 5-year EFS rates were 65.9%±3.2% and 77.3%±2.0% for CD20 positive and negative patients respectively (P=0.001); the 5-year OS rates were 78.3%±2.9% and 87.5%±1.6% for CD20 positive and negative patients respectively (P=0.005); CD20 positive expression was an independent risk factor for EFS (HR=1.634, P=0.001) and OS (HR=1.761, P=0.005). Among 127 children with WBC>50×109/L (higher WBC count), the 5-year EFS rates was 64.3%±7.7% and 53.7%±5.5% for CD20 positive and negative patients respectively (P=0.135); the 5-year OS rate was 81.4%±6.4% and 58.6%±5.6% for CD20 positive and negative patients respectively (P=0.022); CD20 positive expression was an independent protective factor for OS (HR=0.367, P=0.016).

CONCLUSIONS

In children with B-ALL who are treated with CCLG-ALL2008 regimen, those with CD20 positive expression in lower WBC count at diagnosis have a poor prognosis; however, those with CD20 positive expression in higher WBC count at diagnosis have a better long-time survival.

[Association of cerebrospinal fluid status with prognosis in children with acute lymphoblastic leukemia]

OBJECTIVE

To study the clinical features of central nervous system infiltration-positive (CNSI+) children with acute lymphoblastic leukemia (ALL) based on flow cytometry, as well as the association of such clinical features with prognosis.

METHODS

A retrospective analysis was performed for the clinical data of 66 CNSI+ children with ALL treated from April 2008 to June 2013. Clinical features, laboratory examination results and prognosis were compared between the children in different chemotherapy stages (induction stage and consolidation/maintenance stage).

RESULTS

Among the 66 CNSI+ children, 50 were in the induction stage and 16 in the consolidation/maintenance stage. Compared with the CNSI+ children in the induction stage, the CNSI+ children in the consolidation/maintenance stage had a significantly higher proportion of children with the genes associated with good prognosis based on the results of molecular biology (P<0.05), as well as a significantly higher recurrence rate (P<0.05). Recurrence was observed in 21 CNSI+ ALL children, among whom 10 were in the induction stage and 11 were in the consolidation/maintenance stage. Compared with the children experiencing recurrence in the induction stage, the children experiencing recurrence in the consolidation/maintenance stage had a significantly higher proportion of children with recurrence of the central nervous system and bone marrow (P<0.05), as well as significantly higher proportion of biochemical positive rate of cerebrospinal fluid (P<0.05). The children in the induction stage had a significantly higher recurrence-free survival rate than those in the consolidation/maintenance stage (P<0.001), while there was no significant difference in overall survival rate between the two groups (P>0.05).

CONCLUSIONS

In children with ALL, CNSI+ has a marked effect on recurrence-free survival rate in different chemotherapy stages, but has no obvious effect on overall survival rate. CNSI+ patients in the consolidation/maintenance stage have a higher recurrence.

[Clinical effect of two different regimens in treatment of acute lymphoblastic leukemia children with bone marrow recurrence]

OBJECTIVE

To study the short-term effect of two different re-induction regimens in the treatment of acute lymphoblastic leukemia (ALL) children with bone marrow recurrence.

METHODS

A retrospective analysis was performed for 57 ALL children with bone marrow recurrence. According to their treatment regimen, they were divided into two groups: VMDP (vincristine + mitoxantrone + dexamethasone + PEG-asparaginase; n=42) and VIDP (vincristine + idarubicin + dexamethasone + PEG-asparaginase; n=15). The two groups were compared in terms of complete response rate and incidence rate of adverse reactions.

RESULTS

There was no significant difference in complete response rate between the VMDP and VIDP groups (74% vs 73%, P>0.05). All children experienced grade ≥3 hematological adverse events. The VMDP group had a significantly lower chemotherapy-related mortality rate than the VIDP group (P<0.05). There was no significant difference in the incidence rate of infection between the two groups (P>0.05).

CONCLUSIONS

For ALL children with bone marrow recurrence, both re-induction regimens can achieve a relatively high complete response rate, and VMDP regimen has a lower chemotherapy-related mortality rate and can thus be used as an option for re-induction in ALL children with bone marrow recurrence.

