Performance of a novel eight-color flow cytometry panel for measurable residual disease assessment of chronic lymphocytic leukemia.

BACKGROUND: Measurable residual disease (MRD) is an important prognostic indicator of chronic lymphocytic leukemia (CLL). Different flow cytometric panels have been developed for the MRD assessment of CLL in Western countries; however, the application of these panels in China remains largely unexplored. METHODS: Owing to the requirements for high accuracy, reproducibility, and comparability of MRD assessment in China, we investigated the performance of a flow cytometric approach (CD45-ROR1 panel) to assess MRD in patients with CLL. The European Research Initiative on CLL (ERIC) eight-color panel was used as the "gold standard." RESULTS: The sensitivity, specificity, and concordance rate of the CD45-ROR1 panel in the MRD assessment of CLL were 100% (87/87), 88.5% (23/26), and 97.3% (110/113), respectively. Two of the three inconsistent samples were further verified using next-generation sequencing. In addition, the MRD results obtained from the CD45-ROR1 panel were positively associated with the ERIC eight-color panel results for MRD assessment (R = 0.98, p < 0.0001). MRD detection at low levels (≤1.0%) demonstrated a smaller difference between the two methods (bias, -0.11; 95% CI, -0.90 to 0.68) than that at high levels (>1%). In the reproducibility assessment, the bias was smaller at three data points (within 24, 48, and 72 h) in the CD45-ROR1 panel than in the ERIC eight-color panel. Moreover, MRD levels detected using the CD45-ROR1 panel for the same samples from different laboratories showed a strong statistical correlation (R = 0.99, p < 0.0001) with trivial interlaboratory variation (bias, 0.135; 95% CI, -0.439 to 0.709). In addition, the positivity rate of MRD in the bone marrow samples was higher than that in the peripheral blood samples. CONCLUSIONS: Collectively, this study demonstrated that the CD45-ROR1 panel is a reliable method for MRD assessment of CLL with high sensitivity, reproducibility, and reliability.

[Correlation between Expression Patterns of CD117/CD200 in Plasma Cells and Molecular Genetic Prognostic Parameters in Multiple Myeloma].

OBJECTIVE: To investigate the correlation between the expression of CD117 and CD200 in plasma cells and molecular genetic abnormalities in patients with multiple myeloma (MM). METHODS: 100 newly diagnosed MM patients were selected, and fresh bone marrow fluid was collected from the patients. The immunophenotypes and chromosomal structural variations of plasma cells were detected by flow cytometry (FCM) and fluorescence in situ hybridization (FISH). RESULTS: The positive expression frequencies of CD117 and CD200 in abnormal plasma cells of all MM patients were 44.0% and 44.0%, respectively. At least one molecular genetic abnormality was detected in 53 of the 75 patients who underwent FISH testing, and the overall detection rate was 70.7% (53/75). The detection rates of 1q21 (CKS1B ) duplication, 1p32 (CDKN2C ) deletion, p53 deletion and IgH rearrangement were 48.6% (36/74), 10.6% (7/66), 11.1% (8/72) and 32.9% (24/73), respectively. The incidence of IgH rearrangement in CD117+ patients was significantly lower than that in CD117- patients (P<0.05), and the proportion of 1p32 (CDKN2C ) deletion in CD200- patients was significantly lower than that in CD200+ patients (P<0.05). According to the expressions of CD117 and CD200, the patients were divided into 4 groups: CD117+CD200+, CD117+CD200-, CD117-CD200+ and CD117-CD200-. Further analysis showed that the incidence of IgH rearrangement in the CD117+CD200- group was significantly lower than that in the CD117-CD200+ group (P<0.05), and the deletion rate of 1p32 (CDKN2C ) gene in CD117+CD200- group was significantly lower than that in CD117+CD200+ group and CD117-CD200+ group (P<0.05). CONCLUSION: The difference in the expression patterns of CD117 combined with CD200 shows important value in judging the prognosis of MM patients, and the MM patients with CD117-CD200+ expression patterns in abnormal plasma cells have a worse prognosis.

