Cytology or Multiparameter Flow Cytometry Positivity in the Cerebrospinal Fluid Before Transplantation is Predictive of Poor Outcomes After Allotransplantation in Acute Myeloid Leukemia Patients.

INTRODUCTION: Central nervous system leukemia (CNSL) remains a serious complication in patients with acute myeloid leukemia (AML) and an ambiguous prognostic factor for those receiving allo-geneic hematopoiesis stem cell transplantation (allo-HSCT). It is unknown whether using more sensitive tools, such as multiparameter flow cytometry (MFC), to detect blasts in the cerebrospinal fluid (CSF) would have an impact on outcome. METHODS: We retrospectively analyzed the clinical outcomes of 1472 AML patients with or without cytology or MFC positivity in the CSF before transplantation. Abnormal CSF (CSF+) was detected via conventional cytology and MFC in 44 patients at any time after diagnosis. A control group of 175 CSF-normal (CSF-) patients was generated via propensity score matching (PSM) analyses according to sex, age at transplant, and white blood cell count at diagnosis. RESULTS: Compared to those in the CSF-negative group, the conventional cytology positive and MFC+ groups had comparable 8-year nonrelapse mortality (NRM) (4%, 4%, and 6%, p = 0.82), higher cumulative incidence of relapse (CIR) (14%, 31%, and 32%, p = 0.007), lower leukemia-free survival (LFS) (79%, 63%, and 64%, p = 0.024), and overall survival (OS) (83%, 63%, and 68%, p = 0.021), with no significant differences between the conventional cytology positive and MFC+ groups. Furthermore, multivariate analysis confirmed that CSF involvement was an independent factor affecting OS and LFS. CONCLUSION: Our results indicate that pretransplant CSF abnormalities are adverse factors independently affecting OS and LFS after allotransplantation in AML patients.

Prophylactic NAC promoted hematopoietic reconstitution by improving endothelial cells after haploidentical HSCT: a phase 3, open-label randomized trial.

BACKGROUND: Poor graft function (PGF) or prolonged isolated thrombocytopenia (PT), which are characterized by pancytopenia or thrombocytopenia, have become serious complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Our previous single-arm trial suggests that N-acetyl-L-cysteine (NAC) prophylaxis reduced PGF or PT after allo-HSCT. Therefore, an open-label, randomized, phase 3 trial was performed to investigate the efficacy and tolerability of NAC prophylaxis to reduce PGF or PT after allo-HSCT. METHODS: A phase 3, open-label randomized trial was performed. Based on the percentage of CD34+VEGFR2 (CD309)+ endothelial cells (ECs) in bone marrow (BM) detected by flow cytometry at 14 days before conditioning, patients aged 15 to 60 years with acute leukemia undergoing haploidentical HSCT were categorized as low-risk (EC ≥ 0.1%) or high-risk (EC < 0.1%); patients at high risk were randomly assigned (2:1) to receive NAC prophylaxis or nonprophylaxis. The primary endpoint was PGF and PT incidence at +60 days post-HSCT. RESULTS: Between April 18, 2019, and June 24, 2021, 120 patients with BM EC <0.1% were randomly assigned for NAC (group A, N = 80) or nonprophylaxis (group B, N = 40), and 105 patients with EC≥0.1% (group C) were also analyzed. The +60 days incidence of PGF and PT was 7.5% (95% CI, 1.7 to 13.3%) and 22.5% (95% CI, 9.1 to 35.9%) in group A and group B (hazard ratio, 0.317; 95% CI, 0.113 to 0.890; P = 0.021) and 11.4% (95% CI, 5.2 to 17.6%) in group C (hazard ratio, 0.643; 95% CI, 0.242 to 1.715; P = 0.373). Consistently, NAC prophylaxis gradually improved BM ECs and CD34+ cells in group A, whereas reduced their reactive oxygen species (ROS) levels post-HSCT. Within 60 days post-HSCT, the most common grade 3 to 5 adverse events for the NAC and control groups were infections (19/80 [24%] vs. 10/40 [25%]) and gastrointestinal adverse events (16/80 [20%] vs. 7/40 [18%]). There were no treatment-related deaths. CONCLUSIONS: N-Acetyl-L-cysteine prophylaxis can prevent the occurrence of poor hematopoietic function and is well tolerated in haploidentical HSCT. It may offer a potential pathogenesis-oriented therapeutic approach for patients with poor hematopoietic function. TRIAL REGISTRATION: This trial was registered at ClinicalTrials.gov as #NCT03967665.

Improved function and balance in T cell modulation by endothelial cells in young people.

