Relationship between air quality and asthma-related emergency hospital admissions in Mexico City 2017-2019.

BACKGROUND: Previous studies found exposure to air pollution leads to exacerbations of asthma in paediatric and adult patients and increases asthma-related emergency hospital admissions (AREHA). METHODS: AREHAs and levels of air pollutants (PM10, PM2.5 and NO2) were obtained from Mexico City for the period 2017-2019. A time-series approach was used to explore the relationship between air pollutants and AREHA. Relative risks of AREHA were estimated using a negative binomial regression in young children (less than 5 years) and adults (greater than 18 years). RESULTS: There was a positive association between AREHA and PM10, PM2.5 and NO2 in adults, which remained after mutual adjustment for these pollutants. The relative risk (RR) of admission in adults increased by 3% (95% CI 1% to 4%) for a 10 µg/m3 increase in PM10, 1% (0.03% to 3%) for a 5 µg/m3 increase in PM2.5 and by 1% (0.06% to 2%) for a 5 µg/m3 increase in NO2. In contrast, in young children, AREHAs were negatively associated with PM10 after adjustment for NO2 (RR 0.97 (0.95 to 0.99) for a 10 µg/m3 and with NO2 after adjustment for PM10 and PM2.5 (RR 0.98 (0.96 to 0.99) and 0.97 (0.96 to 0.99), respectively, for a 5 µg/m3 increase in NO2). AREHAs in children were not associated with PM2.5 after adjustment for NO2. CONCLUSIONS: Ambient air pollution, within the previous week, was associated with emergency hospital admissions for asthma to public hospitals in adults in Mexico City. The relationship in children was less consistent. Further work is needed to explore why differences between adults and children exist to inform appropriate interventions to benefit public health.

Semiquantitative analysis of cerebral [18F]FDG-PET uptake in pediatric patients.

BACKGROUND: Glycolytic metabolism in the brain of pediatric patients, imaged with [18F]  fluorodeoxyglucose-positron emission tomography (FDG-PET) is incompletely characterized. OBJECTIVE: The purpose of the current study was to characterize [18F]FDG-PET brain uptake in a large sample of pediatric patients with non-central nervous system diseases as an alternative to healthy subjects to evaluate changes at different pediatric ages. MATERIALS AND METHODS: Seven hundred ninety-five [18F]FDG-PET examinations from children < 18 years of age without central nervous system diseases were included. Each brain image was spatially normalized, and the standardized uptake value (SUV) was obtained. The SUV and the SUV relative to different pseudo-references were explored as a function of age. RESULTS: At all evaluated ages, the occipital lobe showed the highest [18F]FDG uptake (0.27 ± 0.04 SUV/year), while the parietal lobe and brainstem had the lowest uptake (0.17 ± 0.02 SUV/year, for both regions). An increase [18F]FDG uptake was found for all brain regions until 12 years old, while no significant uptake differences were found between ages 13 (SUV = 5.39) to 17 years old (SUV = 5.52) (P < 0.0001 for the whole brain). A sex dependence was found in the SUVmean for the whole brain during adolescence (SUV 5.04-5.25 for males, 5.68-5.74 for females, P = 0.0264). Asymmetries in [18F]FDG uptake were found in the temporal and central regions during infancy. CONCLUSIONS: Brain glycolytic metabolism of [18F]FDG, measured through the SUVmean, increased with age until early adolescence (< 13 years old), showing differences across brain regions. Age, sex, and brain region influence [18F]FDG uptake, with significant hemispheric asymmetries for temporal and central regions.

Infant feeding practices and childhood acute leukemia: Findings from the Childhood Cancer & Leukemia International Consortium.

