[The Correlation of Minimal Residual Disease with Prognosis in TCF3-PBX1+ Acute Lymphoblastic Leukemia in Children].

OBJECTIVE: To investigate the consistency between FCM and PCR on the detecting of MRD in TCF3-PBX1+ ALL, and to investigate the prognosis value of these 2 methods. METHODS: 55 cases of paediatric TCF3-PBX1+ ALL patients from April 2008 to April 2015 were enrolled and analyzed. The FCM and PCR was used to detect the MRD in 239 bone marrow samples of 55 patients. All statistical analyses were carried out by using SPSS software version 16. RESULTS: Among the 55 children with TCF3-PBX1+ ALL, there were 30 male and 25 female. The median age was 5 (1-14) years. 20 patients relapsed during follow-up. The MRD results from PCR and FCM showed a strong correlation between both methods (K=0.774, P<0.001). There was no significant difference in 5-years DFS and OS between the patients in PCR+ and PCR- groups on day 15 or day 33. The 5 year DFS rate between the patients in FCM- and FCM+ was 63.9%±7.0% and 0; the 5 year OS rate was 66.5%±7.9% and 0. Combined with the result of FCM and PCR, at the d 33 of treatment, the 5-year DFS rate in FCM-/PCR- and single positive group was 65.4%±7.2% and 25.0%±15.3% (P<0.01). CONCLUSION: The detection result of MRD in TCF3-PBX1 detect by FCM and PCR shows better consistency. MRD positivity detected by FCM at the end of induction therapy (day 33) predicts a high risk of relapse in TCF3-PBX1 ALL patients.

[Diagnostic Significance of BIOMED-2 Standardized Gene Rearran-gement System in Patients with Non-Hodgkin's Lymphoma].

OBJECTIVE: To detect the immunoglobulin(Ig) and T cell receptor(TCR) gene rearrangement in bone marrow of non-Hodgkin's lymphoma(NHL) patients by using BIOMED-2 standardized system, and to explore the potential clinical significance of Ig/TCR gene rearrangement. METHODS: DNA was extracted in bone marrow and Formalin-fixed and Paraffin-embedded(FFPE) samples of NHL patients, the Ig/TCR gene rearrangements were analyzed by using BIOMED-2 multiple primers system and multiplex PCR assay. RESULTS: Among 235 T-NHL cases, 71.9% showed TCR gene rearrangement. The positive rate of TCRγ and the TCRß were 57.9% and 50.2%. Out of 583 B-NHL cases, 81.6% showed Ig gene rearrangement. The positive rate of IgH and the IgK were 70.7% and 69.3%. MCL patients showed 84.8% IgH rearrangement and 75.8% IgK rearrangement, as compared with FL(34.0%, 50.9%) and DLBCL(9.2%, 16.1%) patients, the difference was statistically significant (P<0.05). Out of Ig rearrangement positive B-NHL cases, 65 showed TCR gene rearrangement. None TCR rearrangement positive T-NHL cases showed Ig gene rearrangement, 25 cases(83.3%) showed Ig gene rearrangement in FFPE samples of 30 DLBCL patients, as compared to Ig rearrangement positive rate of bone marrow, the difference was statistically significant (P<0.001). CONCLUSION: BIOMED-2 standardized Ig/TCR gene rearrangement system shows assistance for lymphoma diagnosis. The PCR sequencing analysis is much more sensitive and specific and has significance for clinical diagnosis.

[Application of Combined Detection of Fusion Gene and BIOMED-2 Standardized Ig Gene Rearrangement System in Childhood B-cell Acute Lymphoblastic Leukemia].

