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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 <0.2 µT was used to define the reference group. ELF-MF exposure at ≥0.3 µT was observed in 11.3% of the controls. Different ELF-MF intensity cutoff values were used to define the highest exposure category; the highest exposure category for each cutoff value was associated with an increased risk of B-ALL compared with the corresponding lower exposure categories. The aORs were as follows: ≥0.2 µT = 1.26 (95% CI: 0.84-1.89); ≥0.3 µT = 1.53 (95% CI: 0.95-2.48); ≥0.4 µT = 1.87 (95% CI: 1.04-3.35); ≥0.5 µT = 1.80 (95% CI 0.95-3.44); ≥0.6 µT = 2.32 (95% CI: 1.10-4.93). ELF-MF exposure as a continuous variable (per 0.2 µT intervals) was associated with B-ALL risk (aOR = 1.06; 95% CI: 1.01-1.12). In the present study, the proportion of children exposed to ≥0.3 µT is among the highest reported worldwide. Additionally, an ELF-MF exposure ≥0.4 µT may be associated with the risk of B-ALL. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.
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Exposición a Riesgos Ambientales/efectos adversos , Campos Magnéticos/efectos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Adolescente , Estudios de Casos y Controles , Niño , Preescolar , Ciudades/epidemiología , Femenino , Humanos , Incidencia , MasculinoRESUMEN
Background: A heterogeneous geographic distribution of childhood acute lymphoblastic leukemia (ALL) cases has been described, possibly, related to the presence of different environmental factors. The aim of the present study was to explore the geographical distribution of childhood ALL cases in Greater Mexico City (GMC). Methods: A population-based case-control study was conducted. Children <18 years old, newly diagnosed with ALL and residents of GMC were included. Controls were patients without leukemia recruited from second-level public hospitals, frequency-matched by sex, age, and health institution with the cases. The residence address where the patients lived during the last year before diagnosis (cases) or the interview (controls) was used for geolocation. Kulldorff's spatial scan statistic was used to detect spatial clusters (SCs). Relative risks (RR), associated p-value and number of cases included for each cluster were obtained. Results: A total of 1054 cases with ALL were analyzed. Of these, 408 (38.7%) were distributed across eight SCs detected. A relative risk of 1.61 (p<0.0001) was observed for the main cluster. Similar results were noted for the remaining seven ones. Additionally, a proximity between SCs, electrical installations and petrochemical facilities was observed. Conclusions: The identification of SCs in certain regions of GMC suggest the possible role of environmental factors in the etiology of childhood ALL.
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BACKGROUND: Acute lymphoblastic leukemia (ALL) is characterized by an abnormal proliferation of immature lymphocytes, in whose development involves both environmental and genetic factors. It is well known that single nucleotide polymorphisms (SNPs) in coding and noncoding genes contribute to the susceptibility to ALL. This study aims to determine whether SNPs in miR-146a, miR-196a-2, miR-499a, and miR-612 genes are associated with the risk to ALL in pediatric Mexican population. METHODS: A multicenter case-control study was carried out including patients with de novo diagnosis of ALL and healthy subjects as control group. The DNA samples were obtained from saliva and peripheral blood, and the genotyping of rs2910164, rs12803915, rs11614913, and rs3746444 was performed using the 5'exonuclease technique. Gene-gene interaction was evaluated by the multifactor dimensionality reduction (MDR) software. RESULTS: miR-499a rs3746444 showed significant differences among cases and controls. The rs3746444G allele was found as a risk factor to ALL (OR, 1.6 [95% CI, 1.05-2.5]; p = 0.028). The homozygous GG genotype of rs3746444 confers higher risk to ALL than the AA genotype (OR, 5.3 [95% CI, 1.23-23.4]; p = 0.01). Moreover, GG genotype highly increases the risk to ALL in male group (OR, 17.6 [95% CI, 1.04-298.9]; p = 0.00393). In addition, an association in a gender-dependent manner among SNPs located in miR-146a and miR-196a-2 genes and ALL susceptibility was found. CONCLUSION: Our findings suggest that SNP located in miR-499a, miR-146a, and miR-196a-2 genes confer risk to ALL in Mexican children. Experimental analysis to decipher the role of these SNPs in human hematopoiesis could improve our understanding of the molecular mechanism underlying the development of ALL.
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BACKGROUND: 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. METHODS: 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. RESULTS: 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 was <20 years of age, however, a very wide confidence interval was noted (aOR, 12.26; 95 % CI, 1.41-106.83). CONCLUSION: 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.
