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To date, the research on dendritic cells (DCs) and their correlated neoplasms has not been clear. Blastic plasmacytoid dendritic cell neoplasm (BPDCN) and mature plasmacytoid dendritic cell proliferation (MPDCP) are two types of malignancies originating from plasmacytoid dendritic cells (pDCs). Some evidence has indicated the existence of other pDC neoplasms. In addition, cases of myeloid neoplasms (MNs), acute myeloblastic leukemia (AML), and myelodysplastic syndrome (MDS) with increased pDCs (AML/MDS‐pDCs) seem to have immature DCs according to the vaguely consistent expression of markers among MNs and pDCs, which appear to fit the developmental pattern of normal DCs. We analyzed 14 AML/MDS‐pDC cases mainly for their immunophenotype by flow cytometry and inferred their CD expression pattern. The patients' clinical information and other laboratory data were collected and reviewed. AML/MDS‐pDCs show a different pattern of markers from BPDCN and MPDCP. Three maturation‐involved stages were found in these AML/MDS‐pDCs patients. Stage I was the most immature stage and displayed an expression profile of CD34+/st+ CD117+/st+ BDCA2− BDCA4− CD123+ HLA‐DR+/st+ CD4− CD45dim+; Stage II was the more immature stage displayed a phenotype of CD34dim+ CD117dim+ BDCA2−/dim+ BDCA4−/dim+ CD123st+ HLA‐DR+/st+ CD4− CD45+; and Stage III was the mature stage showed CD34− CD117− BDCA2+/BDCA4+ CD123st+ HLA‐DR+/st+ CD4+ CD45+/st+. Three maturation‐involved stages overlapped well with the phenotypes of normal DC progenitors in a continuously developmental process: granulocyte, monocyte, and DC progenitors (GMDPs) and/or monocyte and DC progenitors (MDPs), common DC progenitors (CDPs), pDCs, and/or pre‐DCs. In this study, we considered AML/MDS‐pDCs as entities that were distinct from BPDCN and MPDCP and correlated the components of this tumor with the normal DC differentiation pathway, which provides new evidence for understanding DC neoplasms. © 2019 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]

Objective: To investigate the clinical and prognostic characteristics of primary acute myeloid leukemia (AML) with 11q23/KMT2A rearrangements., Methods: Clinical data of 90 patients with primary AML and 11q23/KMT2A rearrangements were analyzed retrospectively., Results: By karyotyping analysis, 80 of the 90 patients had translocations involving 11q23/KMT2A, with t(9;11)(p22;q23), t(6;11)(q27;q23), t(10;11)(p12;q23) and t(11;19)(q23;p13) being the most common ones, while 10 cases were found to have non-translocation abnormalities. The overall complete remission (CR) rate was 75.6%, and patients with t(6;11) had lower CR rate compared with non-t(6;11) patients (47.1% vs. 82.2%, P = 0.005). After a median follow-up of 24.5 months, the patients receiving allo-hematopoietic stem cell transplantation (allo-HSCT) had significantly higher 3-year overall survival (OS) (80.3% vs. 16.6%, P < 0.001) and 3-year event-free survival (EFS) (73.5% vs. 16.3%, P < 0.001) compared with non-transplant patients. Patients with t(6;11) had the lowest 3-year OS (11.8% vs. 56.0%, P < 0.001) and 3-year EFS (5.9% vs. 53.8%, P < 0.001) compared with other type of abnormalities. No significant difference was noted in the survival between patients with t(9;11) and non-t(9;11) regardless whether they had received HSCT., Conclusion: The clinical characteristics of primary AML with 11q23/KMT2A rearrangements are heterogeneous. Patients did not receive HSCT had poorer survival, particularly with the presence of t(6;11). Allo-HSCT could significantly improve the survival of such patients.

