Integrative genomic and transcriptomic profiling reveals distinct molecular subsets in adult mixed phenotype acute leukemia.

Mixed phenotype acute leukemia (MPAL) is a subtype of leukemia in which lymphoid and myeloid markers are co-expressed. Knowledge regarding the genetic features of MPAL is lacking due to its rarity and heterogeneity. Here, we applied an integrated genomic and transcriptomic approach to explore the molecular characteristics of 176 adult patients with MPAL, including 86 patients with T-lymphoid/myeloid MPAL (T/My MPAL-NOS), 42 with Ph+ MPAL, 36 with B-lymphoid/myeloid MPAL (B/My MPAL-NOS), 4 with t(v;11q23), and 8 with MPAL, NOS, rare types. Genetically, T/My MPAL-NOS was similar to B/T MPAL-NOS but differed from Ph+ MPAL and B/My MPAL-NOS. T/My MPAL-NOS exhibited higher CEBPA, DNMT3A, and NOTCH1 mutations. Ph+ MPAL demonstrated higher RUNX1 mutations. B/T MPAL-NOS showed higher NOTCH1 mutations. By integrating next-generation sequencing and RNA sequencing data of 89 MPAL patients, we defined eight molecular subgroups (G1-G8) with distinct mutational and gene expression characteristics. G1 was associated with CEBPA mutations, G2 and G3 with NOTCH1 mutations, G4 with BCL11B rearrangement and FLT3 mutations, G5 and G8 with BCR::ABL1 fusion, G6 with KMT2A rearrangement/KMT2A rearrangement-like features, and G7 with ZNF384 rearrangement/ZNF384 rearrangement-like characteristics. Subsequently, we analyzed single-cell RNA sequencing data from five patients. Groups G1, G2, G3, and G4 exhibited overexpression of hematopoietic stem cell disease-like and common myeloid progenitor disease-like signatures, G5 and G6 had high expression of granulocyte-monocyte progenitor disease-like and monocyte disease-like signatures, and G7 and G8 had common lymphoid progenitor disease-like signatures. Collectively, our findings indicate that integrative genomic and transcriptomic profiling may facilitate more precise diagnosis and develop better treatment options for MPAL.

[Clinical Characteristics and Prognosis of Acute Myeloid Leukemia Patients with inv(16)/t(16;16)(p13.1;q22) and/or CBFß-MYH11].

OBJECTIVE: To summarize the clinical and laboratory characteristics of patients with acute myeloid leukemia (AML) with inv(16)/t(16;16) (p13.1;q22), and to analyze the risk factors affecting the prognosis of the patients. METHODS: AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFß-MYH11+ admitted to the Department of Hematology, The First Affiliated Hospital of Soochow University from January 1, 2008 to October 30, 2019 were retrospective analyzed, the clinical and laboratory indicators, as well as treatment plans and efficacy evaluations of the patients were all recorded. Furthermore, related factors affecting the overall survival (OS) and event-free survival (EFS) of the patients were analyzed. RESULTS: Among 151 AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFß-MYH11+, the percentage of additional chromosomal abnormalities was about 27.8%, and the most common additional chromosomal abnormality was +22 (33/151, 21.8%), followed by +8 (11/151, 7.3%). There were 112 patients with perfect NGS examination, and the result showed the most common accompanying gene mutations were KIT mutation (34/112, 30.4%) and FLT3 mutation (23/112, 20.5%). Univariate analysis showed that factors affecting EFS included: NE≤0.5×109/L (P=0.006) and combined K-RAS mutation (P=0.002); Factors affecting OS included: Age≥50 years old (P<0.001) and NE≤0.5×109/L (P=0.016). Multivariate analysis showed that NE≤0.5×109/L (P=0.019) was the risk factors affecting OS. The proportion of bone marrow eosinophilia (BME)≥10.00% (P=0.029) was the risk factors affecting EFS. CONCLUSION: The prognosis for those newly diagnosed AML patients who were of advanced age, the high proportion of bone marrow eosinophils, K-RAS mutations, and agranulocytosis is poor. The treatment plans can be adjusted in the early stage to improve the prognosis of such patients.