Elderly individuals exhibit unbalanced bone marrow (BM) effector T cell subset differentiation, such as increased T helper type 1 (Th1) and T cytotoxic type 1 (Tc1) cell frequencies, but the underlying mechanism is still unclear. Endothelial cells (ECs), which are instructive components of the BM microenvironment, exhibit the phenotype of semi-professional antigen-presenting cells and regulate T cell recruitment and activation. Thus, we compared the frequency and function of BM ECs, especially their capacity to regulate effector T cell subsets, between young and elderly healthy individuals, and explored the underlying mechanism of this immunomodulatory discrepancy. Although the young and elderly EC percentages were comparable, young ECs showed fewer reactive oxygen species and better migratory and tube-forming abilities than elderly ECs. Notably, increased T cell activation molecules and inflammatory cytokines were found in elderly ECs which regulated T cells to differentiate into more proinflammatory T cells, including Th1 and Tc1 cells, than young ECs.

Overexpressed WT1 exhibits a specific immunophenotype in intermediate and poor cytogenetic risk acute myeloid leukemia.

Many studies have confirmed that overexpressed WT1 exists in leukemic cells, especially in AML. However, the immunophenotypic features of this sort of leukemic cells remain to be unclarified. We retrospectively analyzed the immunophenotype of 283 newly diagnosed AML patients with intermediated and poor cytogenetic risk to evaluate the correlation between phenotype and WT1 overexpression. EVI1 transcripts, KMT2A-PTD, FLT3-ITD, and NPM1 mutations were simultaneously assessed. Our results revealed that overexpressed WT1 was significantly associated with the expression of CD117, CD13, and CD123. Besides, leukemic cells with WT1 overexpression also lacked lymphoid and myeloid differentiation-related markers. FAB subtype M2 patients had higher WT1 levels, compared with other FAB subtype. Multivariate analysis was proved that NPM1 mutation, M2 subtype, and the expression of CD123 were independently associated with WT1 overexpression. These indicated that AML with overexpressed WT1 was proliferated and blocked in the early stage of AML development. It presumably provided some clues to detect overexpressed WT1 cells via multiparameter flow cytometry. CD123-targeted drugs might become one of the alternative treatments for patients with WT1 overexpression.

Minimal residual disease status determined by multiparametric flow cytometry pretransplantation predicts the outcome of patients with ALL receiving unmanipulated haploidentical allografts.

This study evaluated the effects of pretransplantation minimal residual disease (pre-MRD) on outcomes of patients with acute lymphoblastic leukemia (ALL) who underwent unmanipulated haploidentical stem cell transplantation (haplo-SCT). A retrospective study including 543 patients with ALL was performed. MRD was determined using multiparametric flow cytometry. Both in the entire cohort of patients and in subgroup cases with T-ALL or B-ALL, patients with positive pre-MRD had a higher incidence of relapse (CIR) than those with negative pre-MRD in MSDT settings (P < 0.01 for all). Landmark analysis at 6 months showed that MRD positivity was significantly and independently associated with inferior rates of relapse (HR, 1.908; P = 0.007), leukemia-free survival (LFS) (HR, 1.559; P = 0.038), and OS (HR, 1.545; P = 0.049). The levels of pre-MRD according to a logarithmic scale were also associated with leukemia relapse, LFS, and OS, except that cases with MRD <0.01% experienced comparable CIR and LFS to those with negative pre-MRD. A risk score for CIR was developed using the variables pre-MRD, disease status, and immunophenotype of ALL. The CIR was 14%, 26%, and 59% for subjects with scores of 0, 1, and 2-3, respectively (P < 0.001). Three-year LFS was 75%, 64%, and 42%, respectively (P < 0.001). Multivariate analysis confirmed the association of the risk score with CIR and LFS. The results indicate that positive pre-MRD, except for low level one (MRD < 0.01%), is associated with poor outcomes in patients with ALL who underwent unmanipulated haplo-SCT.

Higher frequency of regulatory T cells in granulocyte colony-stimulating factor (G-CSF)-primed bone marrow grafts compared with G-CSF-primed peripheral blood grafts.

