SARS-CoV-2 in children with cancer in Brazil: Results of a multicenter national registry.

BACKGROUND: Strategies to mitigate the impact of COVID-19 in special populations are complex and challenging. Few studies have addressed the impact of COVID-19 on pediatric patients with cancer in low- and middle-income countries. METHODS: Multicenter observational cohort study with prospective records and retrospective analyses starting in April 2020 in 21 pediatric oncology centers distributed throughout Brazil. PARTICIPANTS: Patients under 18 years of age who are infected by the SARS-CoV-2 virus (confirmed diagnosis through reverse transcriptase-polymerase chain reaction [RT-PCR]) while under treatment at pediatric oncology centers. The variables of interest included clinical symptoms, diagnostic and therapeutic measures. The repercussions of SARS-CoV-2 infection on cancer treatment and general prognosis were monitored. RESULTS: One hundred seventy-nine patients were included (median age 6 [4-13] years, 58% male). Of these, 55.9% had acute leukemia and 34.1% had solid tumors. The presence of SARS-CoV-2 was diagnosed by RT-PCR. Various laboratory markers were analyzed, but showed no correlation with outcome. Children with low or high BMI for age had lower overall survival (71.4% and 82.6%, respectively) than those with age-appropriate BMI (92.7%) (p = .007). The severity of presentation at diagnosis was significantly associated with outcome (p < .001). Overall mortality in the presence of infection was 12.3% (n = 22). CONCLUSION: In children with cancer and COVID-19, lower BMI was associated with worse prognosis. The mortality in this group of patients (12.3%) was significantly higher than that described in the pediatric population overall (∼1%).

Flow cytometry as a diagnostic tool in childhood solid tumors / Citometria de fluxo como ferramenta diagnóstica em tumores sólidos da infância

RESUMEN Los tumores sólidos infantiles representan aproximadamente el 30% de todos los cánceres pediátricos. En los últimos años se ha incrementado el uso de la citometría de flujo (CF) en el diagnóstico y seguimiento de estas patologías, ya que es un método que permite obtener resultados rápidos y precisos, posibilitando un manejo más precoz. Realizamos esta revisión sistemática para la búsqueda bibliográfica de los siguientes términos en las plataformas de datos Lilacs, PubMed y Scielo: neoplasma, oncología, pediatría, inmunofenotipificación y citometría de flujo. Así, describimos los principales hallazgos hasta la fecha sobre el uso de CF en el diagnóstico diferencial de los cinco principales tumores de células pequeñas, redondas y azules de la infancia: neuroblastoma, sarcoma de Ewing, tumor neuroectodérmico primitivo, tumor de Wilms y rabdomiosarcoma. Además, describimos las principales ventajas y desventajas del método y paneles que se proponen en el diagnóstico diferencial de estas patologías a través de la literatura internacional. A través de esta revisión, observamos que el uso de CF en el diagnóstico de tumores sólidos puede ser útil para la identificación rápida y precisa de la efermedade, así como para el inicio más temprano del tratamiento.

Transplantation of Hematopoietic Stem Cells for Primary Immunodeficiencies in Brazil: Challenges in Treating Rare Diseases in Developing Countries.

The results of hematopoietic stem cell transplant (HSCT) for primary immunodeficiency diseases (PID) have been improving over time. Unfortunately, developing countries do not experience the same results. This first report of Brazilian experience of HSCT for PID describes the development and results in the field. We included data from transplants in 221 patients, performed at 11 centers which participated in the Brazilian collaborative group, from July 1990 to December 2015. The majority of transplants were concentrated in one center (n = 123). The median age at HSCT was 22 months, and the most common diseases were severe combined immunodeficiency (SCID) (n = 67) and Wiskott-Aldrich syndrome (WAS) (n = 67). Only 15 patients received unconditioned transplants. Cumulative incidence of GVHD grades II to IV was 23%, and GVHD grades III to IV was 10%. The 5-year overall survival was 71.6%. WAS patients had better survival compared to other diseases. Most deaths (n = 53) occurred in the first year after transplantation mainly due to infection (55%) and GVHD (13%). Although transplant for PID patients in Brazil has evolved since its beginning, we still face some challenges like delayed diagnosis and referral, severe infections before transplant, a limited number of transplant centers with expertise, and resources for more advanced techniques. Measures like newborn screening for SCID may hasten the diagnosis and ameliorate patients' conditions at the moment of transplant.

