Subclassification of B-acute lymphoblastic leukemia according to age, immunophenotype and microenvironment, predicts MRD risk in Mexican children from vulnerable regions

Introduction

The decisive key to disease-free survival in B-cell precursor acute lymphoblastic leukemia in children, is the combination of diagnostic timeliness and treatment efficacy, guided by accurate patient risk stratification. Implementation of standardized and high-precision diagnostic/prognostic systems is particularly important in the most marginalized geographic areas in Mexico, where high numbers of the pediatric population resides and the highest relapse and early death rates due to acute leukemias are recorded even in those cases diagnosed as standard risk.

Methods

By using a multidimensional and integrated analysis of the immunophenotype of leukemic cells, the immunological context and the tumor microenvironment, this study aim to capture the snapshot of acute leukemia at disease debut of a cohort of Mexican children from vulnerable regions in Puebla, Oaxaca and Tlaxcala and its potential use in risk stratification.

Results and discussion

Our findings highlight the existence of a distinct profile of ProB-ALL in children older than 10 years, which is associated with a six-fold increase in the risk of developing measurable residual disease (MRD). Along with the absence of CD34+ seminal cells for normal hematopoiesis, this ProB-ALL subtype exhibited several characteristics related to poor prognosis, including the high expression level of myeloid lineage markers such as MPO and CD33, as well as upregulation of CD19, CD34, CD24, CD20 and nuTdT. In contrast, it showed a trend towards decreased expression of CD9, CD81, CD123, CD13, CD15 and CD21. Of note, the mesenchymal stromal cell compartment constituting their leukemic niche in the bone marrow, displayed characteristics of potential suppressive microenvironment, such as the expression of Gal9 and IDO1, and the absence of the chemokine CXCL11. Accordingly, adaptive immunity components were poorly represented. Taken together, our results suggest, for the first time, that a biologically distinct subtype of ProB-ALL emerges in vulnerable adolescents, with a high risk of developing MRD. Rigorous research on potential enhancing factors, environmental or lifestyle, is crucial for its detection and prevention. The use of the reported profile for early risk stratification is suggested.

Differential DNA Methylation from Autistic Children Enriches Evidence for Genes Associated with ASD and New Candidate Genes

The etiology of Autism Spectrum Disorders (ASD) is a result of the interaction between genes and the environment. The study of epigenetic factors that affect gene expression, such as DNA methylation, has become an important area of research in ASD. In recent years, there has been an increasing body of evidence pointing to epigenetic mechanisms that influence brain development, as in the case of ASD, when gene methylation dysregulation is present. Our analysis revealed 853 differentially methylated CpG in ASD patients, affecting 509 genes across the genome. Enrichment analysis showed five related diseases, including autistic disorder and mental disorders, which are particularly significant. In this work, we identified 64 genes that were previously reported in the SFARI gene database, classified according to their impact index. Additionally, we identified new genes that have not been previously reported as candidates with differences in the methylation patterns of Mexican children with ASD.

Association of total and pancreatic serum amylase enzymatic activity with insulin resistance and the glucose and insulin responses to oral starch test in Mexican children

BACKGROUND/OBJECTIVES

Little is known about the effect of serum amylase enzymatic activity on glucose metabolism. We investigated the association of serum amylase enzymatic activity with fasting plasma glucose, insulin resistance (IR), and the plasma glucose and insulin response to an oral starch test (OST) in Mexican children.

METHODS

Anthropometric data, glucose and insulin levels, and the serum enzymatic activity of total (AMYt), salivary (AMY1), and pancreatic (AMY2) amylase were analysed in 764 children (N_{normal weight}  = 427/N_obesity  = 337). After categorization into low (LA) and high (HA) AMYt, an OST with commercial white bread was performed in 39 children (N_{normal weight}  = 17/N_obesity  = 22).

RESULTS

A positive association between serum enzymatic activity of AMY2 and IR was observed in children with obesity (p = 0.018). Children with normal weight had lower plasma glucose and insulin response to OST than children with obesity (P_glucose  = 4.1 × 10^-12 ; P_insulin  = 2.1 × 10^-15 ). Compared with the LA group, children with HA showed lower plasma glucose and insulin response to OST (P_glucose  ≤ 0.040; P_insulin  ≤ 0.015).

CONCLUSION

Our results suggest that AMY2 is positively associated with IR. A high level of AMYt is related to lower glucose and insulin responses to OST in Mexican children, regardless of their weight status.

