Acute lymphoblastic leukemia expressing the gamma delta T-cell receptor (γδ T-ALL) is a poorly understood disease. We studied 200 children with γδ T-ALL from 13 clinical study groups to understand the clinical and genetic features of this disease. We found age and genetic drivers were significantly associated with outcome. γδ T-ALL diagnosed in children under 3 years of age was extremely high-risk and enriched for genetic alterations that result in both LMO2 activation and STAG2 inactivation. Mechanistically, using patient samples and isogenic cell lines, we show that inactivation of STAG2 profoundly perturbs chromatin organization by altering enhancer-promoter looping, resulting in deregulation of gene expression associated with T-cell differentiation. High-throughput drug screening identified a vulnerability in DNA repair pathways arising from STAG2 inactivation, which can be targeted by poly(ADP-ribose) polymerase inhibition. These data provide a diagnostic framework for classification and risk stratification of pediatric γδ T-ALL. Significance: Patients with acute lymphoblastic leukemia expressing the gamma delta T-cell receptor under 3 years old or measurable residual disease ≥1% at end of induction showed dismal outcomes and should be classified as having high-risk disease. The STAG2/LMO2 subtype was enriched in this very young age group. STAG2 inactivation may perturb chromatin conformation and cell differentiation and confer vulnerability to poly(ADP-ribose) polymerase inhibition.

• MeSH
• adaptorové proteiny signální transdukční * genetika   metabolismus   MeSH
• dítě MeSH
• genová přestavba MeSH
• kojenec MeSH
• lidé MeSH
• lymfoblastická leukemie-lymfom z prekurzorových T-buněk genetika   patologie   MeSH
• předškolní dítě MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• proteiny s doménou LIM * genetika   MeSH
• protoonkogenní proteiny MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adaptorové proteiny signální transdukční * MeSH
• LMO2 protein, human MeSH Prohlížeč
• proteiny buněčného cyklu MeSH
• proteiny s doménou LIM * MeSH
• protoonkogenní proteiny MeSH

• MeSH
• aneuploidie * MeSH
• chromozomální aberace * MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Spojené království MeSH

The incidence of hypersensitivity reactions (HSRs) to PEG-asparaginase (PEG-ASNase) was evaluated in 6136 children with ALL enrolled in the AIEOP-BFM ALL 2009 study. Patients with B-cell precursor-acute lymphoblastic leukemia (BCP-ALL) were stratified as standard-risk/medium-risk (MR)/high-risk (HR) and those with T-ALL as non-High/HR. PEG-ASNase was administered intravenously at 2500 IU/sqm/dose. All patients received 2 PEG-ASNase doses in induction; thereafter non-HR versus HR patients received 1 versus 6 PEG-ASNase doses, respectively. After the single regular dose of PEG-ASNase at the beginning of delayed intensification, BCP-ALL-MR patients were randomized to receive 9 additional PEG-ASNase doses every 2 weeks (experimental arm [EA]) versus none (standard arm [SA]); HR patients were randomized to receive, in consolidation, 4 weekly PEG-ASNase doses (EA) versus none (SA). The HSR cumulative incidence (CI) was estimated adjusting for competing risks. An HSR occurred in 472 of 6136 (7.7%) patients. T-non- HR/BCP-Standard-Risk, BCP-MR-SA, BCP-MR-EA, HR-SA and HR-EA patients had 1-year-CI-HSR (±SE) rates of 5.2% (0.5), 5.2% (0.5), 4.0% (0.8), 20.2% (1.2), and 6.4% (1.3), respectively. The randomized intensification of PEG-ASNase did not significantly impact on HSR incidence in BCP-MR patients (1-y-CI-HSR 3.8% [0.8] versus 3.2% [0.6] in MR-EA versus MR-SA; P = 0.55), while impacted significantly in HR patients (1-y-CI-HSR 6.4% [1.3] versus 17.9% [1.8] in HR-EA and HR-SA, respectively; P < 0.001). The CI-HSR was comparable among non-HR groups and was not increased by a substantial intensification of PEG-ASNase in the BCP-MR-EA group whilst it was markedly higher in HR-SA than in HR-EA patients, suggesting that, in such a chemotherapy context, a continuous exposure to PEG-ASNase reduces the risk of developing an HSR.

