T-acute Lymphoblastic Leukemia Research Articles

Single-cell sequencing technology to characterize stem T-cell subpopulations in acute T-lymphoblastic leukemia and the role of stem T-cells in the disease process.

Precursor T-cell acute lymphoblastic leukemia (Pre-T ALL) is a malignant neoplastic disease in which T-cells proliferate in the bone marrow. Single-cell sequencing technology could identify characteristic cell types, facilitating the study of the therapeutic mechanisms in Pre-T ALL. The single-cell sequencing data (scRNA-seq) of Pre-T ALL were obtained from public databases. Key immune cell subpopulations involved in the progression of Pre-T ALL were identified by clustering and annotating the cellular data using AUCell. Next, pseudo-temporal analysis was performed to identify the differentiation trajectories of immune cell subpopulations using Monocle. Copy number mutation landscape of cell subpopulations was characterized by inferCNV. Finally, cellphoneDB was used to analyze intercellular communication relationships. A total of 10 cellular subpopulations were classified, with Pre-T ALL showing a higher proportion of NK/T cells. NK/T cells were further clustered into two subpopulations. Stem T cells showed a high expression of marker genes related to hematopoietic stem cells, Naive T cells had a high expression of CCR7, CCR7, RCAN3, and NK cells high-expressed KLRD1, TRDC. The cell proliferation was reduced and the activation of T cell was increased during the differentiation of stem T cells to Naive T cells. We observed interaction between stem T cells with dendritic cells such as CD74-COPA, CD74-MIF as well as co-inhibition-related interactions such as LGALS9-HAVCR2, TGFB1-TGFBR3. Stem T cells were involved in the development of Pre-T-ALL through the regulatory effects of transcription factors (TFs) KLF2 and FOS and multiple ligand-receptor pairs.

Prognostic factors in children with acute T-lymphoblastic leukemia: a single-center clinical study of the CCCG-ALL-2015 protocol

To explore the clinical characteristics of children with acute T-lymphoblastic leukemia (T-ALL) and analyze their relationship with prognosis. A retrospective analysis was conducted on the clinical data and follow-up results of 50 children with T-ALL who were treated using the CCCG-ALL-2015 protocol at the Department of Hematology and Oncology, Children's Hospital of Nanjing Medical University from November 2015 to December 2019. Kaplan-Meier survival analysis and Cox regression analysis were employed to identify factors affecting prognosis. Among the 50 T-ALL patients, there were 7 cases of relapse. There was no statistically significant difference in the baseline clinical data between the relapse group and the non-relapse group (P>0.05). However, the positive rate of minimal residual disease (MRD) (≥0.01%) on day 46 after induction remission therapy in the relapse group was significantly higher than that in the non-relapse group (P=0.037). The 5-year overall survival rate for the 50 patients was (87±5)%, and the 5-year event-free survival rate was (86±5)%. Multivariate Cox regression analysis indicated that the MRD level on day 46 after induction remission therapy was an independent prognostic factor (HR=0.104, 95%CI: 0.015-0.740, P=0.024). MRD is of significant importance for the prognosis of T-ALL children. Personalized treatment should be provided based on MRD levels to prevent relapse and improve prognosis in these patients.

Outcome of Pneumocystis Jirovecii pneumonia (PcP) in post-CAR-T patients with hematological malignancies

BackgroundPneumocystis jirovecii pneumonia (PcP) is an opportunistic infection associated with immunocompromised patients. The development of novel immunotherapies has promoted the incidence of PcP. This study describes the clinical course and outcome of PcP in chimeric antigen receptor (CAR) T cell recipients with hematological malignancies.MethodsThis is a retrospective case series of CAR-T recipients diagnosed with PcP in our center. The cases were all confirmed by metagenomic next-generation sequencing of clinical samples. The demographic, clinical, and outcome data were retrieved from the patients’ medical charts and electronic medical record system.ResultsIn total, 8 cases of PcP were identified. The underlying malignancies included T-acute lymphoblastic leukemia (ALL) (n = 1), diffuse large B cell lymphoma (DLBCL) (n = 4), and B-ALL (n = 3). One patient received short-term sulfamethoxazole-trimethoprim (SMZ-TMP) while the others had no prophylaxis. Four patients had neutropenia/lymphopenia at the diagnosis of PcP, and two patients had immunosuppressants within one month before PcP manifestation. The median time from CAR-T infusion to PcP diagnosis was 98.5 days (range 52–251). Seven patients recovered from PcP after proper management while one died of septic shock.ConclusionPcP can occur after different CAR-T product, and the long-term depletion of immune cells seems to be related to PcP. SMZ-TMP is effective in this setting. More real-world experience of CAR-T therapy is required to assess the incidence and outcome of PcP in this population.

