Transfer of antibodies across the placenta and in breast milk from mothers on intravenous immunoglobulin

Neonatal Gut Mycobiome: Immunity, Diversity of Fungal Strains, and Individual and Non-Individual Factors

The human gastrointestinal ecosystem, or microbiome (comprising the total bacterial genome in an environment), plays a crucial role in influencing host physiology, immune function, metabolism, and the gut-brain axis. While bacteria, fungi, viruses, and archaea are all present in the gastrointestinal ecosystem, research on the human microbiome has predominantly focused on the bacterial component. The colonization of the human intestine by microbes during the first two years of life significantly impacts subsequent composition and diversity, influencing immune system development and long-term health. Early-life exposure to pathogens is crucial for establishing immunological memory and acquired immunity. Factors such as maternal health habits, delivery mode, and breastfeeding duration contribute to gut dysbiosis. Despite fungi's critical role in health, particularly for vulnerable newborns, research on the gut mycobiome in infants and children remains limited. Understanding early-life factors shaping the gut mycobiome and its interactions with other microbial communities is a significant research challenge. This review explores potential factors influencing the gut mycobiome, microbial kingdom interactions, and their connections to health outcomes from childhood to adulthood. We identify gaps in current knowledge and propose future research directions in this complex field.

A literature review of drug transport mechanisms during lactation

Despite the benefits of breastfeeding, lactating mothers who take prescribed medications may discontinue breastfeeding due to concerns associated with infant drug exposure in breastmilk. Consolidating the current knowledge of drug transport to breastmilk may inform understanding of the safety of medication use during lactation. This literature review summarizes the mechanisms of drug transport to breastmilk, details the physicochemical drug properties that may alter the extent of passive transport, and describes the expressional changes in mammary drug transporters that may affect active transport. During the period of 20 July 2023 to 11 August 2023, PubMed® was searched to identify journal articles pertinent to the mechanisms of drug transport from maternal plasma to breastmilk and the expression of mammary drug transporters during lactation. From the 28 studies included in this review, four mechanisms were identified for transporting drugs from maternal plasma to breastmilk: passive transport, active transport, lipid co-transport, and transcytosis. The lactational expression of 20 drug transporters was further summarized, with 9 transporters demonstrating downregulated expression during lactation and 11 transporters demonstrating upregulated expression during lactation. Understanding the mechanisms of drug transport to breastmilk may aid in estimating infant drug exposure, developing physiologically based pharmacokinetic (PBPK) models that describe drug transfer, and initiating clinical drug development programs in the lactating population.

Life-threatening infections in human newborns: Reconciling age-specific vulnerability and interindividual variability

In humans, the interindividual variability of clinical outcome following exposure to a microorganism is immense, ranging from silent infection to life-threatening disease. Age-specific immune responses partially account for the high incidence of infection during the first 28 days of life and the related high mortality at population level. However, the occurrence of life-threatening disease in individual newborns remains unexplained. By contrast, inborn errors of immunity and their immune phenocopies are increasingly being discovered in children and adults with life-threatening viral, bacterial, mycobacterial and fungal infections. There is a need for convergence between the fields of neonatal immunology, with its in-depth population-wide characterization of newborn-specific immune responses, and clinical immunology, with its investigations of infections in patients at the cellular and molecular levels, to facilitate identification of the mechanisms of susceptibility to infection in individual newborns and the design of novel preventive and therapeutic strategies.

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.

Reproductive health after thoracic transplantation: An ISHLT expert consensus statement

Pregnancy after thoracic organ transplantation is feasible for select individuals but requires multidisciplinary subspecialty care. Key components for a successful pregnancy after lung or heart transplantation include preconception and contraceptive planning, thorough risk stratification, optimization of maternal comorbidities and fetal health through careful monitoring, and open communication with shared decision-making. The goal of this consensus statement is to summarize the current evidence and provide guidance surrounding preconception counseling, patient risk assessment, medical management, maternal and fetal outcomes, obstetric management, and pharmacologic considerations.

Biomonitoring bisphenols, parabens, and benzophenones in breast milk from a human milk bank in Southern Spain

BACKGROUND

Human breast milk is considered the optimal source of nutrition for infants. Milk from breast milk banks offers an alternative to infant formulas for vulnerable hospitalized neonates most likely to benefit from exclusive human milk feeding. However, breast milk can also be a source of exposure to environmental contaminants, including endocrine-disrupting chemicals (EDCs).

AIM

To evaluate concentrations of phenolic EDCs, including bisphenols, parabens (PBs), and benzophenones (BPs), in samples from a human milk bank in Granada, Southern Spain and to explore sociodemographic, reproductive, and lifestyle factors related to their concentrations in the milk.

METHODS

Concentrations of three bisphenols [bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS)], four PBs [methyl- (MeP), ethyl- (EtP), propyl- (n-PrP), and butyl-paraben (n-BuP)], and six BPs [BP-1, BP-2, BP-3, BP-6, BP-8, and 4-hydroxy-BP] were determined in milk samples from 83 donors. Information on potential explanatory variables was gathered using the milk bank donor form and an ad hoc questionnaire. Multiple linear and logistic regression models were fitted.