OBJECTIVE: To explore the application of combined detection of fusion gene and BIOMED-2 standardized immunoglobulin (Ig) gene rearrangement system in diagnosis and treatment of children with acute lymphoblastic leukemia (ALL). METHODS: Multiplex-PCR amplifications and RQ-PCR of RNA/DNA were performed using ALL fusion gene detection kit and BIOMED-2 primer. The Ig gene rearrangements were analyzed by using PCR fragment analysis system. RESULTS: Out of 251 children with B-ALL, 77 cases were TEL-AML1(+) , 28 cases were E2A-PBX1(+) , 10 cases were MLL-AF4(+) , 11 cases were BCR-ABL(+) , the total positive rate was 50.2%, 82.5% showed IgH VH-JH rearrangement, 53.4% showed IgK rearrangement. The positive rate of combined detection of fusion gene and gene rearrangement was 99%. E2A-PBX1(+) and MLL-AF4(+) with IgK(+) gene rearrangement group was compared with negative control group, the difference was statistically significant (P < 0.001 or P = 0.005); 105 ALL fusion gene positive cases had been detected by fluorescence in situ hybridization (FISH) simultaneously, the accordance rate of fusion gene and FISH was more than 94%. CONCLUSION: The combined detection of ALL fusion gene and BIOMED-2 standardized clonality analysis system can improve the positive detected rate of B-ALL dramatically, and make the grouping of disease prognosis more accurately; this combined detection is a more faster and sensitive method than FISH.

Long-term outcomes of imatinib in patients with FIP1L1/ PDGFRA associated chronic eosinophilic leukemia: experience of a single center in China.

BACKGROUND: The FIP1L1/PDGFRA (F/P) fusion gene is the most common clonal genetic abnormality of chronic eosinophilic leukemia (CEL). Tyrosine kinase inhibitors (TKI), such as imatinib, have been demonstrated to be effective therapies for F/P mutated disease. The aim of this study was to analyze the treatment response and long term prognosis in patients with F/P mutated CEL. METHODS: The clinical features and treatment responses of 33 consecutive patients with F/P mutated CEL between August 2006 and October 2014 were analyzed. The 33 cases received imatinib therapy at an initial dose of 100 mg/day (30 patients) or 200 mg/day (3 patients); the maintenance dose depended on the response condition and patient willingness. Through the follow up, the molecular responses were regularly monitored. RESULTS: With a median follow up of 64 months, 94% of the 33 patients with F/P mutated CEL achieved a complete hematologic remission (CHR), and 97% achieved a complete molecular remission (CMR) after a median of 3 (1.5-12) months. Twenty-four cases received maintenance therapy, with a median CMR duration of 43 (5-88) months. Imatinib therapy was discontinued in 8 cases, including 4 cases who experienced relapse, and 4 patients who maintained CHR or CMR after discontinuing therapy with a median time of 47 (2-74) months. One case exhibited primary resistance with a PDGFRA T674I mutation. CONCLUSIONS: F/P mutated CEL has an excellent long-term prognosis following imatinib therapy. A 100 mg daily dose of imatinib is sufficient to induce remission, and a single 100 mg weekly dose maintains a durable remission. A subgroup of patients may maintain a durable remission after discontinuing therapy with a CMR.

[CEBPA gene mutation analysis in acute myeloid leukemia].

OBJECTIVE: To investigate the incidence, molecular features and clinical significance of CCAAT/enhancer binding protein alpha (CEBPA) gene mutation in patients with acute myeloid leukemia (AML). METHODS: Mutation analysis of the entire coding region of CEBPA gene in 206 de novo AML patients was performed by using polymerase chain reaction (PCR) followed by sequence analysis and fragment length analysis. RESULTS: Of 206 AML patients, 31 (15%) had CEBPA gene mutations, including 23 with double mutations (duCEBPA) and 8 with single mutation (siCEBPA). CEBPA gene mutations presented mainly in M2 subtype or intermediate risk patients. As compared with those with wild type CEBPA gene, patients with mutated CEBPA gene were of higher white blood cell counts [20.92(0.86-351.43)× 10(9)//L vs 8.17(0.47-295.2) × 10(9)/L, P=0.003], higher hemoglobin levels [97.5(51-128) g/L vs 80.5(13-153) g/L, P=0.015] and lower platelet counts [27.5(5-81)× 10(9)//L vs 44(3-548)× 10(9)/L, P=0.004]. Patients with CEBPA gene mutation had higher complete remission (CR) rate than those with wild type (P=0.009). While co-existing of NPM1 and siCEBPA mutations was observed in M5 subtype (2/8, 25%), NPM1 gene mutation was not present in any patients with duCEBPA mutation (0/23, 0%). Dynamic tracking analysis showed that CEBPA mutations disappeared at CR, and the same mutations re-appeared at relapse. When compared to sequence analysis, the coincidence rate of CEBPA mutations detected by fragment length analysis was 100% (54/54). CONCLUSION: CEBPA gene mutation is a recurring genetic change in AML patients and has a certain correlation with clinical and laboratory features. It could be reliably used as a potential marker for minimal residual disease follow up. The prognostic significance of co-existing of siCEBPA with NPM1 mutations in patients with AML-M5 subtype needs further investigation.