Biallelic Loss of 7q34 (TRB) and 9p21.3 (CDKN2A/2B) in Adult Ph-Negative Acute T-Lymphoblastic Leukemia

Tumor cells of acute lymphoblastic leukemia (ALL) may have various genetic abnormalities. Some of them lead to a complete loss of certain genes. Our aim was to reveal biallelic deletions of genes in Ph–negative T-ALL. Chromosomal microarray analysis (CMA) was performed for 47 patients with de novo Ph–negative T-ALL, who received treatment according to RALL-2016m clinical protocol at the National Medical Research Center for Hematology (Moscow, Russia) from 2017 to 2023. Out of forty-seven patients, only three had normal molecular karyotype. The other 44 patients had multiple gains, losses, and copy neutral losses of heterozygosity. Biallelic losses were found in 14 patients (30%). In ten patients (21%), a biallelic deletion of 9p21.3 involved a different number of genes, however CDKN2A gene loss was noted in all ten cases. For seven patients (15%), a biallelic deletion of 7q34 was found, including two genes—PRSS1, PRSS2 located within the T-cell receptor beta (TRB) locus. A clonal rearrangement of the TRB gene was revealed in 6 out of 7 cases with 7q34 biallelic loss. Both biallelic deletions can be considered favorable prognostic factors, with an association with 9p21 being statistically significant (p = 0.01) and a trend for 7q34 (p = 0.12) being observed.

Ruxolitinib combined with venetoclax and azacitidine in the treatment of refractory T-ALL patients with JAK1, JAK3, and STAT5B gene mutations: a case report and literature review

Refractory acute T-lymphoblastic leukemia (T-ALL), which is characterized by a low sensitivity to conventional induction therapy and poor prognosis, poses significant challenges during treatment. This study reported a case of refractory T-ALL patient with mutations in the JAK1, JAK3, and STAT5B genes from Nanjing University's Gulou Hospital. Following an unsuccessful course of standard VDLP regimen chemotherapy, the treatment was modified to include ruxolitinib in combination with venetoclax and azacitidine. Subsequent to this therapy, the patient achieved bone marrow minimal residual disease (MRD) negativity. Notably, pleural effusion and mediastinal mass significantly improved the post-chest cavity infusion of dexamethasone combined with etoposide at the same stage. The patient also underwent allogeneic hematopoietic stem cell transplantation upon achieving bone marrow remission and was followed up until January 2024. Ruxolitinib combined with venetoclax and azacytidine has shown promising efficacy and safety in treating refractory T-ALL harboring the JAK1, JAK3, and STAT5B mutations, providing a novel therapeutic approach for such patients.

Biallelic Loss of Certain Genes in Adult Ph-Negative T-Acute Lymphoblastic Leukemia

Biallelic Loss of Certain Genes in Adult Ph-Negative T-Acute Lymphoblastic Leukemia

ALL-480 Biallelic Loss of Certain Genes in Adult Ph-Negative T-Acute Lymphoblastic Leukemia

ALL-480 Biallelic Loss of Certain Genes in Adult Ph-Negative T-Acute Lymphoblastic Leukemia

Flow Cytometry-Based Detection of Minimal/Measurable Residual Disease Predicts Survival Outcomes in Pediatrics, Adolescents, and Young Adults With T-acute Lymphoblastic Leukemia.

