A sensitive and inexpensive high-resolution melting-based testing algorithm for diagnosis of transient abnormal myelopoiesis and myeloid leukemia of Down syndrome.

Patients with Down syndrome (DS) are commonly affected by a pre-leukemic disorder known as transient abnormal myelopoiesis (TAM). This condition usually undergoes spontaneous remission within the first 2 months after birth; however, in children under 5, 20%-30% of cases evolve to myeloid leukemia of Down syndrome (ML-DS). TAM and ML-DS are caused by co-operation between trisomy 21 and acquired mutations in the GATA1 gene. Currently, only next-generation sequencing (NGS)-based methodologies are sufficiently sensitive for diagnosis in samples with small GATA1 mutant clones (≤10% blasts). Alternatively, this study presents research on a new, fast, sensitive, and inexpensive high-resolution melting (HRM)-based diagnostic approach that allows the detection of most cases of GATA1 mutations, including silent TAM. The algorithm first uses flow cytometry for blast count, followed by HRM and Sanger sequencing to search for mutations on exons 2 and 3 of GATA1. We analyzed 138 samples of DS patients: 110 of asymptomatic neonates, 10 suspected of having TAM, and 18 suspected of having ML-DS. Our algorithm enabled the identification of 33 mutant samples, among them five cases of silent TAM (5/110) and seven cases of ML-DS (7/18) with blast count ≤10%, in which GATA1 alterations were easily detected by HRM. Depending on the type of genetic variation and its location, our methodology reached sensitivity similar to that obtained by NGS (0.3%) at a considerably reduced time and cost, thus making it accessible worldwide.

Identifying childhood leukemia with an excess of hematological malignancies in first-degree relatives in Brazil.

Background: Familial aggregation in childhood leukemia is associated with epidemiological and genomic factors. Albeit epidemiological studies on the familial history of hematological malignancies (FHHMs) are scarce, genome-wide studies have identified inherited gene variants associated with leukemia risk. We revisited a dataset of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) patients to explore the familial aggregation of malignancies among their relatives. Methods: A series of 5,878 childhood leukemia (≤21 years of age) from the EMiLI study (2000-2019) were assessed. Lack of well-documented familial history of cancer (FHC) and 670 cases associated with genetic phenotypic syndromes were excluded. Leukemia subtypes were established according to World Health Organization recommendations. Logistic regression-derived odds ratios (ORs) and 95% confidence intervals (CIs) were performed and adjusted by age as a continuous variable, where ALL was the reference group for AML and conversely. The pedigree of 18 families with excess hematological malignancy was constructed. Results: FHC was identified in 472 of 3,618 eligible cases (13%). Ninety-six of the 472 patients (20.3%) had an occurrence of FHHMs among relatives. Overall, FHC was significantly associated with AML (OR, 1.36; 95% CI, 1.01-1.82; p = 0.040). Regarding the first-degree relatives, the OR, 2.92 95% CI,1.57-5.42 and the adjOR, 1.16 (1.03-1.30; p0.001) were found for FHC and FHHM, respectively. Conclusion: Our findings confirmed that AML subtypes presented a significant association with hematological malignancies in first-degree relatives. Genomic studies are needed to identify germline mutations that significantly increase the risk of developing myeloid malignancies in Brazil.

NQO1 rs1800566 (C609T), PON1 rs662 (Q192R), and PON1 rs854560 (L55M) polymorphisms segregate the risk of childhood acute leukemias according to age range distribution.

PURPOSE: The risk of developing childhood leukemia has been associated with gene polymorphisms that decrease the activity of detoxifying metabolic enzymes and enzymes involved in systemic oxidative stress. We investigated the NQO1 and PON1 polymorphisms for associations with susceptibility to childhood leukemia. METHODS: Samples from 1,027 Brazilian children (519 acute lymphoblastic leukemia, ALL; 107 acute myeloid leukemia, AML; 401 controls) were analyzed. TaqMAN real-time assays were used to determine the NQO1 rs1800566 (C609T), PON1 rs662 (Q192R), and PON1 rs854560 (L55M) frequencies. Logistic regression was used to evaluate the association of polymorphisms with cases and controls, with age and somatic fusion genes (MLL-r and ETV6-RUNX1) as covariables. RESULTS: Children with at least one NQO1 variant allele were at lower risk for developing infant AML (odds ratio (OR) 0.26, 95 % confidence interval (CI) 0.10-0.68); no association was detected for ALL. PON1 rs854560 (L55M) was associated with an increased risk of developing childhood leukemia (LM + MM, OR 1.93, 95 % CI 1.32-2.81). The PON1 rs662 R192R genotype had a statistically significant decreased frequency in ALL (OR 0.64, 95 % CI 0.43-0.93). Infant ALL cases were more likely to harbor homozygous PON1 rs854560 alleles than controls (OR 1.72, 95 % CI 1.03-2.89); at least one M allele was associated with an increased risk of ALL in children older than 1 year (OR 1.99, 95 % CI 1.17-3.3). CONCLUSIONS: The NQO1 rs1800566 (C609T), PON1 rs854560 (L55M), and PON1 rs662 (Q192R) polymorphisms modified risk depending on leukemia subtype (decreased in AML, increased and decreased in ALL, respectively), age strata, and variant genotype combinations.