[Clinical Characteristics and Prognosis of Acute Myeloid Leukemia Patients with inv(16)/t(16;16)(p13.1;q22) and/or CBFß-MYH11].

OBJECTIVE: To summarize the clinical and laboratory characteristics of patients with acute myeloid leukemia (AML) with inv(16)/t(16;16) (p13.1;q22), and to analyze the risk factors affecting the prognosis of the patients. METHODS: AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFß-MYH11+ admitted to the Department of Hematology, The First Affiliated Hospital of Soochow University from January 1, 2008 to October 30, 2019 were retrospective analyzed, the clinical and laboratory indicators, as well as treatment plans and efficacy evaluations of the patients were all recorded. Furthermore, related factors affecting the overall survival (OS) and event-free survival (EFS) of the patients were analyzed. RESULTS: Among 151 AML patients with inv(16)/t(16;16) (p13.1;q22) and/or CBFß-MYH11+, the percentage of additional chromosomal abnormalities was about 27.8%, and the most common additional chromosomal abnormality was +22 (33/151, 21.8%), followed by +8 (11/151, 7.3%). There were 112 patients with perfect NGS examination, and the result showed the most common accompanying gene mutations were KIT mutation (34/112, 30.4%) and FLT3 mutation (23/112, 20.5%). Univariate analysis showed that factors affecting EFS included: NE≤0.5×109/L (P=0.006) and combined K-RAS mutation (P=0.002); Factors affecting OS included: Age≥50 years old (P<0.001) and NE≤0.5×109/L (P=0.016). Multivariate analysis showed that NE≤0.5×109/L (P=0.019) was the risk factors affecting OS. The proportion of bone marrow eosinophilia (BME)≥10.00% (P=0.029) was the risk factors affecting EFS. CONCLUSION: The prognosis for those newly diagnosed AML patients who were of advanced age, the high proportion of bone marrow eosinophils, K-RAS mutations, and agranulocytosis is poor. The treatment plans can be adjusted in the early stage to improve the prognosis of such patients.

A Recurrent Cryptic MED14-HOXA9 Rearrangement in an Adult Patient With Mixed-Phenotype Acute Leukemia, T/myeloid, NOS.

To define the fusion genes in T/myeloid mixed-phenotype acute leukemia (T/M MPAL), we performed transcriptome sequencing of diagnostic bone marrow samples from 20 adult patients. Our analysis identified a second instance of a recurrent MED14-HOXA9 chimeric gene resulting from the in-frame fusion of exon 23 of MED14 and exon 1 of HOXA9, the first in an adult patient. The MED14-HOXA9 fusion gene was detected in both the diagnostic and relapsed blasts with reverse transcription-polymerase chain reaction and Sanger sequencing. The patient received combined conventional chemotherapy but suffered relapse at 11 months and died of disease progression one year after the initial diagnosis. Our data suggest that MED14-HOXA9 is a cryptic recurrent aberration in T/M MPAL, which might indicate an aggressive clinical course and inferior outcome after conventional chemotherapy. Further studies will be carried out to reveal the effects of the MED14-HOXA9 fusion on the differentiation and proliferation of leukemia stem cells, as well as suitable treatment strategies for this emerging entity.

[Clinical Features and Prognostic Factors of Patients with Multiple Myeloma].

