Triple Trouble.

We present a case of a 24-year-old female recently diagnosed with acute leukemia who came with complaints of fever for 14 days, progressive lower limb weakness, and multiple episodes of vomiting in the last 1 day. In nerve conduction studies, a diagnosis of Guillain-Barré syndrome (GBS) was established. Fever with thrombocytopenia workup revealed a positive dengue nonstructural protein 1 (NS1) and immunoglobulin M (IgM) report. Immunophenotyping confirmed pre-B acute lymphoblastic leukemia (ALL). As leukemia is an immunocompromised state, the peripheral nervous system vulnerability is increased, or infection could precipitate an immune neuropathy. About 10% of adult ALL presents with central nervous system (CNS) leukemias; a higher incidence is seen in mature B ALL. There is some evidence to suggest immunosuppression secondary to intensive chemotherapy (vincristine-induced dying back neuropathy), which was not started in our case. This rare combination in a short period of time with a worsening situation paralyzed the line of management. Few reports described GBS in patients with dengue in adults. The association of Guillan-Barre syndrome and ALL could be coincidental or has a pathophysiological basis and is under basic investigation.

The Evolving Landscape of Flowcytometric Minimal Residual Disease Monitoring in B-Cell Precursor Acute Lymphoblastic Leukemia.

Detection of minimal residual disease (MRD) is a major independent prognostic marker in the clinical management of pediatric and adult B-cell precursor Acute Lymphoblastic Leukemia (BCP-ALL), and risk stratification nowadays heavily relies on MRD diagnostics. MRD can be detected using flow cytometry based on aberrant expression of markers (antigens) during malignant B-cell maturation. Recent advances highlight the significance of novel markers (e.g., CD58, CD81, CD304, CD73, CD66c, and CD123), improving MRD identification. Second and next-generation flow cytometry, such as the EuroFlow consortium's eight-color protocol, can achieve sensitivities down to 10-5 (comparable with the PCR-based method) if sufficient cells are acquired. The introduction of targeted therapies (especially those targeting CD19, such as blinatumomab or CAR-T19) introduces several challenges for flow cytometric MRD analysis, such as the occurrence of CD19-negative relapses. Therefore, innovative flow cytometry panels, including alternative B-cell markers (e.g., CD22 and CD24), have been designed. (Semi-)automated MRD assessment, employing machine learning algorithms and clustering tools, shows promise but does not yet allow robust and sensitive automated analysis of MRD. Future directions involve integrating artificial intelligence, further automation, and exploring multicolor spectral flow cytometry to standardize MRD assessment and enhance diagnostic and prognostic robustness of MRD diagnostics in BCP-ALL.

Flow cytometric minimal residual disease measurement accounting for cytogenetics in children with non-high-risk acute lymphoblastic leukemia treated according to the ALL-MB 2008 protocol.

BACKGROUND: Quantitative measurement of minimal residual disease (MRD) is the "gold standard" for estimating the response to therapy in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Nevertheless, the speed of the MRD response differs for different cytogenetic subgroups. Here we present results of MRD measurement in children with BCP-ALL, in terms of genetic subgroups with relation to clinically defined risk groups. METHODS: A total of 485 children with non-high-risk BCP-ALL with available cytogenetic data and MRD studied at the end-of-induction (EOI) by multicolor flow cytometry (MFC) were included. All patients were treated with standard-risk (SR) of intermediate-risk (ImR) regimens of "ALL-MB 2008" reduced-intensity protocol. RESULTS AND DISCUSSION: Among all study group patients, 203 were found to have low-risk cytogenetics (ETV6::RUNX1 or high hyperdiploidy), while remaining 282 children were classified in intermediate cytogenetic risk group. For the patients with favorable and intermediate risk cytogenetics, the most significant thresholds for MFC-MRD values were different: 0.03% and 0.04% respectively. Nevertheless, the most meaningful thresholds were different for clinically defined SR and ImR groups. For the SR group, irrespective to presence/absence of favorable genetic lesions, MFC-MRD threshold of 0.1% was the most clinically valuable, although for ImR group the most informative thresholds were different in patients from low-(0.03%) and intermediate (0.01%) cytogenetic risk groups. CONCLUSION: Our data show that combining clinical risk factors with MFC-MRD measurement is the most useful tool for risk group stratification of children with BCP-ALL in the reduced-intensity protocols. However, this algorithm can be supplemented with cytogenetic data for part of the ImR group.

