Maternal dietary patterns and acute leukemia in infants: results from a case control study in Mexico.

Background: Childhood cancer is the leading cause of disease-related mortality among children aged 5-14 years in Mexico, with acute leukemia being the most common cancer among infants. Examining the overall dietary patterns allows for a comprehensive assessment of food and nutrient consumption, providing a more predictive measure of disease risk than individual foods or nutrients. This study aims to evaluate the association between maternal dietary patterns during pregnancy and the risk of acute leukemia in Mexican infants. Methods: A hospital-based case-control study was conducted, comparing 109 confirmed acute leukemia cases with 152 age-matched controls. All participants (≤24 months) were identified at hospitals in Mexico City between 2010 and 2019. Data on a posteriori dietary patterns and other relevant variables were collected through structured interviews and dietary questionnaires. Multivariate logistic regression was employed to estimate the association between maternal dietary patterns during pregnancy and the risk of acute leukemia in infants. Results: The "Balanced & Vegetable-Rich" pattern, characterized by a balanced consumption of various food groups and higher vegetable intake, exhibited a negative association with acute leukemia when compared to the "High Dairy & Cereals" Pattern (adjusted odds ratio [OR] = 0.51; 95% confidence interval [CI]: 0.29, 0.90). We observed that mothers who gave birth to girls and adhered to a healthy dietary pattern during pregnancy exhibited significantly lower odds of their children developing AL compared to those who gave birth to boys [OR = 0.32 (95% CI 0.11, 0.97)]. Our results underscore the significance of maternal nutrition as a modifiable factor in disease prevention and the importance of prenatal health education.

Extremely Low-Frequency Magnetic Fields and the Risk of Childhood B-Lineage Acute Lymphoblastic Leukemia in a City With High Incidence of Leukemia and Elevated Exposure to ELF Magnetic Fields.

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.

Low expression of Toll-like receptors in peripheral blood mononuclear cells of pediatric patients with acute lymphoblastic leukemia.

Cancer is the second most common cause of death among children aged 1-14 years. Leukemia accounts for one-third of all childhood cancers, 78% of which is acute lymphoblastic leukemia (ALL). The development of cancer has been associated with malignant cells that express low levels of immunogenic molecules, which facilitates their escape from the antineoplastic immune response. It is thought that it may be possible to rescue the antineoplastic immune response through the activation of recognition receptors, such as Toll-like receptors (TLRs), which activate the innate immune system. TLRs are type I membrane glycoproteins expressed mainly in immune system cells such as monocytes, neutrophils, macrophages, dendritic cells, T, B and natural killer cells. The aim of the present study was to evaluate the expression of TLR1, TLR3, TLR4, TLR7 and TLR9 in peripheral blood mononuclear cells (PBMCs) in patients with ALL and prior to any treatment. PBMCs were obtained from 50 pediatric patients diagnosed with ALL and from 20 children attending the ophthalmology and orthopedics services. The mean fluorescence intensity was obtained by analysis of immunofluorescence. We found lower expression levels of TLR1, TLR3, TLR4, TLR7 and TLR9 in PBMCs from patients with ALL compared with those from control patients. We also observed that the PBMCs from patients with Pre-B and B ALL had lower TLR4 expression than controls and patients with Pro-B, Pre-B, B and T ALL had lower TLR7 expression than controls. The present study is the first to demonstrate reduced expression of TLRs in PBMCs from pediatric patients with ALL. This finding is of great relevance and may partly explain the reduction in the antineoplastic immune response in patients with ALL.