RESULTS

Detectable concentrations were found of at least one of the analyzed compounds in all donor breast milk samples and at least five compounds in one-fifth of them. The most frequently detected compounds were MeP (90.5%), BP-3 (75.0%), EtP (51.2%), n-PrP (46.4%), and BPA (41.7%). Median concentrations ranged between <0.10 ng/mL (n-PrP, n-BuP, BP-1) and 0.59 ng/mL (BP-3). No sample contained detectable concentrations of BPF, BPS, or most BPs (BP-2, BP-6, BP-8, and 4- hydroxy-BP). Breast milk phenol concentrations were associated with parity, the utilization of deodorants, mouthwash, skin care products, and cosmetics, and the intake of nutritional supplements.

CONCLUSIONS

Results reveal the widespread presence of BPA, PBs, and BP-3 in donor breast milk samples, highlighting the need for preventive measures to enhance the benefits of breast milk from milk banks and from breastfeeding women in general.

Specific innate immune cells uptake fetal antigen and display homeostatic phenotypes in the maternal circulation

Pregnancy represents a period when the mother undergoes significant immunological changes to promote tolerance of the fetal semi-allograft. Such tolerance results from the exposure of the maternal immune system to fetal antigens (Ags), a process that has been widely investigated at the maternal-fetal interface and in the adjacent draining lymph nodes. However, the peripheral mechanisms of maternal-fetal crosstalk are poorly understood. Herein, we hypothesized that specific innate immune cells interact with fetal Ags in the maternal circulation. To test this hypothesis, a mouse model was utilized in which transgenic male mice expressing the chicken ovalbumin (OVA) Ag under the beta-actin promoter were allogeneically mated with wild-type females to allow for tracking of the fetal Ag. Fetal Ag-carrying Ly6G+ and F4/80+ cells were identified in the maternal circulation, where they were more abundant in the second half of pregnancy. Such innate immune cells displayed unique phenotypes: while Ly6G+ cells expressed high levels of MHC-II and CD80 together with low levels of pro-inflammatory cytokines, F4/80+ cells up-regulated the expression of CD86 as well as the anti-inflammatory cytokines IL-10 and TGF-β. In vitro studies using allogeneic GFP+ placental particles revealed that maternal peripheral Ly6G+ and F4/80+ cells phagocytose fetal Ags in mid and late murine pregnancy. Importantly, cytotrophoblast-derived particles were also engulfed in vitro by CD15+ and CD14+ cells from women in the second and third trimester, providing translational evidence that this process also occurs in humans. Collectively, this study demonstrates novel interactions between specific maternal circulating innate immune cells and fetal Ags, thereby shedding light on the systemic mechanisms of maternal-fetal crosstalk.

Functional Antibodies Against SARS-CoV-2 Receptor Binding Domain Variants with Mutations N501Y or E484K in Human Milk from COVID-19-Vaccinated, -Recovered, and -Unvaccinated Women

Background: New variants are evolving in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and receptor binding domain (RBD) mutations have been associated with a higher capacity to evade neutralizing antibodies (NAbs). We aimed at determining the impact of COVID-19 vaccine and infection on human milk antibody titers and activity against the RBD mutations from SARS-CoV-2 variants of concern. Materials and Methods: Milk samples were collected from 19 COVID-19 vaccinated women, 10 women who had a positive COVID-19 PCR test, and 13 unvaccinated women. The titers and NAbs of secretory IgA (SIgA)/IgA, secretory IgM (IgM)/IgM, and IgG against SARS-CoV-2 RBD with mutations N501Y or E484K were measured by using ELISA and a surrogate virus neutralization assay. Results: The titers of human milk IgG against N501Y were higher in the COVID-19 vaccine group than in the no-vaccine group but comparable with the COVID-19 PCR group. Other antibody titers did not differ between the three groups. The titers of SIgA/IgA were higher than those of SIgM/IgM and IgG in all three groups. The titers of SIgM/IgM and the inhibition of NAbs were higher against the mutation E484K than N501Y. Milk NAb did not differ between the three groups, but the inhibition of NAb against binding of the two mutant RBD proteins to their receptor was higher in the COVID-19 vaccine and PCR groups than in milk from prepandemic women. Conclusions: COVID-19 vaccination and exposure of mothers to SARS-CoV-2 influenced the titers and NAbs in breast milk against the variants of concern.

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

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.

