Terminal deoxynucleotidyl transferase expression in different subtypes of childhood B-cell acute lymphoblastic leukemia.

The lack of expression of terminal deoxynucleotidyl transferase (TdT) is frequently associated with KMT2A-rearranged subtype of pediatric acute lymphoblastic leukemia (ALL). However, this association has not been investigated extensively in the Asian population. A retrospective analysis of TdT expression in pediatric B-cell ALL (B-ALL) was performed in patients treated using the Taiwan Pediatric Oncology Group (TPOG) ALL 2002 and 2013 protocols. Among the 331 patients with B-ALL, 12 patients showed TdT negativity at initial diagnosis. Among these, eight patients showed KMT2A rearrangement (66.7%). Other patients showing negative TdT expression had ETV6::RUNX1, MEF2D-rearranged, and other B-ALL subtypes. However, in the context of KMT2A-rearranged B-ALL (n = 20), only eight patients showed TdT negativity. The 5-year event-free survival and overall survival of patients with and without TdT expression were 83.8% versus 46.8% (P <0.001) and 86.3% versus 55.4% (P = 0.004), respectively. Moreover, several aberrant markers, such as CD2, CD56, CD7, and CD117, were rarely expressed in the B-ALL samples, and if expressed, they were enriched in specific genetic subtypes. The results of this study indicate that immunophenotypic features are correlated with specific genetic subtypes of childhood B-ALL.

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.

[Use of the ETV6/RUNX1 probe to verify the performance of the fluorescence in situ hybridization probe before clinical detection].

Objective: To explore the standardized performance of a FISH probe before clinical detection. Methods: The probe sensitivity and specificity of ETV6/RUNX1 were analyzed via interphase and metaphase FISH in 20 discarded healthy bone marrow samples. The threshold system of the probe was established using an inverse beta distribution, and an interpretation standard was established. Finally, a parallel-controlled polymerase chain reaction detection study was conducted on 286 bone marrow samples from patients at our hospital. The clinical sensitivity, specificity, and diagnostic coincidence rate of ETV6/RUNX1 FISH detection were analyzed, and the diagnostic consistency of the two methods was analyzed by the kappa test. Results: The probe sensitivity and specificity of the ETV6/RUNX1 probe were 98.47% and 100%, respectively. When 50, 100, and 200 cells were counted, the typical positive signal pattern cutoffs were 5.81%, 2.95%, and 1.49%, respectively, and the atypical positive signal pattern cutoffs were 13.98%, 9.75%, and 6.26%, respectively. The clinical sensitivity of FISH was 96.1%, clinical specificity was 99.6%, diagnostic coincidence rate was 99.00%, diagnostic consistency test kappa value was 0.964, and P value was <0.001. Conclusion: For FISH probes without a national medical device registration certificate, standardized performance verification and methodology performance verification can be performed using laboratory developed test verification standards to ensure a reliable and accurate reference basis for clinical diagnosis and treatment.

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.

[Multicenter evaluation of minimal residual disease monitoring in early induction therapy for treatment of childhood acute lymphoblastic leukemia].

