Vincristine and dexamethasone pulses in addition to maintenance therapy among pediatric acute lymphoblastic leukemia (GD-ALL-2008): An open-label, multicentre, randomized, phase III clinical trial.

The efficacy and safety on the addition of vincristine (VCR) and dexamethasone (DEX) pulses to maintenance therapy among childhood acute lymphoblastic leukemia (ALL) remain uncertain. Herein, we perform an open-label, multicentre, randomized, phase III clinical trial that was conducted at nine major medical centers in Guangdong Province, China. Patients were randomly assigned either the conventional maintenance therapy (control group, n = 384) or the VCR/DEX pulse (treatment group, n = 375). When limited to the SR cohort, 10-year EFS was 82.6% (95% CI: 75.9-89.9) in the control group and 80.7% (95% CI: 74-88.1) in the treatment group (pnon-inferiority  = .0002). Similarly, patients with IR also demonstrated non-inferiority of the treatment group to the control group in terms of 10-year EFS (73.6% [95% CI: 67.6-80] vs. 77.6% [95% CI: 71.8-83.9]; pnon-inferiority  = .005). Among the HR cohort, compared with the control group, patients in the treatment group experienced a significant benefit in terms of 10-year EFS (61.1% [95% CI: 47.7-78.2] vs. 72.6% [95% CI: 55.6-94.7], p = .026) and a trend toward higher 10-year OS (73.8% [95% CI: 61.6-88.4] vs. 87.9% [95% CI: 579.2-97.5], p = .068). In the HR cohort, the total rate of drug-induced liver injury and Grade 3 chemotherapy-induced anemia were both lower for patients in the treatment group than in the control group (55.6% vs. 100%, p = .033; 37.5% vs. 60%, p = .036). Conversely, the total prevalence of chemotherapy-induced thrombocytopenia was higher for patients in the treatment group than in the control group (88.9% vs. 40%, p = .027). Pediatric acute lymphoblastic leukemia with high risk is suitable to VCR/DEX pulse during maintenance phase for the excellent outcome, while the standard-to-intermediate-risk patients could eliminate the pulses.

Reduced intensity of early intensification does not increase the risk of relapse in children with standard risk acute lymphoblastic leukemia - a multi-centric clinical study of GD-2008-ALL protocol.

BACKGROUND: The prognosis of childhood acute lymphoblastic leukemia (ALL) is optimistic with a 5-year event-free survival (EFS) rate of 70-85%. However, the major causes of mortality are chemotherapy toxicity, infection and relapse. The Guangdong (GD)-2008-ALL collaborative protocol was carried out to study the effect of reduced intensity on treatment related mortality (TRM) based on Berlin-Frankfurt-Münster (BFM) 2002 backbone treatment. The study was designed to elucidate whether the reduced intensity is effective and safe for children with ALL. METHODS: The clinical data were obtained from February 28, 2008 to June 30, 2016. A total of 1765 childhood ALL cases from 9 medical centers were collected and data were retrospectively analyzed. Patients were stratified into 3 groups according to bone marrow morphology, prednisone response, age, genotype, and karyotype information: standard risk (SR), intermediate risk (IR) and high risk (HR). For SR group, daunorubicin was decreased in induction IA while duration was reduced in Induction Ib (2 weeks in place of 4 weeks). Doses for CAM were same in all risk groups - SR patients received one CAM, others got two CAMs. RESULTS: The 5-year and 8-year overall survival (OS), event-free survival (EFS) and cumulative incidence of relapse (CIR) were 83.5±0.9% and 83.1±1.0%, 71.9±1.1% and 70.9±1.2%, and 19.5±1.0% and 20.5±1.1%, respectively. The 2-year treatment-related mortality (TRM) was 5.2±0.5%. The 5-year and 8-year OS were 90.7±1.4% and 89.6±1.6% in the SR group, while the 5-year and 8-year EFS were 81.5±1.8% and 80.0±2.0%. In the SR group, 74 (15.2%) patients measured minimal residual disease (MRD) on Day 15 and Day 33 of induction therapy. Among them, 7 patients (9.46%) were MRD positive (≥ 0.01%) on Day 33. The incidence of relapse in the MRD Day 33 positive group (n=7) was 28.6%, while in the MRD Day 33 negative group (n=67) was 7.5% (p=0.129). CONCLUSIONS: The results of GD-2008-ALL protocol are outstanding for reducing TRM in childhood ALL in China with excellent long term EFS. This protocol provided the evidence for further reducing intensity of induction therapy in the SR group according to the risk stratification. MRD levels on Day 15 and Day 33 are appropriate indexes for stratification.