Measurable/minimal residual disease (MRD) is considered the single most powerful high-risk factor in acute leukemia, including T-cell acute lymphoblastic leukemia (T-ALL). In this study, we evaluated the impact of flow cytometry (FC)-based detection of MRD on survival outcomes in pediatrics, adolescents, and young adults (AYA) with T-ALL. We included 139 patients, 88 pediatric patients between the ages of one and 14 years, and 51 AYA patients between 15 and 39 years of age, over a period of three years and were treated with the Indian Collaborative Childhood Leukemia Group (ICiCLe) protocol. MRD assessment was performed on post-induction (PI) bone marrow aspirate samples using a 10-color 11-antibody MRD panel on a Gallios instrument (Beckman Coulter, Miami, FL, USA). MRD value > 0.01% was considered positive. PI-MRD status was available in 131 patients. The five-year event-free survival (5-year EFS) in PI-MRD positive patients was inferior to those of negative patients (13.56% vs 79.06%), which was statistically significant (P < 0.001). However, the five-year overall survival (5-year OS) did not show any statistically significant difference between PI-MRD positive and negative T-ALL patients (92.93% vs 94.28%). The hazard ratio (HR) for 5-year EFS and MRD positivity was 8.03 (p-value < 0.0001). HR for 5-year EFS and early T-cell precursor ALL (ETP-ALL) was 2.63 (p = -0.02). PI-MRD detected using FC is a strong predictive factor of inferior survival outcomes in pediatrics, AYA patients with T-ALL. PI-MRD positivity can be used to modify the treatment of T-ALL patients, especially in resource-constrained developing countries where molecular tests are not widely available.

Transcriptome Analysis Reveals the Induction of Apoptosis-Related Genes by a Monoclonal Antibody against a New Epitope of CD99 on T-Acute Lymphoblastic Leukemia.

CD99 was demonstrated to be a potential target for antibody therapy on T-acute lymphoblastic leukemia (T-ALL). The ligation of CD99 by certain monoclonal antibodies (mAbs) induced T-ALL apoptosis. However, the molecular basis contributing to the apoptosis of T-ALL upon anti-CD99 mAb engagement remains elusive. In this study, using our generated anti-CD99 mAb clone MT99/3 (mAb MT99/3), mAb MT99/3 engagement strongly induced apoptosis of T-ALL cell lines, but not in non-malignant peripheral blood cells. By transcriptome analysis, upon mAb MT99/3 ligation, 13 apoptosis-related genes, including FOS, TNF, FASLG, BCL2A1, JUNB, SOCS1, IL27RA, PTPN6, PDGFA, NR4A1, SGK1, LPAR5 and LTB, were significantly upregulated. The epitope of CD99 recognized by mAb MT99/3 was then identified as the VDGENDDPRPP at residues 60-70 of CD99, which has never been reported. To the best of our knowledge, this is the first transcriptome data conducted in T-ALL with anti-CD99 mAb engagement. These findings provide new insights into CD99 implicated in the apoptosis of T-ALL. The identification of a new epitope and apoptosis-related genes that relate to the induction of apoptosis by mAb MT99/3 may serve as a new therapeutic target for T-ALL. The anti-CD99 mAb clone MT99/3 might be a candidate for further development of a therapeutic antibody for T-ALL therapy.

Pharmacodynamic and Toxicity Studies of 6-Isopropyldithio-2'-guanosine Analogs in Acute T-Lymphoblastic Leukemia.

(1) Background: The research group has developed a new small molecule, 6-Isopropyldithio-2'-deoxyguanosine analogs-YLS004, which has been shown to be the most sensitive in acute T-lymphoblastic leukemia cells. Moreover, it was found that the structure of Nelarabine, a drug used to treat acute T-lymphoblastic leukemia, is highly similar to that of YLS004. Consequently, the structure of YLS004 was altered to produce a new small molecule inhibitor for this study, named YLS010. (2) Results: YLS010 has exhibited potent anti-tumor effects by inducing cell apoptosis and ferroptosis. A dose gradient was designed for in vivo experiments based on tentative estimates of the toxicity dose using acute toxicity in mice and long-term toxicity in rats. The study found that YLS010 at a dose of 8 mg/kg prolonged the survival of late-stage acute T-lymphoblastic leukemia mice in the mouse model study. (3) Conclusions: YLS010 has demonstrated specific killing effects against acute T-lymphoblastic leukemia both in vivo and in vitro. Preclinical studies of YLS010 offer a new opportunity for the treatment of patients with acute T-lymphoblastic leukemia in clinical settings.