BACKGROUND: Regulatory T cells (Treg) in allografts are important for the prevention of graft-versus-host disease (GVHD) post-transplantation. The aim of this study was to compare the contents of Tregs and effector T cells in granulocyte colony-stimulating factor (G-CSF)-primed bone marrow grafts (G-BM) and peripheral blood grafts (G-PB). METHOD: G-BM and G-PB were obtained from 20 allogeneic donors. T-cell subgroups, including conventional T cells and different types of Treg cells, as well as the percentage of Ki67 expression on CD4(+)CD25(high)Foxp3(+) Treg cells, were analyzed using flow cytometry. The levels of interferon-γ (IFN-γ) and interleukin-17 (IL-17) secreted by T cells stimulated with PMA and ionomycin were also determined by flow cytometry. RESULTS: The percentage of CD4(+)CD25(high)CD127(-/dim)CD62L(+) Treg cells was significantly higher in the G-BM group, with higher proportions of CD45RA(+) naïve Treg cells and higher expression of CD69 on Treg cells in G-BM (P < 0.05). The percentage of Ki67 expression in CD4(+)CD25(high)Foxp3(+) Treg cells in G-BM was significantly higher than that on G-PB. The suppressive functions of Treg cells in inhibiting T-cell activation were comparable between G-BM and G-PB. The proportions of CD4(+)CD25(-)CD69(+) Treg subsets as well as Th1 cells in G-BM were also significantly higher than those in G-PB (P < 0.001). The proportions of conventional T cells and Th17 effector cells were comparable in G-BM compared with those in G-PB. Thus, the ratio of conventional T cells and CD4(+)CD25(high)CD127(-/dim) regulatory T cells were lower in G-BM than that in G-PB (P = 0.014). CONCLUSION: In addition to the much higher T-cell counts in G-PB grafts that may contribute to more severe GVHD, the higher frequency of Treg cells and lower ratio of conventional T cells to Treg cells in G-BM compared with G-PB grafts might reduce GVHD post-transplantation in G-BM compared with G-PB transplantation.

Association between an impaired bone marrow vascular microenvironment and prolonged isolated thrombocytopenia after allogeneic hematopoietic stem cell transplantation.

Prolonged isolated thrombocytopenia (PT) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, it remains unclear whether abnormalities of the bone marrow (BM) microenvironment are involved in the pathogenesis of PT. This prospective, nested case-control study included 20 patients with PT, 40 matched patients with good graft function (GGF) after allo-HSCT, and 16 healthy donors (HDs). Cellular elements of the BM microenvironment, including BM endothelial cells (BMECs), perivascular cells, and endosteal cells, were analyzed via flow cytometry and via hematoxylin-eosin and immunohistochemical staining in situ. Moreover, stromal-derived factor 1 (SDF-1) and vascular endothelial growth factor (VEGF) were measured in the plasma of BM via an enzyme-linked immunosorbent assay. No significant differences in endosteal cells (15 per high-power field [hpf] versus 16 per hpf versus 20 per hpf, P > .05) were demonstrated among the patients with PT, GGF, and the HDs. The PT patients exhibited remarkable decreases in cellular elements of the vascular microenvironment, including BMECs (.01% versus .18% versus .20%, P < .0001) and perivascular cells (.01% versus .12% versus .13%, P < .0001), compared with the GGF allo-HSCT recipients and the HDs, respectively. Moreover, significantly lower levels of SDF-1 (3163 pg/mL versus 3928 pg/mL, P = .0002) and VEGF (56 pg/mL versus 123 pg/mL, P < .0001) were found in the BM plasma of the PT patients compared with the BM of the GGF patients. A multivariate analysis revealed that BMECs (odds ratio [OR] = 171.57, P = .002) and cytomegalovirus infection after HSCT (OR = 4.35, P = .009) were independent risk factors for PT. Our data suggested that an impaired BM vascular microenvironment and megakaryocyte-active factors may contribute to the occurrence of PT after HSCT.

[Expression and function of killer immunologublin receptor and CD57 of natural killer cells].

