To describe the ontogeny of the immune system and the adaptive mechanisms of the immune system in the neonatal period, with an emphasis on transplacental antibody transport and breastfeeding. Non-systematic literature review in the PubMed database. The last two decades have witnessed a great advance in the knowledge of the immune system since conception. Several investigation tools have provided insight on phenomena that were previously inadequately understood. Still expanding, the functional and molecular investigation of various aspects of the immune system will make it possible to understand how intra-uterus maternal-fetal exchanges, the maternal microbiota interacting with the fetus and newborn, and the acquisition of immunological competence occur in healthy and disease scenarios. In-depth knowledge of the development of the immune system and of the adaptive mechanisms that allow a safer transition to the extrauterine environment are fundamental components of optimizing maternal and young infant vaccination, as well as the strategies associated with full postnatal development, and the early diagnosis and treatment of innate errors of immunity.

Introduction: Human milk cannot currently be considered a major source of COVID-19 infection. On the other hand, it can contain specific antibodies that could modulate a possible newborn infection by SARS-CoV-2. Main issue: A 32-year-old pregnant woman, gestational age 37 and 3/7 weeks, was admitted with a flu-like syndrome caused by COVID-19. The female newborn was appropriate for gestational age, with a birth weight of 2,890 g, length 48 cm, and head circumference 34 cm. Management: The mother–infant dyad remained in the rooming-in unit during hospitalization, exclusively breastfeeding and following World Health Organization recommendations for contact and airway precautions. On the 3rd day after delivery, two mother’s milk samples (3 and 5 mL) were collected by hand expression. The samples were centrifuged for 10 min twice consecutively to separate fat, which was removed, and the remaining material was transferred to another tube to determine anti-SARS-CoV-2 Immunoglobulin A and Immunoglobulin G (ELISA, Kit EUROIMMUN AG, Luebeck, Germany). Anti-SARS-CoV-2 Immunoglobulin A was detected in the two samples evaluated, whose values were 2.5 and 1.9, respectively. No anti-SARSCoV-2 immunoglobulin G was detected. The exclusively-breastfed infant remained well through 45 days of age. Conclusion: The presence of SARS-CoV-2 Immunoglobulin A in the milk of mothers infected with COVID-19 may be related to protection against the transmission and severity of the disease in their infants.

To describe the participation of the environment in the childhood obesity epidemic, since childhood obesity currently represents a great challenge, with high prevalence worldwide, including in Brazil. Survey of articles published in the last 10 years in PubMed, evaluating the interface between the environment and childhood obesity. Recent studies show that the environment is very important in the etiopathogenesis of obesity and its comorbidities. Therefore, factors such as air pollution, exposure to chemical substances that interfere with the metabolism, excessive consumption of ultra-processed foods, changes in the intestinal microbiota, and sedentary lifestyle are associated with increased obesity, insulin resistance, type 2 diabetes, and changes in lipid metabolism. These factors have a greater impact on some stages of life, such as the first thousand days, as they affect the expression of genes that control the adipogenesis, energy expenditure, and the mechanisms for hunger/satiety control. Environmental aspects must be taken into account in the prevention and treatment of childhood obesity, both from the individual and the population point of view, with adequate and comprehensive public health policies.

Introduction and objectives Cow's milk allergy (CMA) is common, especially in children. The treatment is based on the exclusion of milk and dairy products and guidance regarding the exclusion diet. This study aimed to compare the anthropometric measurements and food intake of children with CMA with those of healthy controls, and to evaluate the serum concentrations of Vitamin A and 25(OH)D in children with CMA. Methods: This is a cross-sectional study with 27 children in the CMA group and 30 in the control group. z-Scores of body mass index and height, skinfolds, food intake and serum concentrations of retinol, beta-carotene, lycopene, 25(OH)D, parathyroid hormone and high sensitivity C-reactive protein were evaluated. Results: Mean age was four years (±1.9). The CMA group evidenced a lower height compared to those from the control group (p = 0.0043). The CMA group showed a lower intake of calcium (p = 0.0033) and lipids (p = 0.0123). Low serum concentrations of retinol, beta-carotene, lycopene, 25(OH)D were found in 25.9%, 59.3%, 48.1% and 70.3% of the CMA group, respectively. Conclusions: Children with CMA consume smaller amounts of calcium and lipids and have shorter height compared to healthy controls. Insufficient levels of vitamins A and D were frequent in the CMA group, emphasizing the need for nutritional guidance and monitoring.