[Serum level of soluble transferrin receptor in children with hemoglobin H disease].

OBJECTIVE: To investigate the serum level of soluble transferrin receptor (sTfR) and its association with the degree of anemia in children with hemoglobin H (HbH) disease. METHODS: A total of 55 children with HbH disease were enrolled as the HbH group, and 30 healthy children were enrolled as the control group. The HbH group was further divided into a deletional HbH disease group and a non-deletional HbH disease group. A retrospective analysis was performed for hematological parameters and serum sTfR level in all groups. RESULTS: Of the 55 children with HbH disease, 39 had deletional HbH disease and 16 had non-deletional HbH disease. Compared with the control group, the deletional and non-deletional HbH disease groups had significantly lower hemoglobin (Hb), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) and a significantly higher serum level of sTfR. Compared with the deletional HbH disease group, the non-deletional HbH disease group had significantly lower red blood cell count (RBC) and Hb level and significantly higher MCV, MCH, and serum sTfR level. In children with HbH disease, serum sTfR level was negatively correlated with RBC and Hb level (r=-0.739 and -0.667 respectively, P<0.05) and positively correlated with MCV and MCH (r=0.750 and 0.434 respectively, P<0.05). CONCLUSIONS: Serum sTfR level is associated the degree of anemia in children with HbH disease, and sTfR may be a target for the treatment of HbH disease.

[One-step multiplex RT-PCR for identifying common fusion transcripts in childhood acute lymphoblastic leukemia].

OBJECTIVE: To evaluate the efficiency of one-step multiplex RT-PCR for identifying four common fusion transcripts (TEL/AML1, E2A/PBX1, MLL/AF4 and BCR/ABL) in children with acute lymphoblastic leukemia (ALL). METHODS: Total RNA was extracted from bone marrow samples of 76 children who were newly diagnosed with ALL between January 2003 and December 2010. These RNAs were analyzed for TEL/AML1, E2A/PBX1, MLL/AF4 and BCR/ABL by one-step multiplex RT-PCR or common nested-multiplex PCR. The PCR products were confirmed by DNA sequencing. RESULTS: TEL/AML1 was found in 12 cases (the length of products was 298 bp in 9 cases and 259 bp in 3 cases), E2A/PBX1 was found in 3 cases (the length of products was 373 bp), BCR/ABL was found in 1 case (the length of products was 2 124 bp), and MLL/AF4 was found in 7 cases (the length of products was 427 bp in 1 case and 673 bp in 6 cases) using one-step multiplex RT-PCR combined with DNA sequencing. The results were consistent with those using common nested-multiplex PCR. CONCLUSIONS: One-step multiplex RT-PCR may be another alternative for detection of common fusion transcripts in children with ALL.

Assessment of iron overload in very young children with limited thalassemia care resources in South China.

Southern China has one of the world's largest population of patients needing transfusions. Transfusion and chelation are not uniformly available and no magnetic resonance imaging (MRI) assessment data exists to date. A total of 153 young ß-thalassemia major (ß-TM) patients were assessed using a validated 1.5T scanner in Hong Kong, People's Republic of China (PRC). Their median age was 13 (range 7 to 30), and most patients were young (22.0% age <10, 73.0% age <15, 88.0% age <18). Erratic health care made estimation of total transfusion and chelation exposure impossible. Despite their early age, 24.0% had severe cardiac hemosiderosis [T2*<10 milliseconds (ms)], at ages as early as 8 years old. Median heart iron was 1.68 mg/g dry weight (range 0.19-7.66) and increased with age (p = 0.017), while liver iron was 22.2 mg/g dry weight (range 3.15 to 39.2). Serum ferritin levels were poor predictors of heart and liver, or pancreatic R* and pituitary R* values. Magnetic resonance imaging scans are needed to screen very young ß-TM patients with immediate risk of premature cardiac death in developing nations and triage them to more intensive treatment. This is particularly important in countries with a large number of patients and limited resources. Our data suggests that in developing countries, there is no lower limit for thalassemia MRI scanning programs.