OBJECTIVE: To explore the functional different natural killer (NK) cell subsets through the expression of killer immunoglobulin receptor (KIR) and CD57 on NK cells. METHODS: From May 2012 to June 2012, the peripheral blood samples of 10 related healthy donors for hematopoietic stem cells transplantation were collected to analyze KIR, CD57 expression and the intracellular cytokines of interferon-γ(IFN-γ), and the CD107a secreted by NK cells through 6-colour flow cytometer to compare the cytokine secretion and cytotoxic function among different NK subset. RESULTS: The expression of CD57 on NK cells were significantly higher than those of KIR on NK cells[(60.71% ± 5.71%) vs. (24.47% ± 3.95%), P < 0.001]. All the NK cells were separated into KIR+CD57-, KIR+CD57+, KIR-CD57+, KIR-CD57- cells based on the expressions of KIR and CD57. The proportions of KIR-CD57+ NK cells (43.03% ± 5.70%) and KIR-CD57-NK cells (32.45% ± 5.50%) among NK cells were comparable(P = 0.189), and were higher than those of KIR+CD57+ NK cells (17.67% ± 3.39%) and KIR+CD57- NK cells (6.69% ± 0.95%). Further functional experiments demonstrated that the cytotoxic function and IFN-γ cytokine secretion of CD57+ NK cells and KIR+ NK cells were comparable, which were significantly lower than those of CD56(bri) NK cells (P = 0.046 and 0.035, respectively), but were equal to those of CD56(dim) NK cells. The cytotoxic function and the IFN-γ secretion of KIR-CD57- NK cells (46.22% ± 9.24% and 23.41% ± 5.82%) were significantly higher than those of the other NK subsets including KIR+CD57- NK cells,KIR-CD57+ NK cells and KIR+CD57+ NK cells, which were similar to those of CD56(bri) NK cells. The cytotoxic function and IFN-γ secretion of KIR+CD57- NK cells were lower than those of KIR-CD57- NK cells, but were higher than those of CD57+ NK cells, whether KIR positive or negative. The cytotoxic function and IFN-γ secretion were similar between KIR+CD57+ and KIR-CD57+ cells. CONCLUSION: The expressions of KIR and CD57 are correlated with the function of NK cells. Therefore, CD57+ cells might be the end stage of NK cells, KIR-CD57- NK cells might be the early stage of NK cells, however, KIR+CD57- showed to be the intermediate stage of the NK cells.

[Effect of 1,25-(OH)2D3 on expression of HMGB1 and TLR4 in the lungs of asthmatic mice].

OBJECTIVE: To investigate the effects of 1,25-(OH)(2)D(3) on the airway remodeling and expression of high-mobility group box 1 (HMGB1) and Toll-like receptor 4 (TLR4) in the lungs among asthmatic mice. METHODS: Thirty female mice (BALB/c strain) were randomly divided into control, asthma and 1,25-(OH)(2)D(3) intervention groups. An asthmatic mouse model was established by intraperitoneal injection and aerosol inhalation of ovalbumin. The intervention group was given 1,25-(OH)(2)D(3) by intraperitoneal injection 0.5 hour before each aerosol inhalation, while the control group used normal saline instead. The hematoxylin-eosin staining was used to observe the mouse airway structural changes. The mRNA and protein expression of HMGB1 and TLR4 was measured by RT-PCR and immunohistochemistry, respectively. Pearson correlation analysis was performed. RESULTS: The asthma group had a significantly increased airway wall thickness compared with the control group (P<0.05); the intervention group had a significantly lower increase in airway wall thickness than the asthma group (P<0.05). The mRNA and protein expression of HMGB1 and TLR4 was significantly higher in the asthma group than in the control group (P<0.05); the mRNA and protein expression of HMGB1 and TLR4 in the intervention group was significantly lower than that in the asthma group, but still higher than that in the control group (P<0.05). A positive correlation was found between the protein expression of HMGB1 and TLR4 (P<0.01), and so was their mRNA expression (P<0.01). CONCLUSIONS: HMGB1 and TLR4 may be involved in asthmatic airway remodeling. 1,25-(OH)(2)D(3) can reduce the airway remodeling in asthmatic mice, which may be related to the downregulation of HMGB1 and TLR4 expression in the lungs of asthmatic mice.

A lasso and random forest model using flow cytometry data identifies primary myelofibrosis.

Thrombocythemia (ET), polycythemia vera (PV), primary myelofibrosis (PMF), prefibrotic/early (pre-PMF), and overt fibrotic PMF (overt PMF) are classical Philadelphia-Negative (Ph-negative) myeloproliferative neoplasms (MPNs). Differentiating between these types based on morphology and molecular markers is challenging. This study aims to clarify the application of flow cytometry in the diagnosis and differential diagnosis of classical MPNs. This study retrospectively analyzed the immunophenotypes, clinical characteristics, and laboratory findings of 211 Ph-negative MPN patients, including ET, PV, pre-PMF, overt PMF, and 47 controls. Compared to ET and PV, PMF differed in white blood cells, hemoglobin, blast cells in the peripheral blood, abnormal karyotype, and WT1 gene expression. PMF also differed from controls in CD34+ cells, granulocyte phenotype, monocyte phenotype, percentage of plasma cells, and dendritic cells. Notably, the PMF group had a significantly lower plasma cell percentage compared with other groups. A lasso and random forest model select five variables (CD34+CD19+cells and CD34+CD38- cells on CD34+cells, CD13dim+CD11b- cells in granulocytes, CD38str+CD19+/-plasma, and CD123+HLA-DR-basophils), which identify PMF with a sensitivity and specificity of 90%. Simultaneously, a classification and regression tree model was constructed using the percentage of CD34+CD38- on CD34+ cells and platelet counts to distinguish between ET and pre-PMF, with accuracies of 94.3% and 83.9%, respectively. Flow immunophenotyping aids in diagnosing PMF and differentiating between ET and PV. It also helps distinguish pre-PMF from ET and guides treatment decisions.