OBJECTIVE: To summarize the clinical and Laboratory characteristics of patients with multiple myeloma (MM) and analyze the prognostic factors. METHODS: Two hundred MM patients were retrospectively analyzed for the following parameters, including peripheral blood, bone marrow morphology, cytogenetics, clinical staging, and response to the chemotherapy in order to summarize related factors affecting overall survival (OS). The prognostic factors were also analyzed. RESULTS: 200 patients with MM were divided into 3 groups according to bone marrow plasma cell percentage (BMPC%) in bone marrow smears: ＜10% group (74 cases, 37.0%), 10%-50% group (75 cases, 37.5%), ＞50% group (51 cases, 25.5%). Compared with the other two groups, patients in BMPC%<10% group were characterized by lower clinical staging levels, lower rates of 13q14 deletion and t(11;14) positive, better response to chemotherapy and favorable three-year OS rate. The univariate analysis showed that prognostic factors indicating favorable outcome as evaluated by OS included age≤55 years old, BMPC%＜10%, WBC＜7.5×109/L, Hb≥68 g/L, PLT≥150×109/L, ß2-MG＜5.5 mg/L, LDH≤230 U/L, Durie-Salmon staging A, achievement of VGPR or better outcome after the first chemotherapy, achievement VGPR or better outcome after the fourth chemotherapy, and presence of autologous hematopoietic stem cell transplantation(auto-HSCT)(P<0.05). The multivariate analysis showed that prognostic factors indicating favorable outcome as evaluated by OS included age≤55 years old, BMPC%≤50%, WBC＜7.5×109/L, Hb≥68 g/L, achievement of VGPR or better outcome after the fourth chemotherapy (P<0.05). CONCLUSION: The clinical characteristics are different among MM patients with different BMPC% in bone marrow smears at initial diagnosis, and prognostic analysis shows that the BMPC% in bone marrow smears has an effect on OS rate. BMPC% in bone marrow smears at initial diagnosis, age, WBC, Hb, response to the fourth chemotherapy are also the main factors impacting the prognosis of patients.

[Clinical Significance of Common Gene Mutations in 53 Patients with Acute Myeloid Leukemia Harboring 11q23/MLL Rearrangements].

OBJECTIVE: To investigate the clinical significance of AML patients with 11q23/MLL rearrangement, and to evaluate the effect of those mutations on the AML patients. METHODS: 53 cases involving translocations of chromosome 11q23 were identified by chromosome banding analysis. MLL rearrangements were detected by fluorescence in situ hybridization and/or multiplex nested PCR. The samples were screened for mutations in the candidate genes FLT3-ITD, FLT3-TKD, TET2, N-RAS, ASXLI, EZH2, DNMT3, C-Kit, NPM1, WT1, CEBPA by using genomic DNA-PCR and deep-sequencing. RESULTS: 21/53 MLL-rearranged AML cases showed at least one additional chromosomal aberrations. The most common additional aberration was +8. Gene mutations were observed in 23 cases (43.4%) and most cases showed singal mutation. N-RAS mutation was more frequent (8 cases, 15.1%), followed by WT1 mutation in 4 cases (7.5%), FLT3-ITD mutation in 3 cases, ASXL1 mutation in 2 cases, DNMT3A mutation in 2 cases, EZH2 mutation in 1 case, c-Kit17 mutation in 1 case, FLT3-TKD mutation in 1 case, and FLT3-ITD and TKD mutation coexistent in 1 case. No mutation was detected in CEBPA, NPM1, C-KIT8, TET2. Median OS for gene mutated patients was 8.5 months and 13 months for no mutated patients. Median OS for patients who received hematopoietic stem cell transplantation (HSCT) was 22.5 months and 7.5 months for patients who olny received chemotherapy. CONCLUSION: A relatively high mutation frequency is observed in AML patients with 11q23/MLL rearrangements and most cases shows single mutation. The RAS signaling pathway alterations are most common. Gene mutation does not affect the OS of these patients, who show poor prognosis. A significantly higher Hb at initial diagnosis in FLT3 mutated patients is significantly higher than that in FLT3 wild-type cases. Patients who underwent HSCT show a better prognosis than those only received chemotherapy.

[Clinical Features and Prognosis of 188 Patients with Acute Myeloid Leukemia-M2].