[Expression of leukocyte-associated Ig-like receptor-1 in children with immune thrombocytopenia].

OBJECTIVE: To study the expression of leukocyte-associated Ig-like receptor-1(LAIR-1) in children with immune thrombocytopenia (ITP), in order to explore the possible role of LAIR-1 in the pathogenesis of childhood ITP. METHODS: Expression levels of LAIR-1 on CD4(+) T cells, CD8(+) T cells and CD19(+)CD20(+) B cells of peripheral blood were measured in 40 children with ITP by flow cytometry. Serum level of solubility LAIR-1 (sLAIR-1) was measured using ELISA. Real-time PCR was used to measure LAIR-1 mRNA expression. Thirty-two healthy children served as the control group. RESULTS: The percentages of CD19(+)CD20(+) B cells in the ITP group were significantly higher than in the control group (P<0.05). In contrast, the percentage of CD4(+) T cells in the ITP group was significantly lower than in the control group (P<0.05). The expression levels of LAIR-1 on CD4(+) T cells and CD8(+) T cells were significantly lower in the ITP group than in the control group (P<0.05). Serum sLAIR-1 level and LAIR-1 mRNA expression in the ITP group significantly increased compared with the control group (P<0.05). CONCLUSIONS: LAIR-1 expression on CD4(+) and CD8(+) T cells decreases and serum sLAIR-1 level increases in children with ITP, suggesting that LAIR-1 may play an important role in immune imbalance in these children.

[Relationship between the methylenetetrahydrofolate reductase gene polymorphism and adverse reactions of high-dose methotrexate in children with acute lymphocytic leukemia].

OBJECTIVE: To study the association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and toxicities after high-dose methotrexate (HD-MTX) infusion in children with acute lymphocytic leukemia (ALL). METHODS: MTHFR variants in 52 children with ALL were determined by reverse transcriptase-polymerase chain reaction-denaturing gradient gel electrophoresis and sequencing. Toxicities of children who received HD-MTX chemotherapy were evaluated according to the National Cancer Institute-Common Toxicity Criteria (NCI-CTC). RESULTS: The children carrying MTHFR 1298AC had a higher risk of developing thrombocytopenia compared with the carriers of the 1298 AA genotype (OR=13.7, 95%CI=1.18-159.36, P=0.036). There was no significant difference in HD-MTX chemotherapy-related adverse effects between the patients with different MTHFR C677T or G1793A genotypes. CONCLUSIONS: MTHFR A1298C polymorohism may associate with the toxicity of HD-MTX chemotherapy in children with ALL.

[Effect of methylation inhibitor on EphB4 gene expression, proliferation and apoptosis in CEM cells].

OBJECTIVE: To study the regulation of methylation inhibitor 5-aza-2'-deoxycytidine on transcription of EphB4 gene and effects on the proliferation and apoptosis of human acute lymphocyte leukemia cell line CEM. METHODS: Bisulfite sequencing PCR was used to detect CpG island methylation density in EphB4 promoter. The expression of EphB4 mRNA and protein was determined by Q-PCR and Western blot. MTS assay and flow cytometry were used to detect the apoptosis of CEM cells after treatment with different concentrations of 5-aza-2'-deoxycytidine (1.0, 2.5 and 5 µmol/L). RESULTS: Methylation of EphB4 gene promoter was detected in CEM cells (31.4%). The methylation level of EphB4 gene was down-regulated after treatment with various concentrations of 5-aza-2'-deoxycytidine. The EphB4 mRNA and protein expression in CEM cells increased after 5-aza-2'-deoxycytidine treatment. 5-Aza-2'-deoxycytidine significantly inhibited the cell growth in dose and time dependent manners. Early apoptosis rates of CEM cells increased from 4.1% to 24.8% 96 hrs after 5-aza-2'-deoxycytidine treatment. CEM cells in G1 phase decreased from 62.4% to 46.8%, cells in G2 phase increased from 2.1% to 16.2%, and CEM cells were arrested in G2 phase after treatment with 5 µmol/L 5-aza-2'-deoxycytidine for 96 hrs. CONCLUSIONS: 5-Aza-2'-deoxycytidine, an inhibitor of specific methylation transferase, can induce expression of the silent EphB4 gene in CEM cells, inhibit the proliferation of leukemia cells and induce cell apoptosis.