A Critical Review on the Standardization and Quality Assessment of Nonfunctional Laboratory Tests Frequently Used to Identify Inborn Errors of Immunity

Inborn errors of immunity (IEI), which were previously termed primary immunodeficiency diseases, represent a large and growing heterogeneous group of diseases that are mostly monogenic. In addition to increased susceptibility to infections, other clinical phenotypes have recently been associated with IEI, such as autoimmune disorders, severe allergies, autoinflammatory disorders, benign lymphoproliferative diseases, and malignant manifestations. The IUIS 2019 classification comprises 430 distinct defects that, although rare individually, represent a group affecting a significant number of patients, with an overall prevalence of 1:1,200-2,000 in the general population. Early IEI diagnosis is critical for appropriate therapy and genetic counseling, however, this process is deeply dependent on accurate laboratory tests. Despite the striking importance of laboratory data for clinical immunologists, several IEI-relevant immunoassays still lack standardization, including standardized protocols, reference materials, and external quality assessment programs. Moreover, well-established reference values mostly remain to be determined, especially for early ages, when the most severe conditions manifest and diagnosis is critical for patient survival. In this article, we intend to approach the issue of standardization and quality control of the nonfunctional diagnostic tests used for IEI, focusing on those frequently utilized in clinical practice. Herein, we will focus on discussing the issues of nonfunctional immunoassays (flow cytometry, enzyme-linked immunosorbent assays, and turbidimetry/nephelometry, among others), as defined by the pure quantification of proteins or cell subsets without cell activation or cell culture-based methods.

Serological Responses to Influenza Vaccination during Pregnancy

Pregnant women, newborns, and infants under six months old are at the highest risk of developing severe and even fatal influenza. This risk is compounded by the inability to vaccinate infants under six months, highlighting the importance of vertically transferred immunity. This review identifies novel insights that have emerged from recent studies using animal models of pregnancy and vaccination. We also discuss the knowledge obtained using existing clinical trials that have evaluated influenza-specific serological responses in pregnant women and how these responses may impact early life immunity. We delineate the mechanisms involved in transferring specific maternal antibodies and discuss the consequences for early life immunity. Most importantly, we highlight the need for continued research using pregnant animal models and the inclusion of pregnant women, a commonly neglected population, when evaluating novel vaccine platforms to better serve and treat communicable diseases.

The Breast Milk Immunoglobulinome

Breast milk components contribute to the infant’s immune development and protection, and among other immune factors, immunoglobulins (Igs) are the most studied. The presence of IgA in milk has been known for a long time; however, less information is available about the presence of other Igs such as IgM, IgG, and their subtypes (IgG1, IgG2, IgG3, and IgG4) or even IgE or IgD. The total Ig concentration and profile will change during the course of lactation; however, there is a great variability among studies due to several variables that limit establishing a clear pattern. In this context, the aim of this review was firstly to shed light on the Ig concentration in breast milk based on scientific evidence and secondly to study the main factors contributing to such variability. A search strategy provided only 75 studies with the prespecified eligibility criteria. The concentrations and proportions found have been established based on the intrinsic factors of the study—such as the sampling time and quantification technique—as well as participant-dependent factors, such as lifestyle and environment. All these factors contribute to the variability of the immunoglobulinome described in the literature and should be carefully addressed for further well-designed studies and data interpretation.

The role of human milk banks in promoting maternal and infant health: a systematic review

Aimed at strengthening breastfeeding policies, human milk banks (HMBs) play an important role in promoting, protecting and supporting this practice. The objective of this study was to undertake a systematic review to identify activities developed by HMBs that demonstrate their role in promoting maternal and infant health. Searches for relevant articles were performed in the following databases: PubMed, Virtual Health Library (BVS), and BVS Breastfeeding linked to the portal of the Brazilian Human Milk Bank Network. Eleven articles were included in the final sample. The main topics covered by the articles were: the characteristics of breast milk donors; the importance of information provided by HMB professionals on maintaining breastfeeding for hospitalized premature infants; weight gain in premature babies fed on donated milk; HMB breastfeeding support actions; and factors influencing human milk donation. The actions developed by HMBs have a positive impact on the promotion of maternal and infant health, representing an important strategy for promoting breastfeeding and supporting the feeding of babies who are not able to feed directly at the breast.

Update on the Use of Intravenous Immunoglobulin in Pregnancy

Intravenous immunoglobulin (IVIG) was first administered to humans in the 1980s. The mechanism of action of IVIG is still a subject of debate but the pharmacokinetics have been well characterized, albeit outside of pregnancy. IVIG has been used in pregnancy to treat several nonobstetrical and obstetrical-related conditions. However, current evidence suggests that IVIG use during pregnancy can be recommended for 1) in utero diagnosis of neonatal alloimmune thrombocytopenia; 2) gestational alloimmune liver disease; 3) hemolytic disease of the fetus and newborn for early-onset severe intrauterine disease; 4) antiphospholipid syndrome (APS) when refractory to or contraindicated to standard treatment, or in catastrophic antiphospholipid syndrome; and 5) immune thrombocytopenia when standard treatment is ineffective or rapid increase of platelet counts is needed. All recommendations are based on case series and cohort studies without randomized trials usually because of the rare prevalence of the conditions, the high incidence of adverse outcomes if left untreated, and ethical concerns. In contrast, IVIG therapy cannot be recommended for recurrent pregnancy loss, and the use of IVIG in subgroups of those with recurrent pregnancy loss requires further investigations. For non-obstetrical-related conditions, we recommend using IVIG as indicated for nonpregnant patients. In conclusion, the use of IVIG during pregnancy is an effective treatment in some obstetrical-related conditions with rare serious maternal side effects. However, the precise mechanisms of action and the long-term immunologic effects on the fetus and neonate are poorly understood and merit further investigations.