OBJECTIVE: To summarize the clinical characteristics of patients with acute myeloid leukemia-type M2 (AML-M2) and analyze the factors affecting the prognosis. METHODS: One hundred eighty-eight AML-M2 patients were retrospectively analyzed for the following parameters including peripheral blood, immune phenotypes, fusion genes and cytogenetics to explore their significance for the overall survival (OS) and progression-free survival (PFS). The prognostic factors were also analyzed. RESULTS: Among 188 patients with AML-M2, the chromosomal abnormality with t (8;21), normal chromosome and other abnormalities accounted for 37% (70/188), 41% (77/188) and 22% (41/188), respectively. For the immunopheno typing of M2 patients, the hematopoietic progenitor cell differentiation antigen CD117 (96.1%) were mainly expressed, CD34 (81.6%) and HLA-DR (55.9%), and myeloid-associated antigen of CD13 (90.5%) and CD33 (89.4%) were also highly expressed. There were lymphoid-associated antigens expressed in some patients, among which the positive expression rate of CD19 was highest (29.6%), and the next was CD7 (28.5%). The most common accompanied mutations was FLT3 mutation (30.2%). The univariate analysis showed that the patients at age＜50 years old, without extramedullary infiltration, with positive expression of CD19, NPM-1 (-), CEBPA double mutation(+), and HSCT were significant superior in OS and PFS (P＜0.05); the multivariate analysis showed that the patient at age＜50 years old, without extramedullary infiltration, with positive expression of CD19 and CEBPA double mutation (+) were significant superior in OS and PFS (P＜0.05). The analysis indicated that the Karytypes affected only OS (P＜0.05), while the NPM-1 gene mutation positive affected only PFS (P＜0.05). The univarate analysis of factors affecting the survival in 70 AML-M2 patients with t (8;21) abnormatity showed that the C-KIT gene mutation was a poor factor for OS and PFS. CONCLUSION: The clinical characteristics are different between M2 patients with different karyotype, and prognostic analysis shows that the karytypes have an impact on overall survival; age, extramedullary infiltration, CD19 expression and CEBPA double mutation are also the main factors impacting the prognosis of patients.

[Effect of Additional Chromosomal Abnormalities on the Outcome of CML-CP Patients Receiving TKI Therapy].

OBJECTIVES: To explore the effect of additional chromosomal abnormalities on the prognosis and outcome of CML-CP patients receiving imatinib therapy. METHODS: The clinical and genetic data of 589 CML-CP patients receiving imatinib treatment between May 2009 and October 2014 in the 1st Affiliated Hospital of Soochow University were analyzed, the 589 patients were divided into 5 groups according to the karyotypes at the initial diagnosis. The OS(overall survival), PFS (progression-free survival), EFS (event-free survival), Cumulative MMR (major molecular remission) and Cumulative CCyR (complete cytogenetic remission) were calculated by using the Kaplan-Meier method and compared by using the log-rank text by Graphpad 6.0. The χ2 test was used to compare the frequency of optimal molecular response at 3, 6, 12 months among the 5 groups. RESULTS: There was significant difference about the frequency of optimal molecular response at 3 and 6 months between CML-CP patients with additional chromosomal abnormalities and those with classic t(9;22) ï¼»50%（12/24） vs. 73.94%(261 /353), P<0.05; 50%(10 /20) vs. 72.05%(232 /322) (P<0.05)ï¼½, and the same significant difference was found at 6 months between the group with variant translocations and that with classic t(9;22) ï¼»53.3% (16 /30) vs. 72.05%(232 /322) (P<0.05)ï¼½. The P values of cumulative CCyR (P<0.05) and EFS (P<0.01) for 4 years were statistically significant between CML-CP patients with additional chromosomal abnormalities and the other 4 groups. Compared one to another, there was the significant difference in cumulative CCyR and EFS for 4 years between CML-CP patients with additional chromosomal.abnormalities and those with classic t(9;22) (47.25% vs. 84.01%)(P<0.05); (75.03% vs. 90.01%)(P<0.01). CONCLUSION: The additional chromosomal abnormalities influence the outcome of CML-CP patients receiving imatinib treatment, which make poor prognosis.

Coexistence of p210BCR-ABL and CBFß-MYH11 fusion genes in myeloid leukemia: A report of 4 cases.