Increasing evidence suggests that breastfeeding may protect from childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). However, most studies have limited their analyses to any breastfeeding, and only a few data have examined exclusive breastfeeding, or other exposures such as formula milk. We performed pooled analyses and individual participant data metaanalyses of data from 16 studies (N = 17 189 controls; N = 10 782 ALL and N = 1690 AML cases) from the Childhood Leukemia International Consortium (CLIC) to characterize the associations of breastfeeding duration with ALL and AML, as well as exclusive breastfeeding duration and age at introduction to formula with ALL. In unconditional multivariable logistic regression analyses of pooled data, we observed decreased odds of ALL among children breastfed 4 to 6 months (0.88, 95% CI 0.81-0.96) or 7 to 12 months (OR 0.85, 0.79-0.92). We observed a similar inverse association between breastfeeding ≥4 months and AML (0.82, 95% CI 0.71-0.95). Odds of ALL were reduced among children exclusively breastfed 4 to 6 months (OR 0.73, 95% CI 0.63-0.85) or 7 to 12 months (OR 0.70, 95% CI 0.53-0.92). Random effects metaanalyses produced similar estimates, and findings were unchanged in sensitivity analyses adjusted for race/ethnicity or mode of delivery, restricted to children diagnosed ≥1 year of age or diagnosed with B-ALL. Our pooled analyses indicate that longer breastfeeding is associated with decreased odds of ALL and AML. Few risk factors for ALL and AML have been described, therefore our findings highlight the need to promote breastfeeding for leukemia prevention.

Prognostic Impact of Somatic Copy Number Alterations in Childhood B-Lineage Acute Lymphoblastic Leukemia.

PURPOSE OF REVIEW: The high prevalence of relapse in pediatric B-lineage acute lymphoblastic leukemia (B-ALL) despite the improvements achieved using current risk stratification schemes, demands more accurate methods for outcome prediction. Here, we provide a concise overview about the key advances that have expanded our knowledge regarding the somatic defects across B-ALL genomes, particularly focusing on copy number alterations (CNAs) and their prognostic impact. RECENT FINDINGS: The identification of commonly altered genes in B-ALL has inspired the development of risk classifiers based on copy number states such as the IKZF1plus and the United Kingdom (UK) ALL-CNA classifiers to improve outcome prediction in B-ALL. CNA-risk classifiers have emerged as effective tools to predict disease relapse; though, their clinical applications are yet to be transferred to routine practice.

Treatment with radiosynoviorthesis in hemophilic patients with and without inhibitor.

BACKGROUND: Spontaneous bleedings occurring into joints (hemarthrosis) are the most common manifestations of hemophilia and causes severe joint damage ultimately resulting in joint disfunction known as hemophilic arthropathy. Among available therapeutic options for reducing recurrent hemarthrosis-associated damage, radiosynoviorthesis (RS) has proven effective in improving joint function. AIM: To assess the impact of RS with Yttrium(90) citrate (C-Y(90)) on frequency of hemarthroses and joint function in a group of pediatric patients. METHODS: Between November 1998 and February 2017, we evaluated 27 pediatric patients with mild, moderate or severe hemophilia with haemophilic arthropathy. Overall, RS was applied in 60 joints. Some patients received more than one single intra-articular injection with C-Y(90). RESULTS: During the follow-up, one patient showed joint bleeding 15 months after RS, one patient after 12 months and one patient after 45 days. The episodes of hemarthrosis were reduced and joint function significantly improved in all patients. CONCLUSION: RS with C-Y(90) is a simple and safe treatment for reducing the frequency of hemarthroses in patients with hemophilia. It decreases the use of factor VIII / IX and improves joint function.

Overweight and obesity as predictors of early mortality in Mexican children with acute lymphoblastic leukemia: a multicenter cohort study.

BACKGROUND: Mexico City has one of the highest incidences and mortality rates of acute lymphoblastic leukemia (ALL) in the world and a high frequency of early relapses (17%) and early mortality (15%). Otherwise, childhood overweight and obesity are reaching epidemic proportions. They have been associated with poor outcomes in children with ALL. The aim of present study was to identify if overweight and obesity are predictors of early mortality and relapse in Mexican children with ALL. METHODS: A multicenter cohort study was conducted. ALL children younger than 15 years old were included and followed-up during the first 24 months after diagnosis. Overweight and obesity were classified according World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) criteria. Early mortality and early relapses were the main outcomes. RESULTS: A total of 1070 children were analyzed. Overweight/obesity at diagnosis were predictors of early mortality (WHO: HR = 1.4, 95%CI:1.0-2.0; CDC: HR = 1.6, 95%CI:1.1-2.3). However, no associations between overweight (WHO: HR = 1.5, 95%CI:0.9-2.5; CDC: HR = 1.0; 95% CI:0.6-1.6) and obesity (WHO: HR = 1.5, 95%CI:0.7-3.2; CDC: HR = 1.4; 95%CI:0.9-2.3) with early relapse were observed. CONCLUSIONS: Overweight and obese patients embody a subgroup with high risk of dying during leukemia treatment.