Body Mass Index and Dental Caries, a Five-Year Follow-Up Study in Mexican Children

There are conflicting reports on a possible association between body mass index (BMI) and caries. Given the ongoing worldwide increase in obesity, we undertook a 5-year follow-up study on 201 Mexican schoolchildren to analyse their BMI and dental caries experience. The children's weight and height were recorded, and their BMI was calculated using the WHO tables. Decayed, missing, and filled surfaces in both dentitions (dmf/DMFS) were assessed annually according to WHO criteria by two calibrated researchers (Kappa value 0.92 p < 0.001). The means, standard deviation, an ANOVA, and Student's t-test were calculated to analyse the relationship between the variables. At baseline, the children had an average of 6.5 ± 0.5 years, a BMI of 17.2 ± 3.1 (CI_95% 16.8-17.6). Their weight's classifications were 61% normal, 19% obese, 17% overweight, and 3% showed thinness. At the end of the study, their BMI were 20.6 ± 4.4 (CI_95% 19.8-21.5), 53% normal, 15% obese, 30% overweight, and 2% thin. The children's dmfs decreased from 5.8 ± 9.2 to 1.8 ± 3.4 and the DMFS increased from 0.07 ± 05 to 1.4 ± 2.3. In this population based on a 5-year follow-up, caries prevalence and incidence were not significantly associated with the BMI. However, schoolchildren with malnutrition had the highest caries indexes.

CRLF2 and IKZF1 abnormalities in Mexican children with acute lymphoblastic leukemia and recurrent gene fusions: exploring surrogate markers of signaling pathways

The gene fusions BCR-ABL1, TCF3-PBX1, and ETV6-RUNX1 are recurrent in B-cell acute lymphoblastic leukemia (B-ALL) and are found with low frequency in coexistence with CRLF2 (cytokine receptor-like factor 2) rearrangements and overexpression. There is limited information regarding the CRLF2 abnormalities and dominant-negative IKZF1 isoforms associated with surrogate markers of Jak2, ABL, and Ras signaling pathways. To assess this, we evaluated 24 Mexican children with B-ALL positive for recurrent gene fusions at diagnosis. We found CRLF2 rearrangements and/or overexpression, dominant-negative IKZF1 isoforms, and surrogate phosphorylated markers of signaling pathways coexisting with recurrent gene fusions. All the BCR-ABL1 patients expressed CRLF2 and were positive for pCrkl (ABL); most of them were also positive for pStat5 (Jak2/Stat5) and negative for pErk (Ras). TCF3-PBX1 patients with CRLF2 abnormalities were positive for pStat5, most of them were also positive for pCrkl, and two patients were also positive for pErk. One patient with ETV6-RUNX1 and intracellular CRLF2 protein expressed pCrkl. In some cases, the activated signaling pathways were reverted in vitro by specific inhibitors. We further analyzed a TCF3-PBX1 patient at relapse, identifying a clone with the recurrent gene fusion, P2RY8-CRLF2, rearrangement, and phosphorylation of the three surrogate markers that we studied. These results agree with the previous reports regarding resistance to treatment observed in patients with recurrent gene fusions and coexisting CRLF2 gene abnormalities. A marker phosphorylation signature was identified in BCR-ABL1 and TCF3-PBX1 patients. To obtain useful information for the assessment of treatment in B-ALL patients with recurrent gene fusions, we suggest that they should be evaluated at diagnosis for CRLF2 gene abnormalities and dominant-negative IKZF1 isoforms, in addition to the analyses of activation and inhibition of signaling pathways.

Association of Family Nutrition and Physical Activity with Preschooler's Working Memory: A Cross-Sectional Study among Mexican Children

Healthy eating and active lifestyles are associated with children’s healthy weight and cognitive development. This study examines whether family behaviors relevant for nutrition and activity levels are associated with children’s working memory, independent of their weight status. A convenience sample of child–caregiver dyads (n = 85 dyads) were recruited from a public preschool serving a low-income community in central Mexico. Caregivers reported the frequency of ten family behaviors using the Family Nutrition and Physical Activity screening tool. Children completed a test of their ability to recall four words after a 60-s distraction task, an assessment of working memory. Multiple linear regression models were used to test the association of children’s working memory with each family behavior, adjusting for children’s sex, age, mother’s age and education, and subjective social status and then also adjusting for children’s age- and sex-specific body mass index percentile (BMI-P) and covariates. Higher frequency of breakfast intake was significantly associated with working memory (β = 0.57, p = 0.013). This association was independent of children’s BMI-P. Other family behaviors (frequent family mealtimes, limiting screen time, and others) were not significantly associated with children’s working memory. Frequent breakfast intake could benefit young children’s working memory, regardless of their weight status. This association merits further investigation.