Benefits and Risks of IgG Transplacental Transfer

Maternal passage of immunoglobulin G (IgG) is an important passive mechanism for protecting the infant while the neonatal immune system is still immature and ineffective. IgG is the only antibody class capable of crossing the histological layers of the placenta by attaching to the neonatal Fc receptor expressed at the level of syncytiotrophoblasts, and it offers protection against neonatal infectious pathogens. In pregnant women with autoimmune or alloimmune disorders, or in those requiring certain types of biological therapy, transplacental passage of abnormal antibodies may cause fetal or neonatal harm. In this review, we will discuss the physiological mechanisms and benefits of transplacental transfer of maternal antibodies as well as pathological maternal situations where this system is hijacked, potentially leading to adverse neonatal outcomes.

Do red cell alloantibodies continue to challenge breast fed babies?

BACKGROUND

Newborns have limited specific immune capability at birth, owing to delayed and constrained development of adaptive immunity. To supplement this period the mother passively transfers antibodies to the child either transplacentally or through breast milk. When maternal alloimmunisation occurs through foreign or fetal red cell surface antigens, stimulating the production of immunoglobulin G (IgG) antibodies, these IgG antibodies can cross the placenta and cause haemolytic disease of the fetus and the newborn.

OBJECTIVE

We present two case reports of a neonate and an infant in whom IgG red cell alloantibodies were transferred through maternal breast milk.

METHODS

Maternal serum, baby's serum and expressed breast milk samples were tested for the presence of red cell alloantibodies using gel card. Antibody screening, antibody identifications and titres alongside monospecific direct antiglobulin test, IgG subtypes were performed using the standard methods.

RESULTS

In the first case, a 6-month-old child was incidentally found to have positive antibody screen. Anti-KELL1 was identified, which was also present in maternal serum and breast milk. The second neonate was evaluated for haemolysis and was found to have anti-D. Anti-D was also detected in the maternal serum and breast milk. Both babies did not have any sensitising events. The first baby was asymptomatic, but the second baby had ongoing haemolysis until 1 month.

CONCLUSION

We report that maternal anti-KELL1 and anti-D antibodies were present in breast milk and were capable of being transferred to a feeding child. Our case report also raises interesting and unanswered immunologic fundamentals that should be considered in neonates with unexplained anaemia or delayed and persistent haemolysis.

The Importance of Vaccinating Children and Pregnant Women against Influenza Virus Infection

Influenza virus infection is responsible for significant morbidity and mortality in the pediatric and pregnant women populations, with deaths frequently caused by severe influenza-associated lower respiratory tract infection and acute respiratory distress syndrome (ARDS). An appropriate immune response requires controlling the viral infection through activation of antiviral defenses, which involves cells of the lung and immune system. High levels of viral infection or high levels of inflammation in the lower airways can contribute to ARDS. Pregnant women and young children, especially those born prematurely, may develop serious complications if infected with influenza virus. Vaccination against influenza will lead to lower infection rates and fewer complications, even if the vaccine is poorly matched to circulating viral strains, with maternal vaccination offering infants protection via antibody transmission through the placenta and breast milk. Despite the health benefits of the influenza vaccine, vaccination rates around the world remain well below targets. Trust in the use of vaccines among the public must be restored in order to increase vaccination rates and decrease the public health burden of influenza.

The Function and Alteration of Immunological Properties in Human Milk of Obese Mothers

Maternal obesity is associated with metabolic changes in mothers and higher risk of obesity in the offspring. Obesity in breastfeeding mothers appears to influence human milk production as well as the quality of human milk. Maternal obesity is associated with alteration of immunological factors concentrations in the human milk, such as C-reactive protein (CRP), leptin, IL-6, insulin, TNF-Alpha, ghrelin, adiponectin, and obestatin. Human milk is considered a first choice for infant nutrition due to the complete profile of macro nutrients, micro nutrients, and immunological properties. It is essential to understand how maternal obesity influences immunological properties of human milk because alterations could impact the nutrition status and health of the infant. This review summarizes the literature regarding the impact of maternal obesity on the concentration of particular immunological properties in the human milk.

An Infant Mouse Model of Influenza Virus Transmission Demonstrates the Role of Virus-Specific Shedding, Humoral Immunity, and Sialidase Expression by Colonizing Streptococcus pneumoniae