Objective: To evaluate the role of minimal residual disease (MRD) monitoring during early induction therapy for the treatment of childhood acute lymphoblastic leukemia (ALL). Methods: This was a multicenter retrospective cohort study. Clinical data of 1 164 ALL patients first diagnosed between October 2016 and June 2019 was collected from 16 hospitals in South China Children's Leukemia Group. According to MRD assay on day 15 of early induction therapy, they were divided into MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group. According to MRD assay on day 33, they were divided into MRD<0.01% group, MRD 0.01%-<1.00% group and MRD≥1.00% group. Age, onset white blood cell count, central nervous system leukemia (CNSL), molecular genetic characteristics and other data were compared between groups. Kaplan-Meier method was used for survival analysis. Cox regression model was used to analyze prognostic factors. Results: Of the 1 164 enrolled patients, there were 692 males and 472 females. The age of diagnosis was 4.7 (0.5, 17.4) years. The white blood cell count at initial diagnosis was 10.7 (0.4, 1 409.0) ×109/L. Among all patients, 53 cases (4.6%) had CNSL. The follow-up time was 47.6 (0.5, 68.8) months. The 5-year overall survival (OS) and 5-year relapse-free survival (RFS) rates were (93.1±0.8) % and (90.3±1.1) %. On day 15 of early induction therapy, there were 466 cases in the MRD<0.10% group, 523 cases in the MRD 0.10%-<10.00% group and 175 cases in the MRD≥10.00% group. The 5-year OS rates of the MRD<0.10% group, MRD 0.10%-<10.00% group and MRD≥10.00% group were (95.4±1.0) %, (93.3±1.1) %, (85.4±2.9) %, respectively, while the RFS rates were (93.2±1.6) %, (90.8±1.4) %, (78.9±4.3) %, respectively (χ2=16.47, 21.06, both P<0.05). On day 33 of early induction therapy, there were 925 cases in the MRD <0.01% group, 164 cases in the MRD 0.01%-<1.00% group and 59 cases in the MRD≥1.00% group. The 5-year RFS rates in the MRD 0.01%-<1.00% group was lowest among three groups ((91.4±1.2) % vs. (84.5±3.2) % vs. (87.9±5.1) %). The difference between three groups is statistically significant (χ2=9.11, P=0.010). Among ALL patients with MRD≥10.00% on day 15 of induction therapy, there were 80 cases in the MRD <0.01% group on day 33, 45 cases in the MRD 0.01%-<1.00% group on day 33 and 45 cases in the MRD≥1.00% group on day 33. The 5-year RFS rates of three groups were (83.9±6.0)%, (67.1±8.2)%, (83.3±6.9)% respectively (χ2=6.90, P=0.032). Univariate analysis was performed in the MRD≥10.00% group on day 15 and the MRD 0.01%-<1.00% group on day 33.The 5-year RFS rate of children with CNSL was significantly lower than that without CNSL in the MRD≥10.00% group on day 15 ((50.0±20.4)% vs. (80.3±4.4)%,χ2=4.13,P=0.042). Patients with CNSL or MLL gene rearrangement in the MRD 0.01%-<1.00% group on day 33 had significant lower 5-year RFS rate compared to those without CNSL or MLL gene rearrangement ((50.0±25.0)% vs. (85.5±3.1)%,χ2=4.06,P=0.044;(58.3±18.6)% vs. (85.7±3.2)%,χ2=9.44,P=0.002). Multivariate analysis showed that age (OR=0.58, 95%CI 0.35-0.97) and white blood cell count at first diagnosis (OR=0.43, 95%CI 0.27-0.70) were independent risk factors for OS. The MRD level on day 15 (OR=0.55,95%CI 0.31-0.97), ETV6-RUNX1 fusion gene (OR=0.13,95%CI 0.03-0.54), MLL gene rearrangement (OR=2.55,95%CI 1.18-5.53) and white blood cell count at initial diagnosis (OR=0.52,95%CI 0.33-0.81) were independent prognostic factors for RFS. Conclusions: The higher the level of MRD in early induction therapy, the worse the OS. The MRD levels on day 15 is an independent prognostic factor for RFS.The MRD in early induction therapy guided accurate risk stratification and individualized treatment can improve the survival rate of pediatric ALL.

Diagnostic significance of cerebrospinal fluid flow cytometry in Chinese children with B lineage acute lymphoblastic leukemia.

