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Hematopoietic stem cell transplantation is a widely used therapy for different diseases in the pediatric population. Haploidentical transplantation with negative immunoselection using electromagnetic fields is an alternative for those patients without an HLA-matched donor. Twenty pediatric patients under 18 years old received a haploidentical CD3+/CD19+-depleted transplant due to the absence of an HLA-matched donor. The mean age at which HSCT was performed was 6.6 years (range 1-18 years), and clinical indications were: acute lymphoblastic leukemia (9 patients), primary immunodeficiency (8 patients), acute myeloid leukemia (2 patients), and severe aplastic anemia (1 patient). The medium dose of cells infused was 10.9 (min. 2, max. 32) x 106/kg CD34+ cells, 3.2-4.1 x 105/kg CD3+ cells and 2.4-3.7 x 105/kg CD19+ cells. Results: Eleven of the twenty patients had donor engraftment (55%) and had complete chimera of their donors. From this group, nine (45%) developed primary graft failure, and four (36%) developed graft-versus-host disease. In the group of leukemia patients, overall survival was 75% while event-free survival was 40%. Haploidentical transplantation with negative immunoselection is a useful and feasible strategy for children without an ideal donor. In our cohort, patients with acute leukemia had better outcomes than patients with non-malignant diseases.

The aim of the study was to measure survival of children with acute lymphoblastic leukemia (ALL) under Mexico’s public health insurance for the population treated under Seguro Popular. A retrospective cohort study using claims data from Mexico’s Seguro Popular program, covering cancer treatment from 2005 to 2015 was conducted. Overall 5-year national and state-specific survival for children with ALL across Mexico who initiated cancer treatment under this program was estimated. From 2005 to 2015, 8,977 children with ALL initiated treatment under Seguro Popular. Under this financing scheme, the annual number of treated children doubled from 535 in 2005 to 1,070 in 2015. The estimates for 5-year overall survival of 61.8% (95%CI 60.8, 62.9) remained constant over time. We observed wide gaps in risk-standardized 5-year overall survival among states ranging from 74.7% to 43.7%. We found a higher risk of mortality for children who received treatment in a non-pediatric specialty hospital (Hazards Ratio, HR = 1.18; 95%CI 1.09, 1.26), facilities without a pediatric oncology/hematology specialist (HR = 2.17; 95%CI 1.62, 2.90), and hospitals with low patient volume (HR = 1.22; 95%CI 1.13, 1.32). In a decade Mexico’s Seguro Popular doubled access to ALL treatment for covered children and by 2015 financed the vast majority of estimated ALL cases for that population. While some progress in ALL survival may have been achieved, nationwide 5-year overall survival did not improve over time and did not achieve levels found in comparable countries. Our results provide lessons for Mexico’s evolving health system and for countries moving toward universal health coverage.

The P2RY8-CRLF2 and IGH-CRLF2 rearrangements induce the overexpression of cytokine receptor-like factor 2 (CRLF2) and have been associated with relapse and poor prognosis in B-cell acute lymphoblastic leukemia (B-ALL). Additionally, they are frequently documented in high-risk Hispanic populations. To better understand the potential causes of the adverse prognosis of childhood B-ALL in Mexico, we analyzed these rearrangements and the CRLF2 mRNA and protein levels in 133 Mexican children with B-ALL. We collected bone marrow samples at diagnosis and evaluated the CRLF2 gene expression by qRT-PCR and the total CRLF2 protein by flow cytometry. P2RY8-CRLF2 and IGH-CRLF2 were detected by RT-PCR and FISH, respectively. The median time of follow-up to determine the prognostic significance of the CRLF2 abnormalities was three years. In 82% of the participants, the mRNA levels correlated with the cell-surface and intracellular CRLF2 protein levels. The P2RY8-CRLF2 rearrangement was present in 31.5% (42/133) of the patients, while the IGH-CRLF2 rearrangement was detected in 13.5% (9/67) of patients with high expression of CRLF2 (6.8% of the total sample). CRLF2 copy number variations (gain) were also detected in 7.5% (5/67) of patients with high protein levels. The overall survival (OS) presented significantly lower rates in patients with high white blood cell count (≥50x10