Incorporation of GSTA1 genetic variations into a population pharmacokinetic model for IV busulfan in paediatric hematopoietic stem cell transplantation.

AIMS: The aim of this study is to develop a population pharmacokinetic (PopPK) model for intravenous busulfan in children that incorporates variants of GSTA1, gene coding for the main enzyme in busulfan metabolism. METHODS: Busulfan concentration-time data was collected from 112 children and adolescents (median 5.4 years old, range: 0.1-20) who received intravenous busulfan during the conditioning regimen prior to stem cell transplantation. Weight, sex, baseline disease (malignant vs. non-malignant), age, conditioning regimen and GSTA1 diplotypes were evaluated as covariates of pharmacokinetic parameters by using nonlinear mixed effects analysis. The ability to achieve the target AUC24h (3600-6000 µM min-1 ) was assessed by estimating the first dose based on the present PopPK model and by comparing the results with other available models in children. RESULTS: A one-compartment model with first-order elimination best described the data. Allometric scaling of weight and a factor of busulfan metabolism maturation were included in the base model. GSTA1 diplotypes were found to be a significant covariate of busulfan clearance, which was 7% faster in rapid metabolizers and 12% slower in poor metabolizers, in comparison with normal ones. Busulfan doses calculated using the parameters of the proposed PopPK model were estimated to achieve the target AUC in 85.2% of the cases (95% CI 78.7-91.7%). CONCLUSION: This is the first PopPK for busulfan that successfully incorporated GSTA1 genotype in a paediatric population. Its use may contribute to better prediction of busulfan exposure in children and adolescents since the first dose, by tailoring the dose according to the individual metabolic capacity.

GSTA1 Genetic Variants and Conditioning Regimen: Missing Key Factors in Dosing Guidelines of Busulfan in Pediatric Hematopoietic Stem Cell Transplantation.

Busulfan (Bu) is a key component of conditioning regimens used before hematopoietic stem cell transplantation (SCT) in children. Different predictive methods have been used to calculate the first dose of Bu. To evaluate the necessity of further improvements, we retrospectively analyzed the currently available weight- and age-based guidelines to calculate the first doses in 101 children who underwent allogenic SCT in CHU Sainte-Justine, Montreal, after an intravenous Bu-containing conditioning regimen according to genetic and clinical factors. The measured areas under the curve (AUCs) were within target (900 to 1500 µM/min) in 38.7% of patients after the administration of the first dose calculated based on age and weight, as locally recommended. GSTA1 diplotypes linked to poor Bu metabolism (G3) and fludarabine-containing regimens were the only factors associated with AUC within target (OR, 4.7 [95% CI, 1.1 to 19.8, P = .04]; and OR, 9.9 [95% CI, 1.6 to 61.7, P = .01], respectively). From the 11 methods selected for dose calculation, the percentage of AUCs within the target varied between 16% and 74%. In some models G3 was associated with AUCs within the therapeutic and the toxic range, whereas rapid metabolizers (G1) were correlated with subtherapeutic AUCs when different methods were used. These associations were confirmed by clearance-prediction analysis, in which GSTA1 diplotypes consistently influenced the prediction errors of the methods. These findings suggest that these factors should be considered in Bu dose prediction in addition to the anthropometric data from patients. Furthermore, our data indicated that GSTA1 diplotypes was a factor that should be included in future population pharmacokinetic models, including similar conditioning regiments, to improve the prediction of Bu exposure after its initial dose.

New photobiomodulation protocol prevents oral mucositis in hematopoietic stem cell transplantation recipients-a retrospective study.