Objective: To assess the value of fluorescence in situ hybridization (FISH) technique for the verification of the clonalities of non-clonal cytogenetic abnormalities (n-CCA) identified by conventional chromosome banding analysis (CBA) in patients with Myelodysplastic syndrome (MDS)., Methods: Clinical data and results of karyotyping and FISH assays for 91 patients of MDS with n-CCA identified by CBA were retrospectively analyzed. In total 94 non-clonal +8, 5q-, -7/7q- or 20q- were detected by CBA, among which 43 (45.7%) were verified to be clonal abnormalities by FISH., Results: The detection rates for +8, 5q-, -7/7q- and 20q- by FISH were 47.6% (30/63), 25% (2/8), 41.7% (5/12), 40% (2/5) and 66.7% (4/6), respectively, with the positive cells accounting for 4% to 90% of all counted cells, with a median value of 7%. The 91 patients were divided into three groups including ≥ 20, 10 ~< 20 and < 10 based on the numbers of metaphase cells in CBA, and the detection rates by FISH for the three groups were 43.7% (31/71), 33.3% (3/9) and 63.6% (7/11), respectively, which showed no statistically difference (P > 0.05). Continuous CBA and FISH surveys were conducted for 26 patients who received supportive treatment, and the results revealed that 91.7% (11/12) of FISH-verified positive abnormalities had persisted, whereas 92.9% (13/14) of the n-CCA verified as negative by FISH was transient., Conclusion: Nearly half of the CBA identified n-CCA have been verified as clonal aberrations by FISH, and the FISH detection rate showed no correlation with the number of metaphase cells. FISH test is strongly recommended for verifying the clonalities of n-CCA detected by CBA, and continuous cytogenetic survey of the patients with MDS is necessary.

Objective: To trace a rare case of chronic myeloid leukemia (CML) with a four-way Philadelphia chromosome variant by cytogenetic analysis in order to provide a basis for the selection of treatment., Methods: Bone marrow morphology, chromosomal karyotyping, fluorescence in situ hybridization (FISH) and real-time quantitative PCR (RQ-PCR) were used for the diagnosis and staging of the disease. Point mutations in the tyrosine kinase domain of ABL1 gene were detected by Sanger sequencing., Results: The patient was initially diagnosed as CML in chronic phase (CML-CP) with a chromosomal karyotype of 46,XX,t(5;9;22;6)(q13;q34;q11;q25), while FISH revealed presence of a variant Philadelphia chromosome translocation. Clonal evolution has occurred after 38 months of tyrosine kinase inhibitor (TKI) treatment, when cytogenetic analysis revealed coexisting t(5;9;22;6)(q13;q34;q11;q25) and t(5;9;22;6;17)(q13;q34;q11;q25;q11). After 57 months of TKIs treatment, only the t(5;9;22;6;17) clone was detected. Three months later, hyperdiploidy with additional abnormalities were detected in addition to t(5;9;22;6;17). Three mutations, including p.Tyr253Phe, p.Thr315Ile and p.Gly250Glu, were identified in the tyrosine kinase domain of the ABL1 gene during the course of disease. The patient did not attain cytogenetic and molecular response to TKIs., Conclusion: The four-way variant translocation may be genetically unstable. Clonal evolution and genetic mutations are likely to occur during TKIs treatment, resulting in poor response to drug therapy. This observation, however, needs to be confirmed by large-scale studies.

Objective: To report on a case of therapy-related acute monocytic leukemia(t-AML) with t(11;17) (q23;q21)/MLL-AF17q after successful treatment for acute promyelocytic leukemia(APL) with t(15;17) (q22;q21)/PML-RARα., Methods: A MICM method (bone marrow morphology(M), immunophenotype(I), cytogenetics(C), and molecular biology(M)) was used for the diagnosis and classification of the disease at the time of onset and transformation., Results: The patient was initially identified with typical morphology and immunophenotype of APL. She has carried t(15;17)(q22;q21) and PML-RARα fusion gene but was without t(11;17)(q23;q21) or MLL gene abnormalities. After 13 months of successful treatment, she has transformed to AML with typical morphology and immunophenotype. t(11;17)(q23;q21) and MLL-AF17q fusion gene were detected in her bone marrow sample, while no PLZF-RARα fusion gene was detected by real-time quantitative reverse-transcription PCR(RQ-PCR) and fluorescence in situ hybridization(FISH)., Conclusion: t-AML is a serious complication after successful treatment of APL. t(11;17)(q23;q21) is not specific for the diagnosis of variant APL and can also be detected in t-AML. RQ-PCR and FISH are essential for the diagnosis of such patients.