A report of two children with Gorham-Stout disease.

BACKGROUND: Gorham-Stout disease is a rare condition characterized by unifocal and massive type IV osteolysis (variant of idiopathic nonhereditary osteolytic disease) with a slow progression, which is self-limiting for some years. It is characterized by recurrent vascular tumors with disruption of the anatomical architecture and intraosseous proliferation of vascular channels that leads to the destruction and resorption of the bone matrix. The aim of this study is to present the clinical features of this disease, as well as the importance of prompt diagnosis and treatment, with a review of the reported cases. CASE REPORTS: We describe two cases of Gorham-Stout disease between 2013 and 2017 with surgical interventions, follow-up and results. Case one involves an 11-year-old male with involvement of the left iliac bone, with adequate evolution after a surgical procedure with a lyophilized cadaveric tricortical bone allograft. Case two involves a 6-year-old male with cervical spine C1-C3 repercussion; in the protocol for surgical treatment, he presented with signs of spinal cord compression and died. CONCLUSION: Diagnosis of Gorham-Stout disease is made by exclusion, and its clinical presentation varies widely, from spontaneous remission to a fatal outcome.

Long Non-Coding RNA and Acute Leukemia.

Acute leukemia (AL) is the main type of cancer in children worldwide. Mortality by this disease is high in developing countries and its etiology remains unanswered. Evidences showing the role of the long non-coding RNAs (lncRNAs) in the pathophysiology of hematological malignancies have increased drastically in the last decade. In addition to the contribution of these lncRNAs in leukemogenesis, recent studies have suggested that lncRNAs could be used as biomarkers in the diagnosis, prognosis, and therapeutic response in leukemia patients. The focus of this review is to describe the functional classification, biogenesis, and the role of lncRNAs in leukemogenesis, to summarize the evidence about the lncRNAs which are playing a role in AL, and how these genes could be useful as potential therapeutic targets.

Identification and Characterization of Novel Fusion Genes with Potential Clinical Applications in Mexican Children with Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia is the most common type of childhood cancer worldwide. Mexico City has one of the highest incidences and mortality rates of this cancer. It has previously been recognized that chromosomal translocations are important in cancer etiology. Specific fusion genes have been considered as important treatment targets in childhood acute lymphoblastic leukemia (ALL). The present research aimed at the identification and characterization of novel fusion genes with potential clinical implications in Mexican children with acute lymphoblastic leukemia. The RNA-sequencing approach was used. Four fusion genes not previously reported were identified: CREBBP-SRGAP2B, DNAH14-IKZF1, ETV6-SNUPN, ETV6-NUFIP1. Although a fusion gene is not sufficient to cause leukemia, it could be involved in the pathogenesis of the disease. Notably, these new translocations were found in genes encoding for hematopoietic transcription factors which are known to play an important role in leukemogenesis and disease prognosis such as IKZF1, CREBBP, and ETV6. In addition, they may have an impact on the prognosis of Mexican pediatric patients with ALL, with the potential to be included in the current risk stratification schemes or used as therapeutic targets.

[Risk factors associated with postoperative acute renal failure in pediatric patients undergoing cardiopulmonary bypass surgery]. / Factores de riesgo asociados a insuficiencia renal aguda postoperatoria en pacientes pediátricos intervenidos de cirugía cardiaca que requirieron de circulación extracorpórea.