Background The association between childhood cancer and socioeconomic status has been widely studied. However, none of the results are conclusive. This study aimed to analyze the association between the Human Development Index (HDI) and the acute lymphoblastic leukemia (ALL) incidence in children under the Popular Medical Insurance Care. Methods We conducted an observational, descriptive, and population-based study covering 55% of the Mexican population (58 million). Results The most impoverished states were located in the south east region of Mexico, while the north was more homogeneous, with HDIs varying between 0.73 and 0.79. Our findings emphasize that the metropolitan area of Mexico City and the State of Nuevo Leon have the highest levels of HDI. Regions were graded from I to IV according to their HDIs in ascending order. The HDIs varied from 0.667 to 0.830/100,000 children/year, with a national average of 0.746. The leukemia incidence for regions I, II, III, and IV was 6.12, 6.53, 4.96, and 9.95. An analysis of ALL incidence in Mexico showed significant differences for region IV in comparison with the other regions based on the HDI values (p = 0.0001). Conclusions Further in-depth studies, including the economic aspects of the different geographic regions and their ethnographic characteristics, would give a more comprehensive panorama.

Acute leukemias represent a tremendous threat to public health around the globe and the main cause of death due to disease in scholar age children from developing nations. Here, we review their current status in Mexico, as a paradigm of study, and the major challenges to control systemic diseases like childhood cancer. A unique molecular epidemiology, late/low precision diagnosis, limited access to treatment, toxicity associated with therapy, continuous exposure to environmental risk factors, and the high frequency of early relapses are some of the factors cooperating to low rates of survival in low-to-medium-income countries. Deliberative dialogues and exhaustive programs have emerged as promising means of advancing evidence-informed policy, by providing a structured forum for key stakeholders to integrate scientific and pragmatic knowledge about complex health concerns. A system-wide strategy based on the comprehensive leukemia identity is essential for a meaningful decline in early childhood mortality.

We aimed to measure survival of children with acute lymphoblastic leukaemia (ALL) under Mexico’s public health insurance for the population without social security, and explore patient groups that may be at risk for increased mortality.We conducted a retrospective cohort study using claims data from Mexico’s Seguro Popular program, covering cancer treatment in people without social security, 2005-15. We estimated 5-year national and state-specific survival for children with ALL across Mexico who initiated cancer treatment under this public healthcare insurance scheme.8,977 children with ALL were treated under Seguro Popular in 2005-15. Under this financing scheme, treated children doubled from 535 in 2005 to 1,070 in 2015, and their 5-year survival was 61.8% (95%CI 60.8, 62.9). Estimates for 5-year survival remained constant over time. We observed wide gaps in risk-standardized 5-year survival among states ranging from 74.7% to 43.7%. We found a higher risk of mortality for children who received treatment in a non-paediatric specialty hospital (Hazards Ratio, HR=1.18; 95%CI 1.09, 1.26), facilities without a paediatric oncology/haematology specialist (HR=2.17; 95%CI 1.62, 2.90), and hospitals with low patient volume (HR=1.22; 95%CI 1.13, 1.32).In a decade Mexico’s Seguro Popular doubled access to ALL treatment for children without social security and by 2015 financed the vast majority of estimated ALL cases for that population. While some progress in ALL survival may have been achieved, nationwide 5-year survival was unsatisfactory and did not improve over time.Our results provide lessons for Mexico’s evolving health system and for countries moving towards universal health coverage.Novelty and impactThere has been no comprehensive assessment of the health outcomes of Mexico’s policy for financing high-cost cancer treatments that was part of Seguro Popular, health reform aimed at providing care to the population without social security. The study identified several factors amenable to intervention that could improve survival for childhood ALL in Mexico and reduce the observed disparities.Decision could consider administrative databases as a source of clinical outcomes to ensure the quality their systems.

It is important to study the relationship between extremely low-frequency magnetic fields (ELF-MFs) and childhood leukemia, particularly in locations with a high incidence of this neoplasm in children and an elevated exposure to ELF-MF, such as Mexico City. The aim was to investigate the association between ELF-MF exposure and the risk of B-lineage acute lymphoblastic leukemia (B-ALL). A case-control study was conducted in Mexico City during the period from 2010 to 2011. Residential 24-h ELF-MF measurements were obtained for 290 incident B-ALL patients and 407 controls, aged less than 16 years. Controls were frequency-matched by sex, age (±18 months), and health institution. The adjusted odds ratios (aOR) and 95% confidence intervals (CIs) were calculated. ELF-MF exposure at