Objective: To evaluate the efficiency of dasatinib as the second- or third-line tyrosine kinase inhibitor (TKI)in imatinib-resistant patients with chronic myeloid leukemia (CML)based on BCR-ABL mutation detection., Methods: 122 CML patients received dasatinib treatment, including 83 with imatinib-resistance and 39 with both imatinib- and nilotinib-resistance, 55 in the chronic-phase (CP), 21 in the accelerated- phase (AP)and 46 in the blast- phase (BP). Those harboring dasatinib highly- resistant mutations (T315I/A, F317L/V/C and V299L)were excluded based on BCR-ABL kinase domain mutation screening by Sanger sequencing at baseline. Hematologic, cytogenetic and molecular responses were evaluated regularly, and rates of progression-free-survival (PFS)and overall survival (OS)were analyzed. BCR- ABL mutation detection was performed once the patients failed on dasatinib., Results: In the CP patients, the rates of complete hematological response (CHR), complete cytogenetic response (CCyR), major molecular response (MMR)and molecular response 4.5 (MR4.5)were 92.7%, 53.7%, 29.6% and 14.8%, respectively. 4-year PFS and OS rates were 84.4% and 89.5%, respectively. In the AP patients, HR and CCyR rates were 81.0% and 35.0%; and 3-year PFS and OS rates were 56.1% and 59.3%, respectively. In the BP patients, HR and CCyR rates were 63.0% and 21.4%; and 1-year PFS and OS rates were 43.6% and 61.8%, respectively. Outcomes were similar when dasatinib was used as the second- line TKI or the third-line TKI. Of the 75 patients who were resistant to dasatinib, 37 (48.7%)developed new mutation(s), and T315I (59.5%)was the most common mutation type. The patients who already harbored mutation(s)before dasatinib therapy achieved similar responses and outcomes to those with no mutation at baseline. However, they had higher likelihood of developing additional mutations associated with resistance to dasatinib (65.7%vs 34.1%,P=0.006)., Conclusions: Dasatinib was proved to be effective in the treatment of imatinib- or/and nilotinib-resistant CML patients, especially in both CP and AP cohorts. The significance of BCR-ABL mutation screening and monitoring should be highlighted before and during dasatinib therapy.

Objective: Compare the correlation and the concordance of simultaneous bone marrow cytogenetic and peripheral blood molecular responses in patients with chronic myeloid leukemia (CML) during tyrosine kinase inhibitor (TKI) treatment., Methods: A total of 1 030 pairs of simultaneous bone marrow and peripheral blood samples from 419 patients with CML during TKI treatment were analyzed with standard G-banding techniques and real-time quantitative reverse transcriptase PCR (Q-PCR)., Results: The Spearman correlation coefficient for the paired analysis of the percentage of Ph- positive metaphases versus Q-PCR (BCR-ABL/ABL) values was 0.655 (n=1 030, P<0.01). There was a significant difference in terms of BCR-ABL values among all three cytogenetic response groups of no partial cytogenetic (no PCyR), partial cytogenetic (PCyR) and complete cytogenetic responses(CCyR) (P<0.01). 93.8% of the patients in CCyR had BCR-ABL≤1% [International Scale (IS)], and 97.5% of those with BCR-ABL≤0.1% (IS) were in CCyR. There was good concordance of 86.2% (888 of 1 030 samples) when BCR-ABL values according to cutoffs of BCR-ABL>10%(IS), ≤10%->1%(IS)and ≤1%(IS) were coupled with cytogenetic responses including no PCyR, PCyR and CCyR. Furthermore, 497 pairs of samples from 279 patients with newly diagnosed CML in chronic phase during the first year on TKI as first-line therapy were analyzed. Concordances between major cytogenetic response and BCR-ABL≤10%(IS) at 3 months, CCyR and BCR-ABL≤1%(IS) at 6 months and 12 months were 89%, 83.5% and 92.1%, respectively., Conclusion: There were significant correlation and concordance between cytogenetic and molecular responses, and some differences in assessment of early responses between using cytogenetic and molecular analyses in CML patients during TKI treatment.