[Evaluation of heart and liver iron deposition status in patients with ß- thalassemia intermedia and major with MRI T2* technique].

OBJECTIVE: To study the status of iron deposition in patients with ß-thalassemia intermedia and major in mainland China. METHODS: The status of transfusion and chelation was examined in 39 patients with ß-thalassemia intermedia or major. Serum ferritin levels were measured. MRI T2* technique was used to detect cardiac and hepatic iron deposition. RESULTS: Serum ferritin levels ranged from the minimum of 1500 ng/mL up to a maximum of 11491 ng/mL. From liver MRI T2* measurement, 15 cases had severe hepatic iron deposition (38%) and moderate deposition was found in 15 cases (38%), mild in 7 cases (18%), and normal in 2 cases (5%). Heart MRI T2* showed severe heart iron deposition in 7 cases (18%), mild in 5 cases (13%), and normal in 27 cases (69%). One case had cardiac arrhythmia. Four cases were over 20 years of age, and presented with gonadal function hypoplasia. The majority of patients did not receive regular transfusion and they had delayed, suboptimal chelation due to financial problems. Serum ferritin level was closely related with timing and dosage of chelation. CONCLUSIONS: In patients with ß-thalassemia who do not receive early regular transfusion and iron chelation therapy, iron deposition may occur at an early age. Important organs and tissue functional lesions and related complications also result. Relevant agencies and family members should be aware of this trend and develop appropriate strategies to improve the medical condition and quality of life of patients with this disorder.

[Genetic factors in the occurrence of neonatal unconjugated hyperbilirubinemia].

OBJECTIVE: To study association of uridine-diphosphate-glucuronosyltransferase1A1 (UGT1A1) Gly71Arg, UGT1A1 promoter TATA-box and glucose-6-phosphate dehydrogenase (G6PD) gene mutations with the occurrence of neonatal unconjugated hyperbilirubinemia. METHODS: The TATA-box, exon 1 and exon 5 of the UGT1A1 gene and the exon 12 of G6PD gene were amplified by PCR. The products of PCR were analyzed by direct DNA sequencing. Clones for the mutations of the UGT1A1 gene and the G6PD gene were constructed in order to identify the results of the products of PCR. Seventy-two neonates with unconjugated hyperbilirubinemia (case group) and 65 healthy neonates (control group) were enrolled. The genotypes and allele frequencies of the polymorphisms of UGT1A1 Gly71Arg and UGT1A1 TATA-box were compared between the two groups. The effects of UGT1A1 Gly71Arg, UGT1A1 promoter TATA-box and G6PD gene mutations on the development of neonatal unconjugated hyperbilirubinemia were estimated using logistic regression models. RESULTS: There were significant differences in the genotype distribution of Gly71Arg polymorphism of UGT1A1 gene between the case and control groups (P<0.01). The Arg allele frequency of the polymorphisms of UGT1A1 gene in the case group was significantly higher than in the control group (P<0.01). There were no significant differences in the genotype distribution of the UGT1A1 promoter TATA-box between the two groups (P>0.05). The OR and 95%CI values of UGT1A1 Gly71Arg, UGT1A1 TATA-box and G6PD gene mutations associated with the development of neonatal unconjugated hyperbilirubinemia were 5.468 (2.274, 12.818), 0.688 (0.266, 1.778) and 5.081 (1.070, 24.133) respectively. CONCLUSIONS: UGT1A1 Gly71Arg and G6PD gene mutations may be involved in the development of neonatal unconjugated hyperbilirubinemia.