Investigates the genetic types of acute lymphoblastic leukemia in full remission Indonesian patients: a cross-sectional analysis

Acute lymphoblastic leukemia (ALL) is most common in children, especially those aged 1–4 years old, and the second most common acute leukemia in adults. The updated International Consensus Classification (ICC) of B-acute lymphoblastic leukemia (B-ALL) and T-acute lymphoblastic leukemia (T-ALL) includes recent clinical, cytogenetic, and molecular data. Transcriptome sequencing (RNA-seq) was performed on 200 bone marrow specimens using TruSeq library preparation and HiSeq 2000/2500 or NovaSeq 6000 sequencers (Illumina). The purpose of this study was to define the frequency of chromosomal abnormalities of ALL patients in adults and children in Indonesian patients after full remission for international collaboration has improved and advanced the diagnosis and treatment of ALL in Indonesia. Our resulting data showed that the most common structural abnormality was t(9;22) in 15% of the patients. The frequency of genetic abnormalities was 69 % and 60% for numerical and/or structural in the B-ALL and T-ALL patients, respectively. The adults had a higher incidence of t(9;22) and a lower incidence of hyperdiploid than children. In conclusion: The results of this study molecular subtypes differ strikingly in their responses to treatment that needs more assessment.

Exploring novel protein biomarkers for early-stage diagnosis and prognosis of T-acute lymphoblastic leukemia (T-ALL)

BackgroundEfficient classification of T-acute lymphoblastic leukemia (T-ALL) involves considering various factors, such as age, white blood cell count, and chromosomal alterations. However, studying protein markers are crucial to improving T-ALL patients' diagnosis and treatment. A study analyzing the expression of proteomes was conducted to identify promising early-stage biomarkers for T-ALL patients MethodsLabel-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze the blood proteins of both patients and healthy individuals to identify new biomarkers for T-ALL. The findings were validated by RT-PCR, ELISA and computational analysis ResultsThe study identified 1467 proteins in the blood, of which nine were upregulated and 35 were downregulated by more than 2-fold. T-ALL patients showed a significant increase in specific disease-related proteins, such as eleven-nineteen lysine-rich leukemia protein, triggering receptor expressed on myeloid cells 1, cisplatin resistance-associated-overexpressed protein, X-ray radiation resistance-associated protein 1, tumor necrosis factor receptor superfamily member 10D, protein S100-A8, and copine-4, by more than 3-fold ConclusionThe findings of this study provide a valuable protein map of leukemic cells and identify potential biomarkers for leukemic aggressiveness. However, further studies using larger T-ALL patient samples must confirm these preliminary results.

Resveratrol Inhibits T-acute Lymphoblastic Leukemia in Mice by Regulating Notch1 Signaling Pathway

To observe the effect of resveratrol (Res) on T-acute lymphoblastic leukemia (T-ALL) mice, and further explore its mechanism on Notch1 signaling pathway. Twenty-five 6-8 weeks old female C57BL/6 mice were randomly divided into control group, T-ALL group and Res group. Res group was further divided into low-Res, middle-Res and high-Res group. The percentage of leukemia cells in peripheral blood and spleen cell suspension were detected by flow cytometry and Wright-Giemsa staining, pathological morphology of spleen and bone marrow tissues were observed by HE staining, the expression levels of Notch1, Hes-1, c-Myc, miR-19b and PTEN mRNA in spleen tissue were detected by RT-qPCR, and the protein levels of Notch1, Hes-1, c-Myc, p-PTEN and PTEN were detected by Western blot. Compared with control group, the leukemia cells in peripheral blood of mice in T-ALL group were markedly increased, accompanied by diffuse infiltration of leukemia cells in spleen and bone marrow tissues, the mRNA levels of Notch1, Hes-1, c-Myc, miR-19b and the protein levels of Notch1, Hes-1, c-Myc were increased (P <0.01), while the expression of PTEN mRNA and protein were significantly decreased in the spleen tissue of T-ALL mice (P <0.01). The above indicators in the H-Res group were reversed compared with T-ALL group after administration of resveratrol. Resveratrol may play a role in anti T-ALL by inhibiting Notch1 signaling pathway in mice.