Acute renal failure (ARF) is a complication associated with cardiac surgery with cardiopulmonary bypass (CPB) with an impact on morbidity and mortality. OBJECTIVE: To identify risk factors associated with postoperative IRA according to pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease scale in children undergoing cardiac surgery with CPB. PATIENTS AND METHOD: A nested case-control study was conducted. We included children under 16 years of age attended postoperative for CBP in a pediatric intensive care unit over a period of 18 months. The cases were those who developed ARF according to the classification pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease scale during their stay in the pediatric intensive care unit. Controls were those who did not develop this complication. Logistic regression analysis was performed and adjusted odds ratio (OR) and confidence intervals at 95% (95% CI) were calculated. RESULTS: 91 patients (31 cases and 60 controls) with a median age of 20 months and predominance of males (53.8%) were analyzed. Independent risk factors for ARF were the intraoperative lactate level > 6 mmol/l (OR = 4.91; 95% CI 1.26-19.05; p = .02) and cyanotic heart disease (OR = 3.62; 95% CI 1.11-11.63; p = .03). CONCLUSIONS: This study identified that pediatric patients with lactate levels >6 mmol/l during CPB and those with cyanotic congenital heart disease are a subgroup of high risk to develop ARF after heart surgery and should be closely monitored to prevent, detect and/or treat this complication timely manner.

[Descriptive epidemiology of children with acute myeloid leukemia residing in Mexico City: a report from the Mexican Inter-Institutional Group for Identifying Childhood Leukemia Causes]. / Epidemiología descriptiva de la leucemia mieloide aguda (LMA) en niños residentes de la Ciudad de México: reporte del Grupo Mexicano Interinstitucional para la Identificación de las Causas de la Leucemia en Niños.

INTRODUCTION: Acute myeloid leukemias represent the second most common childhood leukemia subtype. In Mexico, there are few studies on descriptive epidemiology for this disease. AIMS: To report acute myeloid leukemia incidence for children less than 15 years of age in the Metropolitan Area of the Valley of Mexico for a period of five years (2010-2014) and to analyze whether there are differences in the incidence of acute myeloid leukemia by regions. MATERIAL AND METHODS: A descriptive study was conducted in nine public hospitals in Mexico City. The crude annual average incidence rate and adjusted average annual incidence rate were calculated. RESULTS: A total of 190 patients with diagnosis of de novo acute myeloid leukemia were analyzed. Male sex (57.2%) and acute myeloid leukemia-M3 subtype (25.3%) were more frequent. The adjusted average annual incidence rates for Mexico City and for the Metropolitan Area of the Valley of Mexico were 8.18 and 7.74 per million children under 15 years old, respectively. CONCLUSIONS: It seems that childhood acute myeloid leukemia incidence is increasing in Mexico City, which makes the identification of associated risk factors imperative.

Sociodemographic and Lifestyle Characteristics Associated with Maternal Dietary Patterns in Mexico.

There is scarce evidence on sociodemographic and lifestyle characteristics that may explain adherence to different dietary patterns (DPs) during pregnancy. Our aims were to identify dietary patterns in a sample of pregnant Mexican women and to describe their association with selected sociodemographic and lifestyle characteristics. This is a secondary cross-sectional analysis of 252 mothers of children that participated as controls in a hospital-based case-control study of childhood leukemia. We obtained parents' information about selected sociodemographic characteristics, as well as alcohol and tobacco consumption. We also obtained dietary information during pregnancy. We identified DPs using cluster and factor analyses and we estimated their association with characteristics of interest. We identified two DPs using cluster analysis, which we called "Prudent" and "Non healthy", as well as three DPs through factor analysis, namely "Prudent", "Processed foods and fish", and "Chicken and vegetables". Characteristics associated with greater adherence to "Prudent" patterns were maternal education, older paternal age, not smoking, and being a government employee and/or uncovered population. Likewise, the "Processed foods and fish" pattern was associated with greater maternal and paternal education, as well as those with less household overcrowding. We did not identify sociodemographic variables related to the "Chicken and Vegetables" pattern. Our results may be useful to identify target populations that may benefit from interventions aimed to improve individual dietary decisions during pregnancy.

IKZF1plus is a frequent biomarker of adverse prognosis in Mexican pediatric patients with B-acute lymphoblastic leukemia.

