Pediatric Acute Lymphoblastic Leukemia Patients Research Articles

Total body irradiation versus chemotherapy conditioning in pediatric acute lymphoblastic leukemia patients undergoing hematopoietic stem cell transplant: A systematic review and meta-analysis.

e22002 Background: Hematopoietic stem cell transplant (HSCT) is indicated in pediatric acute lymphoblastic leukemia (ALL) patients who have relapsed or are at a very high risk of relapse during first complete remission. Two types of myeloablative conditioning have been employed before HSCT: total body irradiation (TBI) based regimens and chemotherapy alone (CHT). The use of TBI is favorable in adults with ALL, and it has also demonstrated excellent efficacy in the pediatric population. However, the lifelong adverse events of TBI are a substantial concern in younger patients. This study compares the efficacy and safety of TBI and CHT conditioning in pediatric, adolescent and young adult ALL patients (0-24 years old). Methods: A systematic literature search was conducted on PubMed, Embase, Cochrane, and Clinicaltrials.gov from inception to November 25, 2021, using MeSH terms and keywords for ‘acute lymphoblastic leukemia’, ‘whole body irradiation’, ‘child’, ‘adolescent’ and ‘young adult’. Efficacy outcomes considered were overall survival (OS), event-free survival (EFS), and relapse. Safety outcomes were acute (a) and chronic (c) graft-versus-host disease (GVHD), and non-relapse mortality/transplant-related mortality (NRM/TRM). Estimates of risk ratios (RR) for dichotomous variables and hazard ratios (HR) for OS and EFS were pooled using a random-effects model in Revman v5.4. Results: The initial search revealed 1544 articles. After excluding reviews, duplicates, and non-relevant articles, we included data from 16 studies (2 randomized controlled trials, 1 non-randomized prospective study and 13 retrospective studies). TBI based and CHT conditioning were evaluated in 4656 and 1500 patients, respectively. The most common TBI and CHT regimens were TBI + cyclophosphamide (Cy) + etoposide (3 studies) and busulfan + Cy (6 studies), respectively. The TBI dose utilised ranged from 8-12 Gy, with 12 Gy being the most common (8 studies). The median age ranged from 4 months to 13.3 years; and the median follow up was 1.2-9.7 years. In comparison with TBI conditioning, CHT alone was associated with significantly worse OS (HR 1.61, 95% CI 1.06-2.44; p = 0.03; I2 = 79%), EFS (HR 2.01, 95% CI 1.26-3.20; p = 0.003; I2 = 60%) and risk of relapse (RR 1.44, 95% CI 1.23-1.68; p = 0.00001; I2 = 37%). There was reduced risk of aGVHD with CHT (RR 0.79, 95% CI 0.66-0.93; p = 0.006; I2 = 51%), but the difference was not significant when only grade 3-4 aGVHD was considered (RR 1.01, 95% CI 0.80-1.27; p = 0.95; I2 = 0%). The two regimens were comparable in terms of risk of cGVHD (RR 0.87, 95%CI 0.64-1.18; p = 0.38; I2 = 43%) and NRM/TRM (RR 1.24, 95% CI 0.99-1.55; p = 0.06; I2 = 66.8%). Conclusions: In pediatric and young adult ALL patients undergoing HSCT, TBI conditioning has better efficacy and similar safety compared to CHT alone.

Measurable residual disease analysis in paediatric acute lymphoblastic leukaemia patients with ABL-class fusions

BackgroundABL-class fusions including NUP214-ABL1 and EBF1-PDGFRB occur in high risk acute lymphoblastic leukaemia (ALL) with gene expression patterns similar to BCR-ABL-positive ALL. Our aim was to evaluate new DNA-based measurable residual disease (MRD) tests detecting these fusions and IKZF1-deletions in comparison with conventional immunoglobulin/T-cell receptor (Ig/TCR) markers.MethodsPrecise genomic breakpoints were defined from targeted or whole genome next generation sequencing for ABL-fusions and BCR-ABL1. Quantitative PCR assays were designed and used to re-measure MRD in remission bone marrow samples previously tested using Ig/TCR markers. All MRD testing complied with EuroMRD guidelines.ResultsABL-class patients had 46% 5year event-free survival and 79% 5year overall survival. All had sensitive fusion tests giving high concordance between Ig/TCR and ABL-class fusion results (21 patients, n = 257 samples, r2 = 0.9786, P < 0.0001) and Ig/TCR and IKZF1-deletion results (9 patients, n = 143 samples, r2 = 0.9661, P < 0.0001). In contrast, in BCR-ABL1 patients, Ig/TCR and BCR-ABL1 tests were discordant in 32% (40 patients, n = 346 samples, r2 = 0.4703, P < 0.0001) and IKZF1-deletion results were closer to Ig/TCR (25 patients, n = 176, r2 = 0.8631, P < 0.0001).ConclusionsMRD monitoring based on patient-specific assays detecting gene fusions or recurrent assays for IKZF1-deletions is feasible and provides good alternatives to Ig/TCR tests to monitor MRD in ABL-class ALL.