[Curative effects and safety of deferasirox in treatment of iron overload in children with ß-thalassemia major].

OBJECTIVE: To study the effectiveness and safety of deferasirox (DFX) in the treatment of iron overload in children with ß-thalassemia major. METHODS: Twenty-four ß-thalassemia major children with iron overload who received regular blood transfusion were randomly enrolled. The serum feritin (SF) levels were measured in the patients after different doses of DFX treatment. The DFX treatment-related adverse events were observed. The values of cardiac MRI T2* and liver MRI T2* were compared between the patients receiving DFX treatment for 5 years and the patients treated with deferoxamine and deferiprone. RESULTS: The patients with iron overload did not respond to DFX at the initial dose of 20-30 mg/kg•d. However, the SF level decreased significantly after the dose of DFX increased to 30-40 mg/kg•d (U=58, P<0.01). Serum liver transaminase elevation was the most common adverse effect, followed by non-progressive elevation in serum creatinine level. The mean SF level was significantly lower (1748±481 ng/mL vs 3462±1744 ng/mL; P<0.05), in contrast, the liver MRI T2* value was significantly higher (8.5±2.9 ms vs 2.7±1.9 ms; P<0.01) in patients receiving DFX treatment for 5 years than in the controls. There were no significant differences in the cardiac MRI T2* value between the two groups. CONCLUSIONS: DFX can reduce SF levels in a dose-dependent manner in children with ß-thalassemia major. It can significantly lower liver iron overload but not cardiac overload. Serum liver transaminase elevation and non-progressive elevation in serum creatinine level are major adverse effects in DFX treatment.

Prognostic Value and Outcome for ETV6/RUNX1-Positive Pediatric Acute Lymphoblastic Leukemia: A Report From the South China Children's Leukemia Group.

PURPOSE: To analyzed the outcome of ETV6/RUNX1-positive pediatric acute B lymphoblastic leukemia (B-ALL) with the aim of identifying prognostic value. METHOD: A total of 2,530 pediatric patients who were diagnosed with B-ALL were classified into two groups based on the ETV6/RUNX1 status by using a retrospective cohort study method from February 28, 2008, to June 30, 2020, at 22 participating ALL centers. RESULTS: In total, 461 (18.2%) cases were ETV6/RUNX1-positive. The proportion of patients with risk factors (age <1 year or ≥10 years, WB≥50×109/L) in ETV6/RUNX1-positive group was significantly lower than that in negative group (P<0.001), while the proportion of patients with good early response (good response to prednisone, D15 MRD < 0.1%, and D33 MRD < 0.01%) in ETV6/RUNX1-positive group was higher than that in the negative group (P<0.001, 0.788 and 0.004, respectively). Multivariate analysis of 2,530 patients found that age <1 or ≥10 years, SCCLG-ALL-2016 protocol, and MLL were independent predictor of outcome but not ETV6/RUNX1. The EFS and OS of the ETV6/RUNX1-positive group were significantly higher than those of the negative group (3-year EFS: 90.11 ± 4.21% vs 82 ± 2.36%, P<0.0001, 3-year OS: 91.99 ± 3.92% vs 88.79 ± 1.87%, P=0.017). Subgroup analysis showed that chemotherapy protocol, age, prednisone response, and D15 MRD were important factors affecting the prognosis of ETV6/RUNX1-positive children. CONCLUSIONS: ETV6/RUNX1-positive pediatric ALL showed an excellent outcome but lack of independent prognostic significance in South China. However, for older patients who have the ETV6/RUNX1 fusion and slow response to therapy, to opt for more intensive treatment.

[Status of iron metabolism and erythropoietic proliferation in children with various genotypes of thalassemia].