Numerous acquired molecular and cytogenetic abnormalities are strongly associated with hematological malignancies. The breakpoint cluster region-ABL proto-oncogene 1 (BCR-ABL) rearrangement leads to a p210 chimeric protein in typical chronic myeloid leukemia (CML), whereas 17-25% of patients with acute lymphocytic leukemia and 0.9-3% patients with de novo acute myeloid leukemia (AML) carry a p190BCR-ABL fusion protein. Cases of patients with AML/CML carrying two specific primary molecular changes, BCR-ABL and core binding factor-ß-myosin heavy chain 11 (CBFß-MYH11) fusion genes have been rarely reported. The present study aimed to understand the nature and mechanism of this particular type of leukemia through case reports and literature review. A total of four patients who were diagnosed as AML/CML with BCR-ABL and CBFß-MYH11 fusion genes in the First Affiliated Hospital of Soochow University (Suzhou, China) between January 2004 and December 2012 were examined. Morphological analysis of bone marrow cells, flow cytometry, quantitative polymerase chain reaction of p210BCR-ABL and CBFß-MYH11 transcripts as well as cytogenetic and fluorescence in situ hybridization analyses were performed. A total of 4 patients who exhibited fusion of p210BCR-ABL and CBFß-MYH11 were identified. A single patient (case 1) was first diagnosed CML-acute phase (AP), which progressed rapidly to CML-blast crisis (BC), and three patients (cases 2, 3 and 4) were diagnosed with AML with bone marrow eosinophilia at first presentation with no evidence of previous onset of CML. All cases achieved remission following conventional chemotherapy/hematological stem cell transplantation combined with the inhibitor of tyrosine kinase (TKI) maintenance therapy. The patients with CML carrying and expressing BCR-ABL and CBFß-MYH11 fusion genes appeared more likely to rapidly progress to AP or BC. Therefore, the product of the CBFß-MYH11 fusion gene may serve an important role in the transformation of CML. The co-expression of p210BCR-ABL and CBFß-MYH11 fusion genes in myeloid leukemia may be a molecular event occurring not only during the development of CML, but also in AML.

[Autophagy Activity of CD34+ Cells in MDS Patients and Its Clinical Significance].

OBJECTIVE: To explore the autophagy activity of CD34+ cells in bone marrow of MDS patients and its clinical significance. METHODS: The activity of autophagy in bone marrow CD34+ cells from 20 MDS patients, 20 non-malignant anemia patients and 5 AML patients admitted in our hospital from October 2012 to March 2014 was detected by flow cytometry (FCM). RESULTS: The autophagy activity in low risk MDS patients and non-malignant anemia patients were both significantly higher than that in both high risk MDS and AML patients (P<0.05), and more interestingly, the autophagy activity in MDS negatively correlated with World Health Organization classification-based prognostic system (WPSS) score (r=-0.877) . CONCLUSION: The autophagy activity CD34+ cells in the patients with MDS is higher than that in AML patients, and negatively correlated with WPSS scores, indicating that the decrease of autophagy activity maybe accelerate the genesis and development of MDS and relate with the prognosis of MDS patients.

[Clinical and Laboratorial Characteristics of Primary Acute Myeloid leukemia with Philadelphia Chromosome and Inversion 16].

OBJECTIVE: To summarize the clinical characteristics as well as diagnosis and treatment in 1 case of acute myeloid leukemia(AML) with coexpression of Ph and inv(16). METHODS: A series of clinical tests, the cellular morphological, immunological, cytogenetic and molecular biological examinations of leukemia cells were performed. RESULTS: The clinical characteristics of this patient were very common. The cellular morphology is similar to the AML with inv(16). The leukemia cells were stained positively for CD13, CD33, CD34, CD117 and HLA-DR. Karyotypic analysis showed a complex chromosome abnormality including inv(16) and Ph, and the FISH analysis showed that the percentage of rearrangement of CBFß allele was over that of the BCR-ABL fusion signals. The obvious adverse events did not occur in this patient within 3 years. CONCLUSION: Ph as secondary aberration of inv(16) rarely occures in primary AML cases, and so far there have not been the clear criteria of diagnosis and treatment. The cytogenetic and molecular biology could provide the basis for diagnosis. Moreover, autologous hematopoietic stem cell transplantation combined with imatinib probably is one of the effective treatment methods.

Clonal origin and evolution of myelodysplastic syndrome analyzed by dysplastic morphology and fluorescence in situ hybridization.

Myelodysplastic syndromes (MDS) are clonal disorders of hematopoietic stem/progenitor cells. As bone marrow cells are extremely diverse in these disorders, the origin and evolution of MDS clones are difficult to identify and trace. Cellular dysplasia is a distinct morphologic feature; however, whether the dysplastic cells represent abnormal clones or only nonspecific superficial phenomena remains to be clarified. To address this question, 97 patients were examined for dysplasia features, among them bone marrow slides of 16 patients with chromosomal abnormalities were subjected to fluorescence in situ hybridization (FISH) to determine the karyotype of these dysplastic cells. Furthermore, the emerging frequencies of abnormal karyotypes in various differentiated stages of each lineage were also evaluated by a combination of morphological evaluation and FISH karyotyping. Our results indicate that the overall percentage of dysplastic cells does not differ significantly among the WHO subtypes, while the megakaryoid lineage presents the most frequent dysplasia in all subtypes. A positive correlation between dysplastic cells and FISH-detectable abnormal clones was observed, but the dysplastic morphology was not a specific feature of FISH-detectable abnormal clones. FISH-detectable abnormal clones can differentiate into mature granulocytes and erythrocytes, in coexistence with cells originating from the normal clones.