CMV-colitis in a pediatric non-transplant ALL patient receiving chemotherapy; A case report

Cytomegalovirus (CMV) is the leading cause of viral-associated congenital infections. Moreover, it can also be acquired. Between 50 to 80 percent of the world’s population is seropositive for CMV and most clinical disease occurs in individuals previously infected with CMV. Rarely, serious CMV infection has occurred in individuals with healthy immune system. In contrast to immunocompetent patients, higher morbidity and mortality of CMV end organ disease is considered in immunocompromised patients. According to available evidence, gastrointestinal (GI) disease has lower prevalence in case of CMV-induced organ involvement, especially in pediatric non-transplant acute leukemia. In this report, we present a 12-year-old girl, known case of acute lymphoblastic leukemia (ALL) receiving maintenance chemotherapy with manifestations of gastroenteritis and significant weight loss. Initial laboratory data, demonstrated mild pancytopenia especially lymphopenia and thrombocytopenia. After excluding more common etiologies, colonoscopy with multiple biopsies were taken which was indicative of CMV-colitis. Intravenous (IV) ganciclovir for 3 weeks and oral valganciclovir for about 9 months were initiated. Follow-up courses for CMV surveillance included blood qualitative CMV polymerase chain reaction (PCR) and colonoscopy with biopsy which were negative for CMV but tissue qualitative CMV PCR was positive for CMV in about 7 months after initiation of treatment. Oral treatment was decided to be continued. To sum up, plenty of guidelines have been developed in stem cell transplantation and human immunodeficiency virus (HIV) patients but non-transplant leukemic setting, is a neglected area in the field of CMV infection management.

Prospective quantitative gene expression analysis of kallikrein-related peptidase KLK10 as a diagnostic biomarker for childhood acute lymphoblastic leukemia.

BackgroundThe most common malignancy in children is acute lymphoblastic leukemia (ALL). This study aimed to explore KLK10 mRNA expression as a potential diagnostic biomarker for ALL in children and to examine the effect of chemotherapy on KLK10 mRNA expression following the induction and after three months of receiving chemotherapy.MethodsIn this prospective study, total RNA was extracted from blood samples of 23 pediatric ALL patients on diagnosis, after one month and three months of receiving chemotherapy. Healthy pediatric volunteers (n = 12) were selected as control individuals. After cDNA synthesis, KLK10 mRNA gene expression levels were quantified using quantitative real-time PCR (qRT-PCR).ResultsKLK10 mRNA expression levels were significantly decreased in leukemic cells compared to their levels in cells of normal blood samples (p = 0.0001). KLK10 expression levels in ALL patients after one month and three months of receiving chemotherapy decreased compared to normal blood samples (p < 0.0001 and p = 0.0175 respectively). The expression level of KLK10 mRNA in ALL patients after one month of chemotherapy was decreased compared to their level on diagnosis (p = 0.4413). KLK10 mRNA expression levels in ALL patients after three months of chemotherapy were increased compared to their level on diagnosis (p = 0.0602). The ROC curve illustrated that KLK10 mRNA expression could very efficiently discriminate ALL patients from normal counterparts (AUC=0.886, 95% CI [0.7720–1.000], SE = 0.0582, p = 0.0004).ConclusionKLK10 mRNA expression could serve as a potential diagnostic molecular biomarker for ALL in children.

Gut Microbiome Suffers from Hematopoietic Stem Cell Transplantation in Childhood and Its Characteristics Are Positively Associated with Intra-Hospital Physical Exercise.