Vitamin D deficiency is a global public health issue. More than half of pregnant women are affected by vitamin D insufficiency/deficiency. Studies suggest an association between low vitamin D concentrations during pregnancy with intrauterine growth restriction and prematurity. This study aimed to describe the concentrations of 25(OH)D (25-hydroxyvitamin D) of mothers who delivered preterm newborns compared to women with full-term pregnancy deliveries, as well as to relate 25(OH)D blood concentrations of mothers with those of their newborns. This cross-sectional study was conducted with 66 mothers who had given birth to preterm babies and their preterm newborns (PTNB, < 32 weeks), and 92 women who had given birth at the full-term of their pregnancy and their newborns (FTNB). Data were collected on the characteristics of mothers (gestational age, diseases, and habits) and newborns (anthropometry and adequacy for gestational age). Ten milliliters of blood were drawn from the mothers and the umbilical cord of newborns at birth to identify the 25(OH)D, parathyroid hormone, calcium, phosphorus, and alkaline phosphatase concentrations. Mothers in the PTNB group had significantly lower mean 25(OH)D blood levels (21.7 ± 10.8 ng/mL vs. 26.2 ± 9.8 ng/mL; p = 0.011) and were three times more likely to have insufficiency when compared to mothers in the FTNB group (OR = 2.993; 95%CI 1.02–8.74). Newborns in the PTNB group also had lower 25(OH)D concentrations compared to FTNB group (25.9 ± 13.9 ng/dL vs. 31.9 ± 12.3 ng/dL; p = 0.009). There was a directly proportional correlation between mother and newborn umbilical cord 25(OH)D concentrations in PTNB (r = 0.596; p < 0.001) and FTNB (r = 0.765; p < 0.001). Mothers who delivered preterm babies and their preterm newborns had lower 25(OH)D concentrations compared to women who had given birth at the full-term of their pregnancy. In both groups, 25(OH)D concentrations of the mothers correlated directly with those of the newborns, and this correlation was higher in the full-term birth group. Nevertheless, the recommended universal vitamin D supplementation in pregnant women to curb the risk of preterm birth is still incipient. More studies are required to clarify the particularities of vitamin D metabolism further and define the adequate 25(OH)D concentrations throughout pregnancy.

Ataxia telangiectasia (A-T) is a neurodegenerative disease that leads to mitochondrial dysfunction and oxidative stress. Insulin resistance (IR), type 2 diabetes and the risk for development of cardiovascular disease was recently associated as an extended phenotype of the disease. We aimed to assess IR; liver involvement; carotid intima-media thickness (cIMT) and metabolic alterations associated to cardiovascular risk in A-T patients, and relate them with age. Glucose metabolism alterations were found in 54.6% of the patients. Hepatic steatosis was diagnosed in 11/17 (64.7%) A-T patients. AST/ALT ratio > 1 was observed in 10/17 (58.8%). A strong positive correlation was observed between insulin sum concentrations with ALT (r = 0.782, p < 0.004) and age (r = 0.818, p = 0.002). Dyslipidemia was observed in 55.5% of the patients. The apolipoprotein (Apo-B)/ApoA-I ratio (r = 0.619; p < 0.01), LDL/HDL-c (r = 0.490; p < 0.05) and the Apo-B levels (r = 0.545; p < 0.05) were positively correlated to cIMT. Metabolic disorders implicated in cardiovascular and liver diseases are frequently observed in adolescent A-T patients and those tend to get worse as they become older. Therefore, nutritional intervention and the use of drugs may be necessary.