[Long-term clinical effect of the CCLG-ALL2008 regimen in treatment of childhood acute lymphoblastic leukemia with different molecular biological features]

OBJECTIVE

To study the long-term clinical effect of the CCLG-ALL2008 regimen in the treatment of children newly diagnosed with acute lymphoblastic leukemia (ALL) with different molecular biological features.

METHODS

A total of 940 children who were newly diagnosed with ALL were enrolled in this study. The children were treated with the CCLG-ALL2008 regimen. A retrospective analysis was performed for the long-term outcome of ALL children with different molecular biological features.

RESULTS

Among the 940 children with ALL, there were 570 boys and 370 girls, with a median age of onset of 5 years (range 1-15 years) and a median follow-up time of 65 months (range 3-123 months). The complete response (CR) rate was 96.7%, the predicted 10-year overall survival (OS) rate was 76.5%±1.5%, and the event-free survival (EFS) rate was 62.6%±3.0%. After CR was achieved after treatment, the overall recurrence rate was 21.9%. The children with positive ETV6-RUNX1 had the lowest recurrence rate and were prone to late recurrence, and those with positive MLL rearrangement had the highest recurrence rate and were prone to early recurrence. The children with positive ETV6-RUNX1 had a significantly higher predicted 10-year OS rate than those with positive TCF3-PBX1, BCR-ABL, or MLL rearrangement and those without molecular biological features (P<0.05). The children with positive ETV6-RUNX1 had a significantly higher predicted 10-year EFS rate than those with positive BCR-ABL or MLL rearrangement (P<0.05).

CONCLUSIONS

Molecular biological features may affect the long-term prognosis of children with ALL, and positive MLL rearrangement and BCR-ABL fusion gene are indicators of poor prognosis. Children with positive ETV6-RUNX1 fusion gene have the highest long-term survival rate.

[Clinical features and prognosis of children with acute lymphoblastic leukemia and different platelet levels]

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 <100×10⁹/L; n=629). The thrombocytopenia group was further divided into (50- <100)×10⁹/L (n=243), (20- <50)×10⁹/L (n=263), and <20×10⁹/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 <20×10⁹/L subgroup had significantly lower 10-year EFS and OS rates than the normal platelet count group, the (50- <100)×10⁹/L subgroup, and the (20- <50)×10⁹/L subgroup (P<0.05). After the children with MLL gene rearrangement were excluded, the <20×10⁹/L subgroup still had significantly lower 10-year EFS and OS rates than the normal platelet count group, the (50-<100)×10⁹/L subgroup, and the (20- <50)×10⁹/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 <20×10⁹/L have the worst prognosis.

[Effect of increasing the intensity of chemotherapy on the prognosis of acute lymphoblastic leukemia in children with IKZF1 deletion]

OBJECTIVE

To study the clinical features of acute lymphoblastic leukemia (ALL) in children with IKAROS family zinc finger 1 (IKZF1) deletion, and to observe the effect of increasing the intensity of chemotherapy on the prognosis of this disease.

METHODS

A total of 278 children diagnosed with ALL between December 2015 and February 2018 were systematically treated according to the Chinese Children's Leukemia Group-ALL 2008 protocol (CCLG-ALL 2008). The patients were divided into an IKZF1-deleted group and a control group according to the presence or absence of IKZF1. The IKZF1-deleted group was treated with the regimen for high-risk group (HR) in the CCLG-ALL 2008 protocol, while the control group received different intensities of chemotherapy according to clinical risk classification. The clinical features and event-free survival rate (EFS) were compared between the two groups.

RESULTS

A total of 24 (8.6%) cases of 278 children were found to have large deletions of exons of the IKZF1 gene. The IKZF1-deleted group had significantly higher proportions of cases with white blood cell count ≥50×10⁹/L at initial diagnosis, BCR-ABL1 fusion gene positive, minimal residual disease ≥10% on the 15th day of induction remission treatment, minimal residual disease-high risk and clinical risk classification-high risk compared with the control group (P<0.05). The 3-year EFS rate (76%±10%) in the IKZF1-deleted group was lower than that in the control group (84%±4%), but with no significant difference between the two groups (P=0.282). The estimated 3-year EFS rate in the IKZF1-deleted-non-HR group (actually treated with the chemotherapy regimen for HR in the CCLG-ALL 2008 protocol) was 82%±12%, which was lower than that in the control-non-HR group (86%±5%), but there was no significant difference (P=0.436).