An Anti-CD7 Antibody-Drug Conjugate Target Showing Potent Antitumor Activity for T-Lymphoblastic Leukemia (T-ALL).

Acute T-lymphoblastic leukemia (T-ALL) is a type of leukemia that can occur in both pediatric and adult populations. Compared to acute B-cell lymphoblastic leukemia (B-ALL), patients with T-cell T-ALL have a poorer therapeutic efficacy. In this study, a novel anti-CD7 antibody-drug conjugate (ADC, J87-Dxd) was successfully generated and used for T-ALL treatment. Firstly, to obtain anti-CD7 mAbs, we expressed and purified the CD7 protein extracellular domain. Utilizing hybridoma technology, we obtained three anti-CD7 mAbs (J87, G73 and A15) with a high affinity for CD7. Both the results of immunofluorescence and Biacore assay indicated that J87 (KD = 1.54 × 10-10 M) had the highest affinity among the three anti-CD7 mAbs. In addition, an internalization assay showed the internalization level of J87 to be higher than that of the other two mAbs. Next, we successfully generated the anti-CD7 ADC (J87-Dxd) by conjugating DXd to J87 via a cleavable maleimide-GGFG peptide linker. J87-Dxd also possessed the ability to recognize and bind CD7. Using J87-Dxd to treat T-ALL cells (Jurkat and CCRF-CEM), we observed that J87-Dxd bound to CD7 was internalized into T-ALL cells. Moreover, J87-Dxd treatment significantly induced the apoptosis of Jurkat and CCRF-CEM cells. The IC50 (half-maximal inhibitory concentration) value of J87-Dxd against CCRF-CEM obtained by CCK-8 assay was 6.3 nM. Finally, to assess the antitumor efficacy of a J87-Dxd in vivo, we established T-ALL mouse models and treated mice with J87-Dxd or J87. The results showed that on day 24 after tumor inoculation, all mice treated with J87 or PBS died, whereas the survival rate of mice treated with J87-Dxd was 80%. H&E staining showed no significant organic changes in the heart, liver, spleen, lungs and kidneys of all mice. In summary, we demonstrated that the novel anti-CD7 ADC (J87-Dxd) had a potent and selective effect against CD7-expressing T-All cells both in vitro and in vivo, and could thus be expected to be further developed as a new drug for the treatment of T-ALL or other CD7-expression tumors.

Histone deacetylase inhibitors: targeting epigenetic regulation in the treatment of acute leukemia.

Acute leukemia (AL) is a rare yet perilous malignancy. Currently, the primary treatment for AL involves combination chemotherapy as the cornerstone of comprehensive measures, alongside hematopoietic stem cell transplantation as a radical approach. However, despite these interventions, mortality rates remain high, particularly among refractory/recurrent patients or elderly individuals with a poor prognosis. Acetylation, a form of epigenetic regulation, has emerged as a promising therapeutic avenue for treating AL. Recent studies have highlighted the potential of acetylation regulation as a novel treatment pathway. Histone deacetylase inhibitors (HDACis) play a pivotal role in modulating the differentiation and development of tumor cells through diverse pathways, simultaneously impacting the maturation and function of lymphocytes. HDACis demonstrate promise in enhancing survival rates and achieving a complete response in both acute myeloid leukemia and acute T-lymphoblastic leukemia patients. This article provides a comprehensive review of the advancements in HDACi therapy for AL, shedding light on its potential implications for clinical practice.