Simple SummaryGut microbiome research has rapidly advanced with good perspectives for the diagnostics and/or therapy of a plethora of diseases, including metabolic and neurodegenerative diseases and various types of cancer. In this study, we examined the composition of the fecal microbiota of eligible children with acute lymphoblastic leukemia (ALL) after hematopoietic stem cell transplantation (HSCT). We found a negative effect of HSCT treatment on microbiome bacterial diversity and richness with microbial monodominance by pathogenic bacteria in pediatric ALL patients after 3 months. The changes in the gut microbiota were associated with systemic inflammation on day + 28. However, promisingly, we have observed an association between bacterial diversity and physical exercise during HSCT treatment. Our findings provide additional support for the importance of investigating the gut microbiome in children with cancer.Gut microbiome impairment is a serious side effect of cancer treatment. The aim of this study was to identify the effects of hematopoietic stem cell transplantation (HSCT) treatment on gut microbiota composition in children with acute lymphoblastic leukemia (ALL). Fecal microbiotas were categorized using specific primers targeting the V1–V3 region of 16S rDNA in eligible pediatric ALL patients after HSCT (n = 16) and in healthy controls (Ctrl, n = 13). An intra-hospital exercise program was also organized for child patients during HSCT treatment. Significant differences in gut microbiota composition were observed between ALL HSCT and Ctrl with further negative effects. Plasma C-reactive protein correlated positively with the pathogenic bacteria Enterococcus spp. and negatively with beneficial bacteria Butyriccocus spp. or Akkermansia spp., respectively (rs = 0.511, p = 0.05; rs = −0.541, p = 0.04; rs = −0.738, p = 0.02). Bacterial alpha diversity correlated with the exercise training characteristics. Therefore, specific changes in the microbiota of children were associated with systemic inflammation or the ability to exercise physically during HSCT treatment.

Effect of Treatment in a Specialized Pediatric Hemato-Oncology Setting on 5-Year Survival in Acute Lymphoblastic Leukemia: A Quasi-Experimental Study.

Simple SummaryAdolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) have a worse prognosis than children. In addition to differences in biology—such as higher incidence of unfavorable genetic alterations in the AYA population—this might be related to the fact that ALL patients under a certain age (often 18 years) are generally treated in special pediatric hemato-oncology settings, which is associated with improved survival, while patients above that age are treated in adult hemato-oncology care settings. Based on previous research, adult treatment settings have increasingly adopted pediatric-inspired protocols, which appear to have led to increased survival of adolescent ALL patients. This study aims to assess whether there remains an effect of treatment of ALL patients in a specialized pediatric hemato-oncology setting on 5-year survival. This study provides insight into the effects of such treatment for ALL patients, and may stimulate further research into causal relationships in other oncological conditions.Survival rates of adolescents and young adults (AYAs) with acute lymphoblastic leukemia (ALL) are inferior to those of pediatric ALL patients. In part, this may be caused by differences in treatment setting. Generally, children are treated in specialized pediatric hemato-oncology settings, whereas AYAs are treated in adult hemato-oncology settings. Since 2005, adult treatment protocols have included pediatric-inspired chemotherapy, which has been the standard of care for AYAs from 2008 onwards. This study aims to assess whether, despite protocols in both settings having become more similar, there remains an effect of treatment in specialized pediatric hemato-oncology settings on 5-year survival for ALL patients in the Netherlands. We used nationwide registry data (2004–2013) on 472 ALL patients aged between 10 and 30 years old. A fuzzy regression discontinuity design was applied to estimate the treatment effect using two-stage least squares regression with the treatment threshold at 17 years and 7 months of age, adjusting for sex, age at diagnosis, and immunophenotype. We found a risk difference of 0.419 (p = 0.092; 95% CI = −0.0686; 0.907), meaning a 41.9 percentage point greater probability of surviving five years after diagnosis for ALL patients treated in specialized pediatric hemato-oncology settings. Our results suggest that ALL patients around the threshold could benefit from increased collaboration between pediatric and adult hemato-oncology in terms of survival.

Case Series of False-Positive HIV Test Results in Pediatric Acute Lymphoblastic Leukemia Patients Following Chimeric Antigen Receptor T-Cell Therapy: Guidance on How to Avoid and Resolve Diagnostic Dilemmas.

Chimeric antigen receptor T-cell (CAR-T) Cell Therapy is approved for the treatment of pediatric patients with relapsed/refractory acute lymphoblastic leukemia B-ALL. Lentiviral vector technology, highly modified from HIV-1, is used to induce stable, long-term transgene expression by integration into the host genome. This integration may interfere with HIV-1 NAAT producing false-positive results. Guidance for HIV diagnostic testing in pediatric B-ALL undergoing this type of therapy is lacking. Herein, we report case series with presented scenarios in which HIV-1 NAAT testing among CAR-T cell patients produced false-positive results, highlighting the importance careful assay selection and performance among this patient population.