[The Expression and Function of NK Cells in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To explore the expression characteristics of antigens and functional markers of natural killer (NK) cells in patients with acute myeloid leukemia (AML). METHODS: Multi-parameter flow cytometry was used to detect NK cell surface markers and their functional indicators in 56 newly diagnosed AML patients and 24 healthy controls, including activating receptors NKG2D, NKP46, DNAM-1, and killing indicators granzyme B, perforin. RESULTS: Referring to the WHO hematopoiesis and lymph tissue tumor classification criteria, 56 cases were roughly divided into three types: AML M1, M2, and M4/M5. However, there was no differences about NK cells among the three types, so it was no longer subdivided. NK cells were divided into two groups: CD3-CD56hiCD16- (CD56hiNK) and CD3-CD56dimCD16+ (CD56dimNK). Compared with CD56dimNK cell population, except for NKP46, the positive expression levels of NKG2D and other receptors of CD56hiNK cells in AML patients decreased (P<0.001). Compared with healthy controls, the proportion of CD56hiNK cells in AML patients increased, while the number and proportion of NK cells and proportion of CD56dimNK cells significantly decreased (P<0.05). The proportion of perforin in CD56hiNK cells significantly increased (P<0.05). The expression of DNAM-1 in CD56hiNK cells, NKG2D, DNAM-1, and perforin in CD56dimNK cells decreased significantly (P<0.05). There was no statistically significant difference in expression of other functional indexes in AML patients compared with corresponding indexes of healthy controls. In addition, the proportion of CD56hiNK cells was positively correlated with the expression of CD34+ in AML (r=0.303). CONCLUSION: Compared with CD56dimNK, the ratio of CD56hiNK and the expression of functional markers in AML patients are lower. Compared with healthy controls, the number and expression ratio of NK cells in AML patients decrease and the expression of functional markers is abnormal, indicating that its function is impaired.

BCL-2 expression promotes immunosuppression in chronic lymphocytic leukemia by enhancing regulatory T cell differentiation and cytotoxic T cell exhaustion.

BACKGROUND: Chronic lymphocytic leukemia (CLL) results in increased susceptibility to infections. T cell dysfunction is not associated with CLL in all patients; therefore, it is important to identify CLL patients with T cell defects. The role of B-cell lymphoma-2 (BCL-2) in CLL has been explored; however, few studies have examined its role in T cells in CLL patients. Herein, we have investigated the regulatory role of BCL-2 in T cells in the CLL tumor microenvironment. METHODS: The expression of BCL-2 in T cells was evaluated using flow cytometry. The regulatory roles of BCL-2 were investigated using single-cell RNA sequencing (scRNA-seq) and verified using multi-parameter flow cytometry on CD4 and CD8 T cells. The clinical features of BCL-2 expression in T cells in CLL were also explored. RESULTS: We found a significant increase in BCL-2 expression in the T cells of CLL patients (n = 266). Single cell RNA sequencing (scRNA-seq) indicated that BCL-2+CD4+ T cells had the gene signature of increased regulatory T cells (Treg); BCL-2+CD8+ T cells showed the gene signature of exhausted cytotoxic T lymphocytes (CTL); and increased expression of BCL-2 was associated with T cell activation and cellular adhesion. The results from scRNA-seq were verified in peripheral T cells from 70 patients with CLL, wherein BCL-2+CD4+ T cells were enriched with Tregs and had higher expression of interleukin-10 and transforming growth factor-ß than BCL-2-CD4+ T cells. BCL-2 expression in CD8+T cells was associated with exhausted cells (PD-1+Tim-3+) and weak expression of granzyme B and perforin. T cell-associated cytokine profiling revealed a negative association between BCL-2+ T cells and T cell activation. Decreased frequencies and recovery functions of BCL-2+T cells were observed in CLL patients in complete remission after treatment with venetoclax. CONCLUSION: BCL-2 expression in the T cells of CLL patients is associated with immunosuppression via promotion of Treg abundance and CTL exhaustion.

The potential differential diagnosis value and clinical significance of CD35 expression in B-chronic lymphoproliferative disorders.