[Correlation between expression of SIL-TAL1 fusion gene and deletion of 6q in T-cell acute lymphoblastic leukemia].

The present study was designed to investigate the prevalence and clinical significance of SIL-TAL1 rearrangements in T-cell acute lymphoblastic leukemia (T-ALL). The incidence of SIL-TAL1 rearrangements was analyzed by nest real-time quantitative polymerase chain reaction (RT-PCR) in 68 patients with T-ALL. Karyotypic analysis was performed by conventional R-banding assay and array-based comparative genomic hybridization (array-CGH). The results showed that SIL-TAL1 rearrangements were identified in 10/26 (38.5%) pediatric and 2/42 (4.8%) adult T-ALL cases, which indicate a pediatric preference for SIL-TAL1 rearrangements in T-ALL. Two different transcripts were detected in 6/12(50%) T-ALL samples. Abnormal karyotypes were detected in 6 out of 11 cases (54.5%) and a deletion of the long arm of chromosome 6 was observed in 4 cases. Array-CGH results of 2 T-ALL cases with SIL-TAL1 rearrangement revealed that this fusion gene was resulted from a cryptic deletion of 1p32, and the overlap region of 6q deletion was 6q14.1-16.3. These cases with SIL-TAL1 fusion had a higher white blood cell (WBC) count and higher serum levels of lactate dehydrogenase (LDH) than cases without SIL-TAL1 fusion. It is concluded that SIL-TAL1 rearrangements are associated with loss of heterozygosity of chromosomal 6q, and SIL-TAL1-positive patients are younger than SIL-TAL1-negative patients. In contrast to the cases without SIL-TAL1 fusion, there are many adverse prognostic factors in the cases with SIL-TAL1 fusion, such as higher WBC count and higher LDH levels.

[Deletions and rearrangements of PAX5 gene in B-lineage acute lymphoblastic leukemia].

OBJECTIVE: To determine the frequency paired-box domain 5 (PAX5) gene alterations in B-lineage acute lymphoblastic leukemia (B-ALL) harboring 9p abnormalities and its implication for clinical prognosis. METHODS: Bacterial artificial chromosomes RP11-344B23 and RP11-652D9 encompassing the PAX5 gene were selected. DNA was extracted with conventional method and labeled with fluorescein by nicking transition. Fluorescence in situ hybridization (FISH) was used to determine the rearrangement or deletion of the PAX5 gene in B-ALL harboring chromosome 9p abnormalities. Clinical and laboratory features of patients were analyzed. RESULTS: Fifty cases were analyzed with FISH. Complete deletion was observed in 23 patients (46%), partial deletion was observed in 2 patients (4%), and rearrangement was detected only in 1 case. The total frequency of abnormalities was 52% (26/50). No significant difference was found in clinical features of patients with or without PAX5 rearrangement or deletion. CONCLUSION: The frequency of PAX5 gene alterations in B-ALL harboring 9p abnormalities was 52%. However, no significant difference was found between patients with and without PAX5 alterations.

[Clinical and laboratorial analysis for 15 adult cases of mixed phenotypic acute leukemia with Ph chromosome and/or positive BCR-ABL].