Identification of Prognostic Markers in Argentinian Acute Lymphoblastic Leukemia Pediatric Patients Through Transcriptome Analysis: Differential Gene Expression, Mutational Status and Immune Microenvironment

PURPOSE Acute lymphoblastic leukemia (ALL) is the most incident pediatric cancer. Although considerable progress has been made on treatment efficacy and survival rates, 15%-30% of patients relapse and/or die. We aimed to identify molecular profiles and microenvironment makeup in leukemic bone marrow samples that could help to better predict disease outcome. METHODS We performed RNA-seq on bone marrow samples from pediatric ALL patients at diagnosis (n = 37). Patients were recruited under a multi-center clinical protocol in Argentina (median follow-up: 31 months). We analyzed differential gene expression, gene set variations, mutations in candidate genes, and fusion genes among clinico-pathological features. The abundance of immune-cell populations was inferred by digital cytometry (MIXTURE) and a “cytolytic score” based on the expression of five genes specific to cytotoxic cells. RESULTS We detected: (1) 37 differentially expressed genes (DEG) between poor vs good responders to prednisone; (2) 71 DEG between high vs standard-risk groups; (3) 13 DEG between patients who died/relapsed vs those who did not; and (4) 35 DEG between patients that developed severe therapy-related acute toxicity vs those who did not (|log2FC|&gt; 1; P.adj &lt; .05). We observed that 15%-30% of the DEG corresponded to lncRNAs. We found six differentially expressed pathways relevant to cancer and leukocyte biology among risk groups ( P &lt; .01). We identified 17 mutations and three fusion genes in 44% of patients; the presence of these mutations shortened the relapse-free survival (Cox- P-val = .006). High cytolytic score was associated with activated CD8+T cells, immune cell trafficking, and bone marrow niche signaling genesets, suggesting potential candidates for immunotherapies. Higher CD8+T-cell/NK at diagnosis was marginally associated with worse event-free survival (hazard-ratio = 5.39; Cox- P-val = .08). CONCLUSION Transcriptomic sequencing allowed the analysis and integration of multiple molecular features that might improve pediatric ALL outcome prediction.

Correlation Between Risk of Febrile Neutropenia Based on Rondinelli Score with Clinical Outcomes in Acute Lymphoblastic Leukemia Patients

Febrile neutropenia (FN) is the most severe complication in patients with blood cancer and chemotherapy. Acute lymphoblastic leukemia (ALL) is the most common type of cancer in children and the most common cause of febrile neutropenia. The low number of neutrophils in ALL patients due to lymphoblast cancer cells and the toxicity of chemotherapy makes patients susceptible to infection which, if not treated immediately, can lead to death. Early risk assessment for infectious complications in FN patients is needed to increase clinician awareness in high-risk patients and eliminate unnecessary therapy for low-risk patients. The Rondinelli scoring system is a reasonably good instrument for predicting severe infectious complications in pediatric patients with ALL who have febrile neutropenia. This study aims to determine the relationship between the risk category for febrile neutropenia (FN) based on the Rondinelli score with clinical outcomes in FN patients with acute lymphoblastic leukemia (ALL) in the Hematology-Oncology division of the child health department of RSUD Dr. Soetomo. This analytic observational study used secondary data FN patients with acute lymphoblastic leukemia (ALL) implementing a total sampling. From 30 samples of pediatric ALL patients with febrile neutropenia at Dr. Soetomo Hospital for June 2018-June 2020 it was found 17 patients (56.7%) had a moderate risk score category, and 13 others were in a low-risk category (43.3 %). Patients were dominated by moderate and severe severity of neutropenia respectively, 43.3%, had neutropenia for 1-7 days (50%), fever less than seven days (66.7%), had a length of stay of 8-14 days, and 15-30 days 33.3% each. Conclusion from this research is that there was a signifi cant relationship between the Rondinelli score category in pediatric ALL patients with FN with the severity of neutropenia p=0.037; R=0.383), duration of neutropenia (p=0.021; R=0.420), duration of fever (p=0.000; R=0.618), and length of stay (p-value 0.005; R=0.496).

Physical Therapy Utilization Among Hospitalized Patients With Pediatric Acute Lymphoblastic Leukemia.