CONCLUSIONS

ALL children with IKZF1 deletion have worse early treatment response, and increasing the intensity of chemotherapy might improve the prognosis.

[Expression and significance of dishevelled proteins in the Wnt pathway in childhood acute lymphoblastic leukemia]

OBJECTIVE

To study the significance of dishevelled (DVL) proteins in the Wnt signaling pathway in the pathogenesis and prognosis of childhood acute lymphoblastic leukemia (ALL).

METHODS

A total of 33 children with new-onset ALL were enrolled as the case group. According to the degree of risk, they were divided into 3 groups: low-risk (n=14), intermediate-risk (n=5) and high-risk (n=14). A total of 29 children with immune thrombocytopenia were enrolled as the control group. At diagnosis and on day 33 of induction therapy, 2 mL bone marrow samples were collected from the case and control groups, and qRT-PCR was used to measure the mRNA expression of DVL1, DVL2 and DVL3 in blood cells of bone marrow.

RESULTS

The mRNA expression of DVL1, DVL2 and DVL3 in the case group in the incipient stage was significantly higher than that in the remission stage and the control group (P<0.05). Compared with the control group, the case group had a significant increase in the mRNA expression of DVL2 in the remission stage (P<0.05). The mRNA expression of DVL2 was significantly higher than that of DVL1 and DVL3 in both remission and incipient stages (P<0.05). The high- and intermediate-risk groups had significantly higher mRNA expression of DVL1 and DVL2 than the low-risk group (P<0.05). The mRNA expression of DVL2 was significantly higher than that of DVL1 and DVL3 in the low-, intermediate- and high-risk groups (P<0.05).

CONCLUSIONS

The change in the expression of DVL, especially DVL2, in the Wnt signal pathway has certain significance in the pathogenesis and prognosis of childhood ALL.

[Clinical effect of CCLG-ALL2008 regimen in treatment of children and adolescents aged >10 years with acute lymphoblastic leukemia]

OBJECTIVE

To study the long-term clinical effect of CCLG-ALL2008 regimen in the treatment of children and adolescents, aged >10 years, with newly diagnosed acute lymphoblastic leukemia (ALL).

METHODS

A retrospective analysis was performed for the clinical data of 150 ALL children and adolescents aged >10 years who were treated with CCLG-ALL2008 regimen from April 2008 to April 2015. The Kaplan-Meier method was used to analyze overall survival (OS) rate and event-free survival (EFS) rate.

RESULTS

Among the 150 children and adolescents, there were 87 (58.0%) boys and 63 (42.0%) girls, with a median age of 11 years (range 10-15 years). Of the 150 children and adolescents, 84 (56.0%) had intermediate risk and 66 (44.0%) had high risk; 122 (81.3%) had B-lineage acute lymphoblastic leukemia (B-ALL) and 28 (18.7%) had T-lineage acute lymphoblastic leukemia (T-ALL). The fusion gene test yielded positive results in 51 children and adolescents (34.0%), among whom 16 (31%) had positive BCR-ABL, 11 (22%) had positive TEL-AML1, 8 (16%) had positive E2A-PBX1, and 16 (31%) were positive for other fusion genes. The complete remission rate was 96.0% (144/150) after one course of treatment with CCLG-ALL2008 regimen. The median follow-up time was 52 months (range 3-122 months). The 5-year OS rate was 79.0%±3.5%, and the 5-year EFS rate was 67.3%±4.1%. There were no significant differences in 5-year OS and EFS rates between the children with intermediate or high risk, as well as between the children with B-ALL or T-ALL (P>0.05). The children and adolescents who achieved complete remission of bone marrow at the end of induction therapy had significantly higher 5-year OS and EFS rates than those who did not achieve complete remission (P<0.05).

CONCLUSIONS

In ALL children and adolescents aged >10 years, CCLG-ALL2008 regimen can help to achieve high complete remission rate, 5-year OS rate and 5-year EFS rate. The children and adolescents failing to achieve complete remission at the end of induction therapy tend to have a poor prognosis.

[Value of S100A8 in evaluating the prognosis of children with acute lymphoblastic leukemia]

OBJECTIVE

To study the association between S100A8 expression and prognosis in children with acute lymphoblastic leukemia (ALL).