[Characteristics of cytogenetics and molecular biology in patients with eosinophilia].

The aim of study is to explore the characteristics of cytogenetics and molecular biology in patients with eosinophilia. Bone marrow samples from 79 cases of eosinophilia (AEoC ≥ 1.5×10(9)/L) were detected for PDGFRA/B and FGFR1 gene rearrangement by fluorescence in situ hybridization and reverse transcription polymerase chain reaction (RT-PCR). Forty-four samples were detected for T cell receptor (TCR) clonal rearrangement by PCR. The results showed that among 76 cases the FIP1L1/PDGFRA (F/P) fusion gene was detected in 19 cases, the CHIC2 deletion was detected in 19 cases, the PDGFRA rearrangement was detected in 4 cases, and no FIP1L1 rearrangement was detected. According to the 2008 WHO classification, diagnosis were revised as myeloid neoplasms with PDGFRA/B rearrangement in 20 (42%) of 48 patients and 5 (83%) of 6 patients with hypereosinophilia syndrome (HES) or chronic eosinophilic leukemia (CEL), respectively. The diagnosis in (17%) of 6 patients with CEL was revised as chronic eosinophilic leukemia, not otherwise as specified (CEL-NOS). Clonal cytogenetic abnormalities were detected in 1 case of CEL-NOS and 3 cases with PDGFRB rearrangement. Karyotypic abnormalities involved in chromosome 4q12 were not detected in all of the 21 cases with PDGFRA rearrangement. The clonal TCR gene rearrangement were detected in 33% (5/15), 40% (6/15), and 36% (5/14) cases with PDGFRA/B rearrangement, HES, or secondary eosinophilia, respectively. There was no statistical difference in incidence rate among 3 subgroups. It is concluded that PDGFRA/B rearrangement can be detected in many cases of HES or CEL. Interphase FISH and PCR testing can enhance the diagnostic rate of myeloid neoplasms with PDGFRA/B rearrangement.

[JAK2 exon 12 mutations in patients with Philadelphia (Ph) chromosome-negative myeloproliferative neoplasms].

OBJECTIVE: To investigate JAK2 exon 12 mutations in patients with Philadelphia (Ph) chromosome-negative myeloproliferative neoplasms (MPN) and the clinical characteristics of patients with JAK2 exon 12 mutants. METHODS: Allele-specific PCR (AS-PCR) was applied to identify JAK2 V617F mutation. Genomic DNA corresponding to exon 12 of JAK2 gene and epigenetic regulator gene (TET2, ASXL1, EZH2) were amplified by polymerase chain reaction (PCR). Identification of mutants was by direct sequencing and classification of mutation types by sequencing followed by plasmid cloning. SNP genotyping of two 46/1 tag SNPs, rs12340895 and rs10974944, was analyzed using commercially available Taqman assays on the 7500HT real-time PCR instrument according to standard protocols. RESULTS: No JAK2 exon 12 mutation was detected in patients with ET, PMF or JAK2 V617F positive PV. Among 13 JAK2 V617F negative PV patients, JAK2 exon 12 mutation was detected as N542-E543del in 2(15.4%) patients who presented with a phenotype of predominant erythrocytosis and erythroid colonic grown from their bone marrow samples in the absence of exogenous EPO, reduced serum erythropoietin (EPO) level, and no mutations in TET2, ASXL1 or EZH2 genes. One of the affected patients was heterozygous for 46/1 but the second was negative for this haplotype. CONCLUSION: There was no need to detect JAK2 exon 12 mutation in ET, PMF or MPN-U patients without JAK2 V67F mutation. Ph negative MPN patients with JAK2 exon 12 mutations had somewhat unique clinical and laboratory features.