The purpose of this study was to summary the clinical and laboratorial features in 15 adult cases of mixed phenotypic acute leukemia with Ph chromosome and/or BCR-ABL fusion gene positive (Ph(+)MPAL), 15 adult patients with Ph(+)MPAL were defined by WHO-2008 classification. The clinical characteristics, results of morphology, immunology, cytogenetics and molecular genetic detections and results of follow-up in 15 adult patients with Ph(+)MPAL were analyzed retrospectively. The results showed that 15 patients among 87 cases of MPAL demonstrated Ph(+)MPAL (17.2%; 15/87) (7 males and 8 females), their median age was 51 (range 16-81) year old and median WBC count at diagnosis was 69 (12.7-921)×10(9)/L. Based on FAB criteria, these patients showed different morphologic types, including AML (13.3%; 2/15), ALL (40.0%; 6/15), HAL (46.7%; 7/15). Immunologic analysis indicated that 15 cases of Ph(-)MPAL were all classified as B-lymphoid +myeloid mixed immunophenotype. Except one patient, all expressed CD34 antigen on the surface of leukemia cells with 64.3% strong positive, only Ph (53.3%; 8/15), Ph with additional chromosomal abnormalities (33.3%; 5/15) and normal karyotype (13.3%; 2/15) were cytogenetically identified. BCR-ABL fusion gene transcript positive were detected by multiplex reverse transcription PCR in all cases, with e1a2 subtype (p190) (40.0%; 6/15) and b2a2 or b3a2 (p210) subtype (60.0%; 9/15). Four out of 7 (57.1%) patients were found to have IKZF1 gene deletion, without other common gene mutations. Seven out of 10 cases (70.0%) achieved complete remission (CR) after one cycle of induction chemotherapy. In the induction stage, CR rate seemed higher when tyrosine kinase inhibitors (TKI) were added to chemotherapy (83.3%:50.0%; P = 0.206). Overall survival (OS) in 4 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT) was longer than that in 4 patients received chemotherapy alone (P = 0.004). It is concluded that Ph(+)MPAL mainly is expressed as B+My phenotype. The majority of patients is older and has CD34 overexpression. In the aspect of molecular genetics, the Ph(+)MPAL is similar to other acute leukemia with Ph chromosome. Ph(+)MPAL is a subtype of acute leukemia with poor prognosis. WBC count at diagnosis is an independent prognostic factor. The combination of TKI and allo-HSCT can improve their long-term survival, which needs to be confirmed through carrying out a prospective and multicenter clinical trial for newly diagnosed Ph(+)MPAL.

[Clinical and experimental characteristics of 20 patients with acute myeloid leukemia with complex variant of t(8; 21)].

This study was aimed to summarize and analyze the morphology, immunophenotype, cytogenetics, molecular biology (MICM), tyrosine kinase (TK) gene mutations and clinical features of acute myeloid leukemia (AML) with complex variant of t(8;21). A retrospective study was performed for 20 AML patients with complex variant of t(8;21) in our hospital from January 1994 to April 2012, including analysis of clinical feature, immunophenotype, chromosome karyotype, treatment regimen, as well as the overall survival (OS) and relapse-free survival (RFS). Mutations of C-KIT, FLT3-ITD, FLT3-TKD and JAK2V617F were detected by genomic DNA PCR and the sequencing was per-formed in 13 AML patients with complex variant of t(8;21). The results showed that (1) the incidence of 20 AML patients with complex variant of t(8; 21) was 2.4% of total t(8; 21) AML patients. In 20 AML patients with complex variant of t(8;21), 1 case was M1, 17 cases were M2, 2 cases were M4; 10 cases were myeloid phenotype and the other 3 were myeloid plus lymphoid phenotype. There were 16 kinds of cytogenetics additional involvement of chromosomal breakpoints: lp22, 1p32, 2q35, 2q14, 3p25, 5q13, 6p22, 7q21, llq11, 1lq13, 12q14, 12q24, 12p12, 14q32, 15p13, 20q12. (2) C-KIT aberrations were detected in 30.8% cases, all mutated in exon 17 (mutkit 17), only 1 case had JAK2V617F mutation. The result of FLT3 mutation screenings in AML patients with complex variant of t(8; 21) was negative. Of 5 patients with gene mutations, 1 patient (20%) achieved complete remission (CR), the median RFS and median OS time were 6.5 months and 8.9 months respectively. Of the 8 patients without gene mutations, 6 patietns (75%) achieved CR; the median RFS and median OS time were 26.6 months and 27.7 months respectively. It is concluded that the AML patients with complex variant of t(8;21) shows typical features of t(8;21) AML, but the existence of the tyrosine kinase-related gene mutation has important implications on remission rate and long-term survival of patients treated by induction chemotherapy.