Background: Recurrent genetic alterations contributing to leukemogenesis have been identified in pediatric B-cell Acute Lymphoblastic Leukemia (B-ALL), and some are useful for refining classification, prognosis, and treatment selection. IKZF1plus is a complex biomarker associated with a poor prognosis. It is characterized by IKZF1 deletion coexisting with PAX5, CDKN2A/2B, or PAR1 region deletions. The mutational spectrum and clinical impact of these alterations have scarcely been explored in Mexican pediatric patients with B-ALL. Here, we report the frequency of the IKZF1plus profile and the mutational spectrum of IKZF1, PAX5, CDKN2A/2B, and ERG genes and evaluate their impact on overall survival (OS) in a group of patients with B-ALL. Methods: A total of 206 pediatric patients with de novo B-ALL were included. DNA was obtained from bone marrow samples at diagnosis before treatment initiation. A custom-designed next-generation sequencing panel was used for mutational analysis. Kaplan-Meier analysis was used for OS estimation. Results: We identified the IKZF1plus profile in 21.8% of patients, which was higher than that previously reported in other studies. A significantly older age (p=0.04), a trend toward high-risk stratification (p=0.06), and a decrease in 5-year Overall Survival (OS) (p=0.009) were observed, although heterogeneous treatment protocols in our cohort would have impacted OS. A mutation frequency higher than that reported was found for IKZF1 (35.9%) and CDKN2A/2B (35.9%) but lower for PAX5 (26.6%). IKZF1MUT group was older at diagnosis (p=0.0002), and most of them were classified as high-risk (73.8%, p=0.02), while patients with CDKN2A/2BMUT had a higher leukocyte count (p=0.01) and a tendency toward a higher percentage of blasts (98.6%, >50% blasts, p=0.05) than the non-mutated patients. A decrease in OS was found in IKZF1MUT and CDKN2A/2BMUT patients, but the significance was lost after IKZF1plus was removed. Discussion: Our findings demonstrated that Mexican patients with B-ALL have a higher prevalence of genetic markers associated with poor outcomes. Incorporating genomic methodologies into the diagnostic process, a significant unmet need in low- and mid-income countries, will allow a comprehensive identification of relevant alterations, improving disease classification, treatment selection, and the general outcome.

Implementation of a roadmap for the comprehensive diagnosis, follow-up, and research of childhood leukemias in vulnerable regions of Mexico: results from the PRONAII Strategy.

The main objective of the National Project for Research and Incidence of Childhood Leukemias is to reduce early mortality rates for these neoplasms in the vulnerable regions of Mexico. This project was conducted in the states of Oaxaca, Puebla, and Tlaxcala. A key strategy of the project is the implementation of an effective roadmap to ensure that leukemia patients are the target of maximum benefit of interdisciplinary collaboration between researchers, clinicians, surveyors, and laboratories. This strategy guarantees the comprehensive management of diagnosis and follow-up samples of pediatric patients with leukemia, centralizing, managing, and analyzing the information collected. Additionally, it allows for a precise diagnosis and monitoring of the disease through immunophenotype and measurable residual disease (MRD) studies, enhancing research and supporting informed clinical decisions for the first time in these regions through a population-based study. This initiative has significantly improved the diagnostic capacity of leukemia in girls, boys, and adolescents in the regions of Oaxaca, Puebla, and Tlaxcala, providing comprehensive, high-quality care with full coverage in the region. Likewise, it has strengthened collaboration between health institutions, researchers, and professionals in the sector, which contributes to reducing the impact of the disease on the community.

Not All Populations of Hispanic Children Have an Increased Frequency of Acute Lymphoblastic Leukemia.

The frequency of acute lymphoblastic leukemia (ALL) has been reported with a higher incidence among the populations of Hispanic children. However, in the article by Montes-Rodríguez and colleagues, they found that in the Puerto Rican population, the frequency was below the incidence reported for the U.S. Hispanic pediatric population, but they found that the incidence of ALL had an annual increase of 5%. In other Hispanic pediatric populations during the 1980s, the incidence of ALL was found to be even lower than the general rate in the United States. However, in less than 20 years that incidence had already been exceeded. It is evident that the Hispanic pediatric population is more susceptible to develop ALL than other populations, so it is important to consider that what is happening to the pediatric population of Puerto Rico gives us a great opportunity to identify risk factors that could potentially explain this increase. It is more likely that the risk factors that are capable of causing ALL could be identified in their role in the origin of the disease in populations with high susceptibility, given the greater number of cases of ALL that said factor is causing in that population. See related article by Montes-Rodríguez et al., p. 1030.