OBJECTIVE: To study the status of iron metabolism and erythropoietic proliferation in children with various genotypes of thalassemia. METHODS: Serum concentrations of ferritin (SF), transferrin receptor (sTfR) and erythropoietin (EPO) were measured in 158 children with thalassemia. The differences in the concentrations of the three indices among children with different genotypes of thalassemia were compared. The correlations of the hemoglobin level with sereum SF, sTfR and EPO levels were assessed. RESULTS: Among the 158 children with thalassemia, 52(32.9%) were diagnosed with alpha-thalassemia minor, 27(17.1%) with HbH disease, 59(37.4%) with beta-thalassemia minor, 13(8.2%) with beta-thalassemia major, and 7(4.4%) with combining alpha beta thalassemia. The SF levels in children with HbH disease or beta-thalassemia major were significantly higher than those in the other thalassemia groups (P<0.01). The sTfR levels in children with beta-thalassemia major were the highest when compared with those in the other thalassemia groups (P<0.05). The EPO levels in children with beta-thalassemia major were also the highest when compared with those in the other thalassemia groups (P<0.01). There was a negative correlation between hemoglobin and EPO levels in children with HbH disease (r=-0.656, P<0.01) and beta-thalassemia major (r=-0.641; P<0.05). CONCLUSIONS: The status of iron metabolism and erythropoietic proliferation is different in children with different genotypes of thalassemia. A combined measurement of SF, sTfR and EPO may reflect the status of erythropoietic proliferation.

[Application Value of Capillary Electrophoresis in Screeningß-Thalassemia of Children].

OBJECTIVE: to explore the value of capillary electrophoresis in screening ß- thalassemia of children, and to establish the cutoff values of HbA2 and HbF in our laboratory. METHODS: The data of hemoglobin capillary electrophoresis and genetic diagnosis of ß- thalassemia from 886 examined children were retrospectively analyzed. The cutoff values of HbA2 and HbF were determined by ROC curve. RESULTS: The cutoff value of HbA2 screening minor ß- thalassemia was 3.65%, the specificity was 0.996, and the sensitivity was 0.995. The cut-off value of HbF for screening minor ß- thalassemia was 1.45%, specificity was 0.751 and sensitivity was 0.675. Thus, 1 case with codon5 (CCT→C) mutation, 1 case with SEA -HPFH ß deletion, 1 case with - 28 (A→G) merger IVS-Ι-128 (T→G) double heterozygous mutations yet were found out, 1 case with 47 bp ß gene missing has not yet been reported in literature. CONCLUSION: Capillary electrophoresis has more high sensitivity and specificity in the screening of ß- thalassemia in children, especially for the detection of rare ß- thalassemia.

Thalassemia incidence and treatment in China with special reference to Shenzhen City and Guangdong province.

According to the data from different screening studies, thalassemia is the most commonly seen hereditary hemolytic disease in China. The reported prevalence of thalassemia carriers varies but it is most prevalent in Southern China. In the past, the outcome of patients with thalassemia major has been very poor due to unfavorable economic background. With economic improvement in the past 10 years, increasing number of patients can get regular transfusion and chelation, and more patients can be treated by hemopoietic stem cell transplantation. A better prevention network has been built up over the years, but there are still babies being born with severe forms of thalassemia every year. A more comprehensive preventive program and public education are vital.

[Studies on the mutation and polymorphism of the TPMT gene in Chinese children with acute leukemia].

OBJECTIVE: To investigate the allelic frequencies and distribution of single-nucleotide polymorphisms within the coding region (cSNPs) of thiopurine S-methyltransferase gene (TPMT) in Chinese children with acute leukemia (AL) and healthy controls, in order to provide genetic references for individual chemotherapy for AL patients by studying the relationship between the cSNP in human TPMT and chemotherapeutic effect of thiopurine drugs. METHODS: The bone marrow samples from 53 children with AL and peripheral blood samples from 115 healthy children were obtained to prepare complementary DNAs (cDNAs). The cDNAs were analyzed for the polymorphisms in the TPMT gene by reverse transcriptase-polymerase chain reaction (RT-PCR)-denaturing gradient gel electrophoresis (DGGE) and DNA sequencing. The distribution of each genotype was evaluated. RESULTS: Two novel heterozygote mutations, 210C>T (C70C, silent) and 622T>C (F208L), were identified in the coding region of the TPMT in a single sample, respectively. The mother of the child with mutation 622T>C was confirmed as the same genotype by DGGE and sequencing (NCBI_ss accession numbers 107796292 and 107795933). Two known polymorphisms, 474T>C (silent) and 719A>G (T240C), were identified. The allelic frequencies were 14.2%, 2.83% and 17.0%, 3.04% in the AL children and control children respectively, with the total allelic frequencies of 16.2% (first reported in the Chinese Han population) and 2.99% respectively. No association with susceptibility to disease was observed. CONCLUSION: Two novel mutations and two known polymorphisms were identified in Chinese children by RT-PCR-DGGE combined with DNA sequencing, which provides the first step to identify genetic markers for predicting variability in response to and toxicity of thiopurine drugs.