BACKGROUND: Central nervous system leukemia (CNSL) is one of the major causes of the poor prognosis of childhood leukemia. We aimed to compare the sensitivity of cytomorphology (CM) and flow cytometry (FCM) in diagnosing CNSL, emphasizing the importance of FCM in the diagnosis process. METHODS: One-hundred-sixty-five children with newly diagnosed B-cell Acute Lymphoblastic Leukemia (B-cell ALL) were included in this study. Cerebrospinal fluid (CSF) samples were taken for routine CSF analysis, CM analysis, and FCM examination. Computed tomography scans and/or magnetic resonance imaging were performed at diagnosis. Patients with CNS2, CNS3, and traumatic lumbar puncture (TLP) at diagnosis received two additional courses of triple intrathecal injections during induction treatment. We compared the sensitivity of FCM and CM in the diagnosis of children with CNSL. RESULTS: One hundred and twenty-eight (77.58%) CSF samples were negative by either CM or FCM (CM-/FCM-), four (2.42%) were positive by both CM and FCM (CM+/FCM+), and thirty-three (20%) displayed a single positive finding by FCM (CM-/FCM+) (p = 0.044). By adding two intrathecal injections in the induction treatment, ten children with TLP+ had no CNS relapse, like those with TLP-. However, compared to CNS1 and TLP, the event-free survival (EFS) did not significantly improve in patients with CNS2 and CNS3. Moreover, CNSL status was associated with worse 3-year EFS (p < 0.05). CONCLUSIONS: We have validated that FCM is more accurate in stratifying the status of the CNS compared to CM analysis. However, to improve the EFS rate of childhood leukemia, it is necessary to combine CM examination, FCM, and cranial imaging for the early diagnosis of CNSL.

Identifying a core protein signature of small extracellular vesicles derived from B-cell precursor acute lymphoblastic leukaemia.

Acute paediatric leukaemia is diagnosed and monitored via bone marrow aspirate assessment of blasts as a measure of minimal residual disease. Liquid biopsies in the form of blood samples could greatly reduce the need for invasive bone marrow aspirations, but there are currently no blood markers that match the sensitivity of bone marrow diagnostics. Circulating extracellular vesicles (EVs) represent candidate biomarkers that may reflect the blast burden in bone marrow, and several studies have reported on the utility of EVs as biomarkers for adult haematological malignancies. Increased levels of EVs have been reported for several haematological malignancies, and we similarly report here elevated EV concentrations in plasma from paediatric BCP-ALL patients. Plasma EVs are very heterogeneous in terms of their cellular origin, thus identifying a cancer selective EV-marker is challenging. Here, we undertook a reductionistic approach to identify protein markers selectively associated to plasma EVs derived from BCP-ALL patients. The EV proteome of primary BCP-ALL cell-derived EVs were compared against EVs from healthy donor B cells and the BCP-ALL cell line REH, and further against EVs isolated from plasma of healthy paediatric donors and paediatric BCP-ALL patients. With this approach, we identified a signature of 6 proteins (CD317, CD38, IGF2BP1, PCNA, CSDE1, and GPR116) that were specifically identified in BCP-ALL derived EVs only and not in healthy control EVs, and that could be exploited as diagnostic biomarkers.

Flow cytometric detection of leukemic blasts in Libyan pediatric patients with acute lymphoblastic leukemia.

The diagnosis of acute lymphoblastic leukemia (ALL), which is the most common type of cancer in children, has become more accurate with the use of flow cytometry. Here, this technology was used to immunophenotype leukemic cells in peripheral blood samples from Libyan pediatric ALL patients. We recruited 152 newly diagnosed patients at Tripoli Medical Center (Tripoli, Libya) by morphological examination of blood and bone marrow. Twenty-three surface and cytoplasmic antigen markers were used to characterize B and T cells in circulating blood cells by four-color flow cytometry. Six children (3.9%) turned out to have biphenotypic acute leukemia, 88 (57.9%) had B ALL, and 58 (38.1%) had T ALL. There were 68 cases of pro-B ALL CD10-positive (44.7%), 8 cases of pro-B ALL CD10-negative (5.2%), 6 cases of pre-B ALL (3.9%), and 6 of mature-B ALL (3.9%). CD13 was the most commonly expressed myeloid antigen in ALL. We present immunophenotypic data for the first time describing ALL cases in Libya. The reported results indicate that the most common subtype was pro-B ALL, and the frequency of T-ALL subtype was higher compared to previous studies. Six cases were positive for both myeloid and B lymphoid markers. Our findings may provide the basis for future studies to correlate immunophenotypic profile and genetic characteristics with treatment response among ALL patients.

Assessment on the use of allopurinol to improve safety and efficacy of mercaptopurine in pediatric patients with Acute Lymphoblastic Leukemia and Lymphoma during maintenance therapy.