BACKGROUND: Flow cytometry for immunophenotyping is the main method for diagnosing chronic lymphocytic leukemia (CLL). Differential diagnosis between CLL and other B-chronic lymphoproliferative disorders (B-CLPDs) is sometimes difficult. This study aimed to investigate whether cluster of differentiation 35 (CD35) could be a useful marker for the differential diagnosis of CLL and other B-CLPDs. METHODS: The CD35 expression on lymphoma cells from 516 B-CLPD patients (347 CLL, 169 other B-CLPDs) was investigated through flow cytometry analysis. Serum C3 and C4 levels in B-CLPD patients were also evaluated. RESULTS: The results showed that the expression percentage and mean fluorescence intensity of CD35 were reduced in CLL cases compared with other B-CLPD patients. Furthermore, CD35 <17% produced a sensitivity of 81.8% and a specificity of 88.4% for supporting the diagnosis of CLL. Additionally, the addition of CD35 to Matutes score improved the score's discriminative power. The sensitivity of the Matutes score was improved from 81.3% to 88.5%, and the accuracy was improved from 96.6% to 97.6%. Finally, 15.0% and 16.4% of CLL patients had defective serum C3 and C4 levels at diagnosis, respectively. CONCLUSIONS: Evaluating CD35 expression could have potential differential diagnostic value in distinguishing CLL from other B-CLPDs, especially between CLL and mantle cell lymphoma (MCL).

Prognostic value of circulating clonal plasma cells in newly diagnosed multiple myeloma.

OBJECTIVES: Multiple myeloma (MM) involves a clinically and biologically heterogeneous malignancy of plasma cells. It is difficult to predict the prognosis of MM. The presence of circulating clonal plasma cells (CPC) has been associated with a worse prognosis in patients with MM. METHODS: This study retrospectively analysed CPC in 108 newly diagnosed MM patients by 8-colour flow cytometry to investigate their value for predicting the outcome and combined the level of CPC with the revised International Staging System (R-ISS) to stratify the MM patients according to risk. RESULTS: CPC were detected in 58/108 patients (53.7%). The optimum cut-off for the prediction of overall survival was determined to be 0.105%. Patients with higher R-ISS stages seemed to harbour more CPC. A level of CPC≥0.105% was an independent risk factor for adverse outcomes (P<0.001). The combination of the R-ISS staging system and level of CPC was used to stratify MM patients according to risk, and the combination of R-ISS stage III and a level of CPC≥0.105% defined the ultra-high-risk group. CONCLUSION: This study suggests that a high proportion of CPC is associated with aggressive disease and that the use of the current R-ISS system in conjunction with assessment of the level of CPC may facilitate the stratification of newly diagnosed MM patients into clinically relevant prognostic subgroups.

Next-generation sequencing reveals gene mutations landscape and clonal evolution in patients with acute myeloid leukemia.

OBJECTIVES: The study aims to understand geneome diversification and complexity that developed in Acute myeloid leukemia (AML). METHODS: Next-generation sequencing (NGS) was used to identify the genetic profiles of 22 genes relevant to hematological malignancy in 204 patients with de novo non-M3 AML. RESULTS: At time of initial diagnosis, at least one mutation was identified in 80.9% of patients (165/204). The most commonly mutated gene was NPM1 (22.1%), followed by ASXL1 (18.1%), TET2 (18.1%), IDH2 (15.7%), CEBPA (14.7%), FLT3-ITD (13.2%) and DNMT3A (11.8%). Mutations landscape analysis indicated several patterns of co-occurring and mutual exclusive gene mutations. Some correlation was observed between gene mutations and clinicohematological features. Multivariate analysis showed that age >60 years, karyotypes, IDH2 and KIT mutations were the independent unfavorable prognostic factors for OS; NPM1-mut/ FLT3-ITD-wt was independently correlated with prolonged OS; whereas the independent poor risk factors for RFS were karyotypes, high WBC and RUNX1 mutation. According to different genotype demonstrated by multivariate analysis, 163 patients with intermediate-risk cytogenetics were classified into three subgroups: patients with NPM1-mut/ FLT3-ITD-wt or biallelic CEBPA mutation as favorable risk, patients with KIT, IDH2, TP53 or NRAS mutations as unfavorable risk, and the remaining was the intermediate risk. We also obtain information of clonal evolution during leukemia progression by observing five patients who underwent repeat NGS at relapse in our cohort. CONCLUSION: NGS techniques is a useful tool for discovering related gene mutations and clonal evolution in AML genomes, leading to novel targeted therapeutic approaches that could improve patients outcomes.