[Polymorphisms of thymidylate synthase gene detected by RT-PCR-denaturing gradient gel electrophoresis in children with acute leukemia].

OBJECTIVE: Thymidylate synthase (TS) catalyses the conversion of deoxy-uridylate to deoxy-thymidylate and is a key enzyme for DNA synthesis. TS is the target enzyme of 5-fluorouracil (5-FU) and involved in folate metabolism. TS gene polymorphisms play an important role in the efficiency of fluorouracil activity in vivo. This study investigated the allelic frequencies and distribution characters of single-nucleotide polymorphisms within the coding region (cSNPs) of TS gene in Chinese children with acute leukemia (AL) and normal control children in order to explore the possible relationship between the cSNP in human TS gene and chemotherapeutic effects of 5-fluorouracils. METHODS: Bone marrow samples from 53 children with AL and peripheral blood samples from 115 normal children were obtained to prepare complementary DNAs (cDNAs). The cDNAs were analyzed for the polymorphisms in TS gene by reverse transcriptase (RT)-polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and direct sequencing. The distributive difference of each genotype between AL children and control children was evaluated. RESULTS: A polymorphism 381 A>G (E127E) in the coding region of TS gene was firstly identified in the Chinese population. The 381 A>G allelic frequency in AL children and control children was 12.3% and 13.5% respectively (P>0.05), which were similar to that in the International SNP Bank (12.3%). The allelic frequency of cSNPs was not associated with the susceptibility to AL. CONCLUSIONS: A polymorphism 381 A>G (E127E) in TS gene was successfully identified in children using RT-PCR-DGGE combined with DNA sequencing. There was no significant difference in the allelic frequency of cSNPs in AL children and normal children.

[Relationship between glucocorticoid receptors and glucocorticoid resistance in children with idiopathic thrombocytopenia purpura].

OBJECTIVE: To identify the relationship between the expression of alpha and beta-isoforms of glucocorticoid receptors (GR) in peripheral blood mononuclear cells (PBMC) and glucocorticoid resistance in children with idiopathic thrombocytopenia purpura (ITP). METHODS: Real-time PCR was used to detect the expression of GR alpha and GR beta mRNA in PBMC from 30 children with ITP (glucocorticoid-sensitive, n=18; glucocorticoid-resistant, n=12) and 10 healthy children (control group). Enzyme immunoassay was used to measure plasma levels of total glucocorticoids. RESULTS: There were no significant differences in PBMC GR alpha mRNA levels among the glucocorticoid sensitive, the glucocorticoid-resistant and the control groups. Compared with the glucocorticoid-sensitive and the control groups, the expression of GR beta mRNA in the glucocorticoid-resistant group was significantly up-regulated (p<0.01). Plasma total glucocorticoids level in the glucocorticoid-resistant group was found to be much higher than that in the glucocorticoid-sensitive and the control groups (p<0.01). CONCLUSIONS: The up-regulated expression of GR beta mRNA may associated with glucocorticoid resistance in children with ITP.

[Genetic diagnosis for female carriers of glucose-6-phosphate dehydrogenase deficiency by RT-PCR-DGGE].