METHODS

The clinical data of 377 children with ALL who were treated with the CCLG-2008-ALL regimen were retrospectively reviewed. ELISA and PCR were used to measure serum protein levels and mRNA expression of S100A8. The Kaplan-Meier method was used for survival analysis and a Cox regression analysis was also performed.

RESULTS

The children were followed up for 56 months, and the overall survival rate of the 377 children was 89.1%. The prednisone good response group had significantly lower S100A8 protein and mRNA levels than the prednisone poor response group (P<0.01). In the children with standard or median risk, both S100A8 protein and mRNA levels were associated with event-free survival rate (P<0.05). There were significant differences in S100A8 protein and mRNA levels between the children with different risk stratifications (P<0.01). The children who experienced events had significantly higher S100A8 protein and mRNA levels than those who did not (P<0.01). The Kaplan-Meier survival analysis and the Cox regression model suggested that S100A8 overexpression was an independent risk factor for the prognosis of children with ALL.

CONCLUSIONS

High S100A8 expression may be associated with the poor prognosis of children with ALL and is promising as a new marker for individualized precise treatment of children with ALL.

[Significance of NUDT15 gene in individualized treatment with 6-mercaptopurine in children with acute lymphoblastic leukemia]

As an important drug during maintenance treatment of acute lymphoblastic leukemia (ALL), 6-mercaptopurine (6-MP) has several side effects, including hepatotoxicity and bone marrow suppression. Since its tolerability varies from person to person, 6-MP treatment should be individualized. The deficiency of thiopurine methyltransferase (TPMT) enzyme activity is associated with 6-MP intolerance. There is a lower frequency of mutation in TPMT alleles among Asian patients. Recent studies have shown that in ALL patients with NUDT15 gene mutation, the maximum tolerated dose of 6-MP is lower than the conventional dose. The article reviews the significance of NUDT15 gene in individualized treatment with 6-MP in children with ALL.

[Effects of minimal residual disease level on day 33 of remission induction and IKZF1 genotype on the survival of children with B-lineage acute lymphoblastic leukemia]

OBJECTIVE

To study the effects of minimal residual disease (MRD) level on day 33 of remission induction and IKZF1 genotype on the survival of children with B-lineage acute lymphoblastic leukemia (B-ALL).

METHODS

A total of 152 children with newly-diagnosed B-ALL who had complete remission after the first cycle of the chemotherapy and had complete follow-up information were enrolled in this study. According to the MRD detection by flow cytometry on day 33 of remission induction, they were divided into three groups: standard-risk (SR) group (MRD <10^-4; n=60), intermediate-risk (IR) group (10^-4≤ MRD <10^-2; n=55), and high-risk (HR) group (MRD ≥10^-2; n=37). Nested RT-PCR was used to determine the IKZF1 genotype of all children before chemotherapy. The effects of MRD level on day 33 of remission induction and IKZF1 genotype on the recurrence-free survival (RFS) of children with B-ALL were analyzed.

RESULTS

There were 7 common IKZF1 subtypes in all the 152 children with B-ALL: IK1, IK2/3, IK4, IK6, IK8, IK9, and IK10. Of the 152 children, 130 had functional subtypes of IKZF1 and 22 had non-functional subtypes of IKZF1. During the follow-up period, relapse occurred in 26 (17%) children, and the recurrence rate was highest in the HR group (P<0.05). However, there was no significant difference in the recurrence rate between the SR group and the IR group (P>0.05). The cumulative recurrence rate of the children with non-functional subtypes of IKZF1 was significantly higher than that of those with functional types of IKZF1 (P<0.01). The predicted 5-year RFS rates in the SR, IR, and HR groups were (94.2±2.9)%, (86.7±3.8)%, and (56.2±4.5)% respectively (P<0.05). The 5-year RFS rate of the children with functional subtypes of IKZF1 was significantly higher than that of those with non-functional subtypes of IKZF1 (P<0.01). There was no significant difference in the predicted 5-year RFS rate between the children with functional subtypes of IKZF1 and those with non-functional subtypes of IKZF1 in the SR group (P>0.05). However, the predicted 5-year RFS rate of the children with functional subtypes of IKZF1 was significantly higher than that of those with non-functional subtypes of IKZF1 in the IR group and the HR group (P<0.05).

