Evaluation of next-generation sequencing versus next-generation flow cytometry for minimal-residual-disease detection in Chinese patients with multiple myeloma.

PURPOSE: To evaluate the efficacy of next-generation sequencing (NGS) in minimal-residual-disease (MRD) monitoring in Chinese patients with multiple myeloma (MM). METHODS: This study analyzed 60 Chinese MM patients. During MRD monitoring in these patients' post-therapy, clonal immunoglobulin heavy chain (IGH) rearrangements were detected via NGS using LymphoTrack assays. MRD monitoring was performed using NGS or next-generation flow cytometry (NGF), and the results were compared. Additionally, the sensitivity and reproducibility of the NGS method were assessed. RESULTS: The MRD detection range of the NGS method was 10-6-10-1, which suggested good linearity, with a Pearson correlation coefficient of 0.985 and a limit of detection of 10-6. Intra- and inter-assay reproducibility analyses showed that NGS exhibited 100% reproducibility with low variability in clonal cells. At diagnosis, unique clones were found in 42 patients (70.0%) with clonal IGH rearrangements, which were used as clonality markers for MRD monitoring post-therapy. Comparison of NGS and NGF for MRD monitoring showed 79.1% concordance. No samples that tested MRD-positive via NGF were found negative via NGS, indicating the higher sensitivity of NGS. MRD could be detected using NGS in 6 of 7 samples before autologous hematopoietic stem-cell transplantation, and 5 of them tested negative post-transplantation. In contrast, the NGF method could detect MRD in only 1 sample pre-transplantation. CONCLUSION: Compared with NGF, NGS exhibits higher sensitivity and reproducibility in MRD detection and can be an effective strategy for MRD monitoring in Chinese MM patients.

Identification of concurrent STAT3::RARA and RARA::STAT5b fusions in a variant APL case.

Acute promyelocytic leukemia (APL) with typically PML::RARA fusion gene caused by t (15;17) (q22; q12) was distinguished from other types of acute myeloid leukemia. In a subset of patients with APL, t (15;17) (q22;q21) and PML::RARA fusion cannot be detected. In this report, we identified the coexistence of STAT3::RARA and RARA::STAT5b fusions for the first time in a variant APL patient lacking t (15;17)(q22;q21)/PML::RARA fusion. Then, this patient was resistant to all-trans retinoic acid combined arsenic trioxide chemotherapy. Accurate detection of RARA gene partners is crucial for variant APL, and effective therapeutic regime is urgently needed.

Molecular characteristics in Chinese with chronic lymphocytic leukemia by next-generation sequencing: A single-center retrospective analysis.

INTRODUCTION: Although the prevalence of Asian chronic lymphocytic leukemia (CLL) patients is not as high as that of Caucasians, there are more atypical CLLs in Asia whose genetic characteristics and their clinical significance are distinct and remain unclear. METHODS: A retrospective analysis of 85 CLL samples in our center was conducted from 2019 to 2022. We used next-generation sequencing with a 172 gene panel to explore the multi-gene mutational data and the mutational status of immunoglobulin heavy variable (IGHV) gene. RESULTS: MYD88 (20.0%) was the most frequently mutated gene, much higher than in Europe, followed in order by TP53 (18.8%), NOTCH1 (14.1%), IGLL5 (11.8%), and DNMT3A (8.2%). In addition, the incidence of ATM and SF3B1 mutations was relatively lower in our centre compared to Europe. Mutated (M)-IGHV patients were more likely to have a cooccurrence of MYD88 mutation, while complex karyotype and DNMT3A mutation were more common in the unmutated (U)-IGHV group. MYD88 mutated CLL was characterized by prevalence in young males in high-risk staging, with isolated 13q deletion and concomitant mutation of IGLL5. CLL patients with MYD88 and TP53 mutation showed an unfavorable prognosis. CONCLUSION: These results would be valuable in helping to understand the characteristics and significance of cytogenetic genetics in Chinese patients with CLL.

Blast phase of chronic myeloid leukemia with concurrent BCR::ABL1 and SET::NUP214: A report of two cases.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm defined by the presence of t(9;22)(q34;q11.2)/BCR::ABL1. Additional chromosomal abnormalities play an important role in the progression to CML. However, the additional fusion gene was rarely reported such as CBFB::MYH11. In this report, we described two cases of the co-occurrence of BCR::ABL1 and SET::NUP214 in CML-BP for the first time, which is associated with poor outcomes during tyrosine kinase inhibitor (TKI) treatment. Meanwhile, we retrospectively analyzed SET::NUP214 fusion transcript of the two cases at initial diagnosis of the CML chronic phase by quantitative RT-PCR, and detected at a ratio of 1.63% and 1.50%, respectively. SET::NUP214 may promote disease progression during the transformation of CML. This study highlights the importance of extended molecular testing at the initial diagnosis of CML-CP at TKI resistance and/or disease transformation.