BACKGROUND B-cell acute lymphoblastic leukemia (B-ALL) is the most commonly diagnosed childhood malignancy worldwide and is especially common in Mexico. Additionally, the number of cases has increased in recent years. Thus, it is very important to develop molecular strategies to diagnose leukemia. The aim of this study was to investigate MYB expression and to determine its impact on the diagnosis of B-ALL. METHODS We analyzed the B-ALL gene expression profile by microarray data mining. Bioinformatics analysis was performed to identify the genes that are overexpressed in leukemia. We determined that MYB was highly expressed in leukemia. Then, we validated MYB expression in 70 patients with B-ALL and in 16 healthy controls (HCs) using qRT-PCR. The results were statistically analyzed using the Kolmogorov-Smirnov Z test, Mann-Whitney U test, receiver operating characteristic curves, and the Youden index. RESULTS The microarrays showed that MYB was overexpressed in B-ALL patients with a fold change of 57.8728 and a P value of 2.56-195 . MYB expression showed great variability among the patients analyzed. However, compared to the HCs, the B-ALL patients had a P value

In Mexico, childhood cancer (0-18 years) is treated in a multidisciplinary way while providing care for more than half of the affected children through a public medical insurance. This insurance is given to all children who do not have any health care coverage in Mexico. This program is offered to the poorest of all Mexicans. All the children with this disease are submitted to pathology diagnosis and treatment according to national treatment protocols from 57 accredited medical institutions. From 2007 to 2015, a total of 24,039 children with cancer have been registered; the male gender predominates by 55%. The highest incidence was in the group aged between 0 and 4 years. Every year, there has been an increment in registration. In 2015, there were 3,433 new patients with an incidence of 150.1/million. In the same year, the incidence for all types of leukemia increased to 89.5/million. But for acute lymphoblastic leukemia, the incidence was found to be 79.8/million, which is extremely high. The mortality rate for all these patients in 2015 was 5.3/100,000. However, with regard to children aged between 15 and 18 years, the mortality rate was 8.5/100,000. Abandonment rate was 10%, and there were nine state institutions that had a mortality rate between 25% and 50% among their patients. Coincidentally, as per the Human Development Index, the parameters for education, health, and income were low for those nine institutions. The purpose of this work is to show the epidemiology and the burden we are facing due to this disease.

Background Uncomplicated urinary tract infection is considered an infection that occurs in healthy individuals who have a normal urinary tract, representing 5% of all annual medical visits. Several quinolones are available as second-line agents for treatment; however, we do not know which is the best antibiotic scheme for urinary tract infection; therefore, we conducted a network meta-analysis to hierarchize each quinolone according to its efficacy and safety. Methods MEDLINE, EMBASE and other databases were subjected to non-language-restricted searches up to 2018 for trials that included women treated with quinolones for uncomplicated urinary tract infection. Bias in the trials was assessed by two reviewers; the Cochrane Collaboration tool was used to analyze clinical and bacteriological remission, relapse, resistance, and adverse events. For direct comparisons, we obtained risk ratios and 95% confidence intervals by applying a fixed events model using Tau2 and Q2 tests to calculate the heterogeneity using trimethoprim/sulfamethoxazole as the common comparator across studies. For the network meta-analysis, we analyzed the indirect comparisons by Bucher's method. The results were summarized in a correlation matrix. Results We included 18 trials with 8765 women. For pre-menopausal women and treatment duration

Background Feeding difficulties and disorders are a common problem in the pediatric population, which involve a series of deficient behaviors about nutrition processes that can adversely affect psychomotor, psychosocial, and physical development of children. This study aimed to describe the frequency of feeding difficulties or disorders in pediatric patients with cancer. Methods A prospective study which included 125 children from 1-19 years treated at the Department of Oncology of the Instituto Nacional de Pediatria, Mexico City, was conducted. The diagnosis of eating disorders and feeding difficulties was determined during the first 48 h since admission, and the age of the patient influenced the type of disorder and feeding difficulties. Results Children older than 11 years presented more frequently an intense resistance of feeding because of discomfort pain (fear of feeding) than younger children (11.4 ± 4.7 vs. 7.4 ± 4.9, p ≤ 0.001). The most frequent alteration associated with malnutrition was loss of appetite (odds ratio [OR]: 8.8, confidence interval [CI] 95% 2.9-26.9, p