The pandemic potential of influenza A viruses (IAV) depends on the infectivity of the host, transmissibility of the virus, and susceptibility of the recipient. While virus traits supporting IAV transmission have been studied in detail using ferret and guinea pig models, there is limited understanding of host traits determining transmissibility and susceptibility because current animal models of transmission are not sufficiently tractable. Although mice remain the primary model to study IAV immunity and pathogenesis, the efficiency of IAV transmission in adult mice has been inconsistent. Here we describe an infant mouse model that supports efficient transmission of IAV. We demonstrate that transmission in this model requires young age, close contact, shedding of virus particles from the upper respiratory tract (URT) of infected pups, the use of a transmissible virus strain, and a susceptible recipient. We characterize shedding as a marker of infectiousness that predicts the efficiency of transmission among different influenza virus strains. We also demonstrate that transmissibility and susceptibility to IAV can be inhibited by humoral immunity via maternal-infant transfer of IAV-specific immunoglobulins and modifications to the URT milieu, via sialidase activity of colonizing Streptococcus pneumoniae Due to its simplicity and efficiency, this model can be used to dissect the host's contribution to IAV transmission and explore new methods to limit contagion.IMPORTANCE This study provides insight into the role of the virus strain, age, immunity, and URT flora on IAV shedding and transmission efficiency. Using the infant mouse model, we found that (i) differences in viral shedding of various IAV strains are dependent on specific hemagglutinin (HA) and/or neuraminidase (NA) proteins, (ii) host age plays a key role in the efficiency of IAV transmission, (iii) levels of IAV-specific immunoglobulins are necessary to limit infectiousness, transmission, and susceptibility to IAV, and (iv) expression of sialidases by colonizing S. pneumoniae antagonizes transmission by limiting the acquisition of IAV in recipient hosts. Our findings highlight the need for strategies that limit IAV shedding and the importance of understanding the function of the URT bacterial composition in IAV transmission. This work reinforces the significance of a tractable animal model to study both viral and host traits affecting IAV contagion and its potential for optimizing vaccines and therapeutics that target disease spread.

Pharmacological Approach to Managing Childhood-Onset Systemic Lupus Erythematosus During Conception, Pregnancy and Breastfeeding

Pediatric patients often have poor pregnancy outcomes. Systemic lupus erythematosus predominantly impacts women in their second to fourth decade of life, with childhood-onset disease being particularly aggressive. Reproductive issues are an important clinical consideration for pediatric patients with systemic lupus erythematosus (SLE), as maintaining good disease control and planning a pregnancy are important for maternal and fetal outcomes. In this clinical review, we will consider the safety of medications in managing childhood-onset SLE during conception, pregnancy, and breastfeeding. The developing fetus is at highest risk for teratogenicity from maternal medications during the period of critical organogenesis, which occurs between the first 3-8 weeks following conception. Medications known to be teratogenic, leading to a specific pattern of malformations, include mycophenolic acid, methotrexate, and cyclophosphamide. These should be discontinued prior to a planned pregnancy or as soon as pregnancy is suspected. Hydroxychloroquine is safe and should be continued throughout pregnancy and breastfeeding in those without contraindications to it. Azathioprine and calcineurin inhibitors are felt to be compatible with pregnancy in usual doses and may be used prior to and throughout pregnancy and lactation. Non-fluorinated corticosteroids including methylprednisolone and prednisone are inactivated by the placenta and can be used if needed for maternal indication during gestation. Addition of aspirin may be considered around the 12th week of gestation for prevention of pre-eclampsia. Illustrative cases are presented that demonstrate management of adolescents with childhood-onset SLE through conception, pregnancy, and breastfeeding.

Pregnancy, child bearing and prevention of giving birth to the affected children in patients with primary immunodeficiency disease; a case-series

BACKGROUND

Patients with primary immunodeficiency disease (PID) who survive to adulthood and willing to have a child mostly are worried whether their disease affects their fertility and/or pregnancy and also if their child would be predisposed to PID.

CASE PRESENTATION

We report the outcome of conception, pregnancy and their management in 9 families with definite diagnosis of PID. A chronic granulomatous disease subject with an uneventful pregnancy developed fungal sacral osteomyelitis few weeks after delivery. A pregnant common variable immunodeficiency disease (CVID) patient with idiopathic thrombocytopenia had platelet count dropped before delivery. A sever neutropenic mother who refused to get IFNγ delivered two healthy children. A CVID case intolerant to IVIg with eclampsia and PTE delivered a baby. Another CVID female gave birth to a baby without being on any treatment since she was not diagnosed with immunodeficiency disease at that time. A healthy girl was implanted via preimplantation gender selection in a family who owned a Wiskott Aldrich-affected son. A family who had two children with Ataxia Telangiectasia used donated oocyte for their 3rd child. Prenatal genetic diagnosis was used to screen the fetus for the impaired BTK and CVID genes detected in sibling and father respectively in 2 separate families.

CONCLUSION

Pregnancy in PID patients is more complex than normal population. Because, not only it has the chance of being inherited by the offspring, but also there are some risks for the mother if she has any kind of immunity component defects. So consultation with a clinical geneticist is crucial to choose the best available approach. They also should be observed and followed by a clinical immunologist to take the best possible safe care.

Vedolizumab Levels in Breast Milk of Nursing Mothers With Inflammatory Bowel Disease

INTRODUCTION

There are no data on the transfer of vedolizumab in breast milk of nursing mothers. We aimed to assess the presence of vedolizumab in breast milk of nursing inflammatory bowel disease [IBD] patients.