Barriers to medication adherence by caregivers of children with leukemia: an observational study / Barreiras de adesão medicamentosa por cuidadores de crianças com leucemia: um estudo observacional

ABSTRACT Objective: To identify barriers to adherence to home oral maintenance chemotherapy in children with leukemia treated at a specialized cancer center. Methods: We used the Brief Medication Questionnaire (BMQ) as a tool for screening barriers to adherence. The level of adherence was calculated considering at least one positive response in each BMQ domain, defined as Regimen Screen, Belief Screen, and Recall Screen. A positive screening for belief barriers (PSB) indicates that the caregiver reports not understanding the medication's mechanism of action and adverse effects. Results: Three important barriers to adherence were identified: beliefs, number of children of the caregiver, and age of the caregiver. The primary caregivers included 32 mothers (80%), four fathers (10%), three grandmothers (7.5%), and one unrelated caregiver (2.5 %). Most caregivers with a PSB were mothers. A PSB indicates that the caregiver reports not understanding the medication's mechanism of action and adverse effects. Caregivers with two or more children (median, three) had more barriers to adherence. Caregivers with potential non-adherence tended to be older than those with potential adherence, although without statistical significance (p=0.079, Mann-Whitney U test). Conclusions: The main barriers to adherence to home oral maintenance chemotherapy in children with leukemia identified through interviews with their caregivers, most often mothers, were lack of understanding of the treatment regimen, a greater number of children, and older age.

RESUMO Objetivo: Identificar barreiras de adesão ao tratamento de manutenção da quimioterapia via oral domiciliar, em uma amostra de crianças diagnosticadas com leucemia atendidas em um serviço especializado em oncologia. Métodos: O Brief Medication Questionnaire (BMQ) foi utilizado como instrumento de coleta para a identificação de barreiras de adesão. O nível de adesão foi calculado considerando-se pelo menos uma resposta positiva no domínio do BMQ, definido como regime, crença e recordação. Uma crença positiva mostra que o cuidador reporta não entender o mecanismo de ação e os efeitos adversos. Resultados: Três importantes barreiras de adesão foram identificadas, incluindo crença, o número de filhos do casal e a idade dos cuidadores. A mãe como principal responsável pelo tratamento da criança apresentou frequência maior entre as pessoas com rastreamento positivo para barreiras de crenças (BPC). Crença positiva significa que o cuidador relata não entender o mecanismo de ação dos medicamentos e os efeitos adversos. Quanto ao número de filhos, o estudo mostrou que quanto mais filhos (dois filhos ou mais, mediana=três) maior a barreira de adesão. Houve tendência de responsáveis com potencial não adesão serem mais velhos que os responsáveis com potencial adesão, embora sem significância estatística ao nível de significância de 5% (p=0,079, teste U de Mann-Whitney). Conclusões: As principais barreiras de adesão dos cuidadores de crianças com leucemia ao tratamento medicamentoso de manutenção foram dificuldades relatadas pelos cuidadores, na maioria das vezes as mães, que não entenderam como o medicamento funcionava, o número de filhos — quanto mais filhos menor a adesão — e a idade dos cuidadores. Cuidadores mais velhos aderiram menos ao tratamento prescrito.

Partição de Comprimidos Antineoplásicos Utilizados no Tratamento de Leucemias Agudas em Crianças e Adolescentes / Splitting of Antineoplastic Tablets Used in Acute Leukemias Treatment in Children and Adolescents / Partición de Comprimidos Antineoplásicos Empleados en el Tratamiento de Leucemias Agudas en Niños y Adolescentes