Feeding difficulties and disorders are a common problem in the pediatric population, which involve a series of deficient behaviors about nutrition processes that can adversely affect psychomotor, psychosocial, and physical development of children. This study aimed to describe the frequency of feeding difficulties or disorders in pediatric patients with cancer.A prospective study which included 125 children from 1-19 years treated at the Department of Oncology of the Instituto Nacional de Pediatría, Mexico City, was conducted. The diagnosis of eating disorders and feeding difficulties was determined during the first 48 h since admission, and the age of the patient influenced the type of disorder and feeding difficulties.Children older than 11 years presented more frequently an intense resistance of feeding because of discomfort pain (fear of feeding) than younger children (11.4 ± 4.7 vs. 7.4 ± 4.9, p ≤ 0.001). The most frequent alteration associated with malnutrition was loss of appetite (odds ratio [OR]: 8.8, confidence interval [CI] 95% 2.9-26.9, p0.001), followed by fear of feeding (OR: 3.14, CI 95% 1.24-7.9, p=0.015), and the organic causes showed the highest risk for malnutrition (OR: 3.1, CI 95% 0.98-9.7, p=0.054).Over 90% of the studied population demonstrated at least one eating disorder or feeding difficulty. The principal effect is inadequate nutritional intake due to limited appetite and fear of feeding, which can result in undernutrition. For this reason, the identification of alterations in nutrition processes should be part of the comprehensive assessment of cancer patients.Los trastornos y dificultades para la alimentación son problemas comunes en la edad pediátrica. Estas situaciones conllevan una serie de comportamientos inadecuados respecto de los procesos de nutrición que pueden afectar de manera adversa el desarrollo psicomotor, psicosocial y físico del niño. El objetivo de este trabajo fue describir la frecuencia de desórdenes y dificultades en la alimentación en niños con cáncer a través de un estudio prospectivo.Se incluyeron 125 niños de 1 a 19 años de edad del Servicio de Oncología del Instituto Nacional de Pediatría, Ciudad de México. El diagnóstico de desorden y dificultad en la alimentación se determinó en las primeras 48 horas del ingreso.Los niños mayores de 11 años presentan con mayor frecuencia resistencia a comer debido a dolor o malestar (miedo a comer) (11.4±4.7 años versus 7.4±4.9 años; p≤0.001). La alteración más frecuente asociada a malnutrición fue la disminución del apetito (razón de momios [RM]: 8.8; intervalo de confianza [IC] 95%: 2.9-26.9; p0.001), seguido del miedo a comer (RM: 3.14; IC 95%: 1.24-7.9; p=0.015) y las causas con mayor riesgo de malnutrición fueron las orgánicas (RM: 3.1; IC 95%: 0.98-9.7; p=0.054).Se encontró que en más del 90% de esta población se presentó por lo menos un desorden alimentario o dificultad al alimentarse. El principal efecto es la ingesta nutricional inadecuada debida al apetito limitado y al miedo a alimentarse, lo que puede resultar en desnutrición. Por esta razón, la identificación de alteraciones en los procesos de nutrición deben ser parte de la valoración integral de los pacientes con cáncer.

Total body irradiation (TBI) is conditioning regimen in children with acute lymphoblastic leukemia (ALL) with a very high risk of relapse or in those who have not achieved remission and have relapsed and subsequently received allogenic hematopoietic stem cell transplantation (HSCT). A retrospective evaluation of 33 ALL patients in full remission with an indication of HSCT was performed to evaluate overall survival (OS) and event-free survival (EFS). The inclusion criteria included a myeloablative conditioning regimen of TBI at a dose of 600 cGy. The observed OS at 5 years was 50%, and the EFS of 32% we observed difference in the EFS stem cell origin; the peripheral blood (PB) 60%, and the umbilical cord blood (UC) accounted for 40%. Overall, 45% had a documented chimerism. The OS at 5 years from patients with chimeras was 75%, while those without chimeras had an OS at 5 years of 25%. The mortality in the first 100 days was 24%. A total of 24.2% of children presented with acute graft versus-host disease (GVHD), while 33% had chronic GVHD. Currently, there is no general agreement among all international centers regarding the optimum TBI dose. Our study reports an acceptable range of adverse events with a relatively low dose of 600 cGy.

Background: In Mexico, AML survival is referred in 30%. Our aim was to evaluate results with ADE protocol as induction treatment in children with non-M3 AML in a public Mexican institution. Method: We included patients with AML in a single institution between 2005 and 2013. All non-M3-AML patients received ADE as induction therapy (cytarabine 100 mg/m2 in continuous infusion from day 1 to 7, daunorrubicin 30 mg/m2 days 1, 3, 5 and etoposide 100 mg/m2 over days 1 to 5). Patients received antibiotic prophylaxis and strict scheduled appointments to assure adherence and prevent avoidable emergencies. Main Results: Eighteen patients were included. Median age was 106 months. One patient died at diagnosis so 17 were eligible for induction results analysis; eleven needed two cycles and six patients three. Remission rate was 100%. Analyzing non-M3 patients overall survival was 80.2% at 100 months. No fatal complications were observed. Stratifying by number of cycles we observe that patients receiving one ADE cycle had a 0% overall survival at short follow up, with 2 ADE cycles 80% at 100 months and with 3 cycles 100% at 60 months. Conclusion: ADE induction therapy showed improved results in overall survival compared with other standard regimens. Following the protocol we obtained 100% remission. This is an important achievement in our population. Our focus must be to ameliorate maintenance final results. These results should be reproduced in other hospitals in Mexico and other countries.