[Surgical management of duodenal atresia due to annular pancreas and intestinal atresia IIIb]. / Manejo quirúrgico de atresia duodenal por páncreas anular y atresia intestinal IIIb.

Background: The presence of duodenal atresia related to type IIIb intestinal atresia is a rare association, with few cases reported in the literature, representing a surgical challenge considering that even isolated cases of type IIIb intestinal atresia are a challenge. The objective was to report the successful surgical management of a case of a complex intestinal malformation, characterized by duodenal occlusion secondary to annular pancreas and type IIIb intestinal atresia, with intestinal malrotation by definition and the presence of Meckel's diverticulum. Clinical case: We present the case report of a newborn sent to the second level of care with a diagnosis of duodenal obstruction not diagnosed prenatally, which resulted in duodenal atresia due to annular pancreas and type IIIb intestinal atresia according to the Grosfeld classification. The presence of duodenal atresia with type IIIb intestinal atresia is an extremely rare condition, even more so associated with annular pancreas. These cases are a challenge considering the short length of the small intestine and its consequent need for total parenteral nutrition for a prolonged period. Conclusions: The surgical management of this complex intestinal malformation resulted in a case with an adequate post-surgical evolution, based on the immediate start of enteral feeding with a short period of need for total parenteral nutrition that finally resulted in a short hospital stay.

Introducción: la presencia de atresia duodenal relacionada con atresia intestinal tipo IIIb es una asociación rara, con pocos casos reportados en la literatura, y representa un reto quirúrgico si se toma en cuenta que incluso los casos aislados de atresia intestinal tipo IIIb lo representan. El objetivo fue reportar el manejo quirúrgico exitoso del caso de una malformación intestinal compleja, caracterizada por una oclusión duodenal secundaria a páncreas anular y atresia intestinal tipo IIIb, con una malrotación intestinal por definición y la presencia de divertículo de Meckel. Caso clínico: reportamos el caso de un recién nacido enviado de segundo nivel de atención con un diagnóstico de obstrucción duodenal no diagnosticado prenatalmente, que resultó en atresia duodenal por páncreas anular y atresia intestinal tipo IIIb, según la clasificación de Grosfeld. La presencia de atresia duodenal con atresia intestinal tipo IIIb es una condición extremadamente rara y todavía lo es más asociada con páncreas anular. Estos casos son un desafío si se toma en cuenta la corta longitud de intestino delgado y su consiguiente necesidad de nutrición parenteral total por un periodo prolongado. Conclusiones: el manejo quirúrgico de esta malformación intestinal compleja resultó en un caso con una adecuada evolución postquirúrgica, basada en el inicio mediato de alimentación enteral con un periodo corto de necesidad de nutrición parenteral total que finalmente resultó en una corta estancia hospitalaria.

[Electroencephalographic findings in preterm neonates]. / Hallazgos electroencefalográficos en recién nacidos pretérmino.

Background: The electroencephalogram (EEG) in the newborn period is highly superior to the clinical exam in the detection and prognosis of brain dysfunctions, since it allows continuous functional documentation of the brain at the patient's bedside in a non-invasive way. However, there is still some disagreement about these findings. Objective: To describe the electroencephalographic findings in newborns with a history of prematurity. Material and methods: Cross-sectional, descriptive, retrospective study. The inclusion criteria were: newborns with a history of prematurity, regardless of gender, who underwent an EEG from June 2017 to June 2021. Patients with incomplete electroencephalographic records or clinical records without complete data were excluded; patients using sedatives (thiopental, fentanyl, midazolam, diazepam) were eliminated from the study. Results: 107 patients (37 women and 70 men) with a history of prematurity were included, with a mean gestational age at birth of 30.9 WOG ± 3.25. Electroencephalographic findings were normal in 40%, abnormal in 32%, and immature in 28%. The most frequent abnormal finding was focal paroxysmal activity in 86%. 93.4% of the participants presented comorbidities, the most frequent being neurological. Conclusion: Preterm neonates are at high risk of neurologic sequelae, and EEG is a sensitive method for assessing neuromotor and cognitive prognosis. In our study population, one-third had abnormal findings. Early postnatal screening is helpful, but additional records are usually needed to detect high-risk newborns. It would be important to continue studying this line of research in pediatrics.