Post-Allograft Romidepsin Maintenance Mitigates Relapse Risk and Stimulates the Graft-Versus-Malignancy Effect through Enhanced NK-Cell Cytotoxicity in Patients with T-Cell Malignancies: Final Results of a Phase I/II Trial

Background: For patients with high risk, and relapsed/refractory T-cell malignancies allogeneic stem cell transplant (allo-SCT) is the only available potentially curative therapy. The efficacy of allo-SCT is limited in this population by high rates of relapse, with rates up to 55-60% post-allo-SCT. We designed a phase I/II trial, evaluating the combination of the histone deacetylases inhibitor romidepsin (rom) with busulfan/fludarabine (BuFlu) conditioning, followed by romidepsin maintenance (m-rom) in patients receiving allo-SCT for T-cell malignancies (NCT02512497). Here we present final clinical results of this therapeutic approach, including an evaluation of the stimulatory effects of m-rom on the graft-versus-malignancy effect through NK-cells post-allo-SCT. Methods: This was a phase I/II clinical trial. Eligible patients had: a diagnosis of T-cell leukemia (including T-acute lymphoblastic leukemia) or T-cell lymphoma (TCL, cutaneous or peripheral) in at least a partial remission requiring an allo-SCT, &amp;lt;70 years of age, with a matched sibling/unrelated donor. Patients received myeloablative (20K) or reduced intensity (16K) BuFlu with rom, followed by standard tacrolimus/methotrexate GVHD prophylaxis and anti-thymocyte globulin for unrelated donors (MUD). An expansion cohort of up to 30 patients (total) was included. M-rom was initiated between day +28 and +100 for 1 year (2 nd year optional), with built in dose reductions for toxicity. An efficacy endpoint of 20% reduction in relapse risk at 1-year in the whole cohort or any individual disease cohort was set based upon historical/CIBMTR (Center for Blood and Marrow Transplant Research) controls was pre-specified. The effect of m-rom on NK-cell cytotoxicity was assessed on samples taken pre-transplant, and 1, 3, 6, 12 months post allo-SCT. NK cytotoxicity was assessed by isolating mononuclear cells from patient samples at each timepoint, comparing those on m-rom (n=13) versus those who did BuFlu controls who did not receive m-rom (n=16). Cells were targeted against K562 targets using the calcein-AM assay. K-M and Fine-Gray models were used to estimate PFS, OS, and cumulative incidence, and compare survival across groups. Results: 28 patients were enrolled on this trial (Table). With a median follow-up time of 15 months, the median OS is 3.3 years (95% CI: 0.85-not reached), with a 1 and 3 year OS probability of 68% and 54%. The median PFS is 2.3 years (95% CI: 0.6-not reached), with 1 and 3-year PFS of 61% and 41%. Cumulative incidence (CI) of NRM at day 100 and 1 year were 14.3% and 21.4%. CI of grade II-IV aGHVD and extensive cGVHD were 46.4% and 38%. The CI of relapse (CIR) was 18.1% at 1 year and 33% at 3 -years. There was no difference between PFS among patients with MRD versus those without MRD prior to transplant (p=0.43). The CIR of patients with TCL was 9.3% at 1 and 3 years, whereas the CIR of patients with leukemia was 25% at 1 year and 48% at 3 years. No patients with PTCL relapsed, 1/2 patients with CTCL relapsed, and 4/6 patients with T-PLL are alive, disease free. Pre-specified general CIR was 55% for all patients. With an overall CIR of 18% at 1 year, and 33% at 3-years, this trial met its pre-specified endpoint of decreasing relapse by 20% at 1-year, and performed well compared to published CIBMTR control populations. Matched propensity score analysis across disease subsets with CIBMTR controls will be presented. 18/28 (64%) of patients received m-rom with a median number of 13 cycles (range 1-47). 8 patients experienced grade 3/4 adverse events (AE), and 1 patient discontinued m-rom due to toxicity, unlikely related to romidepsin (loss of CD3 chimerism). When NK-cytotoxicity was assessed between the two groups after starting maintenance, NK-cytotoxicity in the m-rom group was significantly higher than in those without m-rom (p&amp;lt;0.0001) (Figure). Conclusions: BuFluRom with m-rom is effective at decreasing relapse in patients with T-cell malignancies, with 1-year CI relapse below expected relapse rates for this set of diseases, meeting the pre-specified efficacy endpoint. NK-cell cytotoxicity data in a large sample set of trial patients demonstrates that m-rom enhances NK-cell cytotoxicity post allo-SCT, augmenting the GVL effect and likely accounting for at a minimum, some of the decrease in relapse seen on this trial. M-rom should be considered a new option post allo-SCT to mitigate relapse in patients with T-cell malignancies.