Aggressive precursor B cell ALL of cervix with obstructive uropathy.

Involvement of the cervix with acute lymphoblastic leukaemia (ALL) is extremely rare. In this case report, we discuss an unmarried woman in her early 20s, who presented in the emergency with lower abdominal pain and irregular vaginal bleeding for 1 month. Clinical examination and imaging revealed a large cervical mass probably neoplastic with obstructive uropathy. On evaluation, she was diagnosed incidentally with CALLA-positive precursor B cell ALL in peripheral blood flow cytometry. Involvement of B cell ALL in cervical mass was confirmed by histopathological examination of cervical biopsy and immunohistochemistry markers. Her history was not suggestive of signs and symptoms pertaining to leukaemia. Literature is sparse with only a few cases reporting cervical leukaemic infiltration. The present case report is a rarest case where the primary/initial presentation of precursor B cell ALL was seen with cervical involvement and obstructive uropathy mimicking characteristics of advanced cervical malignancy.

The RAS-signaling-pathway-mutation-related prognosis in B-cell acute lymphoblastic leukemia: A report from South China children's leukemia group.

The next-generation sequencing technologies application discovers novel genetic alterations frequently in pediatric acute lymphoblastic leukemia (ALL). RAS signaling pathway mutations at the time of relapse ALL frequently appear as small subclones at the time of onset, which are considered as the drivers in ALL relapse. Whether subclones alterations in the RAS signaling pathway should be considered for risk group stratification of ALL treatment is not decided yet. In this work, we investigate the RAS signaling pathway mutation spectrum and the related prognosis in pediatric ALL. We employed an NGS panel comprising 220 genes. NGS results were collected from 202 pediatric ALL patients. 155 patients (76.7%) harbored at least one mutation. The incidences of RAS signaling pathway mutations are different significantly between T-ALL and B-ALL. In B-ALL, the RAS pathway is mostly involved, and NRAS (17.6%), KRAS (22.7%), and PTPN11 (7.7%) were the three most frequently mutated genes. Co-occurring mutations of CREBBP and NRAS, FLT3, or PTPN11 (p = 0.002, p = 0.009, and p = 0.003, respectively) were found in this cohort. The 3-year RFS rates for the RAS signaling pathway mutation-positive and negative cases was 76.5 % versus 89.7 % (p = 0.012). Four cases relapsed in the lately 3 years were RAS signaling pathway mutation-positive. RAS signaling pathway mutation is an important biomarker for poorer relapse-free survival in pediatric B-ALL patients despite good early MRD levels.

Reduced-dose chemotherapy followed by blinatumomab in induction therapy for newly diagnosed B-cell acute lymphoblastic leukemia.

BACKGROUND: Blinatumomab early-line treatment in B-cell precursor acute lymphoblastic leukemia (B-ALL) might improve clinical outcomes. METHODS: We conducted a retrospective real-world cohort analysis in 20 newly diagnosed B-ALL patients who received reduced-dose chemotherapy (idarubicin, vindesine, and dexamethasone) for 1-3 weeks, followed by blinatumomab for 1-4 weeks as an induction therapy. RESULTS: At the end of the induction therapy, a complete remission rate of 100% was achieved; 17 (85%) patients were minimal residual disease (MRD) negative (<1 × 10-4 ). Adverse events (AEs) were reported in 12 (60%) patients-43.8% were grade 1-2 and 56.2% were grade 3-4. No incidence of neurotoxicity or grade ≥3 cytokine release syndrome was reported. CONCLUSIONS: Blinatumomab demonstrated a significant improvement in clinical outcomes in patients with newly diagnosed B-ALL irrespective of their poor-risk factor status and the pretreatment blast burden.

Refining risk stratification in paediatric B-acute lymphoblastic leukaemia: Combining IKZF1plus and Day 15 MRD positivity.

