Helicobacter pylori-specific immune response in maternal serum, cord blood, and human milk among mothers with and without current Helicobacter pylori infection

Maternal immune factors involved in the prevention or facilitation of neonatal bacterial infections

Newborns, whether born prematurely or at term, have a fully formed but naive immune system that must adapt to the extra-uterine environment to prevent infections. Maternal immunity, transmitted through the placenta and breast milk, protects newborns against infections, primarily via immunoglobulins (IgG and IgA) and certain maternal immune cells also known as microchimeric cells. Recently, it also appeared that the maternal gut microbiota played a vital role in neonatal immune maturation via microbial compounds impacting immune development and the establishment of immune tolerance. In this context, maternal vaccination is a powerful tool to enhance even more maternal and neonatal health. It involves the transfer of vaccine-induced antibodies to protect both mother and child from infectious diseases. In this work we review the state of the art on maternal immune factors involved in the prevention of neonatal bacterial infections, with particular emphasis on the role of maternal vaccination in protecting neonates against bacterial disease.

Breastfeeding Is Associated with Lower Likelihood of Helicobacter Pylori Colonization in Babies, Based on a Prospective USA Maternal-Infant Cohort

BACKGROUND

Mother-to-child transmission of Helicobacter pylori (H. pylori) is the primary source of intrafamilial spread in early childhood in regions of high H. pylori prevalence. However, early-in-life H. pylori colonization and associated protective or risk factors have not been fully evaluated in lower prevalence regions, such as the USA.

AIMS

Therefore, from a well-characterized prospective US cohort, we selected women who provided fecal samples during pregnancy and had paired fecal samples from their babies up to 24 months postpartum. We evaluated maternal and baby factors associated with likelihood of H. pylori colonization in the babies. Fecal antigen testing was used to determine H. pylori status. We also evaluated the association between maternal breastmilk cytokines and H. pylori colonization in breastfed babies.

RESULTS

Among included mother-baby pairs (n = 66), H. pylori prevalence was 31.8% in mothers and 19.7% in their babies. Dominant breastfeeding (adjusted odds ratio [aOR] 0.17, 95% CI 0.03-0.98) and maternal IBD (aOR 0.05, 95% CI 0.01-0.27) were associated with significantly lower likelihood of H. pylori colonization among babies; no other clinical factors were associated with H. pylori colonization in the babies. Matrix metalloproteinase-10 (MMP-10) and tumor necrosis factor-related activation-induced cytokine expression were significantly higher in breastmilk of mothers with H. pylori positive vs negative babies.

CONCLUSIONS

Consistent with data from high H. pylori prevalence regions, our findings suggest dominant breastfeeding may protect against early H. pylori colonization. Downregulation of pro-inflammatory cytokines such as MMP-10 may be relevant in mediating this protection among breastfed babies, but more data are needed.

Prevention of Helicobacter pylori infection in childhood

Helicobacter pylori (H. pylori) infection is one of the most common infections worldwide. Although infection rates are falling in the developed and developing countries, H. pylori is still widespread in the world. This article has reviewed the important publications on H. pylori in childhood with a focus on its evolving transmission route and the source of infection and preventive strategies in childhood, PubMed was searched up to identify eligible studies. Relevant publications were searched using the following.

The utilization of a new immunochromatographic test in detection of Helicobacter pylori antibody from maternal and umbilical cord serum

Background. Helicobacter pylori (H. pylori) was linked with several extragastrointestinal diseases, including preeclampsia and intrauterine growth restriction of fetus. One of the signals which can be transferred from mother to fetus is the H. pylori IgG antibody. Aims. We utilized a commercial immunochromatographic kit to detect the antibody in maternal and cord serum. Methods. Three hundred and forty-six females were enrolled and the blood samples were collected on antenatal examination and on delivery. The maternal H. pylori infection was determined by stool H. pylori antigen test. Results. One hundred and five females (30.3%) were H. pylori-infected, and the prevalence was higher in immigrants (43.5%) than in Taiwanese (28.7%, P = 0.058). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the kit were 77.1%, 88.0%, 73.6%, 89.8%, and 84.7%, respectively. This kit also had similar performance in cord serum. Comparing to the maternal result on delivery, this kit offered a consistent performance in antenatal maternal serum (kappa coefficient 0.92) and in cord serum (kappa coefficient 0.88). Conclusions. H. pylori IgG antibody can be transferred through the placenta into the fetal circulation. However, accuracy of the test kit needs to be evaluated before utilization in screening.

Helicobacter pylori and pregnancy-related disorders

Helicobacter pylori (H. pylori) infection is investigated in gastric diseases even during pregnancy. In particular, this Gram-negative bacterium seems to be associated with hyperemesis gravidarum, a severe form of nausea and vomiting during pregnancy. During the last decade, the relationship among H. pylori and several extra-gastric diseases strongly emerged in literature. The correlation among H. pylori infection and pregnancy-related disorders was mainly focused on iron deficiency anemia, thrombocytopenia, fetal malformations, miscarriage, pre-eclampsia and fetal growth restriction. H. pylori infection may have a role in the pathogenesis of various pregnancy-related disorders through different mechanisms: depletion of micronutrients (iron and vitamin B₁₂) in maternal anemia and fetal neural tube defects; local or systemic induction of pro-inflammatory cytokines release and oxidative stress in gastrointestinal disorders and pre-eclampsia; cross-reaction between specific anti-H. pylori antibodies and antigens localized in placental tissue and endothelial cells (pre-eclampsia, fetal growth restriction, miscarriage). Since H. pylori infection is most likely acquired before pregnancy, it is widely believed that hormonal and immunological changes occurring during pregnancy could activate latent H. pylori with a negative impact not only on maternal health (nutritional deficiency, organ injury, death), but also on the fetus (insufficient growth, malformation, death) and sometime consequences can be observed later in life. Another important issue addressed by investigators was to determine whether it is possible to transmit H. pylori infection from mother to child and whether maternal anti-H. pylori antibodies could prevent infant’s infection. Studies on novel diagnostic and therapeutic methods for H. pylori are no less important, since these are particularly sensitive topics in pregnancy conditions. It could be interesting to study the possible correlation between H. pylori infection and other pregnancy-related diseases of unknown etiology, such as gestational diabetes mellitus, obstetric cholestasis and spontaneous preterm delivery. Since H. pylori infection is treatable, the demonstration of its causative role in pregnancy-related disorders will have important social-economic implications.

Gestational weight gain and body mass index in children: results from three german cohort studies

Introduction

Previous studies suggested potential priming effects of gestational weight gain (GWG) on offspring’s body composition in later life. However, consistency of these effects in normal weight, overweight and obese mothers is less clear.

Methods

We combined the individual data of three German cohorts and assessed associations of total and excessive GWG (as defined by criteria of the Institute of Medicine) with offspring’s mean body mass index (BMI) standard deviation scores (SDS) and overweight at the age of 5–6 years (total: n = 6,254). Quantile regression was used to examine potentially different effects on different parts of the BMI SDS distribution. All models were adjusted for birth weight, maternal age and maternal smoking during pregnancy and stratified by maternal pre-pregnancy weight status.

Results

In adjusted models, positive associations of total and excessive GWG with mean BMI SDS and overweight were observed only in children of non- overweight mothers. For example, excessive GWG was associated with a mean increase of 0.08 (95% CI: 0.01, 0.15) units of BMI SDS (0.13 (0.02, 0.24) kg/m² of ‘real’ BMI) in children of normal-weight mothers. The effects of total and excessive GWG on BMI SDS increased for higher- BMI children of normal-weight mothers.

Discussion

Increased GWG is likely to be associated with overweight in offspring of non-overweight mothers.