Evaluation of aberrant expression of CD markers in acute leukemia cells

Background and objective: Worldwide immunophenotyping by flow cytometry (FCM) in acute leukemia (AL) is the golden step in the diagnosis. It’s very common for acute leukemias to aberrantly express antigens or cluster of differentiation (CD) markers which are usually expressed in other lineages of the disease hence this study aimed at determining the prevalence of aberrancy in AL and to find out the frequency of each aberrant CD marker and their association with the clinic-hematological profile of the cases. Methods: Following history and clinical examination of enrolled patients, blood and/or bone marrow aspirate was drawn for morphological examination and immunophenotyping by FCM from 86 newly diagnosed acute leukemia cases then multiple steps procedure was applied followed by interpretation of the results. Results: The prevalence of aberrant phenotype was 46.5%. The proportional frequency of aberrant phenotype in acute myeloid leukemia (AML) was 41%, in B-acute lymphoblastic leukemia (B-ALL) was 48.8% and in T-acute lymphoblastic leukemia (T-ALL) was 66.6%. The commonest aberrant CD markers in AML were CD22 and CD2, in B-ALL were CD66c and CD13 while in T-ALL were CD13 and CD33. The aberrant phenotype harbored lower white blood cell (WBC) count and blast percentage in PB, also splenomegaly was more frequent in lymphoid positive (Ly+) AML and myeloid positive (My+) T-ALL while in B-ALL, splenomegaly was more frequent in myeloid negative (My-) B-ALL. Conclusion: Aberrant phenotype prevalence in our study sample was comparable to other studies, considerable frequency of aberrant markers is present in cases of AL and some variations exist regarding the clinical and hematological profile of the aberrant group.

Dual Targeting of Apoptotic and Signaling Pathways in T-Lineage Acute Lymphoblastic Leukemia.

Relapsed T-acute lymphoblastic leukemia (T-ALL) has limited treatment options. We investigated mechanisms of resistance to BH3 mimetics in T-ALL to develop rational combination strategies. We also looked at the preclinical efficacy of NWP-0476, a novel BCL-2/BCL-xL inhibitor, as single agent and combination therapy in T-ALL. We used BH3 profiling as a predictive tool for BH3 mimetic response in T-ALL. Using isogenic control, venetoclax-resistant (ven-R) and NWP-0476-resistant (NWP-R) cells, phosphokinase array was performed to identify differentially regulated signaling pathways. Typical T-ALL cells had increased dependence on BCL-xL, whereas early T-precursor (ETP)-ALL cells had higher BCL-2 dependence for survival. BCL-2/BCL-xL dual inhibitors were effective against both subtypes of T-lineage ALL. A 71-protein human phosphokinase array showed increased LCK activity in ven-R cells, and increased ACK1 activity in ven-R and NWP-R cells. We hypothesized that pre-TCR and ACK1 signaling pathways are drivers of resistance to BCL-2 and BCL-xL inhibition, respectively. First, we silenced LCK gene in T-ALL cell lines, which resulted in increased sensitivity to BCL-2 inhibition. Mechanistically, LCK activated NF-κB pathway and the expression of BCL-xL. Silencing ACK1 gene resulted in increased sensitivity to both BCL-2 and BCL-xL inhibitors. ACK1 signaling upregulated AKT pathway, which inhibited the pro-apoptotic function of BAD. In a T-ALL patient-derived xenograft model, combination of NWP-0476 and dasatinib demonstrated synergy without major organ toxicity. LCK and ACK1 signaling pathways are critical regulators of BH3 mimetic resistance in T-ALL. Combination of BH3 mimetics with tyrosine kinase inhibitors might be effective against relapsed T-ALL.