This study investigates the potential utility of IKZF1 deletion as an additional high-risk marker for paediatric acute lymphoblastic leukaemia (ALL). The prognostic impact of IKZF1 status, in conjunction with minimal/measurable residual disease (MRD), was evaluated within the MRD-guided TPOG-ALL-2013 protocol using 412 newly diagnosed B-ALL patients aged 1-18. IKZF1 status was determined using multiplex ligation-dependent probe amplification. IKZF1 deletions, when co-occurring with CDKN2A, CDKN2B, PAX5 or PAR1 region deletions in the absence of ERG deletions, were termed IKZF1plus. Both IKZF1 deletion (14.6%) and IKZF1plus (7.8%) independently predicted poorer outcomes in B-ALL. IKZF1plus was observed in 4.1% of Philadelphia-negative ALL, with a significantly lower 5-year event-free survival (53.9%) compared to IKZF1 deletion alone (83.8%) and wild-type IKZF1 (91.3%) (p < 0.0001). Among patients with Day 15 MRD ≥0.01%, provisional high-risk patients with IKZF1plus exhibited the worst outcomes in event-free survival (42.0%), relapse-free survival (48.0%) and overall survival (72.7%) compared to other groups (p < 0.0001). Integration of IKZF1plus and positive Day 15 MRD identified a subgroup of Philadelphia-negative B-ALL with a 50% risk of relapse. This study highlights the importance of assessing IKZF1plus alongside Day 15 MRD positivity to identify patients at increased risk of adverse outcomes, potentially minimizing overtreatment.

Extracellular matrix protein 1 (ECM1) is a potential biomarker in B cell acute lymphoblastic leukemia.

B cell acute lymphoblastic leukemia (ALL) is characterized by the highly heterogeneity of pathogenic genetic background, and there are still approximately 30-40% of patients without clear molecular markers. To identify the dysregulated genes in B cell ALL, we screened 30 newly diagnosed B cell ALL patients and 10 donors by gene expression profiling chip. We found that ECM1 transcription level was abnormally elevated in newly diagnosed B cell ALL and further verified in another 267 cases compared with donors (median, 124.57% vs. 7.14%, P < 0.001). ROC analysis showed that the area under the curve of ECM1 transcription level at diagnosis was 0.89 (P < 0.001). Patients with BCR::ABL1 and IKZF1 deletion show highest transcription level (210.78%) compared with KMT2A rearrangement (39.48%) and TCF3::PBX1 rearrangement ones (30.02%) (all P < 0.05). Also, the transcription level of ECM1 was highly correlated with the clinical course, as 20 consecutive follow-up cases indicated. The 5-year OS of patients (non-KMT2A and non-TCF3::PBX1 rearrangement) with high ECM1 transcription level was significantly worse than the lower ones (18.7% vs. 72.9%, P < 0.001) and high ECM1 transcription level was an independent risk factor for OS (HR = 5.77 [1.75-19.06], P = 0.004). After considering transplantation, high ECM1 transcription level was not an independent risk factor, although OS was still poor (low vs. high, 71.1% vs. 56.8%, P = 0.038). Our findings suggested that ECM1 may be a potential molecular marker for diagnosis, minimal residual disease (MRD) monitoring, and prognosis prediction of B cell ALL.Trial registration Trial Registration Registered in the Beijing Municipal Health Bureau Registration N 2007-1007 and in the Chinese Clinical Trial Registry [ChiCTR-OCH-10000940 and ChiCTR-OPC-14005546]; http://www.chictr.org.cn .

Dynamic evolution of bone marrow adipocyte in B cell acute lymphoblastic leukemia: insights from diagnosis to post-chemotherapy.

Adipocyte is a unique and versatile component of bone marrow microenvironment (BMM). However, the dynamic evolution of Bone Marrow (BM) adipocytes from the diagnosis of B cell Acute Lymphoblastic Leukemia (B-ALL) to the post-treatment state, and how they affect the progression of leukemia, remains inadequately explicated. Primary patient-derived xenograft models (PDXs) and stromal cell co-culture system are employed in this study. We show that the dynamic evolution of BM adipocytes from initial diagnosis of B-ALL to the post-chemotherapy phase, transitioning from cellular depletion in the initial leukemia niche to a fully restored state upon remission. Increased BM adipocytes retards engraftment of B-ALL cells in PDX models and inhibits cells growth of B-ALL in vitro. Mechanistically, the proliferation arrest of B-ALL cells in the context of adipocytes-enrichment niche, might attribute to the presence of adiponectin secreted by adipocytes themselves and the absence of cytokines secreted by mesenchymal stem cell (MSCs). In summary, our findings offer a novel perspective for further in-depth understanding of the dynamic balance between BMM and B-ALL.