CONCLUSIONS

B-ALL children with non-functional subtypes of IKZF1 have a high recurrence rate, and the recurrence rate will be even higher in B-ALL children with non-functional subtypes of IKZF1 and MRD ≥10^-4 on day 33 of chemotherapy.

[Clinical features of children with acute lymphoblastic leukemia complicated by pulmonary infection after chemotherapy]

OBJECTIVE

To examine the clinical features of children with acute lymphoblastic leukemia (ALL) complicated by pulmonary infection after chemotherapy.

METHODS

The clinical data of 108 ALL children (115 case-times) with post-chemotherapy pulmonary infection were retrospectively reviewed. The risk factors for pulmonary infection and the relationship between pathogens and chest CT findings were evaluated.

RESULTS

The highest incidence (77.4% ) of pulmonary infection occurred during remission induction, peaking at 31-60 days after chemotherapy. Patients with neutropenia had the highest incidence rate of pulmonary infection (67.0%). Bacteria (36%) and fungi (41%) were the two most common pathogens in the 41 patients who were etiologically suspected of or diagnosed with pulmonary infection. There was no significant difference in chest CT findings between patients with bacterial and fungal infections.

CONCLUSIONS

The children with ALL are most susceptible to pulmonary infection during remission induction, especially when they are neutropenic. Bacteria and fungi are the main pathogens of pulmonary infections in these patients. However, the changes in chest CT images are poor indicators of the nature of pulmonary infection.

[Oridonin inhibits proliferation of Jurkat cells via the down-regulation of Brg1]

OBJECTIVE

To investigate the effect of oridonin on the human acute lymphocytic leukemia cell line Jurkat and its mechanism.

METHODS

Jurkat cells were cultured in vitro and treated with various concentrations (0, 1.25, 2.5, 5, and 10 μmol/L) of oridonin for different lengths of time (24, 48, and 72 hours). The proliferation of Jurkat cells was analyzed by MTT assay. The changes in nuclear morphology were evaluated by fluorescence microscopy at 12 hours after treatment with various concentrations of oridonin. The expression levels of Brg1, P53, and C-myc were determined by semi-quantitative Western blot in Jurkat cells treated with various concentrations of oridonin for 24 hours or 5 μmol/L oridonin for various lengths of time (0, 2, 6, 12, and 24 hours). The expression levels of P53 and C-myc and proliferation of Jurkat cells were evaluated after Brg1 expression was knocked down by Brg1-specific siRNA.

RESULTS

Compared with the control group, the proliferation of oridonin-treated Jurkat cells was significantly inhibited in a concentration- and time-dependent manner (P<0.05). According to the florescence microscopic analysis, oridonin treatment led to nuclear pyknosis in Jurkat cells. Compared with the control group, Jurkat cells treated with 5 μmol/L oridonin had reduced expression of Brg1 and C-myc but elevated expression of P53. Brg1 knock-down led to a significant reduction in proliferation of Jurkat cells (P<0.05), up-regulated expression of P53, and down-regulated expression of C-myc.

CONCLUSIONS

Oridonin can inhibit the proliferation of Jurkat cells, probably via the Brg1 signaling pathway.

[Research advances in pharmacogenomics of mercaptopurine]

Mercaptopurine is a common chemotherapeutic drug and immunosuppressive agent and plays an important role in the treatment of acute lymphoblastic leukemia and inflammatory bowel disease. It may cause severe adverse effects such as myelosuppression, which may result in the interruption of treatment or complications including infection or even threaten patients' lives. However, the adverse effects of mercaptopurine show significant racial and individual differences, which reveal the important role of genetic diversity. Recent research advances in pharmacogenomics have gradually revealed the genetic nature of such differences. This article reviews the recent research advances in the pharmacogenomics and individualized application of mercaptopurine.

[Association between BIM gene and glucocorticoid resistance in children with acute lymphoblastic leukemia]

Acute lymphoblastic leukemia (ALL) is the most common malignant hematological disease in childhood. Glucocorticoids are frequently used in the chemoradiotherapy regimen for ALL and can induce the apoptosis of ALL cells through several signaling pathways, but about 10% of ALL children have poor response to glucocorticoids. Studies have revealed that glucocorticoids induce the apoptosis of ALL cells by upregulating the expression of BIM gene, and BIM gene is associated with glucocorticoid resistance in childhood ALL. This article reviews the recent studies on glucocorticoid resistance in childhood ALL, especially the role of BIM and its expression products in this process.