Features and prognostic significance of soluble TIM-3 and its ligands Gal-9 and CEACAM1 levels in the diagnostic bone marrows of adult acute myeloid leukemia patients.

Prognostic significance of soluble immune checkpoint molecule TIM-3 and its ligands in the plasma has been illustrated in various solid tumors, but such study in newly diagnosed acute myeloid leukemia (AML) remains absent. Soluble TIM-3, Gal-9 and CEACAM1 levels in the bone marrow plasma samples collected from 90 adult AML patients at diagnosis and 12 healthy donors were measured by enzyme-linked immunosorbent assays (ELISA), and 16 AML patients were simultaneously tested cell membrane TIM-3 expression by multi-color flow cytometry. AML patients had significantly elevated soluble TIM-3 levels and similar soluble Gal-9 and CEACAM1 levels compared with healthy donors (p = 0.0003, 0.26 and 0.96). In the whole cohort, high soluble TIM-3 level was the sole independent adverse prognostic factor for relapse-free survival (RFS) (p = 0.0060), and it together with adverse ELN genetic risk were independent poor prognostic factors for event-free survival (EFS) (p = 0.0030 and 0.0040); High soluble CEACAM1 level were significantly related to lower RFS (p = 0.028). In addition, high soluble Gal-9 level had significant association with lower RFS in patients receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT) at the first complete remission (p = 0.037). Furthermore, soluble TIM-3 level tended to have positive correlation with the percentage of non-blast myeloid TIM-3+ cells in nucleated cells in AML (r = 0.48, p = 0.073). Therefore, the high soluble TIM-3 level in the diagnostic BM plasma predicted poor outcome in adult AML patients, and high sGal-9 level was associated with relapse after allo-HSCT.

The profile and prognostic significance of bone marrow T-cell differentiation subsets in adult AML at diagnosis.

Background: T lymphocytes in tumor microenvironment play a pivotal role in the anti-tumor immunity, and the memory of T cells contributes to the long-term protection against tumor antigens. Compared to solid tumors, studies focusing on the T-cell differentiation in the acute myeloid leukemia (AML) bone marrow (BM) microenvironment remain limited. Patients and methods: Fresh BM specimens collected from 103 adult AML patients at diagnosis and 12 healthy donors (HDs) were tested T-cell differentiation subsets by multi-parameter flow cytometry. Results: CD4 and CD8 T-cell compartments had different constituted profiles of T-cell differentiated subsets, which was similar between AML patients and HDs. Compared to HDs, AML patients as a whole had a significantly higher proportion of CD8 effector T cells (Teff, P = 0.048). Moreover, the T-cell compartment of AML patients with no DNMT3A mutations skewed toward terminal differentiation at the expense of memory T cells (CD4 Teff: P = 0.034; CD8 Teff: P = 0.030; CD8 memory T: P = 0.017), whereas those with mutated DNMT3A had a decrease in CD8 naïve T (Tn) and CD4 effector memory T cells (Tem) as well as an increase in CD4 central memory T cells (Tcm) (P = 0.037, 0.053 and 0.053). Adverse ELN genetic risk correlated with a lower proportion of CD8 Tn. In addition, the low proportions of CD4 Tem and CD8 Tn independently predicted poorer relapse-free survival (RFS, HR [95%CI]: 5.7 (1.4-22.2), P = 0.017 and 4.8 [1.3-17.4], P = 0.013) and event-free survival (EFS, HR [95% CI]: 3.3 (1.1-9.5), P = 0.029; 4.0 (1.4-11.5), P = 0.010), respectively. Conclusions: AML patients had abnormal profiles of BM T-cell differentiation subsets at diagnosis, which was related to DNMT3A mutations. The low proportions of CD4 Tem and CD8 Tn predicted poor outcomes.

Prognostic significance of the frequencies of bone marrow lymphocyte subsets in adult acute myeloid leukemia at diagnosis.