METHODS

This was a prospective observational study of vedolizumab-treated breastfeeding patients with IBD. Serum and breast milk samples were obtained at pre-defined tim -points. The in-house developed enzyme-linked immunosorbent assay [ELISA] for measuring vedolizumab in blood was adapted and validated for measurement of the drug in breast milk. The level of vedolizumab was also measured in breast milk of a control group of nursing healthy mothers.

RESULTS

Vedolizumab was undetectable in breast milk in IBD patients before the first infusion of vedolizumab [n = 3] and in all of the healthy controls [n = 5]. Vedolizumab was measurable in all lactating women who received vedolizumab [n = 5]. However, on serial measurements in breast milk after an infusion, drug levels did not surpass 480 ng/ml, which was roughly 1/100 of the comparable serum levels.

CONCLUSIONS

Vedolizumab can be detected in the breast milk of nursing mothers. Although more data are imperative, the concentrations of vedolizumab in breast milk are minute and are therefore unlikely to result in systemic or gastro-intestinal immune-suppression of the infant.

B cells control maternofetal priming of allergy and tolerance in a murine model of allergic airway inflammation

BACKGROUND

Allergic asthma is a chronic lung disease resulting from inappropriate immune responses to environmental antigens. Early tolerance induction is an attractive approach for primary prevention of asthma.

OBJECTIVE

We analyzed the mechanisms of perinatal tolerance induction to allergens, with particular focus on the role of B cells in preconception and early intrauterine immune priming.

METHODS

Wild-type (WT) and B cell-deficient mice received ovalbumin (OVA) intranasally before mating. Their offspring were analyzed in a murine model of allergic airway inflammation.

RESULTS

Although antigen application before conception protected WT progeny from allergy, it aggravated allergic airway inflammation in B cell-deficient offspring. B-cell transfer restored protection, demonstrating the crucial role of B cells in perinatal tolerance induction. Effective diaplacentar allergen transfer was detectable in pregnant WT mice but not in pregnant B-cell knockout dams, and antigen concentrations in WT amniotic fluid (AF) were higher than in IgG-free AF of B cell-deficient dams. Application of OVA/IgG immune complexes during pregnancy boosted OVA uptake by fetal dendritic cells (DCs). Fetal DCs in human subjects and mice expressed strikingly higher levels of Fcγ receptors compared with DCs from adults and were highly efficient in taking up OVA/IgG immune complexes. Moreover, murine fetal DCs effectively primed antigen-specific forkhead box P3⁺ regulatory T cells after in vitro coincubation with OVA/IgG-containing AF.

CONCLUSION

Our data support a decisive role for B cells and immunoglobulins during in utero tolerance priming. These findings improve the understanding of perinatal immunity and might support the development of effective primary prevention strategies for allergy and asthma in the future.

Lactation and Management of Postpartum Disease

While much of the existing literature in the field of reproductive rheumatology focuses on fertility, preconception counseling, and pregnancy, there is limited information regarding the postpartum period and lactation. Evidence suggests that many rheumatologic disorders flare after delivery, which, along with limitations in medications compatible with breastfeeding, make this time period challenging for women with rheumatologic conditions. This article discusses rheumatologic disease activity during the postpartum period and reviews the safety during lactation of commonly used medications for the management of rheumatic diseases. Fortunately, many of the commonly used medications are compatible with breastfeeding.

Maternal-Foetal Diabetes Modifies Neonatal Fc Receptor Expression on Human Leucocytes

This study investigated the expression of the neonatal Fc receptor (FcRn) in maternal blood, cord blood and placental cells and determined IgG levels in maternal blood and cord blood from diabetic mothers. Peripheral blood, cord blood and placenta samples were collected from 26 mothers with normoglycaemia (non-diabetic, ND group) and 52 with hyperglycaemia (26 with mild gestational hyperglycaemia, MGH group, and 26 with type 2 diabetes mellitus, DM-2 group). Cells expressing CD19(+) and FcRn were identified by flow cytometry. Total IgG and its subclasses were quantified by ELISA. Maternal blood from DM-2 and cord blood from MGH exhibited a higher proportion of CD19(+) expression by B cells. DM-2 showed a lower proportion of CD19(+) cells in placenta. FcRn expression increased in cells from cord blood and placenta from MGH. Maternal blood, cord blood and placenta cells from DM-2 showed lower FcRn expression. Blood IgG levels were lower in DM-2, and cord blood IgG levels were higher in MGH. The highest levels of IgG4 were detected in the blood of hyperglycaemic mothers. The highest IgG3 and IgG4 levels in cord blood were detected in MGH, and the lowest IgG2 and IgG3 levels in DM-2. Maternal hyperglycaemia compromised placental transfer of IgG1, IgG3 and IgG4. The results suggest that regardless of hyperglycaemia degree, it decreases FcRn expression in placenta and blood cells and compromises the production and transfer of antibodies from maternal blood to newborns.

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

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.