[Relationship between RAD51-G135C/XRCC3-C241T polymorphisms and development of acute myeloid leukemia with recurrent chromosome translocation].

OBJECTIVE: To investigate the relationship between DNA homologous recombination (HR) repair genes RAD51-G135C/XRCC3-C241T polymorphisms and development of acute myeloid leukemia (AML) with recurrent chromosome translocation. METHODS: Genomic DNA was extracted from bone marrow cells of 625 de novo AML patients and peripheral blood cells of 806 patient family members and 704 unrelated volunteers. Genotypes of RAD51-G135C and XRCC3-C241T were analyzed by PCR-RFLP. Cell lines with genotypes differed from XRCC3-C241T were selected and irradiated in vitro. The CBFß-MYH11 fusion gene was detected by TaqMan real-time PCR. RESULTS: The XRCC3-C241T variant (C/T + T/T) showed 6.22-fold and 6.99-fold increase in the risk of developing the AML with inv(16)/t(16;16)/CBFß-MYH11 as compared with the volunteer and family member controls respectively; the RAD51-G135C homozygote-type (C/C) variant showed 0.87-fold (P = 0.010) and 1.15-fold (P = 0.001) respectively increase in the risk of this subtype AML. In the irradiated group, the CBFß-MYH11 mRNA level in HL-60 cells was 59.49 times increased than that in KG1a cells. However, the RAD51-G135C and XRCC3-C241T variants had no correlations with the risk of development of t(15;17)/PML-RARα(+)AML, t(8;21)/AML1-ETO(+) AML and 11q23 AML subtypes. CONCLUSION: The XRCC3-C241T variant and the RAD51-G135C homozygote-type significantly increase the risk of the development of AML with inv(16)/t(16;16)/CBFß-MYH11.

[Relation of HLA-DRB1*15 with pathogenesis in 162 childhood cases of acute lymphoblastic leukemia].

To unravel the relation of HLA-DRB1*15 with childhood acute lymphoblastic leukemia (ALL), 162 childhood patients with ALL were selected for this investigation. 1 000 normal umbilical cord blood samples were used as control.HLA-DRB1*15 and HLA-DRB5* were typed by polymerase chain reaction (PCR) analysis. The relation of HLA-DRB1*15 with childhood ALL was studied by calculating the chi-square test and relative risk. The results showed that the antigen frequencies and allele frequencies of HLA-DRB1*15 in childhood patients with ALL were 40.12% and 22.62% respectively, while the antigen frequencies and allele frequencies of HLA-DRB1*15 in control were 30.80% and 16.81% respectively, there were significant difference between them (chi(2) = 5.560, p = 0.018, RR = 1.506). In conclusion, the antigen frequencies and allele frequencies of HLA-DRB1*15 in childhood patients with ALL were higher than those in control, so the HLA-DRB1*15 gene is one of the genetic risk factors for childhood ALL. These preliminary data may be useful for further study on the pathogenesis of childhood ALL.

[Study on HFE gene mutations in patients with myelodysplastic syndromes and aplastic anemia].