BACKGROUND: Mercaptopurine is an important component of acute lymphoblastic leukemia (ALL) and lymphoma (LLy) maintenance therapy. The 6-thioguanine nucleosides (6-TGN) are believed to be the primary contributor to myelosuppression and immunosuppressive effects, while 6-methylmercaptopurine (6-MMPN) is believed to be responsible for several toxicities including hepatotoxicity, pancreatitis, and hypoglycemia. Previous reports suggest the addition of allopurinol may reduce these toxicities. AIMS: To assess the use of allopurinol to improve both safety and efficacy of mercaptopurine in pediatric patients with ALL and LLy during maintenance therapy. Secondary objectives included evaluating patient tolerability and skewed metabolism. In addition, we also analyzed mercaptopurine daily dose reduction upon allopurinol initiation. METHODS AND RESULTS: The primary endpoint was time within goal ANC prior to and after initiation of allopurinol. Secondary endpoints included; improvement in selective toxicities (hepatotoxicity, pancreatitis, and hypoglycemia) and 6-MMPN to 6-TGN ratio prior to and after allopurinol initiation. In addition, an exploratory endpoint assessing mercaptopurine daily dose reduction prior to and after allopurinol initiation was included. Sixteen patients met inclusion criteria and 15 (94%) of which were included in this study. Median percent of maintenance days within goal ANC prior to and after initiation of allopurinol was 27.8 (IQR 22.6-44.9) and 41.6 (IQR 20.2-58.2) respectively. All patients experienced selective toxicities; 15 (100%) hepatotoxicity, 1 (7%) pancreatitis, and 3 (20%) hypoglycemia. Improvement of toxicities was seen in 13/15 (87%), 1/1 (100%), and 2/3 (67%) respectively. Average 6-MMPN:6-TGN ratio prior to allopurinol initiation was 304:1 and after, allopurinol initiation improved to 15:1, resulting in a 95% reduction. Average mercaptopurine dose prior to and after allopurinol initiation decreased by about 56% (63 to 28 mg/m2 /day). CONCLUSION: Results suggest that the use of allopurinol in pediatric patients with ALL and LLy receiving mercaptopurine during maintenance therapy is both safe and effective.

[Clinical features and prognostic analysis of testicular relapse in pediatric acute lymphoblastic leukemia].

Objective: To investigate the clinical features and prognosis of testicular relapse in pediatric acute lymphoblastic leukemia (ALL). Methods: Clinical data including the age, time from initial diagnosis to recurrence, relapse site, and therapeutic effect of 37 pediatric ALL with testicular relapse and treated in Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences between November 2011 and December 2022 were analyzed retrospectively. Patients were grouped according to different clinical data. Kaplan-Meier analysis was used to evaluate the overall survival (OS) rate and event free survival (EFS) rate for univariate analysis, and Cox proportional-hazards regression model was used to evaluate the influencing factors of OS rate and EFS rate for multivariate analysis. Results: The age at initial diagnosis of 37 pediatric testicular relapse patients was (5±3) years and the time from initial diagnosis to testicular recurrence was (37±15) months. The follow-up time was 43 (22, 56) months. Twenty-three patients (62%) were isolated testis relapse. The 5-year OS rate and EFS rate of the 37 relapsed children were (60±9) % and (50±9) % respectively. Univariate analysis showed that the 2-year EFS rate in the group of patients with time from initial diagnosis to testicular recurrence >28 months was significantly higher than those ≤28 months ((69±10)% vs. (11±11)%, P<0.05), 2-year EFS rate of the isolated testicular relapse group was significantly higher than combined relapse group ((66±11)% vs. (20±13) %, P<0.05), 2-year EFS rate of chimeric antigen receptor T (CAR-T) cell treatment after relapse group was significantly higher than without CAR-T cell treatment after relapse group ((78±10)% vs. (15±10)%, P<0.05). ETV6-RUNX1 was the most common genetic aberration in testicular relapsed ALL (38%, 14/37). The 4-year OS and EFS rate of patients with ETV6-RUNX1 positive were (80±13) % and (64±15) %, respectively. Multivariate analysis identified relapse occurred≤28 months after first diagnosis (HR=3.09, 95%CI 1.10-8.72), combined relapse (HR=4.26, 95%CI 1.34-13.52) and CAR-T cell therapy after relapse (HR=0.15,95%CI 0.05-0.51) were independent prognostic factors for 2-year EFS rate (all P<0.05). Conclusions: The outcome of testicular relapse in pediatric ALL was poor. They mainly occurred 3 years after initial diagnosis. ETV6-RUNX1 is the most common abnormal gene.Patients with ETV6-RUNX1 positive often have a favorable outcome. Early relapse and combined relapse indicate unfavorable prognosis, while CAR-T cell therapy could significantly improve the survival rate of children with testicular recurrence.