Oral mucositis (OM) is an adverse side effect among hematopoietic stem cell transplantation (HSCT) recipients. The objective of this retrospective study was to evaluate the preventive effect of photobiomodulation (PBM) applied three times per week versus seven times per week in patients undergoing HSCT. The risk factors related to the incidence and severity of OM were also assessed. This was a retrospective study that evaluated 99 HSCT recipients who received different PBM protocols. Group I received three sessions per week, and group II received daily treatment. PBM was applied using a continuous-wave diode laser (InGaAlP; MM Optics, São Carlos, SP, Brazil) at a wavelength of 660 nm (visible-red) and a total radiant energy of 0.24 J per point. The baseline disease, type of transplant, type of conditioning, prophylaxis against graft-versus-host disease, OM grade, absolute leukocyte and platelet counts, and levels of liver and renal function markers were collected from medical records. The patients' age ranged from 13 to 71 years (mean/SD, 40.54 ± 16.45). No significant difference was observed between groups I and II regarding sex, age, ethnic, diagnosis, donor type, and conditioning treatment. Both PBM protocols were equally efficient in preventing OM (p = 0.34, ANOVA). Independent of the PBM protocol used, patients who received allogeneic transplant (p < 0.01-Fischer's exact test), total body irradiation (TBI-12Gy) (p = 0.01-chi-square test), busulfan + cyclophosphamide (p < 0.01-chi-square test), or methotrexate-containing regimens (p < 0.01-Fischer's exact test) demonstrated higher OM incidence and severity. Myelosuppression (p < 0.01-Mann-Whitney test) and impaired renal function (p = 0.02-Mann-Whitney test) were also considered risk factors for OM. Based on this retrospective data, PBM was effective in preventing OM in patients undergoing HSCT even when it was applied three times a week. A prospective study might be necessary to confirm these findings.

Assessment of regulatory T cells in childhood immune thrombocytopenic purpura.

This study had the objective to assess the frequency of Tregs in children newly diagnosed with ITP and ascertain whether an association exists between Tregs and platelet counts, by means of a comparison with healthy controls. This case-control study included 19 patients newly diagnosed with ITP-whose blood samples were collected at four points in time: before any therapy and 1, 3, and 6 months after diagnosis-and 19 healthy controls. Tregs (CD4(+) CD25(+)Foxp3 T cells) were evaluated by flow cytometry. There was a statistically significant difference in platelet count between the case and control groups. There were no significant differences in Treg counts between cases and controls at any point during the course of the study and no difference in Treg counts between the chronic and nonchronic groups and no significant correlation between Tregs and platelet counts in the case and control groups. The findings of this study did not show any statistically significant correlation between Tregs and number of platelets in the case and control groups. Treg cells did not play a role in the regulation of autoimmunity in children with ITP.

Indicações de transplante de células-tronco hematopoéticas em pediatria: consenso apresentado no I Encontro de Diretrizes Brasileiras em Transplante de Células-Tronco Hematopoéticas - Sociedade Brasileira de Transplante de Medula Óssea, Rio de Janeiro, 2009 / Indications for pediatric hematopoietic stem cell transplantation: consensus presented at the First Meeting on Brazilian Hematopoietic Stem Cell Transplantation Guidelines - Brazilian Society of Bone Marrow Transplantation, Rio de Janeiro, 2009

A Sociedade Brasileira de Transplante de Medula (SBTMO) promoveu o I Encontro de Diretrizes do Transplante de Medula Óssea em 2009. Para revisão das indicações de transplante em Pediatria baseadas em evidências foi constituído grupo de trabalho com oncologistas e hematologistas com experiência em pediatria. Os artigos científicos foram cuidadosamente avaliados e, para cada doença, foram definidas as evidências para recomendação dos transplantes (de A a C) e a qualidade destas evidências (de 1 a 3). As recomendações incluem doenças hematológicas malignas e não malignas, tumores sólidos, imunodeficiências e doenças de depósito tratadas com transplantes de células-tronco hematopoéticas, quer autólogos, alogênicos de irmão HLA compatível ou não aparentados (doadores adultos ou sangue de cordão umbilical). Como não existem recomendações uniformemente aceitas em pediatria, não foram incluídas recomendações para transplantes de intensidade reduzida, com manipulação do enxerto e nem parcialmente compatíveis. É importante ressaltar que todas as indicações são baseadas no conhecimento atual e podem modificar-se com o tempo. Assim, esta revisão não deve ser utilizada para aplicação direta no cuidado do paciente sem levar em conta características da doença, do doador e fatores de risco do próprio paciente. Este trabalho não deve ainda ser utilizado como documento que limite o acesso do paciente ao transplante adequadamente indicado. Ressaltamos ainda, nesta revisão, diferenças entre transplantes em crianças e em adultos, com algumas recomendações específicas para os transplantes em pediatria.