Faster clinical decisions in B-cell acute lymphoblastic leukaemia: A single flow cytometric 12-colour tube improves diagnosis and minimal residual disease follow-up.

Assessing minimal residual disease (MRD) in B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) is essential for adjusting therapeutic strategies and predicting relapse. Quantitative polymerase chain reaction (qPCR) is the gold standard for MRD. Alternatively, flow cytometry is a quicker and cost-effective method that typically uses leukaemia-associated immunophenotype (LAIP) or different-from-normal (DFN) approaches for MRD assessment. This study describes an optimized 12-colour flow cytometry antibody panel designed for BCP-ALL diagnosis and MRD monitoring in a single tube. This method robustly differentiated hematogones and BCP-ALL cells using two specific markers: CD43 and CD81. These and other markers (e.g. CD73, CD66c and CD49f) enhanced the specificity of BCP-ALL cell detection. This innovative approach, based on a dual DFN/LAIP strategy with a principal component analysis method, can be used for all patients and enables MRD analysis even in the absence of a diagnostic sample. The robustness of our method for MRD monitoring was confirmed by the strong correlation (r = 0.87) with the qPCR results. Moreover, it simplifies and accelerates the preanalytical process through the use of a stain/lysis/wash method within a single tube (<2 h). Our flow cytometry-based methodology improves the BCP-ALL diagnosis efficiency and MRD management, offering a complementary method with considerable benefits for clinical laboratories.

Tyrosine kinase inhibitor resistance in de novo BCR::ABL1-positive BCP-ALL beyond kinase domain mutations.

ABSTRACT: A better understanding of ABL1 kinase domain mutation-independent causes of tyrosine kinase inhibitor (TKI) resistance is needed for BCR::ABL1-positive B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Although TKIs have dramatically improved outcomes, a subset of patients still experiences relapsed or refractory disease. We aimed to identify potential biomarkers of intrinsic TKI resistance at diagnosis in samples from 32 pediatric and 19 adult patients with BCR::ABL1-positive BCP-ALL. Reduced ex vivo imatinib sensitivity was observed in cells derived from newly diagnosed patients who relapsed after combined TKI and chemotherapy treatment compared with cells derived from patients who remained in continuous complete remission. We observed that ex vivo imatinib resistance was inversely correlated with the amount of (phosphorylated) BCR::ABL1/ABL1 protein present in samples that were taken at diagnosis without prior TKI exposure. This suggests an intrinsic cause of TKI resistance that is independent of functional BCR::ABL1 signaling. Simultaneous deletions of IKZF1 and CDKN2A/B and/or PAX5 (IKZF1plus), as well as deletions of PAX5 alone, were related to ex vivo imatinib resistance. In addition, somatic lesions involving ZEB2, SETD2, SH2B3, and CRLF2 were associated with reduced ex vivo imatinib sensitivity. Our data suggest that the poor prognostic value of IKZF1(plus) deletions is linked to intrinsic mechanisms of TKI resistance other than ABL1 kinase domain mutations in newly diagnosed pediatric and adult BCR::ABL1-positive BCP-ALL.

Enhanced Risk Stratification for Children and Young Adults with B-Cell Acute Lymphoblastic Leukemia: A Children's Oncology Group Report.

Current strategies to treat pediatric acute lymphoblastic leukemia rely on risk stratification algorithms using categorical data. We investigated whether using continuous variables assigned different weights would improve risk stratification. We developed and validated a multivariable Cox model for relapse-free survival (RFS) using information from 21199 patients. We constructed risk groups by identifying cutoffs of the COG Prognostic Index (PICOG) that maximized discrimination of the predictive model. Patients with higher PICOG have higher predicted relapse risk. The PICOG reliably discriminates patients with low vs. high relapse risk. For those with moderate relapse risk using current COG risk classification, the PICOG identifies subgroups with varying 5-year RFS. Among current COG standard-risk average patients, PICOG identifies low and intermediate risk groups with 96% and 90% RFS, respectively. Similarly, amongst current COG high-risk patients, PICOG identifies four groups ranging from 96% to 66% RFS, providing additional discrimination for future treatment stratification. When coupled with traditional algorithms, the novel PICOG can more accurately risk stratify patients, identifying groups with better outcomes who may benefit from less intensive therapy, and those who have high relapse risk needing innovative approaches for cure.