[Neurocognitive function of children with acute lymphoblastic leukemia and long-term disease-free survival and related influencing factors]

OBJECTIVE

To investigate the neurocognitive function of children with acute lymphoblastic leukemia (ALL) and long-term disease-free survival and related influencing factors.

METHODS

A total of 40 ALL children with long-term disease-free survival were enrolled as study group, and 40 healthy children were enrolled as control group. The Chinese Wechsler Intelligence Scale for Children (C-WISC), continuous performance test (CPT), and Stroop test software were used for the evaluation of all children. Neurocognitive function was compared between groups and influencing factors were analyzed.

RESULTS

Compared with the control group, the study group had significantly lower full intelligence quotient, verbal intelligence quotient, and performance intelligence quotient in C-WICS (P<0.05) and significantly higher numbers of mistakes and misses in CPT (P<0.05). There were no significant differences in the numbers of correct answers, mistakes, and misses of word-color consistency between the study group and the control group (P>0.05), while the study group had significantly higher numbers of mistakes and misses of word-color contradiction and irrelevance (P<0.05). The total dose of high-dose methotrexate and ALL risk classification were associated with the reduction in intelligence quotient, and children's younger age at diagnosis of ALL was associated with the higher numbers of misses and mistakes. Girls tended to have a significantly lower performance intelligence quotient than boys (P<0.05).

CONCLUSIONS

ALL children with long-term disease-free survival have neurocognitive impairment, which may be associated with the dose of chemotherapeutic drugs, age at diagnosis, and sex.

[Neurocognitive function of children with acute lymphoblastic leukemia and long-term disease-free survival and related influencing factors]

OBJECTIVE

To investigate the neurocognitive function of children with acute lymphoblastic leukemia (ALL) and long-term disease-free survival and related influencing factors.

METHODS

A total of 40 ALL children with long-term disease-free survival were enrolled as study group, and 40 healthy children were enrolled as control group. The Chinese Wechsler Intelligence Scale for Children (C-WISC), continuous performance test (CPT), and Stroop test software were used for the evaluation of all children. Neurocognitive function was compared between groups and influencing factors were analyzed.

RESULTS

Compared with the control group, the study group had significantly lower full intelligence quotient, verbal intelligence quotient, and performance intelligence quotient in C-WICS (P<0.05) and significantly higher numbers of mistakes and misses in CPT (P<0.05). There were no significant differences in the numbers of correct answers, mistakes, and misses of word-color consistency between the study group and the control group (P>0.05), while the study group had significantly higher numbers of mistakes and misses of word-color contradiction and irrelevance (P<0.05). The total dose of high-dose methotrexate and ALL risk classification were associated with the reduction in intelligence quotient, and children's younger age at diagnosis of ALL was associated with the higher numbers of misses and mistakes. Girls tended to have a significantly lower performance intelligence quotient than boys (P<0.05).

CONCLUSIONS

ALL children with long-term disease-free survival have neurocognitive impairment, which may be associated with the dose of chemotherapeutic drugs, age at diagnosis, and sex.

[Clinical characteristics and prognostic analysis of children and adolescents over 10 years of age with acute lymphoblastic leukemia]

OBJECTIVE

To explore the clinical characteristics and prognosis of children and adolescents over 10 years of age with acute lymphoblastic leukemia (ALL).

METHODS

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.

RESULTS

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 (≥50×10⁹/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.

CONCLUSIONS

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.

[Clinical characteristics and prognostic analysis of children and adolescents over 10 years of age with acute lymphoblastic leukemia]

OBJECTIVE

To explore the clinical characteristics and prognosis of children and adolescents over 10 years of age with acute lymphoblastic leukemia (ALL).

METHODS

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.

RESULTS

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 (≥50×109/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.

CONCLUSIONS

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.

[Pathogens of infections in the induction period of childhood acute lymphoblastic leukemia and drug resistance of isolated strains]

OBJECTIVE

To investigate the infections occurring in the induction period of childhood acute lymphoblastic leukemia (ALL), the pathogens of the infections, and drug resistance of isolated strains.

METHODS

A retrospective analysis was performed for the clinical data of 130 children with newly-diagnosed childhood ALL. Infections occurring during the induction chemotherapy, pathogenic strains, and drug-resistance spectrum were analyzed.