Clinical features, laboratory characteristics, and outcome of ETP and TCRA/D aberrations in pediatric patients with T-acute lymphoblastic leukemia

BackgroundT-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy with few accepted prognostic factors that limit the efficiency of therapy. The aim of the current study was to assess the clinical and laboratory features of T-cell receptor (TCR) aberrations and early T-cell precursor (ETP) subtype as well as their outcome to therapy.MethodsSixty-three newly diagnosed pediatric T-ALL patients were assessed for the ETP status using immunophenotyping. Screening of TCRA/D aberrations was done by fluorescent in situ hybridization (FISH). The data were correlated to the patients’ clinical features, response to treatment, and survival rates.ResultsSeven patients (11%) had ETP-ALL. The ETP-ALL patients were older (P = 0.013), presented with lower white blood cell (WBC) count (P = 0.001) and lower percentage of peripheral blood (PB) blast cells (P = 0.037), more likely to have hyperdiploid karyotype (P = 0.009), and had been associated with TCRA/D gene amplification (P = 0.014) compared to other T-ALL patients. Of note, the same associations had been significantly observed in patients with TCRA/D gene amplification. Patients with TCRA/D amplification frequently coincided with TCRβ aberrations (P = 0.025). TCR-β aberrations were significantly associated with negative MRD at the end of induction compared to TCR-β-negative patients. There was a nonsignificant trend of ETP-positive cases to have lower overall survival (OS) (P = 0.06). Patients with TCR aberrations had no significant differences regarding disease-free survival (DFS) or OS rates compared to those with normal TCR.ConclusionETP-ALL patients tend to have increased mortalities. There was no significant impact of TCR aberrations on the survival rates of the patients.

Treatment outcomes for acute T-lymphoblastic leukemias/lymphomas: data from the ALL-2016 multicenter prospective randomized trial

Background . The effectiveness of therapy for acute T-lymphoblastic leukemia (T-ALL) and T-lymphoblastic lymphoma (T-LBL) has significantly improved over the past decades, including through the implementation of hematopoietic stem cell transplantation (HSCT). The Russian multicenter ALL-2009 study (ClinicalTrials.gov NCT01193933) showed that performing autologous HSCT (auto-HSCT) in patients with T-ALL/LBL improves long-term results. However, the study was non-randomized and the need for auto-HSCT in clinical practice requires careful study. Aim . To assess the significance of auto-HSCT in patients with T-ALL/LBL in the framework of ALL-2016 multicenter, prospective, randomized study (ClinicalTrials.gov NCT03462095). Materials and methods . The study included 109 adult patients with T-ALL/LBL (m:f 82:27). Median age was 31 (18– 52) years. T-ALL was diagnosed in 88 (81 %) patients, T-LBL in 21 (19 %) patients. All patients are treated according to the ALL-2016 protocol. Using the web platform, upon completion of induction therapy (+70 days), all T-ALL/LBL patients who achieved clinical and hematological remission were randomized to the auto-HSCT arm or chemotherapy alone (CT). Centralized monitoring of minimal residual disease (MRD) in bone marrow samples was performed by multicolor flow cytometry at the control points according to the ALL-2016 protocol. Statistical analysis was performed using SAS 9.4. Results . 87 patients with T-ALL/LBL were randomized: 44 to the auto-HSCT arm and 43 to the CT arm. Further analysis included 25 patients who underwent auto-HSCT and 36 patients receiving only CT. Three-year relapse-free survival in T-ALL is estimated at 62 % (auto-HSCT) vs. 81 % (CT) (p = 0.3422), and in T-LBL – 67 % (auto-HSCT) vs. 79 % (CT) (p = 0.59). MRD persistence on the +70 th day of therapy according to the ALL-2016 protocol was determined in 40 % of patients (autoHSCT) and in 67 % (CT) (p = 0.057). In a multivariate analysis, it was determined that T-ALL from early T-cell precursor (ETP-variant) and MRD persistence after the end of II phase induction are the main risk factors for relapse in the treatment according to the ALL-2016 protocol. Conclusion . Performing auto-HSCT both in patients with T-ALL and T-LBL, and with MRD persistence on day +70 according to the ALL-2016 protocol did not improve long-term results. The development of new programs for the treatment of patients with MRD persistence, as well as the ETP variant of T-ALL, is of current interest.