Early Exposure to Respiratory Allergens by Placental Transfer and Breastfeeding

The relationship between allergen exposure and the onset of or protection from allergic diseases remains unclear. Many factors could be related to immunological responses, such as the age when the exposure occurs, type of allergen, timing, dose, and allergen route. In this study, we investigated whether exposure to respiratory allergens could occur in pregnancy or early life. In particular, we assessed whether Der p 1 and Blo t 5, as well as specific antibodies against these allergens, could be detected in 90 paired cord blood and colostrum samples. Der p 1 was detected in 58.6% of colostrum and 29% of cord blood samples, whereas Blot 5 was positive in 41.3% and 9.6% of the samples, respectively. Similar to specific IgA, which could be detected in all samples for both mites, specific IgG was found in a high number of colostrum samples, 93.5% and 94.8% for Dp and Bt, respectively. Although allergens were not detected in all cord blood samples, a high percentage of them (≥95%) were positive for specific IgM to both mites in cord blood samples, suggesting that neonates can be exposed and sensitized to airborne allergens during pregnancy. Many studies have attempted to correlate allergen exposure or its prevention in early infancy with the onset of or protection from allergic diseases. However, conflicting and inconsistent data do not show a clear correlation with or suggest a way to prevent allergen sensitization. Nevertheless, these unconvincing results could be better understood if the relationship with many aspects of allergen exposure after pregnancy could be clarified. Thus, it is necessary to address basic issues related to allergen exposure, including the development of reproducible, standardized and reliable methods, and to determine how and where the exposure occurs.

Does the Maternal Serum IgG Level during Pregnancy in Primary Antibody Deficiency Influence the IgG Level in the Newborn?

Purpose. To find out if the serum IgG level in the newborn baby was affected by low maternal serum IgG during pregnancy in two newly diagnosed primary antibody deficient patients. Method. Infant cord blood IgG level was compared with maternal IgG level in 2 mothers with newly diagnosed primary antibody deficiency, who declined replacement IgG treatment during pregnancy. Results. Both mothers delivered healthy babies with normal IgG levels at birth. Conclusions. The normal IgG levels and sound health in these 2 babies in spite of low maternal IgG throughout pregnancy raise interesting discussion points about maternofoetal immunoglobulin transport mechanisms in primary antibody deficiency.

The role of intravenous immunoglobulins in the treatment of rheumatoid arthritis

Intravenous immunoglobulins (IVIGs) are beneficial and safe for various diseases other than primary immunodeficiencies. Over the years, IVIG has been given for autoimmune diseases as an off-label adjunct therapy. While other biologic agents are indicated for rheumatoid arthritis (RA), IVIG may have a role for specific subgroups of RA patients where anti-cytokine blockers or rituximab may be unwarranted. Such subgroups may include patients with vasculitis, overlap rhupus syndrome, severe infections with active disease, and pregnancy. In addition, IVIG may be considered for juvenile chronic arthritis (JCA) and adult Still's disease. We review the literature for IVIG treatment in RA patients and for these subgroups.

Competition between serum IgG, IgM, and IgA anti-glycan antibodies

Anti-glycan antibodies are an abundant subpopulation of serum antibodies with critical functions in many immune processes. Changes in the levels of these antibodies can occur with the onset of disease, exposure to pathogens, or vaccination. As a result, there has been significant interest in exploiting anti-glycan antibodies as biomarkers for many diseases. Serum contains a mixture of anti-glycan antibodies that can recognize the same antigen, and competition for binding can potentially influence the detection of antibody subpopulations that are more relevant to disease processes. The most abundant antibody isotypes in serum are IgG, IgM, and IgA, but little is known regarding how these different isotypes compete for the same glycan antigen. In this study, we developed a multiplexed glycan microarray assay and applied it to evaluate how different isotypes of anti-glycan antibodies (IgA, IgG, and IgM) compete for printed glycan antigens. While IgG and IgA antibodies typically outcompete IgM for peptide or protein antigens, we found that IgM outcompete IgG and IgA for many glycan antigens. To illustrate the importance of this effect, we provide evidence that IgM competition can account for the unexpected observation that IgG of certain antigen specificities appear to be preferentially transported from mothers to fetuses. We demonstrate that IgM in maternal sera compete with IgG resulting in lower than expected IgG signals. Since cord blood contains very low levels of IgM, competition only affects maternal IgG signals, making it appear as though certain IgG antibodies are higher in cord blood than matched maternal blood. Taken together, the results highlight the importance of competition for studies involving anti-glycan antibodies.

Fertility, pregnancies and outcomes reported by females with common variable immune deficiency and hypogammaglobulinemia: results from an internet-based survey

BACKGROUND

Issues of fertility and pregnancy place an extra burden on females with primary immunodeficiencies. Patients lack reliable information and providers lack guidelines to counsel patients on these anxiety-provoking matters.

OBJECTIVE

To collate concerns and experiences related to fertility and pregnancy from females with humoral immune deficiencies.

METHODS

We conducted an internet-based survey of female patients who self-identified as having a diagnosis of primary humoral immune deficiency.