Philadelphia chromosome-positive T-cell acute lymphoblastic leukemia: a case report.

Philadelphia chromosome-positive (Ph+) T-cell acute lymphoblastic leukemia (T-ALL) is a rare and aggressive type of acute leukemia. The Philadelphia chromosome is the hallmark of chronic myeloid leukemia (CML). The differentiation between Ph+ T-ALL and T-cell lymphoblastic crisis of CML may be problematic in some cases. Here, we report a rare case of de novo Ph+ T-ALL that presented a diagnostic challenge. The overall clinical, immunophenotypic, cytogenetic, and xenotransplantation results suggest a diagnosis of Ph+ T-ALL. The patient was treated with induction chemotherapy including imatinib followed by haploidentical stem cell transplantation and achieved complete remission.

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.

Expression and Clinical Significance of CD30 and CD56 in Lymphoblastic Lymphoma: A Retrospective Analysis on Paraffin-Embedded Tissues by Immunohistochemistry.

Background: We evaluated CD30 and CD56 expression in lymphoblastic lymphoma (LBL) and correlated the results with clinicopathological features and prognosis. Methods: Immunohistochemical (IHC) staining was performed on 85 formalin-fixed paraffin-embedded LBL specimens using two CD30 clones and one CD56 antibody clone. Results: Weak and diffuse expression of CD30 was expressed in 4.7% (clone Ber-H2) or 14.1% (clone EPR4102) in LBL, while CD56 was expressed in 24.7%. CD30 and CD56 expression correlated with lactate dehydrogenase levels. CD56-positive expression was closely associated with an unfavorable prognosis. Although CD30 expression exhibited a trend toward poorer overall survival, it did not reach statistical significance. Conclusion: CD56 is a potential negative prognostic marker. These findings suggest that CD30 and CD56 targeted therapies could be potential therapeutic targets for LBL patients.

Measurable residual disease study through three different methods can anticipate relapse and guide early interventions in childhood acute lymphoblastic leukemia

Introduction Acute lymphoblastic leukemia (ALL) is the most common cancer among children. Measurable residual disease (MRD, previously named minimal residual disease) study can guide therapy adjustments or preemptive interventions that might avoid hematological relapse. Methods Clinical decision making and patient outcome were evaluated in 80 real-life childhood ALL patients, according to the results observed in 544 bone marrow samples analyzed with three MRD methods: multiparametric flow cytometry (MFC), fluorescent in-situ hybridization (FISH) on B or T-purified lymphocytes and patient-specific nested reverse transcription polymerase chain reaction (RT-PCR). Results Estimated 5 year overall survival and event-free survival were 94% and 84.1%, respectively. A total of 12 relapses in 7 patients were associated with positive MRD detection with at least one of the three methods: MFC (p < 0.00001), FISH (p < 0.00001) and RT-PCR (p = 0.013). MRD assessment allowed the anticipation of relapse and adapted early interventions with different approaches including chemotherapy intensification, blinatumomab, HSCT and targeted therapy to halt relapse in five patients, although two of them relapsed afterwards. Conclusion MFC, FISH and RT-PCR are complementary methods for MRD monitoring in pediatric ALL. Although, our data clearly show that MDR positive detection is associated with relapse, continuation of standard treatment, intensification or other early interventions were able to halt relapse in patients with different risks and genetic background. More sensitive and specific methods are warranted to enhance this approach. However, whether early treatment of MRD can improve overall survival in patients with childhood ALL needs to be evaluated in adequately controlled clinical trials (AU)