[Study of the clonal origin and development of MDS by FISH analysis of dysplasia cells in bone marrow of patients with MDS].

This study was purpose to explore whether the dysplasia of myelodysplastic syndromes (MDS) is unspecific feature or results of the abnormal clone, and to provide the evaluation of abnormal clone changes in bone marrow cells of MDS patients. The dysplasia cells in bone marrow smears was analyzed by morphologic observation, the clonal origin and development in 16 cases of MDS with abnormality of chromosome karyotypes were investigated by FISH combined with morphologic observation. The results found that both the dysplastic and nondysplastic bone cells displayed abnormal clones in the erythroid and granulocytic cells. The dysplastic bone marrow cells displayed more abnormal clones than the nondysplastic bone marrow cells in most of the patients, and the abnormal clones displayed more dysplastic cells than the normal clones. Most of the dysplastic and nondysplastic megakaryocytes were derived from abnormal clones. The abnormal clone showed a decreasing trend from the primitive stage to the terminal stage of cell differentiation. It is concluded that there is a correlation between the dysplastic cells and the abnormal clones in MDS, but the dysplasia of bone marrow cells is not a specific feature. The abnormal clones can differentiate into mature granulocytes and erythrocytes, and can be in coexistence with cells originated from the normal clones.

[Multivariate analysis of imatinib resistance-related factors during the treatment of chronic myeloid leukemia].

OBJECTIVE: To explore efficacy of imatinib for patients with chronic myeloid leukemia(CML) and its resistance-related factors during the treatment. METHODS: The clinical data of 214 CML patients received imatinib were analyzed respectively in our hospital from April 2005 to December 2010. The therapy history and efficacy of regular follow-up and factors influencing drug resistance were analyzed. COX regression analysis was used to perform the univariate and multivariate analysis. RESULTS: Until the end of follow up, thirty-one patients (14.5%) occurred drug resistance. One of them was in accelerated phase(AP), and two in blast phase(BP); 69.2% of patients achieved a complete cytogenetic response(CCyR), and 31.3% of patients achieved a major molecular response(MMR). COX analysis was performed in 207 chronic phase(CP) patients. Univariate analysis showed that the course of disease before treatment, the hemoglobin count, the white blood cell count, whether achieved CCyR or not and whether achieved MMR or not were the influencing factors for imatinib resistance. Multivariate analysis showed that whether achieved CCyR or not was the independent factor for drug resistance. CONCLUSION: Whether achieved CCyR or not is an independent factor and also a protective factor for imatinib resistance in patients with CML.

[The different characteristics of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant Philadelphia chromosome-positive acute lymphoblastic leukemia and chronic myeloid leukemia].

OBJECTIVE: To identify the distribution and differentiation of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL). METHODS: Bone marrow or peripheral blood samples of 112 imatinib resistant CML patients and 21 Ph(+)ALL patients were obtained from the first affiliated hospital of Soochow university according to local law. Total RNA was extracted from the mononuclear cells using a TRIzol reagent. ABL kinase domain (KD) mutation was detected by direct sequencing. RESULTS: Of the 112 imatinib resistant CML patients, 54.46%(61 cases) had ABL KD mutation. Twenty-three mutants were identified in 20 amino acid sites and 23.21% (26 cases) ABL KD mutations were in P-loop region. ABL KD mutations were also detected in 71.43% (15 cases) imatinib resistant Ph(+)ALL patients, with 10 mutations in 8 amino acid sites. The most frequent mutation was T315I (28.57%), followed by E255K/V (19.05%) and Y253F/H (14.29%). The frequency of T315I was much higher in imatinib resistant Ph(+) ALL than that in imatinib resistant CML (P = 0.001). Ph(+)ALL with additional chromosomal aberrations also had a higher rate of ABL KD mutation than that of CML (P = 0.010). Ph(+)ALL gained ABL KD mutation faster than CML (P < 0.010). CONCLUSION: Chinese imatinib resistant CML and Ph(+)ALL patients had different characteristics in ABL KD mutation. The rate of ABL KD mutation in Ph(+)ALL with additional chromosomal aberrations was much higher than that of CML with additional chromosomal aberrations.