Novel MLL/KMT2A-MON2 fusion in a child with therapy-related acute myeloid leukemia after treatment for acute promyelocytic leukemia.

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML), which is characterized by the reciprocal t (15;17) (q24; q21) translocation, resulting in PML-RARA gene fusion. Therapy-related AML (t-AML) is a serious complication after cytotoxic and/or radiation therapy in many malignant diseases. In this report, MLL/KMT2A-MON2, with balanced chromosomal translocation t (11;12) (q23; q14), was identified as a novel fusion in a child transformed to t-AML after successful treatment of APL. This study emphasized that clinical monitoring with an integrated laboratory approach is essential for the diagnosis and treatment of t-AML.

[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.

[Molecular cytogenetic characterization of five patients with myeloid leukemia and t(12;22)(p13;q12)].

OBJECTIVE: To explore the clinical and laboratory characteristics of 5 patients with myeloid leukemia and t(12;22)(p13;q12). METHODS: Bone marrow cells were cultured for 24 h and analyzed by standard R-banding. Rearrangement of the MN1 gene was detected by fluorescence in situ hybridization (FISH) using dual color break-apart MN1 probes. MN1-ETV6 and ETV6-MN1 fusion genes were detected by reverse transcription polymerase chain reaction (RT-PCR). And the products were subjected to direct sequencing. RESULTS: Among the 5 patients, 2 had AML-M0, 2 had AML-M4, and 1 had CMM0L at the initial diagnosis. t(12;22)(p13;q12) was the primary abnormality among all patients. Rearrangements of MN1 gene were detected by FISH in all patients. MN1-ETV6 and ETV6-MN1 fusion genes were detected respectively in 4 and 3 patients. CONCLUSION: t(12;22)(p13;q12) is a rare but recurrent chromosomal abnormality in myeloid leukemia, and is related to poor prognosis. allo-SCT is valuable for patients with t(12;22)(p13;q12).

The impact of early molecular response in children and adolescents with chronic myeloid leukemia treated with imatinib: a single-center study from China.

Chronic myeloid leukemia (CML) is rare among children and adolescents. The early molecular response (EMR) is an important prognostic significance for adult CML patients. This study explored the impact of EMR on the prognosis in 40 children and adolescents with CML-CP treated with imatinib (IM). Our results showed that a high proportion of patients failed to achieve the BCR-ABL1/ABL1 International Scale (IS) ≤ 10% at 3 months. Children with a BCR-ABL1/ABL1 ≤ 10% at 3 months and <1% at 6 months increased the rate of achieving complete cytogenetic response (CCyR) and/or major molecular response (MMR) at 12 months compared to those with BCR-ABL1/ABL1 > 10%. With a median follow-up of 42 months, patients with BCR-ABL1/ABL1 ≤ 10% showed a better 4-year event-free survival (EFS). In summary, achieving BCR-ABL1/ABL1 IS ≤10% at 3 months and <1% at 6 months would increase the possibility of achieving MMR, CCyR at 12 months and had a better 4-year EFS. EMR is a reliable prognosticator for young CML patients treated with IM.

[The study of 4 cases of myeloid neoplasm with t (5;12) (q33;p13) and the literatures review].

OBJECTIVE: To report clinical and laboratory features of 4 cases of myeloid neoplasm with t (5;12) (q33;p13). METHODS: Cytogenetic examination of bone marrow cells obtained from patients was performed by 24 h culture method. R banding technical was used for karyotype analysis. PDGFRß gene rearrangement was detected by FISH using dual color break apart PDGFRß probe. ETV6-PDGFRß fusion genes were detected by multiple-reverse transcription polymerase chain reaction (RT-PCR). Direct sequencing analysis was performed on the PCR products in case 1. Immunophenotype analysis was carried out by flow cytometry. Four cases were treated with imatinib (IM) and followed up. RESULTS: The diagnoses included 3 MPN and 1 AML-M2. The t (5;12) (q33;p13) was a primary abnormality in 3 cases of MPN and a secondary abnormality in 1 case of AML-M2. PDGFRß gene rearrangement and ETV6-PDGFRß fusion genes were detected by FISH and multiple-RT-PCR in 4 cases, respectively. The immunophenotypical analysis of leukemia cells showed positive for CD13, CD33 and CD34. Two cases obtained MMR after the treatment of IM, one case complete hematologic and complete cytogenetic response. ETV6-PDGFRß was negative detected by multiple-RT-PCR after the treatment of IM, but relapsed and died soon in case 4. CONCLUSIONS: The t (5;12) myeloid neoplasm was a subtype with unique features. The t (5;12) maybe a primary chromosome abnormality in MPN and a secondary in AML. MPN with t (5;12) could benefit from IM, but not for AML. Dual-FISH was a reliable tool for detecting PDGFRß rearrangement.