Patients with pediatric acute lymphoblastic leukemia (ALL) are at risk for impaired physical function from treatment. Early physical therapy (PT) may improve physical function and health in children with ALL, yet little is known about PT utilization in this population. Leveraging the Premier Healthcare Database, we conducted a cohort study including participants hospitalized with ALL at age 0-21 years from January 1, 2010, through March 31, 2017. A generalized mixed linear model assessed sociodemographic and clinical variables associated with receiving PT within 1 year of first hospitalization. Among 5,488 pediatric ALL patients from 330 hospitals (median age 7 years, interquartile range = 4-14 years), only 27.2% overall and 58.9% with neuromuscular conditions received PT within a year of first ALL admission. In multivariable analysis, patients more likely to receive PT were age 10-14 years (odds ratio [OR] = 1.46; 95% CI, 1.20 to 1.76) or 15-21 years (OR = 1.66; 95% CI, 1.36 to 2.02) versus 0-4 years and Hispanic (OR = 1.27; 95% CI, 1.04 to 1.56) versus White. Patients less likely to receive PT were treated by a nonhematology/oncology pediatric (OR = 0.56; 95% CI, 0.46 to 0.70) or adult (OR = 0.50; 95% CI, 0.38 to 0.65) specialist versus a pediatric hematologist/oncologist and treated at a nonteaching hospital (OR = 0.53; 95% CI, 0.36 to 0.79) versus a teaching hospital. Only 27.2% of pediatric ALL patients overall and 58.9% with neuromuscular conditions receive inpatient PT within a year of first ALL admission. Interventions to increase inpatient PT services to pediatric ALL patients and address disparities in PT utilization may improve the physical function and long-term health of survivors.

Effect of ITPA Polymorphism on Adverse Drug Reactions of 6-Mercaptopurine in Pediatric Patients with Acute Lymphoblastic Leukemia: A Systematic Review and Meta-Analysis.

6-Mercaptopurine (6-MP) is a cornerstone of the maintenance regimen for pediatric acute lymphoblastic leukemia (ALL). Inosine triphosphate pyrophosphatase (ITPA) is considered a candidate pharmacogenetic marker that may affect metabolism and 6-MP-induced toxicities; however, the findings are inconsistent. Therefore, we attempted to evaluate the effect of ITPA 94C>A polymorphism on 6-MP-induced hematological toxicity and hepatotoxicity through a systematic review and meta-analysis. A literature search for qualifying studies was conducted using the PubMed, Web of Science, and Embase databases until October 2021. Overall, 10 eligible studies with 1072 pediatric ALL patients were included in this meta-analysis. The results indicated that ITPA 94C>A was significantly associated with 6-MP-induced neutropenia (OR 2.38, 95% CI: 1.56–3.62; p = 0.005) and hepatotoxicity (OR 1.98, 95% CI: 1.32–2.95; p = 0.0009); however, no significant association was found between the ITPA 94C>A variant and 6-MP-induced leukopenia (OR 1.75, 95% CI: 0.74–4.12; p = 0.20). This meta-analysis demonstrated that ITPA 94C>A polymorphism could affect 6-MP-induced toxicities. Our findings suggested that ITPA genotyping might help predict 6-MP-induced myelosuppression and hepatotoxicity.

A Study Protocol for Validation and Implementation of Whole-Genome and -Transcriptome Sequencing as a Comprehensive Precision Diagnostic Test in Acute Leukemias.

BackgroundWhole-genome sequencing (WGS) and whole-transcriptome sequencing (WTS), with the ability to provide comprehensive genomic information, have become the focal point of research interest as novel techniques that can support precision diagnostics in routine clinical care of patients with various cancer types, including hematological malignancies. This national multi-center study, led by Genomic Medicine Sweden, aims to evaluate whether combined application of WGS and WTS (WGTS) is technically feasible and can be implemented as an efficient diagnostic tool in patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). In addition to clinical impact assessment, a health-economic evaluation of such strategy will be performed.Methods and AnalysisThe study comprises four phases (i.e., retrospective, prospective, real-time validation, and follow-up) including approximately 700 adult and pediatric Swedish AML and ALL patients. Results of WGS for tumor (90×) and normal/germline (30×) samples as well as WTS for tumors only will be compared to current standard of care diagnostics. Primary study endpoints are diagnostic efficiency and improved diagnostic yield. Secondary endpoints are technical and clinical feasibility for routine implementation, clinical utility, and health-economic impact.DiscussionData from this national multi-center study will be used to evaluate clinical performance of the integrated WGTS diagnostic workflow compared with standard of care. The study will also elucidate clinical and health-economic impacts of a combined WGTS strategy when implemented in routine clinical care.Clinical Trial Registration[https://doi.org/10.1186/ISRCTN66987142], identifier [ISRCTN66987142].

Efficacy of a Standardized Premedication and Therapeutic Drug Monitoring Protocol for Pegaspargase to Prevent Hypersensitivity Reactions.