The Brazilian Bone Marrow Transplant Society (SBTMO) held its First Meeting on Bone Marrow Transplant Guidelines in 2009. A working group of hematologists and oncologists with experience in pediatrics was formed to review evidence-based indications for pediatric transplants. Scientific publications were carefully assessed and, for each disease, the evidence for recommendation (from A to C) and the quality of the evidence (from 1 to 3) were defined. The recommendations include malignant and non-malignant hematological diseases, solid tumors, immunodeficiency, and storage diseases treated with hematopoietic stem cell transplants: either autologous or allogeneic from matched sibling donors or unrelated donors (adults or umbilical cord blood). Guidelines for reduced-intensity transplants, manipulated grafts or partially compatible donors were not included as there are no uniformly accepted recommendations. All indications are based on the best current knowledge which may change over time. Thus, this review should not be directly applied to patient care without taking into account the disease, donor and patient characteristics. Additionally, this paper should not be used as a document to limit patient access to transplant if correctly indicated. In this review we also point out differences between transplantation in adults and children and make some specific recommendations for pediatric transplants.

Evolução clínica e fusão TEL/AML1 em pacientes pediátricos com síndrome de Down e leucemia linfoblástica aguda / Clinical evolution and TEL/AML1 fusion in pediatric patients with Down syndrome and acute lymphoblastic leukemia

O risco aumentado de desenvolvimento de leucemia apresentado pelos indivíduos portadores de síndrome de Down (SD) já é bem conhecido. Entretanto, a contribuição do cromossomo 21 extraconstitucional ao processo de leucemogênese, ainda não está bem estabelecida. A fusão TEL/AML1 é a anomalia estrutural mais frequentemente encontrada em leucemia linfoblástica aguda (LLA) da infância, mas a sua associação com a LLA em pacientes com SD não é bem clara. Nós investigamos uma amostra de quatro pacientes com LLA e SD (LLA-SD) quanto à sua evolução clínica e seus aspectos citogenéticos, inclusive com pesquisa da fusão TEL/AML1. A idade do diagnóstico variou de 5 anos e 7 meses a 13 anos e 7 meses, o número de leucócitos em sangue periférico de 7.200 a 208.000/mm³ e a porcentagem de blastos na medula óssea de 20 por cento a 95 por cento. Apenas um paciente foi positivo para a fusão TEL/AML1. Todos os pacientes entraram em remissão completa e nenhum apresentou comprometimento extramedular ou recidiva. O tempo de sobrevida variou de 67 a 82 meses e não ocorreu nenhum óbito. Em nossa série de crianças com LLA-SD, os aspectos citogenéticos e a boa evolução clínica observados estão de acordo com o relatado na literatura.

The increased risk of developing leukemia found in Down syndrome (DS) patients is already well-known. However, the contribution of the extra copy of chromosome 21 to this leukemogenesis is still not well established. The TEL/AML1 fusion is the most frequently found structural anomaly in acute lymphoblastic leukemia (ALL) in childhood, but its association with ALL in DS patients is not very clear. We investigated a sample of four patients with ALL and DS (ALL-DS) in terms of their clinical evolution and cytogenetic aspects, including a study of the TEL/AML1 fusion. The ages of the patients ranged from 5 years and 7 months to 13 years and 7 months, the number of leukocytes in peripheral blood was 7,200 to 208,000 x 106 and the percentage of blasts in the bone marrow was 20 to 95 percent. Only one patient tested positive for the TEL/AML1 fusion. All patients achieved complete remission and none presented extramedullary involvement or relapse. The survival period ranged from 67 to 82 months and there was no death. In our series of children with ALL-DS, the cytogenetic aspects and the good clinical evolution observed are in agreement with the literature.