Pro-Inflammatory Diet Is Associated with Adiposity during Childhood and with Adipokines and Inflammatory Markers at 11 Years in Mexican Children

There is limited evidence about the inflammatory potential of diet in children. The aim of this study was to evaluate the association between the Children's Dietary Inflammatory Index (C-DII) from 5 to 11 years with adiposity and inflammatory biomarkers in Mexican children. We analyzed 726 children from a birth cohort study with complete dietary information and measurements to evaluate adiposity at 5, 7 and 11 y and 286 children with IL-6, hsCRP, leptin and adiponectin information at 11 y. C-DII trajectories were estimated using latent class linear mixed models. We used linear mixed models for adiposity and logistic and multinomial regression for biomarkers. In girls, each one-point increase in C-DII score was associated with greater adiposity (abdominal-circumference 0.41%, p = 0.03; skinfold-sum 1.76%, p = 0.01; and BMI Z-score 0.05, p = 0.01). At 11 y the C-DII was associated with greater leptin (34% ≥ 13.0 ng/mL, p = 0.03) and hsCRP concentrations (29% ≥ 3.00 mg/L, p = 0.06) and lower adiponectin/leptin ratio (75% < 2.45, p = 0.02). C-DII trajectory 3 in boys was associated with a 75.2% (p < 0.01) increase in leptin concentrations and a 37.9% decrease (p = 0.02) in the adiponectin/leptin ratio. This study suggests that the inflammatory potential of diet may influence adiposity in girls and the homeostasis of adipose tissue and chronic subclinical inflammation in 11-year-old children.

Hepatocellular Carcinoma of Fibrolamellar Type in an Adolescent: Case Report and Literature Review

We present a female patient, 13 years old, with diagnosis of hepatocellular carcinoma of fibrolamellar type, which was rapidly evolving. The fibrolamellar hepatocellular carcinoma invaded more than 80% of the hepatic parenchyma without surgical possibility or liver transplantation. Measures applied corresponded to chemotherapy of 1 cycle of cisplatin 40 mg/s/5 days + vincristine 1.5 mg/m²/day, 5-fluorouracil, doxorubicin, and dexrazoxane. The case presented aggressive evolution of hepatocellular carcinoma, which led to acute liver failure, with hyperammonemia, sepsis, pulmonary focus plus septic shock, grade III-IV encephalopathy, portal hypertension, and ascites with intra-abdominal hypertension. Death occurred due to multiple organ failure, which involved respiratory failure type KDIGO 1 and 2, acute liver failure, severe pneumonia, pericardial effusion, AKIN 2 acute kidney injury, carcinoma, and pulmonary metastasis. This type of ailment is infrequent in children and adolescents, and the first symptoms are crucial to achieve treatment possibilities.

Risk factors associated with horizontal transmission of hepatitis B viral infection from parents to children in Mexico

INTRODUCTION

Hepatitis B virus (HBV) infection in children is a health problem worldwide. In Mexico, a high prevalence rate of HBV infection and occult HBV infection have been reported in high-risk adults and children. However, studies regarding HBV infection transmitted from HBV-infected parents to children are limited. This study aimed to determine the risk factors associated with HBV transmission of HBV from parents to children in Mexico.

METHODOLOGY

A retrospective case-control study was carried out in 24 pediatric patients with clinical HBV infection and 48 healthy controls. Bivariate and forward conditional logistic regression analysis was used to compare demographic variables, the status of HBV vaccination, and risk factors for HBV infection transmission among children and their parents.

RESULTS

No newborns were diagnosed with HBV infection, and no significant differences were found in age (p = 0.209) or gender (p = 0.612) compared to the control group. The independent risk factor associated with HBV transmission was the presence of a parent with a history of promiscuity (OR = 30.95, 95%CI = 3.382-283.326; p = 0.002), whereas having completed the HBV vaccination schedule for their age was a protective factor against HBV infection in the children (OR = 0.245, 95%CI = 0.079-0.764; p = 0.015).

CONCLUSIONS

HBV infection in Mexican children is associated with close interpersonal contact with a parent engaged in high-risk sexual practices suggesting that the horizontal route could be the primary mode of infection. Child and adult vaccination campaigns should be reinforced to avoid HBV infection in Mexico.