The purpose of this study was to evaluate the efficacy of a standardized premedication and therapeutic drug monitoring (TDM) protocol to prevent hypersensitivity reactions from pegaspargase infusions. Pegaspargase is an essential therapeutic agent used for the treatment of acute lymphoblastic leukemia (ALL) in pediatric patients. This study was a retrospective cohort study conducted at Wolfson Children's Hospital, Jacksonville, Florida, and included pediatric ALL patients 0 to 21 years old. Patients were excluded if they had not received the appropriate premedication after protocol implementation or had received premedication before protocol implementation. Patients were separated into 2 groups: those who received premedication before pegaspargase infusion and those who did not. The primary endpoint was the incidence of documented hypersensitivity reactions. Observational data endpoints included incidence of silent inactivation and cost savings from reducing complicated drug substitutions. A total of 38 patients (50 doses in no premedication group; 80 doses in premedication group) were evaluated. There was not a significant reduction in the incidence of hypersensitivity reactions for patients receiving premedication and TDM (5.3% vs 6.4%, p = 1.0). A trend towards patients reacting earlier with more severe reactions in the post-implementation group was observed. There were no incidences of silent inactivation. Observational cost analysis predicts potential drug cost savings of $106,550.45. A standardized premedication protocol did not reduce the incidence of hypersensitivity reactions. Premedication to prevent hypersensitivity reactions may provide a potential drug cost savings. Further investigation is warranted to assess the efficacy of a standardized premedication and TDM protocol to prevent hypersensitivity reactions.

Evaluation of cytogenetic and molecular markers with MTX-mediated toxicity in pediatric acute lymphoblastic leukemia patients.

Pediatric acute lymphoblastic leukemia (pALL) patients have better overall survival and methotrexate (MTX) is an effective drug used in their treatment. However, the treatment-related adverse effects (TRAEs) have a bigger impact on the therapy. In this study, we have evaluated the association of polymorphisms in genes encoding proteins engaged in MTX metabolism, and the cytogenetic aberrations with TRAEs. A total of 115 patients between the age of 1 and 18years (average: 6.6) under maintenance therapy were selected for the study. SLC19A1 (c.80G > A), MTHFR (c.677C > T; c.1298A > C), and TYMS (c.*450_*455del) genotypes were determined using PCR techniques and Sanger sequencing. Cytogenetic and SNP findings were analyzed for any association with the reported toxicities using odds ratio, chi-square test, multifactor dimensionality reduction (MDR) analysis for synergistic effect and, multinomial logistic regression analysis for the likelihood of adverse events. Among the evaluated genetic variations, SLC19A1 (c.80G > A) was significantly associated with TRAEs (OR = 5.71, p = 0.002). Multinomial logistic regression analysis (chi-sq = 16.64, p < 0.001) and MDR analysis (chi-sq = 10.51 p < 0.001) confirmed the finding. On the other hand, no significant association was observed between adverse events and any specific cytogenetic aberration. SLC19A1 facilitates the import of cyclic dinucleotides and reduced folates, evaluating genotypes in this gene can help in better management of patients on methotrexate treatment. Assessing a broader gene panel can help in finding more associated markers and delivering personalized medicine to the patients.

The expense of sending cerebrospinal fluid for analysis on all lumbar punctures in pediatric acute lymphoblastic leukemia patients.

Central nervous system (CNS) relapse in pediatric acute lymphoblastic leukemia (ALL) patients is uncommon. The cerebrospinal fluid (CSF) of patients with ALL is routinely sampled at each intrathecal chemotherapy treatment to screen for CNS relapse. The analysis of CSF is both time consuming and resource intensive and must be completed approximately 20 times per patient throughout treatment. Our objective was to examine the expense of routine screening on all CSF samples for CNS relapse in ALL patients, and to identify if CNS relapse can be detected clinically. We identified all patients diagnosed with ALL at the Children's Hospital of Eastern Ontario (CHEO) between January 2001 and June 2021. We collected the total number of CSF samples in these patients and the number of CSF samples positive for CNS relapse. An in-depth chart review on the patients who relapsed in the CNS was completed to identify symptoms at relapse. Over the study period, 351 patients were diagnosed with ALL and underwent a total of 6515 lumbar punctures (LPs), each of which examined the CSF. The cost of CSF sample analysis is $14.32 (Canadian dollars [CDN]); thus, the total cost for the study sample was $93,294.80 (CDN). There were 14 CNS relapses and although symptoms including headache, vomiting, and fatigue were common, two patients were asymptomatic at relapse. Given the marginal cost of routine CSF screening and the lack of specific and sensitive symptoms for CNS relapse, we conclude that the routine practice of sending all CSF samples for analysis of CNS relapse in ALL patients is relatively inexpensive and beneficial.