Plasma-derived exosomal miR-326, a prognostic biomarker and novel candidate for treatment of drug resistant pediatric acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is a cancer with high incidence rate in pediatrics and drug resistance is a major clinical concern for ALL treatment. The current study was designed to evaluate the role of exosomal miR-326 in diagnosis and treatment of children with B-ALL. Exosomes were isolated from plasma samples of 30 patients and B-ALL cell lines followed by characterization, using nanoparticle tracking analysis, immunoblotting assay and electron microscopy. qPCR showed significantly increased levels of miR-326 in patients exosomes compared with non-cancer controls (P < 0.05, AUC = 0.7500). Moreover, a comparison between the sensitive and drug resistant patients revealed a prognostic value for the exosomal miR326 (P < 0.05, AUC = 0.7755). Co-culture studies on drug resistant patient primary cells and B-ALL cell lines suggested that exosomes with high miR-326 level act as vehicles for reducing cells viability. B-ALL cell line transfection with naked miR-326 mimic confirmed the results, and fluorescence microscopy validated uptake and internalization of exosomes by target cells. The novel introduced features of the exosomal miR-326 address a non-invasive way of diagnosing primary drug resistance in pediatric ALL and advocates a novel therapeutic strategy for this cancer.

Applying machine learning to identify pediatric patients with newly diagnosed acute lymphoblastic leukemia using administrative data.

Case identification in administrative databases is challenging as diagnosis codes alone are not adequate for case ascertainment. We utilized machine learning (ML) to efficiently identify pediatric patients with newly diagnosed acute lymphoblastic leukemia. We tested nine ML models and validated the best model internally and externally. The optimal model had 97% positive predictive value (PPV) and 99% sensitivity in internal validation; 94% PPV and 82% sensitivity in external validation. Our ML model identified a large cohort of 21,044 patients, demonstrating an efficient approach for cohort assembly and enhancing the usability of administrative data.

ZNF384 fusion transcript levels for measurable residual disease monitoring in adult B-cell acute lymphoblastic leukemia.

Zinc finger protein 384 (ZNF384) rearrangement defined a novel subtype of B-cell acute lymphoblastic leukemia (B-ALL). The prognostic significance of ZNF384 fusion transcript levels represented measurable residual disease remains to be explored. ZNF384 fusions were screened out in 57 adult B-ALL patients at diagnosis by real-time quantitative polymerase chain reaction and their transcript levels were serially monitored during treatment. The reduction of ZNF384 fusion transcript levels at the time of achieving complete remission had no significant impact on survival, whereas its ≥2.5-log reduction were significantly associated with higher relapse free survival (RFS) and overall survival (OS) rates after course 1 consolidation (p = 0.022 and = 0.0083) and course 2 consolidation (p = 0.0025 and = 0.0008). Compared with chemotherapy alone, allogeneic hematopoietic stem cell transplantation (allo-HSCT) significantly improved RFS and OS of patients with <2.5-log reduction after course 1 consolidation (p < 0.0001 and = 0.0002) and course 2 consolidation (p = 0.0003 and = 0.019), whereas exerted no significant effects in patients with ≥2.5-log reduction (all p > 0.05). ZNF384 fusion transcript levels after course 1 and course 2 consolidation strongly predict relapse and survival and may guide whether receiving allo-HSCT in adult B-ALL.

Raccoon Eyes Presentation in a Child Diagnosed With Acute Lymphoblastic Leukemia: A Case Report.

Raccoon's eyes (periorbital ecchymosis) may present as the first sign in patients with skull base/base/facial fractures and tumors. In childhood, orbital metastases of neuroblastoma should be considered in the absence of trauma history. Herein, we report a 3-year-old girl diagnosed with acute lymphoblastic leukemia who presented with periorbital ecchymosis. To the best of our knowledge, this is the first pediatric patient with acute lymphoblastic leukemia in the literature who presented with raccoon eyes.