The gut microbiome of Mexican children affected by obesity

Obesity is a metabolic disorder and global health issue. In Mexico 34.4% of children between 5 and 11 years-old are overweight or obese. Here we address this issue studying the gut microbiome in a sample of Mexican children affected by obesity. We performed metagenomic shotgun-sequencing of DNA isolated from fecal samples from a cohort of normal weight and obese Mexican children using Illumina platform with HiSeq 2500. We also examined their metabolic factors and fecal short-chain fatty acids concentration. The results show that a remarkable dysbiosis of bacteria, archaea and viruses was not observed in the obese children group compared to the normal weight group; however, the archaeal community exhibited an increase of unclassified Methanobrevibacter spp. in obese children. The bacterial communities of all participants were clustered into three different enterotypes. Most normal weight children have a gut bacterial community dominated by Ruminococcus spp. (Enterotype 3), while most obese children had a community dominated by Prevotella spp. (Enterotype 2). On the other hand, changes in the gut microbiome were correlated with clinical metadata and could be used to stratify individuals based on their phenotype. The species Megamonas spp. were over-represented in obese children, whereas members of the family Oscillospiraceae were depleted in the same individuals and negatively correlated with levels of serum cholesterol. A microbiome comparative metabolic pathway analysis showed that two KEGG pathway modules of glycolysis, Glycolysis I (from Glucose 6-Phosphate), and Glycolysis II (from Fructose 6-Phosphate) were significantly overrepresented in normal weight children. Our results establish specific alterations in the gut microbiome of Mexican children affected of obesity, along with clinical alterations, providing information on the microbiome composition that may be useful for prognosis, diagnosis, and treatment.

Altered Gut Microbiota and Compositional Changes in Firmicutes and Proteobacteria in Mexican Undernourished and Obese Children

Mexico is experiencing an epidemiological and nutritional transition period, and Mexican children are often affected by the double burden of malnutrition, which includes undernutrition (13.6% of children) and obesity (15.3%). The gut microbiome is a complex and metabolically active community of organisms that influences the host phenotype. Although previous studies have shown alterations in the gut microbiota in undernourished children, the affected bacterial communities remain unknown. The present study investigated and compared the bacterial richness and diversity of the fecal microbiota in groups of undernourished (n = 12), obese (n = 12), and normalweight (control) (n = 12) Mexican school-age children. We used next-generation sequencing to analyze the V3–V4 region of the bacterial 16S rRNA gene, and we also investigated whether there were correlations between diet and relevant bacteria. The undernourished and obese groups showed lower bacterial richness and diversity than the normalweight group. Enterotype 1 correlated positively with dietary fat intake in the obese group and with carbohydrate intake in the undernourished group. The results showed that undernourished children had significantly higher levels of bacteria in the Firmicutes phylum and in the Lachnospiraceae family than obese children, while the Proteobacteria phylum was overrepresented in the obese group. The level of Lachnospiraceae correlated negatively with energy consumption and positively with leptin level. This is the first study to examine the gut microbial community structure in undernourished and obese Mexican children living in low-income neighborhoods. Our analysis revealed distinct taxonomic profiles for undernourished and obese children.

Composition of gut microbiota in obese and normal-weight Mexican school-age children and its association with metabolic traits

BACKGROUND

Childhood obesity is a serious public health problem in Mexico. Adult gut microbiota composition has been linked to obesity, but few studies have addressed the role of gut microbiota in childhood obesity.

OBJECTIVES

The aim of this study is to compare gut microbiota composition in obese and normal-weight children and to associate gut microbiota profiles with amino acid serum levels and obesity-related metabolic traits.

METHODS

Microbial taxa relative abundance was determined by 16S rRNA sequencing in 67 normal-weight and 71 obese children aged 6-12 years. Serum amino acid levels were measured by mass spectrometry. Associations between microbiota composition, metabolic parameters and amino acid serum levels were tested.

RESULTS

No significant differences in phyla abundances or Firmicutes/Bacteroidetes ratios were observed between normal-weight and obese children. However, Bacteroides eggerthii abundance was significantly higher in obese children and correlated positively with body fat percentage and negatively with insoluble fibre intake. Additionally, Bacteroides plebeius and unclassified Christensenellaceae abundances were significantly higher in normal-weight children. Abundance of both these species correlated negatively with phenylalanine serum levels, a metabolite also found to be associated with obesity in Mexican children.

CONCLUSIONS

The study identified bacterial species associated with obesity, metabolic complications and amino acid serum levels in Mexican children.