Assessment of Minimal Residual Disease in Childhood Acute Lymphoblastic Leukemia: A Multicenter Study From Turkey.

Assestment of minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) is of utmost importance both for risk classification and tailoring of the therapy. The data of pediatric ALL patients that received treatment with Berlin-Frankfurt-Münster (BFM) protocols were retrospectively collected from 5 university hospitals in Turkey. Of the 1388 patients enrolled in the study 390 were treated according to MRD-based protocols. MRD assestment was with real time quantitative polymerase chain reaction (qPCR) in 283 patients and with multiparametric flow cytometry (MFC)-MRD in 107 patients. MRD monitoring had upstaged a total of 8 patients (2%) from intermediate risk group to high-risk group. Univariate analysis revealed age 10 years or above, prednisone poor response, PCR-MRD ≥10-3 on day 33 and on day 78 as poor prognostic factors affecting event-free survival (EFS). Detection of >10% blasts on day 15 with MFC (MFC-high-risk group) was not shown to affect EFS and/or overall survival (log-rank P=0.339). Multiple logistic regression analysis revealed PCR-MRD ≥10-3 on day 78 as the only poor prognostic factor affecting EFS (odds ratio: 8.03; 95% confidence interval: 2.5-25; P=0.000). It is very important to establish the infrastructure and ensure necessary standardization for both MRD methods for optimal management of children with ALL.

CASPorter: A Novel Inducible Human CASP1/NALP3/ASC Inflammasome Biosensor.

BackgroundFollowing our 2015 elucidation of the CASP1/NALP3 inflammasome mechanism of glucocorticoid (GC)-resistance in pediatric acute lymphoblastic leukemia (ALL) patients, we engineered a cell-based CASP1/NALP3 reporter system suitable for high-throughput screening (HTS) of small molecule libraries, with the purpose of identifying compounds capable of inhibiting the CASP1/NALP3 inflammasome and synergizing with GC drugs for the treatment of GC-resistant ALL patients and various autoinflammatory diseases.MethodsA Dox-controlled system was utilized to induce the expression of the ASC transgene in HEK293 cells while simultaneously overexpressing NLRP3 and CASP1. ASC/CASP1/NALP3 inflammasome complex formation was confirmed by co-immunoprecipitation (co-IP) experiments. Next, a LV fluorescence-based biosensor (CASPorter) was transduced in the HEK293-iASC-NLRP3/CASP1 cell line to monitor the real-time activation of CASP1/NALP3 inflammasome in live cells. The applicability and effectiveness of the CASPorter cell line were tested by co-treatment with Dox and four known CASP1/NLRP3 inhibitors (MCC950, Glyburide, VX-765 and VRT-043198). Inflammasome activation and inhibitions were assessed by Western blotting, fluorescence microscopy and flow cytometry (FC) methods.ResultsDox treatment significantly induced ASC expression and increased levels of cleaved and catalytically active CASP1, co-IPs further demonstrated that CASP1 was pulled-down with NLRP3 in HEK293-iASC-NLRP3/CASP1 cells after induction of ASC by Dox treatment. In HEK293-iASC-NLRP3/CASP1-CASPorter cell system, cleavage of the CASP1 consensus site (YVAD) in the CASPorter protein after Dox treatment causing excitation/emission of green fluorescence and the 71% GFP+ cell population increase quantified by FC (78.1% vs 6.90%). Dox-induced activation of the NLRP3 inflammasome was dose-dependently inhibited by Dox co-treatment with four known CASP1/NLRP3 inhibitors.ConclusionWe have established a cell-based CASP1/NLRP3 inflammasome model, utilizing a fluorescence biosensor as readout for qualitatively observing and quantitatively determining the activation of caspase 1 and NLRP3 inflammasomes in living cells and easily define the inhibitory effect of inhibitors with high efficacy.