INTRODUCTION: Immune microenvironment plays an important role in the occurrence and development of acute myeloid leukemia (AML). Studies assessing the prognostic significance of bone marrow (BM) lymphocyte subsets' frequencies at diagnosis in patients with AML were limited. METHODS: Fresh BM samples collected from 97 adult AML patients at diagnosis were tested for lymphocyte, T, CD4+ T, CD8+ T, γδT, NK, and B cell frequencies using multi-parameter flow cytometry. RESULTS: Low frequencies of lymphocytes, T, CD4+ T, and CD8+ T cells were associated with significantly lower rates of one-course complete remission (CR) (all p < 0.05). Moreover, the frequency of CD4+ T cells independently predicted one-course CR achievement (p = 0.021). Low frequencies of T and CD8+ T cells were significantly associated with lower relapse-free survival (RFS) rates (p = 0.032; 0.034), respectively, and a low frequency of CD8+ T cells was associated with a significantly lower overall survival (OS) rate (p = 0.028). Combination of frequency of CD8+ T cells and ELN risk stratification showed that patients with ELN-intermediate/adverse risk + high CD8+ T cell frequency had a similar RFS rate to those with ELN-favorable risk + high CD8+ T cell frequency and those with ELN-favorable risk + low CD8+ T cell frequency (p = 0.88; 0.76), respectively. The RFS rate of patients with ELN intermediate/adverse risk + low CD8+ T cell frequency was significantly lower than that of all aforementioned patients (p = 0.021; 0.0007; 0.028), respectively. CONCLUSION: The frequencies of BM lymphocyte subsets at diagnosis predicted clinical outcomes and could help improve risk stratification in AML.

The Functional and Prognostic Impact of TIGIT Expression on Bone Marrow NK Cells in Core Binding Factor-Acute Myeloid Leukemia Patients at Diagnosis.

Background: The effect of the expression of the newly identified immune checkpoint, T cell immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) on NK cells in core binding factor-acute myeloid leukemia (CBF-AML) remains to be investigated. Methods: Fresh bone marrow samples from a total of 39 newly diagnosed CBF-AML patients and 25 healthy donors (HDs) were collected for testing the phenotype and function state of total NK, CD56bright, and CD56dim NK cell subsets after in vitro stimulation. Results: The frequencies of TIGIT+ cells in total NK, CD56bright, and CD56dim NK cell subsets had no significant difference between patients and HDs. TNF-α and INF-γ levels were uniformly lower in TIGIT+ cells than the corresponding TIGIT- cells in all HDs, whereas those for TIGIT+ to TIGIT- cells in patients were highly heterogenous; TIGIT expression was not related to PFP and GZMB expression in HDs, whereas it was related to higher intracellular PFP and GZMB levels in patients. Patients' TIGIT+ NK cells displayed lower K562 cell-killing activity than their TIGIT- NK cells. In addition, high frequencies of TIGIT+ cells in total NK and CD56dim NK cells were associated with poor RFS. Conclusions: TIGIT expression affected the diagnostic bone marrow-sited NK cell function and had prognostic significance in CBF-AML patients.

Inhibition of TGF-ß signaling in bone marrow endothelial cells promotes hematopoietic recovery in acute myeloid leukemia patients.

Although it is an effective treatment for acute myeloid leukemia (AML), chemotherapy leads to myelosuppression and poor hematopoietic reconstruction. Hematopoiesis is regulated by bone marrow (BM) endothelial cells (ECs), and BM ECs are dysfunctional in acute leukemia patients with poor hematopoietic reconstitution after allogenic hematopoietic stem cell transplantation. Thus, it is crucial to explore the underlying mechanism of EC impairment and establish strategies for targeted therapy. TGF-ß signaling was found to be upregulated in ECs from AML patients in complete remission (CR ECs) and led to CR EC damage. Administration of a TGF-ß inhibitor rescued the dysfunction of ECs caused by TGF-ß1 expression in vitro, especially their hematopoiesis-supporting ability. Moreover, inhibition of TGF-ß expression repaired the BM EC damage triggered by chemotherapy in both AML patients in vitro and in an AML-CR murine model, and restored normal hematopoiesis without promoting AML progression. Mechanistically, our data reveal alterations in the transcriptomic pattern of damaged BM ECs, accompanied by the overexpression of downstream molecules TGF-ßR1, pSmad2/3, and functional genes related to adhesion, angiogenesis suppression and pro-apoptosis. Collectively, our findings reveal for the first time that the activation of TGF-ß signaling leads to BM EC dysfunction and poor hematopoietic reconstitution. Targeting TGF-ß represents a potential therapeutic strategy to promote multilineage hematopoiesis, thereby benefiting more cancer patients who suffer from myelosuppression after chemotherapy.