OBJECTIVE: To study the feasibility of genetic diagnosis for female carriers of human glucose-6-phosphate dehydrogenase (G6PD) deficiency by reverse transcriptase-PCR-denaturing gradient gel electrophoresis (RT-PCR-DGGE). METHODS: Blood samples were collected from suspected 54 female carriers of G6PD deficiency. Total RNAs of peripheral blood were prepared and reverse-transcripted into cDNA. Design of 6 primer pairs for DGGE was based on 17 mutation sites of G6PD cDNA described in the Chinese population. Mutations in the coding region of G6PD gene were screened and genotyped by combination of PCR-DGGE and DNA sequencing. RESULTS: One case of 1024C/T, 20 cases of 1376G/T and 12 cases of 1388G/A were detected in the 54 samples. The total detection rate was 66.1% (33/54). CONCLUSIONS: Heterozygous mutation rate in female carriers of G6PD deficiency detected by RT-PCR-DGGE is high. RT-PCR-DGGE is value of clinical diagnosis for G6PD-deficiency female carriers.

Preliminary investigation on the abnormal mechanism of CD4+FOXP3+CD25high regulatory T cells in pediatric B-cell acute lymphoblastic leukemia.

The current study aimed to investigate the changes and regulatory mechanism of cluster of differentiation (CD)4+CD25high forkhead box protein 3 (Foxp3+) regulatory T cells (Tregs) in childhood B-cell acute lymphocytic leukemia (B-ALL). A total of 18 children with B-ALL and 15 age-matched healthy children were included. Reverse-transcription quantitative polymerase chain reaction was used to evaluate the mRNA levels of Foxp3, cytotoxic T-lymphocyte associated protein 4 (CTLA4), glucocorticoid-induced tumor necrosis factor receptor (GITR), lymphocyte activation gene 3 (LAG3), interleukin (IL)-2 receptor (R)ß/γ, IL-6Rα/ß, mothers against decapentaplegic homolog (Smad)3/4 and runt-related transcription factor (RUNX)1/3 in CD4-positive cells. The concentration of cytokines in plasma were measured using a cytometric bead array. Additionally, the proportion of CD4+CD25highFoxp3+ Tregs and levels of associated proteins was analyzed using flow cytometry. The results demonstrated that the proportion of CD4+CD25highFoxp3+ and expression of Foxp3 in children with B-ALL was significantly higher compared with healthy controls (P<0.05) and that transcription levels of CTLA4, GITR and LAG3 were also significantly elevated (P<0.05). Compared with healthy controls, the expression of IL-2Rα/ß and its downstream molecule phosphorylated signal transducer and activator of transcription 5 (pSTAT5) in CD4-positive cells significantly increased (P<0.05); however, no significant difference of IL-2Rγ levels was identified between the two groups. Correlation analysis demonstrated a significant positive correlation between the expression of phosphorylated (p) signal transducer and activator of transcription factor (STAT)5 and CD4+CD25highFoxp3+ Tregs in children with B-ALL (r=0.17; P<0.05). The plasma concentration of TGF-ß, the expression of its receptor TGF-ßRI/II and downstream molecules Smad3/4 were significantly upregulated in children with B-ALL (P<0.05), whereas the expression of RUNX1/3 was lower compared with healthy controls (P<0.05). Furthermore, the expression of Smad3 and RUNX1 was positively correlated with CD4+CD25highFoxp3+ Tregs in children with B-ALL (r=0.87 and 0.60, respectively; P<0.05). Additionally, the expression of pSTAT3 in CD4-positive cells decreased significantly in pediatric patients with B-ALL when compared with healthy controls; however, plasma concentrations of IL-6 was significantly higher (P<0.05). Furthermore, a negative correlation was identified between pSTAT3 and CD4+CD25highFoxp3+ Tregs in pediatric patients with B-ALL (r=-0.39; P<0.05). However, no significant differences in IL-6Rα/ß expression were identified between the two groups. The results demonstrated that the excessive activation of IL-2/pSTAT5 and TGF-ß/Smad signaling, and insufficiency of pSTAT3 may be correlated with increased CD4+CD25highFoxp3+ Tregs in pediatric B-ALL.