CD371-positive pediatric B-cell acute lymphoblastic leukemia: propensity to lineage switch and slow early response to treatment.

ABSTRACT: In the effort to improve immunophenotyping and minimal residual disease (MRD) assessment in acute lymphoblastic leukemia (ALL), the international Berlin-Frankfurt-Münster (iBFM) Flow Network introduced the myelomonocytic marker CD371 for a large prospective characterization with a long follow-up. In the present study, we aimed to investigate the clinical and biological features of CD371-positive (CD371pos) pediatric B-cell precursor ALL (BCP-ALL). From June 2014 to February 2017, 1812 pediatric patients with newly diagnosed BCP-ALLs enrolled in trial AIEOP-BFM ALL 2009 were evaluated as part of either a screening (n = 843, Italian centers) or validation cohort (n = 969, other iBFM centers). Laboratory assessment at diagnosis consisted of morphological, immunophenotypic, and genetic analysis. Response assessment relied on morphology, multiparametric flow cytometry (MFC), and polymerase chain reaction (PCR)-MRD. At diagnosis, 160 of 1812 (8.8%) BCP-ALLs were CD371pos. This correlated with older age, lower ETV6::RUNX1 frequency, immunophenotypic immaturity (all P < .001), and strong expression of CD34 and of CD45 (P < .05). During induction therapy, CD371pos BCP-ALLs showed a transient myelomonocytic switch (mm-SW: up to 65.4% of samples at day 15) and an inferior response to chemotherapy (slow early response, P < .001). However, the 5-year event-free survival was 88.3%. Among 420 patients from the validation cohort, 27 of 28 (96.4%) cases positive for DUX4-fusions were CD371pos. In conclusion, in the largest pediatric cohort, CD371 is the most sensitive marker of transient mm-SW, whose recognition is essential for proper MFC MRD assessment. CD371pos is associated to poor early treatment response, although a good outcome can be reached after MRD-based ALL-related therapies.

Transcriptome analysis of primary adult B-cell lineage acute lymphoblastic leukemia identifies pathogenic variants and gene fusions, and predicts subtypes for in depth molecular diagnosis.

BACKGROUND: B-cell acute lymphoblastic leukemia (B-ALL) is classified into subgroups based on known driver oncogenes and molecular lesions, including translocations and recurrent mutations. However, the current diagnostic tests do not identify subtypes or oncogenic lesions for all B-ALL samples, creating a heterogeneous B-ALL group of unknown subtypes. METHODS: We sorted primary adult B-ALL cells and performed transcriptome analysis by bulk RNA sequencing (RNA-seq). RESULTS: Transcriptomic analysis of an adult B-ALL cohort allowed the classification of four patient samples with subtypes that were not previously revealed by standard gene panels. The leukemia of two patients were of the DUX4 subtype and two were CRLF2+ Ph-like B-ALL. Furthermore, single nucleotide variant analysis detected the oncogenic NRAS-G12D, KRAS-G12D, and KRAS-G13D mutations in three of the patient samples, presenting targetable mutations. Additional oncogenic variants and gene fusions were uncovered, as well as multiple variants in the PDE4DIP gene across five of the patient samples. CONCLUSION: We demonstrate that RNA-seq is an effective tool for precision medicine in B-ALL by providing comprehensive molecular profiling of leukemia cells, identifying subtype and oncogenic lesions, and stratifying patients for appropriate therapy.

Dose-Dense Mini-Hyper-CVD, Inotuzumab Ozogamicin and Blinatumomab Achieves Rapid MRD-Negativity in Philadelphia Chromosome-Negative B-cell Acute Lymphoblastic Leukemia.