Clinical significance of CD200 expression in newly diagnosed multiple myeloma patients and dynamic changing during treatment.

The aim of our study was to determine the impact of CD200 expression in newly diagnosed myltiple myeloma (MM) patients. CD200+ patients had significantly shorter median overall survival time (OS) than CD200- patients (41.0 months vs. not reached, p = .009). The ratio of CD4+ to CD8+ T cells was lower in CD200+ patients and this reduction was significantly related to the increase of CD8+ T cells (p = .021). Moreover, we analyzed dynamic changes of CD200 expression in 47 CD200+ patients during treatment. Thirty-eight (80.9%) patients switched to CD200- during treatment. Those patients had a favorable survival compared with the others (median OS, 65.0 vs. 32.0 months, p < .001; median PFS, 29.0 vs. 11.5 months, p = .027). We concluded that CD200 expression is an independent marker for MM prognostic estimation during treatment.

Flow Cytometric Pattern of TCRVδ Subtype Expression Rapidly Identifies γδT Cell Lymphoma.

Background: γδT cell lymphoma (γδ TCL) is a class of hematopoietic malignancy that expresses the γδ T cell receptor (TCR) with a low incidence. Determining the clonal proliferation of γδT cells is important for the diagnosis of such malignancies. Few studies have used flow cytometry to detect VδTCR and its subtypes (Vδ1 and Vδ2) at the protein level, although it is a practical method for determining the neoplastic γδT cells. Methods: A TCRVδ-based 10-color protocol was designed for the detection of malignant proliferation of γδT subtype cells by multiparameter flow cytometry, and the diagnostic results were compared with the gene rearrangement results. Results: All 19 cases of γδ TCL were positive for cluster of differentiation 3 (CD3) and TCR γδ and presented with abnormal distribution patterns of Vδ1 and Vδ2, of which 16 of the 19 cases showed a restricted Vδ1 staining pattern and the remaining three cases lacked the expression of either Vδ1 or Vδ2. Among the 10 normal controls and 11 patients with reactively higher CD4 and CD8 double-negative ratio, the percentage of Vδ2 positive events (range: 16.4-99.0%) was significantly higher than that of Vδ1 (range: 0-50.5%; p < 0.0001), and all cases had a normal Vδ distribution pattern. To detect clonality, there was no difference in the detection rate between the TCRVδ analysis and the gene scanning techniques (p = 1.000) with a high degree of coincidence (Kappa = 0.850, p < 0.001). The heteroduplex analysis was less sensitive than the other methods but was more specific (100%) than the gene scanning techniques, and the TCRVδ subtype analysis had the highest sensitivity, specificity, positive predictive value, and negative predictive value. Compared with molecular methods, immunophenotyping is able to distinguish the T cell lineage. Conclusion: The γδT panel, based on the TCRVδ antibody by flow cytometry, could be advantageous for the rapid identification of suspected γδTCL.

Low absolute CD4+ T cell counts in peripheral blood predict poor prognosis in patients with newly diagnosed multiple myeloma.

The T lymphocyte system plays an active role in tumor immunosurveillance in multiple myeloma (MM), and abnormal T lymphocyte populations are often observed in patients with MM. In the current study, we evaluated the prognostic impact of abnormal T lymphocyte subset distributions in patients with newly diagnosed MM (NDMM). Between December 2012 to October 2016, 110 NDMM patients were included in this study. Multiparameter flow cytometry was applied to quantitatively analysis the peripheral blood T lymphocyte subsets, including CD4+ T cell, CD8+ T cell, and CD4/CD8 ratio. Survival analyses were performed based on the patients' clinical data and the quantity of T lymphocyte subsets. The median follow-up time was 27.0 months (range, 2.5-66). Baseline percentages and absolute CD4+ T cell counts and the CD4/CD8 ratio were positively correlated with both overall survival (OS) and progression-free survival (PFS) according to Kaplan-Meier curves (p < .05). In the multivariate COX analysis, lower CD4+ T cell count was an independent unfavorable factor in predicting both OS (p = .016) and PFS (p = .010). Furthermore, lower CD4/CD8 ratio was an independent adverse prognostic factor for shorter PFS (p = .017). These results suggested that T lymphocyte subsets were crucial indicators in correlation with MM patients' prognosis. Low CD4+ T cell counts and CD4/CD8 ratio were independent unfavorable prognostic predictors for patients with MM at diagnosis.