Introducción: el electroencefalograma (EEG) en el periodo neonatal es muy superior al examen clínico en la detección y pronóstico de disfunciones cerebrales, pues permite hacer una documentación funcional cerebral continua y no invasiva junto a la cama del paciente. Sin embargo, todavía hay cierto desacuerdo sobre estos hallazgos. Objetivo: describir los hallazgos electroencefalográficos en recién nacidos (RN) con antecedente de prematurez. Material y métodos: estudio transversal, descriptivo, retrospectivo. Los criterios de inclusión fueron: RN con antecedente de prematurez, sin distinción de género, a quienes se les haya hecho un EEG de junio de 2017 a junio de 2021. Se excluyeron pacientes con registro electroencefalográfico incompleto o expediente clínico sin datos completos; se eliminaron del estudio pacientes que usaran sedantes (tiopental, fentanilo, midazolam, diazepam). Resultados: se incluyeron 107 pacientes (37 mujeres y 70 hombres) con antecedente de prematurez, con una edad gestacional media al nacer de 30.9 SDG ± 3.25. Los hallazgos de EEG fueron normales en 40%, anormales en 32% e inmaduros en 28%. El hallazgo anormal más frecuente fue la actividad paroxística focal en 86%. El 93.4% de los participantes presentaban comorbilidades, sobre todo neurológicas. Conclusión: los RN pretérmino tienen un alto riesgo de secuelas neurológicas y el EEG es un método sensible para evaluar el pronóstico neuromotor y cognitivo. En nuestra población un tercio tuvo hallazgos anormales. El rastreo posnatal temprano es útil, pero se necesitan registros adicionales para detectar RN de alto riesgo. Es importante continuar esta línea de investigación en pediatría.

Characteristics and outcomes of multisystem inflammatory syndrome in children: A multicenter, retrospective, observational cohort study in Mexico.

Introduction: Multisystem inflammatory syndrome in children associated with coronavirus disease 2019 (MIS-C), a novel hyperinflammatory condition secondary to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, is associated with severe outcomes such as coronary artery aneurysm and death. Methods: This multicenter, retrospective, observational cohort study including eight centers in Mexico, aimed to describe the clinical characteristics and outcomes of patients with MIS-C. Patient data were evaluated using latent class analysis (LCA) to categorize patients into three phenotypes: toxic shock syndrome-like (TSSL)-MIS-C, Kawasaki disease-like (KDL)-MIS-C, and nonspecific MIS-C (NS-MIS-C). Risk factors for adverse outcomes were estimated using multilevel mixed-effects logistic regression. Results: The study included 239 patients with MIS-C, including 61 (26%), 70 (29%), and 108 (45%) patients in the TSSL-MIS-C, KDL-MIS-C, and NS-MIS-C groups, respectively. Fifty-four percent of the patients were admitted to the intensive care unit, and 42%, 78%, and 41% received intravenous immunoglobulin, systemic glucocorticoids, and anticoagulants, respectively. Coronary artery dilatation and aneurysms were found in 5.7% and 13.2% of the patients in whom coronary artery diameter was measured, respectively. Any cause in-hospital mortality was 5.4%. Hospitalization after ten days of symptoms was associated with coronary artery abnormalities (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.2-2.0). Age ≥10 years (OR: 5.6, 95% CI: 1.4-2.04), severe underlying condition (OR: 9.3, 95% CI: 2.8-31.0), platelet count <150,000 /mm3 (OR: 4.2, 95% CI: 1.2-14.7), international normalized ratio >1.2 (OR: 3.8, 95% CI: 1.05-13.9), and serum ferritin concentration >1,500 mg/dl at admission (OR: 52, 95% CI: 5.9-463) were risk factors for death. Discussion: Mortality in patients with MIS-C was higher than reported in other series, probably because of a high rate of cases with serious underlying diseases.