Clinical and Epidemiological Characteristics of Burkitt Lymphomas in Pediatric Patients from Two Defined Socioeconomic Regions in Mexico

We analyzed clinical and epidemiological characteristics of Burkitt lymphoma (BL) in two defined socioeconomic regions in Mexico: high socioeconomic region (HSER; with two political jurisdictions) and low socioeconomic region (LSER; with three jurisdictions). Of the 63 cases registered in the Childhood Cancer Registry (1996-2013), 45 (71.4%) were from HSER and 18 (28.6%) from LSER. The incidence was higher in the LSER (3.1 vs. 1.4 cases per million children/year). The sporadic form and Stages III/IV predominated in both regions. Only one post-renal transplant (HSER) was found. The male/female ratio was higher in the LSER (5.0 vs. 1.4). The peak incidence was in the 1-4 age group for LSER, and in the 5-9 age group for HSER. This difference in the sporadic BL by socioeconomic regions may be related to different exposure factors.

Expression of candidate genes associated with obesity in peripheral white blood cells of Mexican children

INTRODUCTION

Obesity is a chronic, complex, and multifactorial disease, characterized by excess body fat. Diverse studies of the human genome have led to the identification of susceptibility genes that contribute to obesity. However, relatively few studies have addressed specifically the association between the level of expression of these genes and obesity.

MATERIAL AND METHODS

We studied 160 healthy and obese unrelated Mexican children aged 6 to 14 years. We measured the transcriptional expression of 20 genes associated with obesity, in addition to the biochemical parameters, in peripheral white blood cells. The detection of mRNA levels was performed using the OpenArray Real-Time PCR System (Applied Biosystems).

RESULTS

Obese children exhibited higher values of fasting glucose (p = 0.034), fasting insulin (p = 0.004), low-density lipoprotein (p = 0.006), triglycerides (p < 0.001), systolic blood pressure and diastolic blood pressure (p < 0.001), and lower values of high-density lipoprotein (p < 0.001) compared to lean children. Analysis of transcriptional expression data showed a difference for ADRB1 (p = 0.0297), ADIPOR1 (p = 0.0317), GHRL (p = 0.0060) and FTO (p = 0.0348) genes.

CONCLUSIONS

Our results suggest that changes in the expression level of the studied genes are involved in biological processes implicated in the development of childhood obesity. Our study contributes new perspectives for a better understanding of biological processes involved in obesity. The protocol was approved by the National Committee and Ethical Committee Board from the Mexican Social Security Institute (IMSS) (IMSS FIS/IMSS/PRIO/10/011).

Association of Leukocyte Telomere Length and Mitochondrial DNA Copy Number in Children from Salamanca, Mexico

AIM

The purpose of this study was to determine if there is a correlation between telomere length (TL) and mitochondrial DNA copy number (mtDNAcn) in children.

METHODS

Leukocyte TL and mtDNAcn were measured by real-time PCR in 98 Mexican children 6-12 years of age from Salamanca, México.

RESULTS

A positive association was found between TL and mtDNAcn after a natural log transformation (Pearson correlation r = 0.72; p < 0.0001). No correlation between age and body mass index (BMI) biomarkers was found, and no differences according to sex were observed. After adjustment for these variables, a linear regression model showed an association between TL and mtDNAcn (β = 0.739, 95% confidence interval 0.594; 0.885, p < 0.0001).

CONCLUSIONS

A strong positive correlation between TL and mtDNAcn was found in the study population; age, sex, and BMI seemed to have no effect on this correlation.

Hearing loss in Mexican children treated with cisplatin

OBJECTIVE

Cisplatin is widely used to treat a variety of pediatric solid tumors. One of the most severe and debilitating adverse drug reactions experienced by patients who receive cisplatin therapy is permanent bilateral hearing loss. The aim of this study was to evaluate the incidence and risk factors for cisplatin-induced hearing loss in Mexican pediatric patients.

METHODS

Detailed medical and drug histories, including use of cisplatin as well as other drugs known to cause hearing loss, were collected from patient medical records. Results of audiology tests on pediatric patients with solid tumors were collected at baseline, during treatment and at the end of cisplatin chemotherapy. Hearing loss was classified according to the Common Terminology Criteria for Adverse Events. Bivariate and multivariate analyses were performed using survival curves.

RESULTS

Fifty-nine pediatric patients, median age 11 years (range, 3-17 years) were included in the study. The incidence of cisplatin-induced hearing loss was 56%. Individual risk factors including age (< 5 years), male sex, and concomitant medications were not associated with an increased risk of cisplatin-induced hearing loss. Patients with a diagnosis of osteosarcoma and a cumulative cisplatin dose greater than 400 mg/m(2) were at higher risk of hearing loss compared with all other tumor and cumulative dose combinations (HR = 2.47 [95% CI, 1.043-5.831]).

CONCLUSIONS

Cumulative dose and tumor type are associated with an increased risk of cisplatin-induced hearing loss. Further research is required to characterize fully the interindividual variation in hearing loss in Mexican patients.