ASH2L-Promoted HOXC8 Gene Expression Plays a Role in Mixed Lineage Leukemia-Rearranged Acute Leukemia.

BACKGROUND: Mixed lineage leukemia (MLL) fusion protein alone exhibits poor histone lysine methyltransferase (HKMT) activity in catalyzing histone H3 Lys4 trimethylation (H3K4me3) in MLL-rearranged acute leukemia. METHODS: To explore the HKMT effect of another regulatory protein within the complex of proteins associated with Set 1 (COMPASS), we analyzed the H3K4me3 modification of the HOXC8 promoter under the action of ASH2L regulation. Small interfering RNA of ASH2L, chromatin immunoprecipitation, real-time-PCR (RT-PCR), and Western blotting were used to detect the expression of specific regions of the HOXC8 promoter, RBBP5, WDR5, MLL, and BRTF in two MLL-rearranged acute leukemia cell lines (RS4:11 and THP-1 cells). RESULTS: The gene and protein expression levels of HOXC8 were significantly downregulated upon treatment with ASH2L-siRNA (as analyzed by targeting specific regions of the HOXC8 promoter located 0 and 3 kb (-3.0 kb) upstream of the transcriptional start site in RSH:11 cells; and -3.0 and -2.0 kb upstream of the transcriptional start site, and +1.4 kb downstream of the transcriptional start site in THP-1 cells). The expression levels of the BRTF, RBBP5, WDR5, and MLL genes were significantly downregulated from the different transcriptional start sites of the HOXC8 promoter in the RSH:11 cell line (P < 0.05). Furthermore, the BPTF and RBBP5 genes were downregulated from the HOXC8 promoter in the THP-1 cell line (P < 0.05). CONCLUSION: Based on these results, we suggest a new concept of histone modification of the ASH2L protein in MLL-rearranged acute leukemia, which cannot carry out methyltransferase activity independently. The protein-protein interactions of ASH2L with other COMPASS members, such as MLL, WDR5, RBBP5, and chromatin remodeling factor BRTF, appear to be essential for its role in the activation of HOXC8 gene transcription.

Decitabine as a treatment choice for de novo acute basophilic leukemia: transient response-a case report.

Acute basophilic leukemia (ABL), as a rare form of acute myeloid leukaemia (AML) accounts for <1% of cases of AML. ABL has not been detected for encouragingly specific targets. Here we report a de novo fragile ABL case treated with decitabine based regimen with transient response even if overall survival was a 3-month. The case of a 79-year-old male who was complained of fever, rashes and cytopenia is reported in the current study. The diagnosis of ABL was identified due to characteristic cytomorphological features and immunophenotype of myeloid blast cells without the Philadelphia chromosome. The patient initially presented with short-term improvement with decitabine. Combination of decitabine and arsenic trioxide in second chemotherapy regimen didn't reverse the end of death with a 3 months overall survival. In conclusion, our study revealed that decitabine may be an efficient therapeutic option in ABL patients and warranted much more exploration in use.

[Correlation of Peripheral Blood T Lymphocyte Subsets with Prognosis of Elderly Patients with Newly Diagnosed Multiple Myeloma].