The Factors Affecting Relapse in Pediatric B-cell Acute Lymphoblastic Leukemia Patients without Prognostic Fusion Genes Following Up for 10 years

To analyze the efficacy of children with B-cell acute lymphoblastic leukemia (B-ALL) without prognostic fusion genes treated by CCLG-ALL 2008, and investigate the related factors affecting the recurrence of the patients. B-ALL patients without prognostic fusion genes treated by the protocol of CCLG-ALL 2008 in our hospital from March 2008 to December 2012 were retrospectively analyzed. Follow-up time was ended in August 31, 2019. The median follow-up time was 92 months (range 0-136 months). Kaplan-Meier was used to detect the RFS, and COX multivariate regression analysis was employed to identify the independent factors affecting the recurrence of the patients. There were 140 males and 99 females enrolled in this study. The ratio of male to female was 1.41∶1. The median age was 4.4 years old and the median number of WBC at initial stage was 4.98×109/L. There were 77 cases relapsed during the observation while 162 without relapsed, 16 cases lost to follow-up and 72 cases died. The recurrence and mortality rate was 32.22% and 30.1%, respectively, in which 45 cases died of recurrence (62.5% of the total deaths). Univariate analysis showed that the age≥6 years old, WBC >100×109/L, the bone marrow blasts on day 15≥25%, the bone marrow minimal residual disease (MRD) at week 12 >10-4, and the higher risk were the main factors affecting the recurrence of the patients (P<0.05). Multivariate COX regression analysis showed that age≥6 years old, WBC >100×109/L, bone marrow MRD >10-4 at the 12th week were the independent risk factors affecting recurrence of the patients. Age, initial WBC, and bone marrow MRD at the 12th week were correlated with recurrence in children with B-ALL without prognostic fusion genes, which can be used as prognostic indices of recurrence risk in clinical.

The effects of NUDT15 and TPMT variants on mercaptopurine treatment in Vietnamese pediatric acute lymphoblastic leukemia patients

6-mercaptopurine (6-MP) plays a critical role in the treatment of pediatric acute lymphoblastic leukemia (ALL). NUDT15 and TPMT gene variants have been strongly associated with myelotoxicity caused by using 6-MP. Therefore, the purpose of this study is to investigate the frequency of NUDT15 and TPMT polymorphisms, as well as the impact of NUDT15 variants on the use of 6-MP to treat pediatric ALL in Vietnam. Sanger sequencing was applied to detect NUDT15 and TPMT gene variants in 70 pediatric ALL patients. Duration of drug interruption, level of neutropenia, and 6-MP tolerance dose were recorded. NUDT15 variants were detected from 23 out of 70 (32.9%) patients. Three well-known haplotype variants were identified as NUDT15 *2 (p.V18_V19insGV and p.R139C), *3 (p.R139C), and *6 (p.V18_V19insGV); besides, a novel NUDT15 p.R11Q was not previously reported. The NUDT15 wild-type, heterozygous variant, and homozygous variant genotypes were 67.1%, 30.1%, and 2.8%, respectively. Two TPMT heterozygous polymorphisms were TPMT*3C and *6, accounted for 2.8%. Patients with intermediate and low activity NUDT15 were given the median 6-MP tolerance dose of 55.2 and 37.2 versus 69.5 mg/m2/day of patients with NUDT15 normal activity (p = 0.0001). Patients with homozygous variant diplotype were drastically sensitive to 6-MP, with an average dose intensity of 49.6%, compared to 73.6% and 92.7% of those with heterozygous and wild-type diplotype, respectively (p = 0.0001). Our results suggest that 6-MP dose adjustment should be based on NUDT15 variants in pediatric Vietnamese ALL patients.

Variation in the rate of diagnosis of childhood acute lymphoblastic leukemia in about to the COVID-19 Pandemic: a single-center study

Background. Greaves delayed infection hypothesis states that acute lymphoblastic leukemia (ALL) in children develops in two critical steps, with the first step (first hit) occurring in utero and the second step (second hit) occurring in the postnatal period and involving leukemia-associated genetic changes, depending upon the timing of exposure to common childhood infections. In this study, we investigated whether isolation of children at home as part of the lockdown during the Coronavirus Disease 2019 (COVID-19) pandemic resulted in a reduction in the number of new childhood ALL cases by avoiding the second hit. Materials and metods. This retrospective study included all newly diagnosed pediatric ALL patients aged 1–18 years. The study periods were from 15 March 2020 to 31 December 2020 (COVID-19 lockdown period) and from 15 March 2019 to 31 December 2019 (control period). Results. Acute leukemia was diagnosed in 73 children between January 2019 and December 2020. Of these, there were 58 ALL cases and 15 acute myeloid leukemia cases. During the COVID-19 lockdown period, 14 of the children were diagnosed with ALL. In the control period, 21 children were diagnosed with ALL. No pediatric patients diagnosed with ALL in August, September, and October 2020. Conclusions. We observed a reduced incidence within the lockdown period, possibly related to the potential role of SARS-CoV-2 infection as a second hit in childhood ALL.