BACKGROUND: The combination of low-intensity chemotherapy and inotuzumab ozogamicin (INO), with sequential blinatumomab, is highly effective in older adults with newly diagnosed B-cell acute lymphoblastic leukemia (ALL) and in relapsed or refractory B-cell ALL. Earlier, "dose-dense" administration of blinatumomab could lead to earlier and deeper measurable residual disease (MRD) responses and better outcomes. PATIENTS AND METHODS: We performed a retrospective analysis of the safety and efficacy of a dose-dense regimen of mini-hyper-CVD (mini-hyperfractionated cyclophosphamide, vincristine, and dexamethasone alternating with mini-methotrexate and cytarabine), INO, and blinatumomab in patients with B-cell ALL. RESULTS: Twenty-one patients were treated (frontline, n = 9; MRD consolidation, n = 4; relapsed/refractory, n = 8). In the frontline cohort, all patients achieved CR/CRi and MRD negativity by flow cytometry at the end of cycle 1. Across the frontline and MRD consolidation cohorts, 10/11 patients (91%) achieved next-generation sequencing MRD negativity at a sensitivity of 10-6, including 6/10 evaluable patients (60%) who achieved next-generation sequencing MRD negativity after cycle 1. The CR/CRi rate in the relapsed/refractory cohort was 63%, and all responders achieved MRD negativity by flow cytometry at the end of cycle 1. The 1-year overall survival rate for the combined cohort of the frontline and MRD-positive patients was 83%. No new safety signals were observed with the dose-dense mini-hyper-CVD, INO, and blinatumomab regimen. CONCLUSION: Dose-dense delivery of mini-hyper-CVD, INO, and blinatumomab was safe and resulted in rapid and deep MRD negativity in patients with B-cell ALL. This regimen is now being prospectively evaluated in both the frontline and relapsed/refractory settings.

Clinicopathologic features of relapsed CD19(-) B-ALL in CD19-targeted immunotherapy: Biological insights into relapse and LILRB1 as a novel B-cell marker for CD19(-) B lymphoblasts.

INTRODUCTION: The mechanism of relapsed CD19(-) B-ALL after anti-CD19 immunotherapy (Kymriah [CART-19] and blinatumomab) is under active investigation. Our study aims to assess LILRB1 as a novel B-cell marker for detecting CD19(-) B-lymphoblasts and to analyze the clinicopathologic/genetic features of such disease to provide biological insight into relapse. METHODS: Six patients (3 males/3 females, median age of 14 years) with relapsed CD19(-) B-ALL were analyzed for cytogenetic/genetic profile and immunophenotype. RESULTS: CD19(-) B-ALL emerged after an interval of 5.8 months following anti-CD19 therapy. Five of six patients had B-cell aplasia, indicative of a persistent effect of CART or blinatumomab at relapse. Importantly, LILRB1 was variably expressed on CD19(-) and CD19(+) B lymphoblasts, strong on CD34(+) lymphoblasts and dim/partial on CD34(-) lymphoblasts. Three of six patients with paired B-ALL samples (pre- and post-anti-CD19 therapy) carried complex and different cytogenetic abnormalities, either as completely different or sharing a subset of cytogenetic abnormalities. CONCLUSION: LILRB1 can be used as a novel B-cell marker to identify CD19(-) B lymphoblasts. The emergence of CD19(-) B-ALL appears to be associated with complex cytogenetic evolutions. The mechanism of CD19(-) B-ALL relapse under anti-CD19 immune pressure remains to be explored by comprehensive molecular studies.

Optimizing CAR-T cell therapy in adults with B-cell acute lymphoblastic leukemia.

Chimeric antigen receptor T-cell (CAR-T) therapy has demonstrated unprecedented success in the treatment of various hematologic malignancies including relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Currently, there are two FDA-approved CD19-directed CAR-T cell products for the treatment of adults with R/R B-ALL. Despite high remission rates following CD19 CAR-T cell therapy in R/R B-ALL, remission durability remains limited in most adult patients, with relapse observed frequently in the absence of additional consolidation therapy. Furthermore, the burden of CAR-T cell toxicity remains significant in adults with R/R B-ALL and further limits the wide utilization of this effective therapy. In this review, we discuss patient and disease factors that are linked to CAR-T cell therapy outcomes in R/R B-ALL and strategies to optimize durability of response to reduce relapse and mitigate toxicity in the adult population. We additionally discuss future approaches being explored to maximize the benefit of CAR-T in adults with B-ALL.