RESULTS

The incidence rate of clinical infection and/or microbial infection reached 76.2%. The lungs were the most common infection site (46.2%). The children with severe infection accounted for 52.3%, among whom 60 had pulmonary infection and/or 21 had sepsis. A total of 50 pathogenic strains were detected, which consisted of 29 bacterial strains and 21 fungal strains. Of all the children, 28.5% experienced infections caused by at least one microbe. Among the 29 bacterial strains, there were 19 (65.5%) Gram-negative bacteria and 10 (34.5%) Gram-positive bacteria. The most common Gram-negative bacteria were Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa, which were 100% sensitive to imipenem. The most common Gram-positive bacterium was Streptococcus viridans, which was 100% sensitive to vancomycin. The infections caused by fungi accounted for 16.2%, with Candida albicans as the most common fungus. Compared with those with non-severe infections, the children with severe infections had a significantly shorter time to the occurrence of agranulocytosis, a significantly longer duration of agranulocytosis, significantly higher incidence of fever and C-reactive protein (CRP) level, and a significantly longer length of hospital stay (P<0.05).

CONCLUSIONS

Pulmonary infections are common in the induction period of childhood ALL. Gram-negative bacteria are the most common pathogenic bacteria. Severe infections can be controlled by carbapenems combined with vancomycin and antifungal agents.

[Pathogens of infections in the induction period of childhood acute lymphoblastic leukemia and drug resistance of isolated strains]

OBJECTIVE

To investigate the infections occurring in the induction period of childhood acute lymphoblastic leukemia (ALL), the pathogens of the infections, and drug resistance of isolated strains.

METHODS

A retrospective analysis was performed for the clinical data of 130 children with newly-diagnosed childhood ALL. Infections occurring during the induction chemotherapy, pathogenic strains, and drug-resistance spectrum were analyzed.

RESULTS

The incidence rate of clinical infection and/or microbial infection reached 76.2%. The lungs were the most common infection site (46.2%). The children with severe infection accounted for 52.3%, among whom 60 had pulmonary infection and/or 21 had sepsis. A total of 50 pathogenic strains were detected, which consisted of 29 bacterial strains and 21 fungal strains. Of all the children, 28.5% experienced infections caused by at least one microbe. Among the 29 bacterial strains, there were 19 (65.5%) Gram-negative bacteria and 10 (34.5%) Gram-positive bacteria. The most common Gram-negative bacteria were Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa, which were 100% sensitive to imipenem. The most common Gram-positive bacterium was Streptococcus viridans, which was 100% sensitive to vancomycin. The infections caused by fungi accounted for 16.2%, with Candida albicans as the most common fungus. Compared with those with non-severe infections, the children with severe infections had a significantly shorter time to the occurrence of agranulocytosis, a significantly longer duration of agranulocytosis, significantly higher incidence of fever and C-reactive protein (CRP) level, and a significantly longer length of hospital stay (P<0.05).

CONCLUSIONS

Pulmonary infections are common in the induction period of childhood ALL. Gram-negative bacteria are the most common pathogenic bacteria. Severe infections can be controlled by carbapenems combined with vancomycin and antifungal agents.

[Expression of Wif-1 and β-catenin in the Wnt pathway in childhood acute lympho-blastic leukemia]

OBJECTIVE

To investigate the expression and possible roles of Wnt inhibitory factor-1 (Wif-1) and β-catenin in the Wnt pathway in childhood acute lymphoblastic leukemia (ALL).

METHODS

The clinical data of 35 children who had newly-diagnosed ALL and achieved complete remission on day 33 of remission induction therapy were retrospectively reviewed. The children before treatment were considered as the incipient group, and those who achieved complete remission on day 33 were considered as the remission group. Fifteen children with non-malignant hematologic diseases were enrolled as the control group. RT-PCR was used to measure the mRNA expression of Wif-1 and β-catenin. ELISA was used to measure the protein expression of Wif-1.