• Publikační typ
• časopisecké články MeSH

Asparagine levels in cerebrospinal fluid and serum asparaginase activity were monitored in children with acute lymphoblastic leukemia treated with pegylated-asparaginase. The drug was given intravenously at a dose of 2,500 IU/m2 on days 12 and 26. Serum and cerebrospinal fluid samples obtained on days 33 and 45 were analyzed centrally. Since physiological levels of asparagine in the cerebrospinal fluid of children and adolescents are 4-10 μmol/L, in this study asparagine depletion was considered complete when the concentration of asparagine was ≤0.2 μmol/L, i.e. below the lower limit of quantification of the assay used. Over 24 months 736 patients (AIEOP n=245, BFM n=491) and 903 cerebrospinal fluid samples (n=686 on day 33 and n=217 on day 45) were available for analysis. Data were analyzed separately for the AIEOP and BFM cohorts and yielded superimposable results. Independently of serum asparaginase activity levels, cerebrospinal fluid asparagine levels were significantly reduced during the investigated study phase but only 28% of analyzed samples showed complete asparagine depletion while relevant levels, ≥1 μmol/L, were still detectable in around 23% of them. Complete cerebrospinal fluid asparagine depletion was found in around 5-6% and 33-37% of samples at serum asparaginase activity levels <100 and ≥ 1,500 IU/L, respectively. In this study cerebrospinal fluid asparagine levels were reduced during pegylated-asparaginase treatment, but complete depletion was only observed in a minority of patients. No clear threshold of serum pegylated-asparaginase activity level resulting in complete cerebrospinal fluid asparagine depletion was identified. The consistency of the results found in the two independent data sets strengthen the observations of this study. Details of the treatment are available in the European Clinical Trials Database at https://www.clin-icaltrialsregister.eu/ctr-search/trial/2007-004270-43/IT.

• MeSH
• akutní lymfatická leukemie mozkomíšní mok   terapie   MeSH
• asparagin mozkomíšní mok   MeSH
• asparaginasa terapeutické užití   MeSH
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• monitorování léčiv MeSH
• polyethylenglykoly terapeutické užití   MeSH
• předškolní dítě MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Česká republika MeSH
• Itálie MeSH
• Německo MeSH
• Rakousko MeSH
• Názvy látek
• asparagin MeSH
• asparaginasa MeSH
• pegaspargase MeSH Prohlížeč
• polyethylenglykoly MeSH

Acute lymphoblastic leukemia (ALL) is the most common malignancy in childhood. Despite enormous improvement of prognosis during the last half century, ALL remains a major cause of childhood cancer-related mortality. During the past decade, whole genomic methods have enhanced our knowledge of disease biology. Stratification of therapy according to early treatment response measured by minimal residual disease allows risk group assignment into different treatment arms, ranging from reduction to intensification of treatment. Progress has been achieved in academic clinical trials by optimization of combined chemotherapy, which continues to be the mainstay of contemporary treatment. The availability of suitable volunteer main histocompatibility antigen-matched unrelated donors has increased the rates of hematopoietic stem cell transplantation (HSCT) over the past two decades. Allogeneic HSCT has become an alternative treatment for selected, very-high-risk patients. However, intensive treatment burdens children with severe acute toxic effects that can cause permanent organ damage and even toxic death. Immunotherapeutic approaches have recently come to the forefront in ALL therapy. Monoclonal antibodies blinatumomab and inotuzumab ozogamicin as well as gene-modified T cells directed to specific target antigens have shown efficacy against resistant/relapsed leukemia in phase I/II studies. Integration of these newer modalities into combined regimens with chemotherapy may rescue a subset of children not curable by contemporary therapy. Another major challenge will be to incorporate less toxic regimens into the therapy of patients with low-risk disease who have a nearly 100% chance of being cured, and the ultimate goal is to improve their quality of life while maintaining a high cure rate.

• Klíčová slova
• ALL, HSCT, immunotherapy, leukaemia, monoclonal antibodies, paediatric,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH