Maternal vaccination as an additional approach to improve the protection of the nursling: Anti-infective properties of breast milk

Abstract Human milk constitutes a secretion with unique functions of both nourishing the nursling and providing protection against enteric and respiratory infections, mainly due to its content of secretory IgA antibodies but also due to the presence of a plethora of bioactive factors. Specific IgA antibodies are produced locally by plasma cells derived from B lymphocytes that migrate from other mucosae to the mammary gland during lactation, particularly from the gastrointestinal and respiratory tracts. Therefore, here, the authors will provide a comprehensive review of the content and functions of different nutritional and bioactive anti-infectious components from breast milk, such as oligosaccharides, lactoferrin, haptocorrin, α-lactalbumin, k-casein, lysozyme, lactoperoxidase, mucin, fatty acids, defensins, cytokines and chemokines, hormones and growth factors, complement proteins, leukocytes and nucleic acids, including microRNAs, among many others, and the induction of antibody responses in breast milk after maternal vaccination with several licensed vaccines, including the anti-SARS-CoV-2 vaccine preparations used worldwide. Currently, in the midst of the pandemic, maternal vaccination has re-emerged as a crucial source of passive immunity to the neonate through the placenta and breastfeeding, considering that maternal vaccination can induce specific antibodies if performed during pregnancy and after delivery. There have been some reports in the literature about milk IgA antibodies induced by bacterial antigens or inactivated virus vaccines, such as anti-diphtheria-tetanus-pertussis, anti-influenza viruses, anti-pneumococcal and meningococcal polysaccharide preparations. Regarding anti-SARS-CoV-2 vaccines, most studies demonstrate elevated levels of specific IgA and IgG antibodies in milk with virus-neutralizing ability after maternal vaccination, which represents an additional approach to improve the protection of the nursling during the entire breastfeeding period.

Monocyte-to-HDL ratio and non-HDL cholesterol were predictors of septic shock in newborns

Abstract Background The association between lipoprotein levels and late-onset neonatal sepsis has shown controversial results. The aims are to assess lipid profile, cytokines, and Monocyte-to-HDL (M/H) ratio as diagnostic and prognostic markers for late-onset neonatal sepsis. Methods This prospective study included 49 septic neonates and 17 controls. Cholesterol (CT), Triglyceride (TG), Very-Low-Density (VLDLc), Low-Density (LDLc), and High-Density Lipoproteins (HDLc) were measured at admission (D0) and on days 3, 7 and 10 to evaluate septic shock outcomes. Cytokines and monocytes were evaluated by flow cytometry. Results Septic newborns showed higher IL-6 and IL-8 at D0 and CT levels on D7 and on D10, which also presented higher TG, VLDLc and non-HDL cholesterol concentrations than controls. The septic shock group (n = 22) revealed a higher number of male subjects, CRP, IL-6, IL-8 and IL-10 levels, while lower TG, HDLc, monocyte numbers and M/H ratio at admission compared to the non-shock group (n = 27). M/H ratio and non-HDL cholesterol on D0 were risk factors for septic shock (OR = 0.70, 0.49‒0.99; OR = 0.96, 0.92‒0.99, respectively). Decreasing levels from D0 to D3 of CT (OR = 0.96, 0.93‒0.99), VLDLc (OR = 0.91, 0.85‒0.98), and non-HDL cholesterol (OR = 0.92, 0.87‒0.98) were also predictors of septic shock. Conclusions Lower M/H ratios and non-HDL cholesterol at admission and decreasing levels of cholesterol, VLDLc and non-HDL cholesterol during a hospital stay are associated with the development of septic shock in newborns with late-onset neonatal sepsis.

Persistent symptoms and decreased health-related quality of life after symptomatic pediatric COVID-19: A prospective study in a Latin American tertiary hospital

OBJECTIVES: To prospectively evaluate demographic, anthropometric and health-related quality of life (HRQoL) in pediatric patients with laboratory-confirmed coronavirus disease 2019 (COVID-19) METHODS: This was a longitudinal observational study of surviving pediatric post-COVID-19 patients (n=53) and pediatric subjects without laboratory-confirmed COVID-19 included as controls (n=52) was performed. RESULTS: The median duration between COVID-19 diagnosis (n=53) and follow-up was 4.4 months (0.8-10.7). Twenty-three of 53 (43%) patients reported at least one persistent symptom at the longitudinal follow-up visit and 12/53 (23%) had long COVID-19, with at least one symptom lasting for >12 weeks. The most frequently reported symptoms at the longitudinal follow-up visit were headache (19%), severe recurrent headache (9%), tiredness (9%), dyspnea (8%), and concentration difficulty (4%). At the longitudinal follow-up visit, the frequencies of anemia (11% versus 0%, p=0.030), lymphopenia (42% versus 18%, p=0.020), C-reactive protein level of >30 mg/L (35% versus 0%, p=0.0001), and D-dimer level of >1000 ng/mL (43% versus 6%, p=0.0004) significantly reduced compared with baseline values. Chest X-ray abnormalities (11% versus 2%, p=0.178) and cardiac alterations on echocardiogram (33% versus 22%, p=0.462) were similar at both visits. Comparison of characteristic data between patients with COVID-19 at the longitudinal follow-up visit and controls showed similar age (p=0.962), proportion of male sex (p=0.907), ethnicity (p=0.566), family minimum monthly wage (p=0.664), body mass index (p=0.601), and pediatric pre-existing chronic conditions (p=1.000). The Pediatric Quality of Live Inventory 4.0 scores, median physical score (69 [0-100] versus 81 [34-100], p=0.012), and school score (60 [15-100] versus 70 [15-95], p=0.028) were significantly lower in pediatric patients with COVID-19 at the longitudinal follow-up visit than in controls. CONCLUSIONS: Pediatric patients with COVID-19 showed a longitudinal impact on HRQoL parameters, particularly in physical/school domains, reinforcing the need for a prospective multidisciplinary approach for these patients. These data highlight the importance of closer monitoring of children and adolescents by the clinical team after COVID-19.

Differences in children and adolescents with SARS-CoV-2 infection: a cohort study in a Brazilian tertiary referral hospital

OBJECTIVES: To compare demographic/clinical/laboratory/treatments and outcomes among children and adolescents with laboratory-confirmed coronavirus disease 2019 (COVID-19). METHODS: This was a cross-sectional study that included patients diagnosed with pediatric COVID-19 (aged <18 years) between April 11, 2020 and April 22, 2021. During this period, 102/5,951 (1.7%) of all admissions occurred in neonates, children, and adolescents. Furthermore, 3,962 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection samples were processed in patients aged <18 years, and laboratory-confirmed COVID-19 occurred in 155 (4%) inpatients and outpatients. Six/155 pediatric patients were excluded from the study. Therefore, the final group included 149 children and adolescents (n=97 inpatients and 52 outpatients) with positive SARS-CoV-2 results. RESULTS: The frequencies of sore throat, anosmia, dysgeusia, headache, myalgia, nausea, lymphopenia, pre-existing chronic conditions, immunosuppressive conditions, and autoimmune diseases were significantly reduced in children and adolescents (p<0.05). Likewise, the frequencies of enoxaparin use (p=0.037), current immunosuppressant use (p=0.008), vasoactive agents (p=0.045), arterial hypotension (p<0.001), and shock (p=0.024) were significantly lower in children than in adolescents. Logistic regression analysis showed that adolescents with laboratory-confirmed COVID-19 had increased odds ratios (ORs) for sore throat (OR 13.054; 95% confidence interval [CI] 2.750-61.977; p=0.001), nausea (OR 8.875; 95% CI 1.660-47.446; p=0.011), and lymphopenia (OR 3.575; 95% CI 1.355-9.430; p=0.010), but also had less hospitalizations (OR 0.355; 95% CI 0.138-0.916; p=0.032). The additional logistic regression analysis on patients with preexisting chronic conditions (n=108) showed that death as an outcome was significantly associated with pediatric severe acute respiratory syndrome (SARS) (OR 22.300; 95% CI 2.341-212.421; p=0.007) and multisystem inflammatory syndrome in children (MIS-C) (OR 11.261; 95% CI 1.189-106. 581; p=0.035). CONCLUSIONS: Half of the laboratory-confirmed COVID-19 cases occurred in adolescents. Individuals belonging to this age group had an acute systemic involvement of SARS-CoV-2 infection. Pediatric SARS and MIS-C were the most important factors associated with the mortality rate in pediatric chronic conditions with COVID-19.

Poor Sleep quality and health-related quality of life impact in adolescents with and without chronic immunosuppressive conditions during COVID-19 quarantine

OBJECTIVE: To assess the possible factors that influence sleep quality in adolescents with and without chronic immunosuppressive conditions quarantined during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This cross-sectional study included 305 adolescents with chronic immunocompromised conditions and 82 healthy adolescents. Online surveys were completed, which included questions on socio-demographic data and self-rated healthcare routine during COVID-19 quarantine and the following validated questionnaires: the Pittsburgh Sleep Quality Index (PSQI), Pediatric Quality of Life Inventory 4.0 (PedsQL4.0), and Pediatric Outcome Data Collection Instrument (PODCI). RESULTS: The median current age [14 (10-18) vs. 15 (10-18) years, p=0.847] and frequency of female sex (62% vs. 58%, p=0.571) were similar in adolescents with chronic conditions compared with healthy adolescents. The frequency of poor sleep quality was similar in both groups (38% vs. 48%, p=0.118). Logistic regression analysis, including both healthy adolescents and adolescents with chronic conditions (n=387), demonstrated that self-reported increase in screen time (odds ratio [OR] 3.0; 95% confidence interval [CI] 1.3-6.8; p=0.008) and intrafamilial violence report (OR 2.1; 95% CI 1.2-3.5; p=0.008) were independently associated with poor sleep quality in these adolescents. However, the PODCI global function score was associated with a lower OR for poor sleep quality (OR 0.97; 95% CI 0.94-0.99; p=0.001). Further logistic regression, including only adolescents with chronic conditions (n=305), demonstrated that self-reported increase in screen time (OR 3.1; 95% CI 1.4-6.8; p=0.006) and intrafamilial violence report (OR 2.0; 95% CI 1.2-3.4; p=0.011) remained independently associated with poor quality of sleep, whereas a lower PODCI global function score was associated with a lower OR for sleep quality (OR 0.96; 95% CI 0.94-0.98; p<0.001). CONCLUSION: Self-reported increases in screen time and intrafamilial violence report impacted sleep quality in both healthy adolescents and those with chronic conditions. Decreased health-related quality of life was observed in adolescents with poor sleep quality.

Neonatal infection and passive acquisition of serum total IgG and reactive with Streptococcus B, anti-LPS of Klebsiella spp and Pseudomonas spp antibodies in twins

SUMMARY OBJECTIVE To describe the concentration of total and specific IgG antibodies anti-Streptococcus B, anti-lipopolysaccharide of Klebsiella spp, and anti-lipopolysaccharide of Pseudomonas spp in the umbilical cord of newborn(NB) twins and to analyze the association between neonatal infection and antibody concentration in the umbilical cord blood. METHODS A prospective cross-sectional study of a cohort of NB twins admitted during the period of 20 months. Patients with malformations and mothers with infection were excluded. Variables analyzed: gestational age(GA); birth weight(BW); antibody concentrations in umbilical cord blood; infection episodes. We used the paired Student t-test, Spearman correlation, and generalized estimation equation. RESULTS 57 pairs of twins were included, 4 excluded, making the sample of 110 newborns. GA=36±1.65weeks and BW=2304.8±460g(mean±SD). Antibody concentrations in twins(mean±SD): total IgG=835.71±190.73mg/dL, anti-StreptococcusB IgG=250.66±295.1 AU/mL, anti-lipopolysaccharide of Pseudomonas spp IgG=280.04±498.66 AU/mL and anti-lipopolysaccharide of Klebsiella spp IgG=504.75±933.93 AU/mL. There was a positive correlation between maternal antibody levels and those observed in newborns(p <0.005). The transplacental transfer of maternal total IgG and anti-LPS Pseudomonas IgG antibodies was significantly lower at NB GA <34 weeks(p <0.05). Five newborns were diagnosed with an infection. Infants with infection had significantly lower total IgG concentration(p <0.05). CONCLUSION This study showed a positive correlation between maternal and newborn antibodies levels. In infants younger than 34 weeks there is less transfer of total IgG and anti-LPS Pseudomonas IgG. The highest incidence of infection in the newborn group who had significantly lower total IgG serum antibodies reinforces the importance of anti-infectious protection afforded by passive immunity transferred from the mother.

RESUMO OBJETIVOS Descrever o título de anticorpos IgG total e específico anti-Streptococcus B, anti-lipopolissacarídeos(LPS) de Klebsiella e Pseudomonas no cordão umbilical em gêmeos e analisar a possível associação entre os títulos desses anticorpos e a ocorrência de infecção. MÉTODOS Estudo prospectivo transversal de uma coorte de recém-nascidos (RN) gemelares em 20 meses. Excluídos: malformação, infecção congênita ou materna. Variáveis estudadas: idade gestacional(IG); peso de nascimento(PN); título de anticorpos e episódios de infecção. Foram utilizados testes t-Student pareado, correlação de Spearman e equações de estimação generalizadas. RESULTADOS Elegíveis 59 pares de gêmeos, excluídos 4 e incluídos 55 pares (n=110RN). A IG foi 36±1,65semanas e o PN foi 2304,8±460g (média±DP). Concentrações de anticorpos dos RN(média±DP): IgG total=835,71±190,73 mg/dL, IgG anti-Streptococcus B=295,1±250,66 UA/mL, IgG anti-LPS Pseudomonas=280,04±498,66 UA/mL e IgG anti-LPS Klebsiella=504,75± 933,93UA/mL. Houve correlação positiva entre níveis de anticorpos maternos e aqueles observados nos RN (p<0,005). A transferência transplacentária de anticorpos maternos IgG total e IgG anti-LPS Pseudomonas foi significativamente menor em RN IG < 34semanas (p<0,05). Foram diagnosticados 5 RN com infecção. Os RN que apresentaram infecção tinham concentração de IgG total significativamente menor (p<0,05). CONCLUSÕES Na população estudada existe correlação entre os anticorpos maternos e os níveis de anticorpos no RN. Nos gêmeos menores que 34 semanas há menor transferência de IgG total e IgG anti-LPS Pseudomonas. Nos RN com infecção a concentração de IgG total é significativamente menor, o que demonstra a maior vulnerabilidade e risco de infecção dessa população e a importância da imunidade passiva transferida pela placenta.

Placental and colostral transfer of antibodies reactive with enteropathogenic Escherichia coli intimins α, ß, or γ / Transferência placentária e colostral de anticorpos reativos a Escherichia coli enteropatogênica com expressão das intiminas α, ß, or γ

Abstract Objective: Intimins are protein adhesins of enteropathogenic Escherichia coli and enterohemorrhagic E. coli capable of inducing attachment and effacement lesions in enterocytes. Anti-intimin antibodies are important for the protection from enteropathogenic E. coli and enterohemorrhagic E. coli infections because these antibodies inhibit bacterial adhesion and impair the initial step of the pathogenesis. We studied the transfer of maternal anti-intimin antibodies from healthy Brazilian mothers to their newborns through the placenta and colostrum. Methods: Serum immunoglobulin G and secretory immunoglobulin A antibodies against conserved and variable regions of intimins α, β, and γ were analyzed using an enzyme linked-immunosorbent assay in the blood and colostrum from 45 healthy women as well as cord blood serum samples from their newborns. Results: The concentrations of antibodies reactive with α intimin were significantly lower than those of anti-γ and anti-conserved intimin antibodies in the colostrum samples. IgG serum antibodies reactive with all the subtypes of intimins were transferred to the newborns, but the concentrations of anti-conserved intimin serum antibodies were significantly higher in mothers and newborns than concentrations of antibodies against variable regions. The patterns of IgG transfer from mothers to newborns were similar for all anti-intimin antibodies. These values are similar to the percentage transference of total IgG. Conclusions: Anti-intimin antibodies are transferred from mothers to newborns through the placenta, and reinforce the protection provided by breastfeeding against diarrheagenic E. coli infections.

Resumo Objetivo: As intiminas são adesinas proteicas de Escherichia coli enteropatogênicas (EPEC) e enterro-hemorrágicas (EHEC) capazes de induzir as lesões attaching and effacing nos enterócitos. Anticorpos anti-intiminas são importantes para a proteção contra infecções por EPEC e EHEC porque esses anticorpos inibem a adesão bacteriana e impedem o passo inicial do mecanismo patogênico dessas bactérias. Nós estudamos a transferência de anticorpos maternos anti-intiminas de mães brasileiras saudáveis para os seus recém-nascidos através da placenta e do colostro. Métodos: Anticorpos séricos da classe IgG e secretórios da classe IgA (SIgA) reativos com as porções conservada (cons) e variáveis das intiminas α (vα), β (vβ) e γ (vγ) foram analisados pelo teste de ELISA no sangue e no colostro de 45 parturientes saudáveis e no sangue de cordão umbilical dos seus respectivos recém-nascidos. Resultados: As concentrações de anticorpos reativos com intimina vα foram significativamente mais baixas que as dos anticorpos anti-vγ e anti-cons nas amostras de colostro. Anticorpos IgG séricos reativos com todas as intiminas foram transferidos para os recém-nascidos, mas as concentrações de anti-cons foram significativamente mais altas tanto nas mães como nos recém-nascidos do que os anticorpos reativos com as regiões variáveis das intiminas. O padrão de transferência de IgG das mães para os recém-nascidos foi muito semelhante para todos os anticorpos anti-intiminas. Os valores de porcentagem de transferência foram semelhantes à transferência de IgG total. Conclusões: Anticorpos anti-intimina são transferidos das mães para os recém-nascidos pela placenta e corroboram a proteção contra infecções por Escherichia coli diarreiogênicas (DEC) conferida pelo aleitamento materno.

Passive acquisition of anti-Staphylococcus aureus antibodies by newborns via transplacental transfer and breastfeeding, regardless of maternal colonization

OBJECTIVE: To investigate the transmission of anti-Staphylococcus aureus (Sa) IgG, IgG1 and IgG2 via placental transfer and the transfer of IgA via the colostrum according to maternal Sa carrier status at delivery. METHODS: We evaluated anti-Sa IgG, IgG1 and IgG2 in maternal and cord sera and IgA in colostrum from a case (n=49, Sa+) and a control group (n=98, Sa-). RESULTS: Of the 250 parturients analyzed for this study, 49 were nasally colonized with S. aureus (prevalence of 19.6%). Ninety-eight non-colonized subjects were selected for the control group. The anti-Sa IgG, IgG1 and IgG2 levels and the IgG avidity indexes in the maternal and cord sera did not differ between the groups, with a low transfer ratio of anti-Sa IgG to the newborns in both groups. The anti-Sa IgG2 titers were significantly higher than the IgG1 titers in the maternal and cord sera. Inversely, the transfer ratios were higher for anti-Sa IgG1 compared with IgG2; however, no differences between the groups were detected. The Sa-specific IgA levels and avidity indexes in the colostrum were equivalent between groups. CONCLUSIONS: Maternal Sa nasal colonization at delivery is not associated with higher antibody levels in the mother or newborns. The high titers of anti-Sa IgG2 found in the cord serum indicate a greater reactivity with non-protein antigens, which may further contribute to the susceptibility to staphylococcal infections at birth. The presence of IgA in the colostrum with avidity to S. aureus reinforces the importance of breastfeeding shortly after birth.

Immunology of breast milk / Imunologia do leite materno

Summary In the critical phase of immunological immaturity of the newborn, particularly for the immune system of mucous membranes, infants receive large amounts of bioactive components through colostrum and breast milk. Colostrum is the most potent natural immune booster known to science. Breastfeeding protects infants against infections mainly via secretory IgA (SIgA) antibodies, but also via other various bioactive factors. It is striking that the defense factors of human milk function without causing inflammation; some components are even anti-inflammatory. Protection against infections has been well evidenced during lactation against, e.g., acute and prolonged diarrhea, respiratory tract infections, including otitis media, urinary tract infection, neonatal septicemia, and necrotizing enterocolitis. The milk’s immunity content changes over time. In the early stages of lactation, IgA, anti-inflammatory factors and, more likely, immunologically active cells provide additional support for the immature immune system of the neonate. After this period, breast milk continues to adapt extraordinarily to the infant’s ontogeny and needs regarding immune protection and nutrition. The need to encourage breastfeeding is therefore justifiable, at least during the first 6 months of life, when the infant’s secretory IgA production is insignificant.

Resumo Na fase crítica de imaturidade imunológica do recém-nascido, em especial do sistema imune de mucosas, o lactente recebe grandes quantidades de componentes bioativos através do colostro e do leite materno. O colostro é o reforço imunológico natural mais potente conhecido pela ciência. O aleitamento materno protege o lactente de infecções principalmente por meio dos anticorpos IgA secretores (IgAS), mas também por meio de vários outros fatores bioativos. É surpreendente que os fatores de defesa do leite humano ajam sem causar inflamação e alguns componentes são, de fato, anti-inflamatórios. A proteção contra infecções tem sido bem evidenciada durante a lactação, combatendo, por exemplo, diarreia aguda e prolongada, infecções do trato respiratório, incluindo otite média, infecção do trato urinário, sepse neonatal e enterocolite necrosante. O conteúdo imunológico do leite evolui ao longo do tempo: nas fases iniciais de lactação, IgAS, fatores anti-inflamatórios e, mais provavelmente, as células imunologicamente ativas provêm ajuda adicional para o sistema imune imaturo do neonato. Depois desse período, o leite materno continua a adaptar-se extraordinariamente à ontogenia infantil, às suas necessidades de proteção imune e nutricionais. Entende-se, portanto, a necessidade de se estimular o aleitamento materno pelo menos durante o primeiro semestre de vida, período em que a produção própria de IgA secretória é ainda pouco significativa.

TLR-2 and TLR-4 expression in monocytes of newborns with late-onset sepsis, / Expressão do TLR-2 e do TLR-4 em monócitos de recém-nascidos a termo com sepse tardia

Objective: To analyze toll-like receptor (TLR)-2 and TLR-4 expression in monocytes of newborns with late-onset sepsis. Methods: This prospective study included 27 full-term newborns aged 8 to 29 days, with clinical and laboratory diagnosis of late-onset sepsis. Ten newborns (37%) had positive cultures. Cytokines were measured by cytometric bead array in peripheral blood, while TLR-2, TLR-4 expression, and median fluorescence intensity (MFI) were determined by immunophenotyping peripheral whole blood monocytes, and were analyzed with a BD FACSDiva flow cytometer (Becton, Dickinson and Company, USA). A comparison was performed with healthy adults. Results: Microorganisms were identified in 37% of these septic newborns, and all of them had high levels of pro-inflammatory cytokines (IL-8, IL-6, IL-1β) and anti-inflammatory cytokine (IL-10) corroborating the inflammatory/septic process. In monocytes, the frequency of TLR-4 expression was higher in infected newborns (p = 0.01). Conclusion: This study investigated the innate immune response in septic newborns. Septic newborns that relied almost exclusively on the innate immune system showed little in vivo response at monocyte activation, suggesting impaired immune response and increased susceptibility to infection. .

Objetivos: Analisar a expressão dos TLR-2 e TLR-4 em monócitos de recém-nascidos com sepse tardia. Métodos: Trata-se de um estudo prospectivo com 27 recém-nascidos a termo entre 8 e 29 dias de vida com diagnóstico clínico e laboratorial de sepse tardia dos quais dez (37%) apresentaram cultura positiva. As citocinas foram determinadas por teste de CBA em sangue periférico enquanto que a expressão e MFI (mediana de intensidade de fluorescência) dos TLR-2 e TLR-4 foi determinado por imunofenotipagem em monócitos de sangue periférico total através de análise pelo citômetro de fluxo BD FACSDiva. O grupo usado para comparação foi de adultos saudáveis. Resultados: Microrganismos foram identificados em 37% dos pacientes e estes juntamente com os pacientes com sepse clínica tiveram níveis elevados de citocinas pró-inflamatórias (IL-8, IL-6, IL-1β) e de citocina anti-inflamatória (IL-10) corroborando o processo inflamatório/infeccioso. No monócito, a frequência de expressão do TLR-4 foi mais elevada (p = 0,01). Conclusões: Este estudo analisou a resposta imune inata no recém-nascido com sepse. Recémnascidos sépticos que dependem quase exclusivamente do sistema imune inato apresentaram pouca resposta in vivo na ativação de monócitos o que sugere uma resposta imune deficiente e maior susceptibilidade à infecção. .

Aquisição passiva de anticorpos anti-dermatophagoides pteronyssinus através de passagem transplacentária e aleitamento materno / Passive acquisition of anti-dermatophagoides pteronyssinus antibodies through placental transfer and breastfeeding

Introdução e objetivos: Eventos nos primeiros anos de vida podem ser responsáveis pelo aumento da prevalência de doenças alérgicas. Tendo em vista que o sistema imunológico da criança recebe anticorpos específicos a alérgenos ainda no útero e através da amamentação, caracterizamos a transferência passiva de IgG e IgA anti-Dermatophagoides pteronyssinus e verificamos o efeito da sensibilização materna na resposta imune humoral no cordão umbilical e no colostro. Métodos: Colostro e amostras pareadas de soro materno e de cordão umbilical foram coletadas de treze mães sensibilizadas (RAST anti-Der p > classe 3) e 25 mães não sensibilizadas (RAST anti-Der p = O). Quantificamos os níveis totais de IgG por nefelometria e a IgA total e os anticorpos específicos anti¬Der p por ELISA. Para análise funcional, verificamos a avidez dos anticorpos ao extrato total do ácaro, também por ELISA. Resultados: Recém-nascidos de mães sensibilizadas apre¬sentaram níveis significativamente mais elevados de IgG anti¬Derp no cordão umbilical (p=O,Ol), no entanto, estes anticor¬pos foram detectados em todas as amostras, estando fortemente correlacionados aos níveis maternos (r=0.81 p

Introduction and objectives: The early life sensitization might be one of the primary causes of the increased prevalen¬ce of allergy. Considering that infants received in the uteri and by the breastfeed specific antibodies to allergens, we investigated the passive transference of IgG and IgA antibodies to Dermatophagoides pteronyssinus to verify if mother sensitization influences the humoral immune response in umbilical cord blood and in colostrum...