RESULTS

Compared with the control and remission groups, the incipient group had significantly lower mRNA and protein expression of Wif-1 and significantly higher mRNA expression of β-catenin (P<0.05). In the incipient and remission groups, high-risk children showed significantly higher mRNA expression of β-catenin and significantly lower mRNA and protein expression of Wif-1 than the medium- and low-risk children (P<0.05). In the incipient and remission group, the children with T-cell acute lymphoblastic leukemia showed significantly higher mRNA expression of β-catenin and significantly lower mRNA and protein expression of Wif-1 compared with those with B-lineage acute lymphoblastic leukemia (P<0.05). In each group, there was a negative correlation between the mRNA expression of Wif-1 and β-catenin (P<0.05).

CONCLUSIONS

Reduced expression of Wif-1 and increased expression of β-catenin may be involved in the pathogenesis of childhood ALL, and the degree of reduction in Wif-1 and/or increase in β-catenin may be related to prognosis.

[Expression of Wif-1 and β-catenin in the Wnt pathway in childhood acute lympho-blastic leukemia]

OBJECTIVE

To investigate the expression and possible roles of Wnt inhibitory factor-1 (Wif-1) and β-catenin in the Wnt pathway in childhood acute lymphoblastic leukemia (ALL).

METHODS

The clinical data of 35 children who had newly-diagnosed ALL and achieved complete remission on day 33 of remission induction therapy were retrospectively reviewed. The children before treatment were considered as the incipient group, and those who achieved complete remission on day 33 were considered as the remission group. Fifteen children with non-malignant hematologic diseases were enrolled as the control group. RT-PCR was used to measure the mRNA expression of Wif-1 and β-catenin. ELISA was used to measure the protein expression of Wif-1.

RESULTS

Compared with the control and remission groups, the incipient group had significantly lower mRNA and protein expression of Wif-1 and significantly higher mRNA expression of β-catenin (P<0.05). In the incipient and remission groups, high-risk children showed significantly higher mRNA expression of β-catenin and significantly lower mRNA and protein expression of Wif-1 than the medium- and low-risk children (P<0.05). In the incipient and remission group, the children with T-cell acute lymphoblastic leukemia showed significantly higher mRNA expression of β-catenin and significantly lower mRNA and protein expression of Wif-1 compared with those with B-lineage acute lymphoblastic leukemia (P<0.05). In each group, there was a negative correlation between the mRNA expression of Wif-1 and β-catenin (P<0.05).

CONCLUSIONS

Reduced expression of Wif-1 and increased expression of β-catenin may be involved in the pathogenesis of childhood ALL, and the degree of reduction in Wif-1 and/or increase in β-catenin may be related to prognosis.

[Brain injury after induction chemotherapy in children with acute lymphoblastic leukemia]

OBJECTIVE

To investigate the changes in brain injury after the induction chemotherapy in children with acute lymphoblastic leukemia (ALL) by cranial MRI.

METHODS

The clinical data and cranial MRI results of 62 children with ALL who were hospitalized from March 2014 to June 2015 were analyzed retrospectively.

RESULTS

Before chemotherapy, MRI showed bone marrow infiltration of the skull in 33 patients (53%); the children with WBC<20×10(9)/Lhad a significantly lower incidence rate of bone marrow infiltration of the skull than those with WBC≥20×10(9)/L (16 patients/42% vs 17 patients/71%; P<0.05), and the high-risk group had a significantly higher incidence rate of bone marrow infiltration of the skull than the non-high-risk group (71% vs 44%; P<0.05). Before chemotherapy, there were 4 cases (7%) of brain atrophy, and 2 cases (3%) of abnormal signals in the sensory conduction bundle. MRI reexamination in 28 patients after 3 months of chemotherapy showed 3 new cases (11%) of brain atrophy and 1 aggravated case of brain atrophy.

CONCLUSIONS

The children with ALL have bone marrow infiltration of the skull, brain atrophy, and abnormal signals in the sensory conduction bundle before chemotherapy, especially bone marrow infiltration of the skull, and some changes in brain injury disappear after treatment.

[Detection of copy number variations in pediatric ETV6/RUNX1-positive acute lymphoblastic leukemia with multiplex ligation-dependent probe amplification]

OBJECTIVE

To 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.

METHODS

The 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.

RESULTS

CNVs 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%.

CONCLUSIONS

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

[Detection of copy number variations in pediatric ETV6/RUNX1-positive acute lymphoblastic leukemia with multiplex ligation-dependent probe amplification]

OBJECTIVE

To 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.

METHODS

The 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.

RESULTS

CNVs 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%.

CONCLUSIONS

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