The parental age at conception has been reported to be a risk factor for childhood acute leukaemia (AL); however, the relationship is controversial. The aim of the present study was to investigate the association between parental age at conception and the risk of AL in Mexican children, a population with a high incidence of the disease and a high prevalence of pregnancies in adolescents and young adults.A multicentre case-control study was conducted. Incident AL cases younger than 17 years of age diagnosed between 2010 and 2015 were included. Controls were matched with cases according to age, sex, and health institution. Using logistic regression analysis, adjusted odds ratios (aOR) and 95 % confidence intervals (95 % CI) were calculated for each maternal stratum after adjusting for paternal age at conception of index child. The maternal age between 25 and 29.99 years was selected as the reference category.In most strata where maternal and paternal ages were assessed, no association was found with the risk of developing acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML) in their offspring. An increased risk for AML was observed when the mother was between 20 and 24.99 years of age and the father aged 25-29.99 years (aOR, 1.94; 95 % CI, 1.03-3.67). In addition, there was a positive association for ALL when the mother´s age was between 20 and 24.99 years and the father was20 years of age, however, a very wide confidence interval was noted (aOR, 12.26; 95 % CI, 1.41-106.83).In the present study, maternal and paternal ages assessed in different strata showed little association with risk of developing ALL and AML in children. Positive associations between risk of both types of childhood AL were observed with younger paternal and maternal ages.

In Mexico, due to the high rates of diabetes, overweight, and obesity, there has also been noted an increased newborn weight, which may be contributing to the elevated incidence rate of childhood acute leukemia (AL). We conducted a case–control study in public hospitals of Mexico City aimed to know whether a greater weight at birth is associated with a higher risk of developing leukemia. We included incident cases with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) diagnosed between 2010 and 2015. Controls were frequency‐matched to the cases by age, sex, and health institution. Logistic regression analysis was performed adjusting risks by child's sex, overcrowding index, birth order, and mother's age at the time of pregnancy. Adjusted odds ratios (aORs) and 95% confidence intervals were calculated. A total of 1455 cases and 1455 controls were included. An evident association between ALL and child's birthweight ≥2500 g was found (aOR 2.06; 95% CI: 1.59, 2.66) and also, in those with birthweight ≥3500 g (aOR 1.19; 95% CI: 1.00, 1.41). In AML patients with birthweight ≥2500 g and ≥3500 g, an aOR of 1.77 (95% CI: 1.07, 2.94) and 1.42 (95% CI: 1.03–1.95) was observed, respectively. No association was noticed with either type of AL and a birthweight ≥4000 g. To sum up, we found a moderate association between not having a low birthweight and an increased risk of acute leukemias. Birthweight ≥3500 g was also a risk factor for both types of leukemia. This suggests that a greater birthweight may increase the risk of acute leukemias in Mexican children.

B-cell acute lymphoblastic leukemia is the most commonly diagnosed childhood malignancy worldwide, more than 50% of these cases are diagnosed in Mexico. Although the five-year survival rate is &gt, 80%, 30% of patients experience relapse with poor prognosis. Cancer-associated gene expression profiles have been identified in several malignancies, and some transcripts have been used to predict disease prognosis. The human transcriptome is incompletely elucidated, moreover, more than 80% of transcripts can be processed via alternative splicing (AS), which increases transcript and protein diversity. The human transcriptome is divided, coding RNA accounts for 2%, and the remaining 98% is noncoding RNA. Noncoding RNA can undergo AS, promoting the diversity of noncoding transcripts. We designed specific primers to amplify previously reported alternative transcript variants of ZNF695 and showed that six ZNF695 transcript variants are co-expressed in cancer cell lines. The amplicons were sequenced and identified. Additionally, we analyzed the expression of these six transcript variants in bone marrow from B-cell acute lymphoblastic leukemia patients and observed that ZNF695 transcript variants one and three were the predominant variants expressed in leukemia. Moreover, our results showed the co-expression of coding and long noncoding RNA. Finally, we observed that long noncoding RNA ZNF695 expression predicted survival rates.

Introduction: Acute lymphoblastic leukemia (ALL) is the most common subtype of leukemia diagnosed in children under 18 years. According to the statistics of the Popular Medical Insurance Program in Mexico, the ALL incidence is 79.8 cases per million per year, and it is significantly increasing. Recently, several SNPs of ARID5B gene have been associated with ALL susceptibility and are more strongly related with ALL risk in Hispanics. However, these observations are not necessarily representative of the situation in Mexico, since the proportion of Mexican patients included in these studies is unknown. It is essential for us to know if the genetic variants of ARID5B confer susceptibility to the development of the disease in our population and if these variants contribute to the higher incidence of childhood ALL in Mexico. Aim: The purpose of this study was to determine the association between the SNPs rs10821936, rs10994982, rs7089424, rs2393732, rs2393782, rs2893881, and rs4948488 of ARID5B gene with the susceptibility to develop ALL in Mexican children. Methods: The study included 384 controls and 298 children with ALL recruited at Instituto Nacional de Pediatria in Mexico city and Hospital de Especialidades Pediatricas de Tuxtla Gutierrez, Chiapas, Mexico. This study was reviewed and approved by the Institutional Research and Ethics Committees from both participant Institutions in accordance to the ethical principles of the Declaration of Helsinki. Volunteers, parents, or legal tutors of patients were previously informed about the study, and before the biological samples were collected, they provided a signed, written informed consent letter to participate. Genomic DNA was extracted from peripheral blood and saliva samples. Genotyping analysis was performed by real-time polymerase chain reaction (RT-PCR) using a pre-designed TaqMan assay for 7 SNPs (rs10821936, rs10994982, rs7089424, rs2393732, rs2393782, rs2893881, and rs4948488) of ARID5B. Genotypic and allelic frequencies were calculated to compare the differences between controls and patients (Fisher's exact test). The odds ratio (OR) was calculated to determine the association between SNPs and ALL susceptibility. Ancestry analysis was conducted for controls and patients (STRUCTURE program), and Haplotype analysis (Haploview program). Results: The estimated proportion of Native American and European ancestry was not statistically different between controls and patients; all SNPs in ARID5B were in Hardy-Weinberg equilibrium. The frequency of the risk alleles was higher in patients than in controls, but only 3 SNPs showed statistically significant differences (p Conslusions: The frequency of the risk alleles was higher than in Hispanic children with ALL. Each SNP of ARID5B confers an individual effect on the risk for developing the disease, and the CAG haplotype was strongly associated with ALL susceptibility. The genetic background of our population could be positively influencing the susceptibility to ALL development, specifically pre-B ALL. The SNPs rs10821936, rs10994982, rs7089424 and rs2393732 of ARID5B gene are significantly associated with an increased risk to develop childhood ALL and this could also explain in part the high incidence of childhood ALL in Mexico. Acknowledgments: This work was supported by the grants from Fondos del Presupuesto Federal para la Investigación (project 085/2012), Consejo Nacional de Ciencia y Tecnologia (CONACyT) - Desarrollo Cientifico para Atender Problemas Nacionales (project 216163), and in part by the Intramural Program of the National Cancer Institute. Conflict-of-interest disclosure: The authors state that there are no conflicts of interest. Disclosures No relevant conflicts of interest to declare.

Background: Philadelphia-like (Ph-like) subtype occurs in 15-20% of children patients diagnosed with precursor B cell (PCB) acute lymphoblastic leukemia (ALL). It is characterized by alterations in kinases and their receptors, affecting signaling pathways such as Jak2-Stat5, class Abl and Ras. It is particularly frequent (35%) in Hispano-Latino high risk PCB-ALL patients, residing in the USA. In Mexico, based on our ethnicity and the poor response to treatment of PCB-ALL pediatric patients, the Ph-like subtype could be frequent. However, this entity is widely variable and the diagnosis is based on genomic methods. In our country the incidence of leukemia is high, 78.1/1,000,000, and 83% of these cases are ALL. Therefore, it is important to detect Ph-like patients using diagnostic methods accessible to Institutions that treat patients with leukemia in our country. Aims: To develop an algorithm adapted to our local capacity for the diagnosis of Ph-like ALL children in Mexico. To determine the frequency of Ph-like patients in two Pediatric Institutions in our country Hypothesis: Ph-like ALL frequency in Mexican children will be higher than that reported in Hispano-Latino PCB-ALL patients. Methods, study design and laboratory studies: Bone marrow samples from 119 PCB-ALL patients (18≤ years old) at diagnosis were studied. Samples were collected at the Instituto Nacional de Pediatría and the Hospital Infantil de México Federico Gómez in Mexico City. Patients with recurrent gene fusions, ETV6-RUNX1, TCF3-PBX1,KMT2A-var and BCR-ABL1, were excluded. The Ph-like status of each patient was determined using molecular and biochemical methods. We analyzed a gene expression signature conformed by the genes: CRLF2, TSPN7, IGJ, PON2, SEMA6A and BMPR1B (q-RT-PCR), and detected the P2RY8-CRLF2 deletion (RT-PCR) in all patients. In those patients with overexpression of CRLF2, but negative to P2RY8-CRLF2, the IGH-CRLF2 rearrangement (FISH) was examined. The positive cases to P2RY8-CRLF2, without overexpression of CRLF2, were analyzed looking for minor subclones (FISH) with the deletion. IKZF1 deletions (nested RT-PCR) were analyzed in all patients. The biochemical studies included CRLF2 protein expression, phosphoflow analysis of Jak2-Stat5, class Abl and Ras targets (flow cytometry). All these assays were performed whenever the cell sample allowed it. Patients with two or more of the following characteristics were considered as Ph-like cases: with overexpression of 50% or more of the expression signature, positive to P2RY8-CRLF2 or IGH-CRLF2, alteration of one or more signaling pathways, with IKZF1 deletions. Results: In 50% (n=74) of patients CRLF2 overexpression was detected, within them 15% were positive to P2RY8-CRLF2 deletion, 17% to IGH-CRLF2 rearrangement, and 18% had an unidentified CRLF2 alteration that cause the overexpression. Within the 50% of cases without CRLF2 overexpression, 18% were positive to the P2RY8-CRLF2 rearrangement. IKZF1 deletion was evaluated in 55 patients and 72% were positive. Results obtained revealed a high frequency of CRLF2 and IKZF1. In 68 patients the gene expression profile was evaluated, 60% presented overexpression of 50% or more genes. The biochemical analysis revealed that 67% (n=42) of patients were positive to CRLF2 protein, 29% (n=21) had abnormal Jak2/Stat5 activation, 34% (n=32) presented abnormal Abl activation, and in 43% (n=7) abnormal Ras activation was detected. Not all the CRLF2 protein positive patients presented Jak2-Stat5 pathway activation (2%). Patients with more than one abnormal pathway were detected (18% with Jak2-Stat5/Abl or Abl/Ras, n=21). Based on our algorithm of analysis, 53% of the analyzed patients present genetic and biochemical characteristics of the Ph-like subtype. Conclusions: The combined methods contributed to identify Ph-like patients, the results demonstrate that the frequency of PCB-ALL children with Ph-like characteristics in Mexican patients is higher compared to other populations. This study demonstrates high frequency of CRLF2 alterations and IKZF1 deletions in PCB-ALL in Mexican population. In our experience, analysis of the pathway activation assays and the identification of CRLF2 and IKZF1 alterations are required to detect Ph-like patients. These results could be useful to stratify the childhood PCB-ALL patients in our country. Acknowledgments: CONACYT: PDCPN-2004/248591; Cátedra 2038. Disclosures No relevant conflicts of interest to declare.

Background: Allergies have been described as protective factors against the development of childhood acute leukaemia (AL). Our objective was to investigate the associations between allergy history and the development of AL and acute lymphoblastic leukaemia (ALL) in children with Down syndrome (DS). Methods: A case–control study was performed in Mexico City. The cases (n=97) were diagnosed at nine public hospitals, and the controls (n=222) were recruited at institutions for children with DS. Odds ratios (OR) were calculated. Results: Asthma was positively associated with AL development (OR=4.18; 95% confidence interval (CI): 1.47–11.87), whereas skin allergies were negatively associated (OR=0.42; 95% CI: 0.20–0.91). Conclusion: Our findings suggest that allergies and AL in children with DS share biological and immune mechanisms. To our knowledge, this is the first study reporting associations between allergies and AL in children with DS.

"Polimorfismo de interleukin-1 receptor antagonista (ILRN) 2 (ILRN * 2) se ha asociado con un pobre pronostico en pacientes septicos debido a una elevada produccion de citoquinas antiinflamatorias. En > 70% de los pacientes, morbilidad y mortalidad en leucemia linfoblastica aguda infantil es causado por infecciones. El objetivo de este estudio fue determinar la asociacion entre este polimorfismo y la frecuencia de choque septico desde el momento del diagnostico hasta la finalizacion del tratamiento. METODOS: Este estudio de cohorte se realizo en 57 ninos consecutivos con leucemia linfoblastica aguda. Al final del seguimiento, los ninos fueron estratificados segun su polimorfismo IL1RN (ILRN * 1/ILRN * 2), evaluando el impacto del genotipo en la severidad de eventos neutropenicos febriles durante el tratamiento. RESULTADOS: En general la supervivencia era del 80% a los 55 meses despues del tratamiento. El numero promedio de eventos neutropenicos febriles en esta cohorte fue de 2.82 por paciente. Distribucion de genotipos fue 50,9% homocigoto IL-1RN * 1, 38.6% heterocigoto ILRN * 1/ILRN * 2 y 10,5% para el homozygote IL-1RN * 2. El riesgo de presentar shock septico para homozigoto IL1RN * 2/IL1RN * 2 y heterocigoto ILRN * 1/ILRN * 2 pacientes fue significativamente mayor (odds-ratio, 45; P = 0,001) ajustado por edad, genero, riesgo de la leucemia y la presencia de bacterias patogenas. Genotipo IL-1RN * 2 se asocia con el riesgo de desarrollo de shock septico en ninos con leucemia linfoblastica aguda. Se necesitan investigaciones adicionales en estudios poblacionales mas grandes para replicar estos resultados. CONCLUSIONES: Esta informacion nos permitiria identificar los factores predictivos mas en este grupo de pacientes de leucemia linfoblastica aguda en quien carece de esta informacion para establecer un enfoque mas agresivo."

The role of malnutrition at diagnosis as a predictor of early mortality in Mexican leukemia children remains controversial. The objective of present study was to investigate whether malnutrition was a predictor of early mortality during the first year of treatment in Mexican acute lymphoblastic leukemia (ALL) children through the first population-based study. A total of 794 newly diagnosed ALL pediatric patients from public hospitals of Mexico City were enrolled. A multivariate Cox proportional hazards regression model was constructed and adjusted by patient’s age at diagnosis, gender, hospital of treatment, and socioeconomic status. Early mortality was high (12.1%) and malnutrition by different indicators was not associated with mortality at induction phase and at 6th month; a high risk of dying (RR = 2.08; 95% CI: 1.08–4.01) was observed in the group of malnourished children with a high-risk ALL.

In Mexico, childhood cancer incidence and mortality have increased in the last decade. Through government actions since 2005, the Popular Medical Insurance (PMI) program for childhood cancer was created. The objective of PMI was to offer early cancer diagnosis, standardized treatment regimens, and numerous pediatric oncology residency programs. It has also accredited 55 national hospitals for the care of these children. Current problems still present under the PMI include shortage of pediatric oncologists and nurses and high rate of abandonment of treatment. Our aim is to describe the current scenario of childhood cancer care in Mexico, especially from the perspective of the PMI and how it has impacted human resources, infrastructure, and medical education.

Worldwide, acute leukaemia (AL) is the commonest type of childhood malignancy with an annual incidence of 30–50 cases per million children (Curado et al, 2007); Mexico City has one of the highest rates, at 58.4 cases per million (Mejia-Arangure et al, 2005a). Among the identified risk factors, individuals with Down syndrome (DS) below 20 years of age have 10- to 20-fold greater risk of developing AL compared with the general population (Robison, 1992; Ross et al, 2005). According to the Greaves' hypotheses, late contact with infectious agents may lead to an abnormal or aberrant immune response that favors the development of acute lymphoblastic leukaemia (ALL) (Greaves, 2005). Correspondingly, early infections have a protective effect in ALL by promoting the physiological maturation of the immune system, whereas late infections promote an excessive proliferation of the lymphocytes (McNally and Eden, 2004; Menegaux et al, 2004; Greaves, 2006; O'Connor and Boneva, 2007). Children with DS, due to their increased susceptibility to AL, provide a natural and valuable model for evaluating the interaction between the susceptibility for AL and the environment. In this study, we assessed whether breastfeeding and early infection were associated with the risk of developing AL in children with DS. Mother's milk is an important modulator of the immune response in infants because, while by providing the child with antibodies and immune cells, it can also be a source of transmission of infectious agents (MacArthur et al, 2008).