OBJECTIVE: To detect the incidence of the HFE gene C282Y and H63D mutations in patients with myelodysplastic syndromes (MDS) and aplastic anemia (AA), and analyze the relationship of these mutations with iron metabolism, and organs impairment from iron overload. METHODS: The incidence of the C282Y and H63D mutations in 271 MDS, 402 AA patients and 1615 normal subjects was measured by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) combining with DNA sequencing. Iron metabolism parameters and iron overload indices were retrospectively compared between HFE gene mutation and unmutation groups in MDS and AA patients with no transfusion history. RESULTS: No C282Y and C282Y/H63D compound mutation was detected in all the three groups. The incidence of H63D heterozygous and homozygous genotype did not significantly differ between AA cases and controls (9.7% vs 10.2%, 0.25% vs 0.24% respectively, both P > 0.05). The frequency of H63D heterozygous genotype in MDS patients was significantly lower than that in controls (4.1% vs 10.2%, P = 0.002). H63D homozygous was not found in MDS patients. In both MDS and AA patients with no RBC transfusion history, serum ferritin (SF), transferrin saturation value (TS), serum iron concentration (SI) were close to or higher than normal; and unsaturated iron-binding capacity (UIBC) value was significantly lower. There was no significant difference in SF, SI, TS values between HFE-mutation and -unmutation MDS patients. For AA patients, only the level of SI was significantly higher in HFE-mutant group than in -unmutation group [42.6 (24.6-60.4) micromol/L vs 32.0 (8.4-63.3) micromol/L, P = 0.011]. There was no significant difference in the values of liver enzyme, fasting blood sugar (FBS), abnormal electrocardiogram (ECG), peripheral blood indices between HFE-mutation and -unmutation MDS and AA groups (all P > 0.05). CONCLUSION: The distribution of C282Y and H63D mutations has ethnic and genetic disparity, the frequency in Chinese population is lower than that in Caucasian. It seems that MDS and AA patients are susceptible to iron overload, in the diseases itself and the mutations of HFE gene are not the major factor for iron overload in the patients.

[Polymorphisms of drug-metabolizing enzymes genes in a Han Chinese population].

OBJECTIVE: To survey the frequencies and characteristics of polymorphism of seven genes coding drug-metabolizing enzymes in a Han Chinese population. METHODS: Genomic DNA was extracted from peripheral blood in 1382 unrelated Han Chinese volunteers. Genotypes of CYP450, NQO1, MPO, MTHFR, NAT2, TPMT*3B(G460A) and TPMT*3C(A719G) were analyzed by PCR-RFLP. GSTM1 and GSTT1 genotypes were detected by multiple PCR and TPMT*2(G238C) genotypes by allele-specific PCR. RESULTS: The allele frequencies of wild-type, heterozygosity and homozygosity were 99.8%, 0.2% and 0 in CYP3A4*1B genotypes, 8.4%, 34.3% and 57.3% in CYP3A5*3 genotypes, 28.7%, 49.7% and 21.6% in NQO1(C609T) genotypes, 75.0%, 23.2% and 1.8% in MPO(G463A) genotypes, 25.9%, 44.9% and 29.2% in MTHFR(C677T) genotypes, 67.3%, 30.4% and 2.3% in MTHFR(A1298C) genotypes, and 96.8% 3.2% and 0 in TPMT*3C(A719G) genotypes, respectively. The frequencies of present and null genotypes were 36.1% and 63.9% in GSTM1, 54.4% and 45.6% in GSTT1 respectively. The frequencies of NAT2*4/*4, *4/*5, *4/*6, *4/*7, *5/*5, *5/*6, *5/*7, *6/*6, *6/*7 and *7/*7 genotypes were 34.5%, 4.3%, 24.3%, 18.2%, 0.1%, 1.8%, 1.5%, 5.0%, 7.6% and 2.6% respectively. The frequencies of specific NAT2 alleles were 57.9%, 3.9%, 21.8% and 16.3% for NAT2*4, *5, *6 and *7 respectively. The frequencies of genophenotypes were 81.4% and 18.6% in NAT2 fast acetylator and low acetylator respectively. The allele frequency of wild type were 100% in both TPMT*2(G238C) genotypes and TPMT*3B(G460A). The variant alleles of TPMT*2(G238C) and TPMT*3B(G460A) were not found in 1382 Han Chinese subjects. CONCLUSION: Significant differences in the distributions and frequencies in genetic polymorphisms of drug-metabolizing enzymes are identified between Han Chinese population and Caucasians, as well between Han Chinese population and Melanoderma while only some heterogeneity has been observed between Han Chinese population and other Xanthoderms in Asia.