Association of an impaired bone marrow microenvironment with secondary poor graft function after allogeneic hematopoietic stem cell transplantation.

Poor graft function (PGF) is a serious complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Whether abnormalities of the bone marrow (BM) microenvironment are involved in the pathogenesis of PGF is unclear. In the present prospective nested case-control study, 19 patients with secondary PGF, 38 matched patients with good graft function (GGF) after allo-HSCT, and 15 healthy donors (HDs) were enrolled. The cellular elements of the BM microenvironment, including endosteal cells, perivascular cells, and vascular cells, were analyzed by flow cytometry as well as hematoxylin and eosin and immunohistochemical staining in situ. The median time to occurrence of secondary PGF was 90 days post-transplantation (range, 58 to 264 days). The patients with PGF showed markedly hypocellular marrow (10% versus 45% versus 45%; P < .0001) with scattered hematopoietic cells and significantly lower CD34(+) cells (0.07% versus 0.26% versus 0.26%; P < .0001), endosteal cells (4 per high-power field [hpf] versus 16 per hpf versus 20 per hpf; P < .001), perivascular cells (0.008% versus 0.10% versus 0.12%; P < .0001), and endothelial progenitor cells (0.008% versus 0.16% versus 0.18%; P < .0001) compared with GGF allo-HSCT recipients and HDs, respectively. Multivariate analyses revealed that endothelial progenitor cells (odds ratio, 150.72; P = .001) and the underlying disease (odds ratio, 18.52; P = .007) were independent risk factors for secondary PGF. Our results suggest that the impaired BM microenvironment may contribute to the occurrence of secondary PGF post-HSCT.

[Effect of 1,25-(OH)2D3 on expression of TIM-4 in the lungs of asthmatic mice].

OBJECTIVE: To establish a mouse model of asthmatic airway remodeling and investigate the effects of 1,25-(OH)2D3 on airway structure and T cell immunoglobulin mucin protein-4 (TIM-4) expression in asthmatic mice. METHODS: Thirty female mice (BALB/c strain) were randomly divided into control, asthma and 1,25-(OH)2D3 intervention groups. An asthmatic mouse model was induced using ovalbumin. Lung tissue of the mice was collected, mRNA expression of TIM-4 was evaluated by RT-PCR and airway remodeling and protein expression of TIM-4 were observed by hematoxylineosin staining and immunohistochemistry. RESULTS: Typical airway remodeling was found in the asthma group, and TIM-4 expression in this group was significantly higher than in the control group (105±9 vs 42±5; P<0.05). Compared with the asthma group, the 1,25-(OH)2D3 intervention group showed improvement in airway remodeling and a decrease in TIM-4 expression (78±6) (P<0.05). CONCLUSIONS: TIM-4 may be involved in the airway remodeling of mice. As a new type of immunoregulator, 1,25-(OH)2D3 can downregulate expression of TIM-4 in the lungs and improve airway remodeling in asthmatic mice.

Immunophenotypic characteristics of ZNF384 rearrangement compared with BCR-ABL1, KMT2A rearrangement, and other adult B-cell precursor acute lymphoblastic leukemia.

BACKGROUND: ZNF384 rearrangement has been recently identified as a new subtype of B-cell precursor acute lymphoblastic leukemia (BCP-ALL). However, comprehensive studies clarifying immunophenotypic features and discriminating them from non-ZNF384 in adult BCP-ALL remain scarce to date. METHODS: Flow cytometric assessments were retrospectively performed in 43 patients with ZNF384 rearrangement, 45 with BCR-ABL1, 29 with KMT2A rearrangement and 44 with other BCP-ALL in the analysis cohort. RESULTS: CD33- and CD13-positive frequencies were significantly higher in patients with ZNF384 rearrangement than in those with non-ZNF384; however, no significant difference was observed in CD10- and CD123-positive frequencies. Analysis of antigen-positive cell proportion and median fluorescence intensity (MFI) further indicated that patients with ZNF384 rearrangement had significantly lower CD10 and higher CD33, CD13, and CD123 proportion and MFI. However, compared with KMT2A rearrangement, the CD10 expression in patients with ZNF384 rearrangement was higher, with the median percentage and MFI of 36.16 (3.63-94.79)% versus 4.53 (0.03-21.00)%, and 4.50 (0.86-32.26) versus 2.06 (0.87-4.04), respectively (p < 0.0001). Furthermore, compared with BCR-ABL1 and other BCP-ALL, ZNF384 rearrangement had significantly higher CD33 and CD13 proportion and MFI (p < 0.0001 and p < 0.05, respectively). In addition, higher CD123 proportion and MFI in ZNF384 rearrangement than those in the other three groups were reported for the first time (p < 0.01). A flow cytometry scoring system, including CD10%, CD33MFI, CD13%, and CD123MFI, was proposed and verified to predict ZNF384 rearrangement with high sensitivity and specificity, that is, 76.74% and 91.53% in the analysis and 87.50% and 91.30% in the validation cohort. CONCLUSIONS: The multiparameter immunophenotypic scoring system could suggest ZNF384 rearrangement.