Introdução: A manipulação de antineoplásicos para ajuste de dose, como partição de comprimidos, é comum no tratamento de leucemias agudas de crianças e adolescentes. Objetivo: Identificar a frequência e descrever a prática da partição domiciliar de comprimidos antineoplásicos utilizados no tratamento oral de crianças e adolescentes com leucemias agudas na fase de manutenção. Método: Trata-se de um estudo transversal descritivo, realizado em um hospital pertencente à rede de saúde pública do Distrito Federal com assistência especializada em pediatria. Foram incluídos no estudo crianças e adolescentes entre 1 e 18 anos, diagnosticados com leucemias agudas e em fase de manutenção do tratamento no período de estudo. Foi aplicado um questionário semiestruturado ao responsável principal pela administração dos medicamentos quimioterápicos via oral, podendo ser o cuidador ou a própria criança/adolescente. Foram coletadas variáveis sociodemográficas dos pacientes e cuidadores e variáveis sobre a prática de partição de medicamentos antineoplásicos no domicílio. Resultados: Todos os 48 entrevistados no período do estudo relataram ter partido comprimidos antineoplásicos ao longo do tratamento de leucemias agudas, sendo estes mercaptopurina (n=45 [93,75%]) e tioguanina (n=3 [6,25%]). Conclusão: A partição de comprimidos antineoplásicos foi uma prática unânime em virtude da necessidade referida de ajuste de dose individual para o tratamento de leucemias agudas de crianças e adolescentes, considerando a indisponibilidade de formulações adequadas. Os resultados reforçam a necessidade de a partição ser uniformizada e realizada de maneira a minimizar os riscos e a garantir a segurança para as crianças e adolescentes e seus cuidadores.

Introduction: Antineoplastic drug manipulation for dose adjustment, such as tablet splitting, is standard in acute leukemia treatment for children and adolescents. Objective: To identify the frequency and describe the practice of household splitting of antineoplastic tablet for oral treatment of children and adolescents with acute leukemias in the maintenance phase. Method: Cross-sectional descriptive study performed in a public health system hospital from Distrito Federal (Brazil) with specialized pediatric assistance. Children and teenagers between 1 and 18 years old, diagnosed with acute leukemia and in treatment maintenance phase during the study period were included. A semi-structured questionnaire was applied to the main responsible for administering oral chemotherapy drugs, which could be the caregiver or the child/adolescent themselves. Sociodemographic variables of patients and caregivers and variables on the practice of splitting antineoplastic drugs at home were collected. Results: All 48 interviewees in the study period reported having split antineoplastic tablets during the treatment for acute leukemias, such as mercaptopurine (n = 45 [93.75%]) and thioguanine (n = 3 [6.25%]). Conclusion: The splitting of antineoplastic tablets was a unanimous practice due to the reported need to adjust the individual dose for acute leukemia treatment in children and adolescents, considering the unavailability of adequate formulations. The results reinforce the need for splitting to be standardized and performed in a way that minimizes risks and ensures safety for patients and their caregivers

Introducción: La manipulación de fármacos antineoplásicos para el ajuste de dosis, como las particiones de comprimidos, es frecuente en el tratamiento de las leucemias agudas en niños y jóvenes. Objetivo: Identificar la frecuencia y describir la práctica de la división domiciliaria de medicamentos antineoplásicos utilizados en el tratamiento oral de niños y adolescentes con leucemias agudas en la fase de mantenimiento. Método: Se trata de un estudio transversal descriptivo realizado en un hospital de la red de salud pública del Distrito Federal (Brasil) con asistencia especializada en pediatría. El estudio incluyó a niños y jóvenes de entre 1 y 18 años de edad diagnosticados con leucemia aguda y en fase de mantenimiento del tratamiento en el período del estudio. Se aplicó un cuestionario semiestructurado a la persona principal responsable de la administración de fármacos quimioterapéuticos por vía oral, que puede ser el cuidador o el propio niño/joven. Fueron colectadas variables sociodemográficas de los pacientes y cuidadores y variables sobre la práctica de la división de los medicamentos antineoplásicos en domicílios. Resultados: Los 48 entrevistados en el período de estudio informaron haber roto las pastillas antineoplásicas durante el tratamiento de la leucemia aguda, siendo éstas mercaptopurina (n=45 [93,75%]) y tioguanina (n=3 [6,25%]). Conclusión: La partición de comprimidos antineoplásicos fue una práctica unánime debido a la necesidad mencionada de ajustar la dosis individual para el tratamiento de las leucemias agudas de niños y adolescentes, considerando la falta de formulaciones apropiadas. Los resultados refuerzan la necesidad de estandarizar y realizar la partición para minimizar los riesgos y garantizar la seguridad de los niños, jóvenes y sus cuidadores.