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Fertilización , Leucemia Mieloide Aguda/epidemiología , Edad Materna , Edad Paterna , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Adolescente , Adulto , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , México/epidemiología , Oportunidad Relativa , Embarazo , Factores de Riesgo , Adulto JovenRESUMEN
Background: Acute lymphoblastic leukemia (ALL) is the main type of cancer in children. In Mexico and other Hispanic populations, the incidence of this neoplasm is one of the highest reported worldwide. Functional polymorphisms of various enzymes involved in the metabolism of xenobiotics have been associated with an increased risk of developing ALL, and the risk is different by ethnicity. The aims of the present study were to identify whether NQO1, CYP2E1, and NAT2 polymorphisms or some genotype-environmental interactions were associated with ALL risk in Mexican children. Methods: We conducted a case-control study including 478 pediatric patients diagnosed with ALL and 284 controls (children without leukemia). Ancestry composition of a subset of cases and controls was assessed using 32 ancestry informative markers. Genetic-environmental interactions for the exposure to hydrocarbons were assessed by logistic regression analysis. Results: The polymorphisms rs1801280 (OR 1.54, 95% CI 1.21-1.93), rs1799929 (OR 1.96, 95% CI 1.55-2.49), and rs1208 (OR 1.44, 95% CI 1.14-1.81) were found to increase the risk of ALL; being the risks higher under a recessive model (OR 2.20, 95% CI 1.30-1.71, OR 3.87, 95% CI 2.20-6.80, and OR 2.26, 95% CI 1.32-3.87, respectively). Gene-environment interaction analysis showed that NAT2 rs1799929 TT genotype confers high risk to ALL under exposure to fertilizers, insecticides, hydrocarbon derivatives, and parental tobacco smoking. No associations among NQO1, CYP2E1, and ALL were observed. Conclusion: Our study provides evidence for the association between NAT2 polymorphisms/gene-environment interactions, and the risk of childhood ALL in Mexican children.
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Background: Annular pancreas is a congenital abnormality which causes duodenal obstruction in neonates. It befalls upon 1 patient amongst every 12 000-15 000 newborns. It often appears in adulthood. Clinical traits include abdominal pain, intestinal obstruction, vomiting, and pancreatitis. The diagnosis requires image studies and surgical exploration. Clinical case: Female patient, 11 years of age, presenting intermittent chronic abdominal pain, underweight for her age. Treated by a private physician with ranitidine (4 mg/kg/day) and ibuprofen (5 mg/kg/dose) orally, for one month, due to acid-peptic disease. On December 31, 2017, she was attended at Pediatric Emergency presenting epigastric pain, and nausea. She vomited bile contents 4 times over a 24 hour span. Other symptoms included painful reaction to epigastric palpation, positive pancreatic points, negative Murphy's sign, no hepatomegaly or splenomegaly, decreased peristaltic noises. Reported: amylase 2163 U/L, lipase 821 U/L, lactic dehydrogenase 461 U/L. Pancreatic ultrasound: 19.3 mm head, 23.2 mm body and 10 mm tail. She was admitted to pediatrics, where the annular pancreas condition was confirmed through ultrasound and computed tomography scan. She then underwent conservative treatment. Conclusion: The patient displayed typical annular pancreas symptoms. Image studies were key to the diagnosis.
Introducción: el páncreas anular es una anomalía congénita que causa obstrucción duodenal en el neonato. Se reporta en 1 por cada 12 000-15 000 recién nacidos, a menudo se revela en la edad adulta. Clínicamente incluye obstrucción intestinal, dolor abdominal, vómitos y puntos pancreáticos positivos. El diagnóstico requiere estudios de imagenología y exploración quirúrgica. Caso clínico: paciente del sexo femenino, de 11 años de edad, con dolor abdominal crónico intermitente, de bajo peso para su edad. Tratada por médico privado con ranitidina (4 mg/kg/día) e ibuprofeno (5 mg/kg/dosis) vía oral, durante un mes, por enfermedad acido-péptica. El 31 de diciembre del 2017 fue atendida en urgencias pediátricas, por dolor en epigastrio, náuseas y vómitos de contenido gastrobiliar en número de 4 en 24 horas. Abdomen doloroso a la palpación en epigastrio, puntos pancreáticos positivos, Murphy negativo, sin hepatomegalia ni esplenomegalia, ruidos peristálticos disminuidos. Se reportó: amilasa 2163 U/L, lipasa 821 U/L, deshidrogenasa láctica 461 U/L. Ultrasonido de páncreas: cabeza de 19.3 mm, cuerpo de 23.2 mm y cola de 10 mm. Fue internada en pediatría, confirmándose páncreas anular por ultrasonido y tomografía; recibió tratamiento conservador. Conclusión: la paciente presentó síntomas típicos del páncreas anular, su estudio mediante imágenes fue decisivo para establecer el diagnóstico.
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Dolor Abdominal/etiología , Páncreas/anomalías , Enfermedades Pancreáticas/complicaciones , Enfermedades Pancreáticas/diagnóstico por imagen , Niño , Femenino , Humanos , Páncreas/diagnóstico por imagen , Radiografía Abdominal , Estómago/diagnóstico por imagen , Tomografía Computarizada por Rayos X , UltrasonografíaRESUMEN
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.