Microarray CGH analysis of hematological patients with del(20q).

Deletion of the long arm of chromosome 20 is a common abnormality underlying hematological malignancy. We analyzed 21 patients with hematologic diseases confirmed to carry the del(20q) by conventional cytogenetics and fluorescence in situ hybridization using microarray comparative genomic hybridization (aCGH). Seventeen patients were positive for del(20q), but this deletion was not detected in four patients. All deletions detected were interstitial of which continuous deletions were seen in 12 patients and discrete deletions in five. Three commonly deleted regions (CDRs) and two commonly retained regions (CRRs) were defined: CDR1 spanning 3.05Mb (34560497-37608229) within 20q11.23, CDR2 spanning 1.76Mb (37851501-39615698) within 20q12, CDR3 spanning 116Kb (48120412-48236791) within 20q13.13, CRR1 spanning 1.1Mb (29374726-30428250) within 20q11.21, and CRR2 spanning 2.5Mb (60484668-62963548) within 20q13.33. Duplications of retained regions (20q11.21) were found in five cases with similar erythroid hyperplasia (2 M6, 3 MDS). Moreover, duplication of 20p13-p11.21 was also found in two cases with M6. Using the CDRs and CRRs, we identified the candidate genes we searched for using the UCSC Genome Browser. Our data suggest that aCGH analysis is useful for more precisely defining breakpoints on 20q. Further work is required to identify candidate pathogenic genes within these CDRs and CRRs.

The characteristics and prognostic analysis in 213 myeloid malignancy patients with del(20q): a report of a single-center case series.

The clinical and hematological characteristics and the prognostic significance of del(20q) were investigated in a consecutive series of 213 myeloid malignancies. In the analyses, the cases were divided into three subgroups according to diagnosis or four subgroups according to cytogenetic data. Patients in the myeloproliferative neoplasms subgroup had high WBCs and platelet counts at initial diagnosis. The del(20q) occurred predominantly in older men. Sole del(20q) was observed most often in myelodysplastic syndromes, while del(20q) as a part of complex karyotypes was observed predominantly in acute myeloid leukemia. The most frequent additional abnormalities accompanying del(20q) were -5/del(5q), -7/del(7q) and +8; t(20;21)(q11;q11) and double del(20q) were two rare but recurrent abnormalities secondary to del(20q). In all types of diseases, patients with a sole del(20q) had a favorable prognosis. The presence of any additional abnormality with del(20q) had an unfavorable outcome. Patients with i(20q) had an unfavorable prognosis. Patients with the minor del(20q) clone had a better median survival than those with the major del(20q) clone.

p210 BCR/ABL1 as a secondary change in a patient with acute myelomonocytic leukemia (M4Eo) with inv(16).

t(9;22) as a secondary change of inv(16) is a rare chromosome aberration in de novo acute myeloid leukemia (AML). Here, we report the case of a 31-year-old man with this rare abnormality. Karyotypic analysis showed a complex chromosome aberration:46,XY,der(8)t(8;10)(p23;q25),der(10)t(8;10)t(10;16)(p13;q22),der(16)inv(16)(p13q22)t(10;16)[4] and 46,XY,idem,t(9;22)(q34;q11)[6]. Fluorescence in situ hybridization detected both the CBFB and the BCR/ABL1 rearrangements. CBFB/MYH11 (A type) and BCR/ABL1 (b3a2) fusion transcripts were both detected by real-time quantitative RT-PCR. The patient was treated with standard AML chemotherapy and autologous peripheral blood stem cell transplantation. He also received imatinib (400 mg/day) during the chemotherapy intervals and after transplantation. Molecular remission was achieved at the beginning of the third chemotherapy and he remained in remission until the last follow-up (22 months after diagnosis). To our knowledge, this is the first reported case of de novo AML in which has p210(BCR/ABL1) occurred as a secondary change of inv(16).