Neural tube defects, micronutrient deficiencies, and Helicobacter pylori: a new hypothesis

BACKGROUND

Previous findings for the Texas Neural Tube Defects Project suggested that while maternal access to nutrients is adequate, bioavailability of nutrients to the fetus is compromised in NTD-affected pregnancies. Helicobacter pylori could cause nutrient loss to the fetus. Folate, B12, and ferritin are depleted in H. pylori infection; these same deficiencies are related to NTD risk.

METHODS

Using H. pylori IgG ELISA Test System, we tested for H. pylori serum antibodies in participants in the population-based case-control study component of the Texas Neural Tube Defect Project conducted along the Texas-Mexico border. Case-women had pregnancies affected by NTD (anencephalus, spina bifida, encephalocele) and resided and delivered in one of the 14 Texas-Mexico border counties from 1995 through 2000. Control-women were study area residents delivering normal live births during the same period.

RESULTS

Of 225 case- and 378 control-women, 103 cases and 156 controls provided questionnaire and H. pylori antibody data. H. pylori seropositivity was modestly associated with NTD-affected pregnancies (OR 1.4; 95% CI: 0.8-2.4). ORs of 2.0 or greater were seen in women younger than age 25 and with less than 7 years education.

CONCLUSIONS

Our findings intimate that H. pylori could play a role in NTD causation in certain populations. While results did not provide compelling support for this proposal, subgroup findings prompt us to advocate an evaluation of this hypothesis in developing nations among populations with higher prevalence of H. pylori, marginal nutrient intake, and young childbearing age.

Adiponectin and Leptin in Maternal Serum, Cord Blood, and Breast Milk

Background: The presence of the adipokines adiponectin and leptin in cord blood and placental and fetal tissues suggests a possible role in fetal development.

Methods: We measured concentrations of adiponectin and leptin in maternal serum, cord blood, and breast milk and examined their correlations within a large, population-based study. Between November 2000 and November 2001, we recruited all mothers and their newborns after delivery at the University of Ulm (Ulm, Germany). The current analysis included 766 mothers with available breast milk samples collected 6 weeks postpartum. Adipokine concentrations were measured with commercially available ELISAs (R&D Systems).

Results: Median adiponectin concentrations in maternal serum (n = 713), cord blood (n = 709), and breast milk (n = 766) were 8.6 mg/L, 30.6 mg/L, and 10.9 μg/L, respectively. Median leptin concentrations were 12.8 μg/L in maternal serum, 7.8 μg/L in cord blood, and 174.5 ng/L in breast milk. Whereas increases in leptin concentrations with increasing birth weight, birth weight according to gestational age, and ponderal index were statistically significant in cord blood (all P values <0.0001), cord blood adiponectin was clearly related only to birth weight (P = 0.0004). Concentrations of both adipokines were moderately correlated in breast milk and maternal serum (both Spearman ρ values were 0.43; P <0.0001).

Conclusions: Concentrations of adiponectin and leptin vary strongly in maternal serum, cord blood, and breast milk, with only moderate correlations between both adipokines in maternal serum and breast milk. The health implications of these patterns warrant further investigation.

Inflammation, immunity, vaccines for Helicobacter infection

The reason why some individuals remain Helicobacter pylori infected for life but without any symptoms while others develop severe diseases is only partially clarified. Presumably, it depends on multifactorial interactions among host immunologic and physiologic factors, bacterial virulence determinants, and environmental influences modulating the host response. Much effort has been made to identify host genetic factors that may explain an individual susceptibility of the host to H. pylori infection. The identification of H. pylori determinants and the elucidation of their role in modifying the host immune responses were further delineated. The ability of H. pylori to overcome the defense mechanisms on mucosal surfaces as well as to modulate the immune response by interfering with host recognition and transduction systems has been shown. Also new bacterial anti-inflammatory defense systems have been described. Findings in experimental animal models and humans with natural H. pylori infection suggested a double role of regulatory T cells in the course of H. pylori infection: protecting the infected host against excessive gastric inflammation and, in contrast, promoting bacterial colonization.