Etiologia da restrição de crescimento intrauterino (RCIU) / Intrauterine growth restriction etiology (IUGR)

A restrição de crescimento intra-uterino ocorre quando o feto não atingeo tamanho esperado ou determinado pelo seu potencial genético, sendoidentificada clinicamente quando o peso fetal está abaixo do percentil10 para a idade gestacional. Essa definição é a mais utilizada na literatura.A restrição de crescimento fetal é um problema clínico comum, associado ao aumento da morbidade e mortalidade perinatal sendo reconhecida em 7% a 15% das gestações. O objetivo dessa revisão foi relacionar os fatores envolvidos na etiologia da restrição de crescimento intra-uterino, por meio de revisão bibliográfica da literatura nas bases de dados medline, pubmed, scielo, além de livros, com ênfase nos últimos 10 anos. A análise da literatura permite concluir que, são múltiplosos fatores relacionados a essa intercorrência, abrangendo fatores maternos, placentários e fetais. Importante ressaltar que esses diferentes fatores podem atuar concomitantemente, alguns são preveníveis e muitos deles estão intimamente relacionados com o estado socioeconômico e cultural da população. Assim, as causas e incidência de RCIU são diferentes segundo a população estudada.

Intrauterine growth restriction (IUGR) happens when the fetus does notreach the expected size or determined by its genetic potential. It is clinicallyidentified when the fetal weight is below the 10th percentile for the gestational age. This definition is frequently used in the literature. Fetal growth restriction is a common clinical problem that is associated with the increase in perinatal morbidity and mortality, and is reported in 7 to 15% of pregnancies. The objective of this review is to describe the factors involved in the etiology of intrauterine growth restriction, by usingthe bibliographic review of the literature on the databases of Medline, Pubmed, Scielo, and also books, with emphasis on the past 10 years. The analysis of the consulted materials shows that there are many factors associated with this condition, including maternal, placental and fetal factors. It´s important to highlight that these different factors can act concomitantly, some of them are predictable, and many of them are intimately related with the socioeconomic and cultural status of the population. Thus, the causes and incidence of IUGR vary according to thestudy population.

Transient neonatal myeloproliferative disorder without Down syndrome and detection of GATA1 mutation.

Transient myeloproliferative disorder is a form of self-limited leukemia that occurs almost exclusively in neonates with Down syndrome. The authors report an unusual case of a newborn without constitutional trisomy 21 who developed undifferentiated leukemia and subsequently achieved clinical and molecular remission without chemotherapy. Cytogenetics and molecular analysis have shown trisomy 21 and GATA1 mutation restricted to leukemic cells. G-to-T transversion was detected, which is predicted to result in a premature stop codon (c.119G>T; pGlu67X) in diagnosis samples. These findings emphasize that there must be a powerful interaction between GATA1 and trisomy 21 in leukemogenesis process.

Fatores prognósticos na leucemia linfoblástica aguda da criança / Prognostic factors in acute lymphocytic leukemia in child

A efetividade do tratamento modifica a importância da maioria dos fatores associados com o prognóstico. Entre as manifestaçöes clínicas e laboratoriais de rotina, apenas a idade e a contagem leucocitária permanecem independentemente correlacionadas ao resultado do tratamento. A imunofenotipagem é útil para a classificaçäo das LLA, mas, possivelmente, com exceçäo do antígeno CD10, tem muito pouca importância prognóstica no contexto de uma abordagem terapêutica efetiva. Alteraçöes cariotípicas continuam a ter importante valor preditivo. Hiperdiplodia (>50 cromossomos) está associada ao bom prognóstico, enquanto que a t (9;22) e t(4;11), ao insucesso terapêutico. Casos com imunofenótipo pré-B e t(1;19) têm mau prognóstico, se tratados com regimes terapêuticos baseados em antimetabólicos, e, portanto, o tratamento desse grupo de pacientes deve incluir outras classes de drogas. Finalmente, algumas alteraçöes cromossômicas, como a dic(9;12), podem estar associadas ao bom prognóstico. Com exceçäo do tratamento da leucemia de células B, protocolos terapêuticos especificamente direcionados a grupos segregados por análise imunofenotípica ou genotípica näo têm sido bem sucedidos. portanto, a seleçao da melhor opçäo terapêutica para um determinado paciente deverá ser orientada pela probabilidade do insucesso terapêutico. Para pacientes com alto risco de recidivas (i.e. com uma probabilidade>70 por cento) a utilizaçäo de protocolos experimentais é justificável, mesmo em face dos efeitos colaterais agudos e tardios decorrentes do tratamento. Para o grupo de crianças de baixo risco de recidiva (<20 por cento de probabilidade), terapia que evita as medicaçöes mais perigosas deve ser administrada.