Low IL7R Expression at Diagnosis Predicted Relapse in Adult Acute Myeloid Leukemia Patients With t(8;21).

Background: Acute myeloid leukemia (AML) with t(8;21) needs to be further stratified. In addition to leukemia cells, immune cells in tumor microenvironment participate in tumor initiation, growth and progression. Interleukins (ILs)/interleukin receptors (ILRs) interaction plays important roles in the antitumor immune response. IL7R is reported to be relevant to prognosis in solid tumor and acute lymphoblastic leukemia. However, the prognostic significance of IL7R in t(8;21) AML remains to be clarified. Methods: Bone marrows collected from 156 newly diagnosed t(8;21) AML patients were used for testing IL7R transcript level by TaqMan-based real-time quantitative PCR (RQ-PCR), and RNAseq were performed in 15 of them. Moreover, IL7R expression at diagnosis were measured by RQ-PCR and flow cytometry (FCM) simultaneously in other 13 t(8;21) AML patients. Results: t(8;21) AML patients had varied IL7R transcript levels and were categorized into low-expression (IL7R-L) and high-expression (IL7R-H) groups; IL7R-L was significantly associated with a lower relapse-free survival (RFS) rate (P=0.0027) and KITD816/D820 mutation (P=0.0010). Furthermore, IL7R-L was associated with a lower RFS rate in KITD816/D820 group (P=0.013) and IL7R-H/KITD816/D820 patients had similar RFS to KITN822/e8/WT patients (P=0.35). GO analysis enrichment showed that down-regulated genes were predominantly involved in the regulation of T cell and leukocyte activation, proliferation and differentiation in IL7R-L group. IL7R-L had significantly lower levels of Granzymes A/B, CCR7, CD28 and CD27 than IL7R-H group (all P<0.05). FCM analysis showed IL7R protein was primarily expressed in CD4+ T and CD8+ T cell subset. A significant association was found between the transcript level of IL7R and the percentage of CD8+ T cells in nucleated cells (P=0.015) but not CD4+ T cells (P=0.47). Conclusion: Low IL7R transcript level of bone marrow at diagnosis predicted relapse in t(8;21) AML, which might be caused by the difference in the amount, status and function of T cells.

Prognostic significance of TIM-3 expression pattern at diagnosis in patients with t(8;21) acute myeloid leukemia.

Acute myeloid leukemia (AML) with t(8;21) is a heterogeneous disease and needs to be stratified. Both, cancer cells and immune cells participate in tumor initiation, growth and progression and might affect clinical outcomes. TIM-3 (T cell immunoglobulin and mucin domain-containing protein 3), an immune checkpoint molecule, is expressed not only on immune cells but also on leukemic stem cells (LSCs) in AML. This prompted us to investigate the prognostic significance of TIM-3 in t(8;21) AML. A total of 47 t(8;21) AML patients were tested for TIM-3 expression by multi-parameter flow cytometry at diagnosis. 35 of these, who received chemotherapy alone or along with allogeneic hematopoietic stem cell transplantation were followed up. The expression pattern of TIM-3 on T-cells and NK (natural killer) cells as a whole (T + NK) and LSCs were evaluated independently. High percentage of T + NK - TIM-3+ and CD34+CD38-TIM-3+ cells were significantly associated with a high 2-year cumulative incidence of relapse (CIR) (p = 0.028, 0.016). Further, concurrent high frequencies of T + NK-TIM-3+ and CD34+CD38-TIM-3+ cells at diagnosis were significantly associated with a high 2-year CIR (p < 0.0001) and this together with c-KIT D816 mutation were the independent adverse prognostic factors for relapse (hazard ratio (HR)=2.5, [95% confidence interval (CI), 1.1-6.0], p = 0.04; HR = 46.5, [95% CI, 2.7-811.5], p = 0.009). In conclusion, the expression pattern of TIM-3 on both T and NK cells and LSCs at diagnosis had prognostic significance in t (8;21) AML.