OBJECTIVE: To investigate the expression level of T lymphocyte subsets in elderly patients with newly diagnosed multiple myeloma (NDMM), and to evaluated the prognostic value of T lymphocytic abnormalities in elderly NDMM patients. METHODS: Pretreated peripheral blood of 39 newly diagnosed elder patients with MM was tested by multi-parameter flow cytometry (MFC) to quantitatively detect T lymphocyte subsets, including CD4+T cell, CD8+T cell, and CD4/CD8 ratio. The prognostic values T-lymphocyte subset were evaluated in newly diagnosed elderly patients with MM. RESULTS: The median follow-up time was 21.5 (range, 3.0-66.0) months. Absolute counts of CD4+T cell and CD4/CD8 ratio positively correlated with prognosis. In the multivariate COX analysis, lower CD4/CD8 ratio and CD4+T cell counts were identified to be independent adverse prognostic factors for OS. CONCLUSION: Lower CD4/CD8 ratio and CD4+T cell counts at initial diagnosis are independent unfavorable prognostic factors for elderly patients with MM, and T lymphocyte subsets are crucial indicators for MM patients' prognosis.

The impacts of zanubrutinib on immune cells in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma.

Ibrutinib, a first-generation Bruton's tyrosine kinase (BTK) inhibitor, could improve immunity of relapsed or refractory (R/R) chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) patients. Whether zanubrutinib, a second-generation selective BTK inhibitor, has similar effects as ibrutinib remains to be determined. Dynamics of number and immunophenotype of immune cells during zanubrutinib treatment in 25 R/R CLL/SLL patients were examined by flow cytometry and blood routine tests. The expression intensity of programmed death-1 (PD-1) on total CD4+ (P < .01), total CD8+ (P < .01), and T helper cells (P < .05) and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) on total CD4+ (P = .010) and regulatory T cells (P < .05) reduced after treatment. There were significant differences in expression intensity of CD19 (P < .01), C-X-C chemokine receptor type 5 (CXCR5) (P < .01), and CD49d (P < .05) on B cells before and after treatment. Downregulation of PD-1 on T cells and CXCR5 and CD19 on B cells were observed in nearly all patients after zanubrutinib treatment. Programmed death-ligand 1 expression downregulated, especially in the female, CLL, normal spleen, normal ß2-macroglobulin (ß2-MG) and abnormal lactate dehydrogenase (LDH) subgroups, and CTLA-4 expression on CD4+ T cells tended to decrease in the male, old, CLL, splenomegaly, abnormal ß2-MG, normal LDH, IGHV-mutated and wild-type tumor protein 53 subgroups after zanubrutinib treatment. These findings suggest that zanubrutinib can regulate immunity primarily by improving T cell exhaustion, inhibiting suppressor cells and disrupting CLL cells migration through downregulation of adhesion/homing receptors. Furthermore, favorable changes in cell number and immunophenotype were preferably observed in patients without adverse prognostic factors.

A higher percentage of cells with 13q deletion predicts worse outcome in Chinese patients with chronic lymphocytic leukemia carrying isolated 13q deletion.

Previous studies showed that, in chronic lymphocytic leukemia (CLL) patients with isolated 13q deletion (13q-), those carrying higher percentage of leukemic cells with 13q- had more aggressive diseases. However, the prognostic value of the percentage of leukemic cells with 13q- in Chinese CLL patients with isolated 13q- remained to be determined. Using interphase fluorescence in situ hybridization (FISH), we identified 82 patients (25.4%) with isolated 13q deletion from a cohort of 323 untreated CLL patients. Among patients with isolated 13q deletion, cases of 13q- cells ≥ 80% (13q-H) had significantly shorter time to first treatment (TTT) than those of < 80% 13q- cells (13q-L) (median 11 vs. 92 months, p = 0.0016). A higher lymphocyte count (p = 0.0650) was associated with 13q-H, while other clinical, immunophenotypic, or molecular features did not differ between patients with 13q-H and 13q-L. Although 13q-H only showed marginal significance in multivariate analysis of TTT (hazards ratio 2.007; 95% confidence interval 0.975-4.129; p = 0.059), it helped refine the risk stratification based on Binet stage or immunoglobulin heavy chain variable gene (IGHV) status. In cases in Binet A or B stage, patients with 13q-H had a significantly shorter TTT (median TTT 18 months vs. undefined, p = 0.0101). And in IGHV mutated patients, 13q-H was also associated with reduced TTT (median TTT 13q-H. 18 months vs. 13q-L undefined, p = 0.0163). In conclusion, the prognosis of CLL patients with isolated 13q deletion was heterogeneous with 13q-H identifying patients with worse outcome.