Association between genetic variants of membrane transporters and the risk of high-grade hematologic adverse events in a cohort of Mexican children with B-cell acute lymphoblastic leukemia.

Background: Advances in the understanding of the pathobiology of childhood B-cell acute lymphoblastic leukemia (B-ALL) have led towards risk-oriented treatment regimens and markedly improved survival rates. However, treatment-related toxicities remain a major cause of mortality in developing countries. One of the most common adverse effects of chemotherapy in B-ALL is the hematologic toxicity, which may be related to genetic variants in membrane transporters that are critical for drug absorption, distribution, and elimination. In this study we detected genetic variants present in a selected group genes of the ABC and SLC families that are associated with the risk of high-grade hematologic adverse events due to chemotherapy treatment in a group of Mexican children with B-ALL. Methods: Next generation sequencing (NGS) was used to screen six genes of the ABC and seven genes of the SLC transporter families, in a cohort of 96 children with B-ALL. The grade of hematologic toxicity was classified according to the National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, Subsequently, two groups of patients were formed: the null/low-grade (grades 1 and 2) and the high-grade (grades 3 to 5) adverse events groups. To determine whether there is an association between the genetic variants and high-grade hematologic adverse events, logistic regression analyses were performed using co-dominant, dominant, recessive, overdominant and log-additive inheritance models. Odds ratio (OR) and 95% confidence intervals (95% CI) were calculated. Results: We found two types of associations among the genetic variants identified as possible predictor factors of hematologic toxicity. One group of variants associated with high-grade toxicity risk: ABCC1 rs129081; ABCC4 rs227409; ABCC5 rs939338, rs1132776, rs3749442, rs4148575, rs4148579 and rs4148580; and another group of protective variants that includes ABCC1 rs212087 and rs212090; SLC22A6 rs4149170, rs4149171 and rs955434. Conclusion: There are genetic variants in the SLC and ABC transporter families present in Mexican children with B-ALL that can be considered as potential risk markers for hematologic toxicity secondary to chemotherapeutic treatment, as well as other protective variants that may be useful in addition to conventional risk stratification for therapeutic decision making in these highly vulnerable patients.

Infections and risk factors for infection-related mortality after pediatric allogeneic hematopoietic stem cell transplantation in Mexico: A single center retrospective study.

OBJECTIVE: To identify the type of infections and risk factors for infection-related mortality (IRM) after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: Retrospective cohort study of patients <16 years of age treated in 2010-2019 was conducted. Unadjusted hazard ratios (HR) and adjusted hazard ratios (aHR) with 95% confidence intervals (95% CIs) were estimated using Cox regression. Cumulative incidence was calculated. RESULTS: Data for 99 pediatric patients were analyzed. The myeloablative conditioning was the most used regimen (78.8%) and the hematopoietic stem cell source was predominantly peripheral blood (80.8%). Primary graft failure occurred in 19.2% of patients. Frequency of acute graft-versus-host disease was 46.5%. Total of 136 infectious events was recorded, the most common of which were bacterial (76.4%) followed by viral infection (15.5%) and then fungal infection (8.1%). The best predictors for infection subtypes where the following: a) for bacterial infection (the age groups of 10.1-15 years: aHR = 3.33; 95% CI: 1.62-6.85 and. >15 years: aHR = 3.34; 95% CI: 1.18-9.45); b) for viral infection (graft versus host disease: aHR = 5.36; 95% CI: 1.62-17.68), however, for fungal infection statistically significant predictors were not identified. Related mortality was 30% (n = 12). Increased risk for infection-related mortality was observed in patients with unrelated donor and umbilical cord stem cells recipients (HR = 3.12; 95% CI: 1.00-9.85). CONCLUSIONS: Frequencies of infections and infection-related mortality appear to be similar to those reported. Unrelated donors and stem cells from umbilical cord recipients were associated with a high risk of mortality.