RESULTS

Responses from 490 women with common variable immune deficiency and 100 with hypogammaglobulinemia were evaluated. The reported fertility measure (% of women who had had a birth) was statistically significantly lower as compared to the general US population (70 % vs. 85 %, p < 0.0001) whereas the rates of spontaneous pregnancy loss were comparable. This group reported a total of 966 pregnancies; 72 % resulted in a live birth. A majority of the pregnancies progressed with no incident and with continuation of their IgG replacement therapy; 23 % reported an increase in IgG dosing during pregnancy. Only 15 % of those reporting a first pregnancy indicated that they had been diagnosed with immune deficiency prior to their first pregnancy; these women expressed concern regarding the effect of immune deficiency on their fertility, pregnancy and decision to have children.

CONCLUSION

With inherent limitations of self-reported responses to surveys, females with humoral immune deficiencies reported relatively good rates of fertility and pregnancies ending in live births. Results of the survey will serve as peer support for patients and inform counseling guidelines for providers.

Placental transfer of a fully human IgG2 monoclonal antibody in the cynomolgus monkey, rat, and rabbit: a comparative assessment from during organogenesis to late gestation

Understanding species differences in the placental transfer of monoclonal antibodies is important to inform species selection for nonclinical safety assessment, interpret embryo-fetal changes observed in these studies, and extrapolate their human relevance. Data presented here for a fully human immunoglobulin G2 monoclonal antibody (IgG2X) revealed that, during organogenesis, in both the cynomolgus monkey (gestation day 35 [gd35]) and the rat (gd10) the extent of IgG2X placental transfer (approximately 0.5% maternal plasma concentration, MPC) was similar to the limited published human data for endogenous IgG. At this early gestational stage, IgG2X placental transfer was approximately 6-fold higher in the rabbit (gd10). By the end of organogenesis, rat embryonic plasma concentrations (gd16) exceeded those in the cynomolgus monkey (gd50) by approximately 3-fold. These data suggest that relative to the cynomolgus monkey, the rabbit (and to a lesser extent the rat) may overestimate potential harmful effects to the human embryo during this critical period of development. Beyond organogenesis, fetal IgG2X plasma concentrations increased approximately 10-fold early in the second trimester (gd50-70) in the cynomolgus monkey and remained relatively unchanged thereafter (at approximately 5% MPC). Late gestational assessment was precluded in rabbits due to immunogenicity, but in rats, fetal IgG2X plasma concentrations increased more than 6-fold from gd16 to gd21 (reaching approximately 15% MPC). In rats, maternal exposure consistent with that achieved by ICH S6(R1) high-dose selection criteria resulted in embryonic plasma concentrations, reaching pharmacologically relevant levels during organogenesis. Furthermore, dose proportional exposure in both mothers and embryos indicated that this was unlikely to occur at the lower therapeutic dose levels used in humans.

Humoral immune response to Shiga Toxin 2 (Stx2) among Brazilian urban children with hemolytic uremic syndrome and healthy controls

Background

Shiga toxin (Stx)-producing Escherichia coli (STEC) infection is associated with hemolytic uremic syndrome (HUS), the main cause of acute renal failure in early childhood. Stx is essential in the pathogenesis of HUS, which has been mostly related to Stx2-producing isolates. Very limited data exist on the immune response to STEC in the Brazilian population. In this study, the prevalence of immunoglobulin G (IgG) antibodies to Stx2 was investigated in sera of children diagnosed with HUS and of healthy children in the city of São Paulo, Brazil.

Methods

IgG-antibody reactivity to Stx2 was determined by immunoblotting (WB) and enzyme-linked immunosorbent assay (ELISA) in sera from 13 children with HUS aged 8 months to 6 years and 54 healthy urban children aged 5 months to 7 years.

Results

A positive immune response to the A and B subunits of Stx2 was observed in 46.1% HUS patients and in 16.6% healthy individuals by WB. All HUS patients and 62.9% healthy children showed IgG antibodies to the Stx2 A subunit. The frequency of antibodies to both subunits or only to the A subunit of Stx2 was significantly higher in HUS patients than controls (p < 0.05). Also, the mean OD value obtained by ELISA was higher in that group. Considering children’s age, the frequency of reactivity to either the A subunit or both subunits of Stx2 was considerably higher in HUS children up to three years old compared to controls in the same age range. Moreover, in almost 37% of healthy children, no immune response to Stx2 was detected independently of the child’s age.

Conclusions

The seroepidemiolgy of anti-Stx2 antibodies was described for the first time in healthy children and children with HUS in Brazil. The percentage of individuals showing antibodies against Stx2 was higher among HUS patients than controls, and in spite of the low number of notified HUS cases, STEC strains are circulating in our settings. In addition, the results obtained also corroborated previous data on the increased sensitivity and specificity of WB compared to toxin-based enzyme immunoassays.

Longevity of Sm-p80-specific antibody responses following vaccination with Sm-p80 vaccine in mice and baboons and transplacental transfer of Sm-p80-specific antibodies in a baboon

Based on data obtained using vaccine efficacy studies in mice, hamsters, and baboons, the credentials of Sm-p80 as a first tier vaccine candidate for schistosomiasis have been well established. Sm-p80-based vaccine formulation(s) have consistently exhibited potent prophylactic efficacy in reducing adult worm burden following cercarial challenge and induce killing of established adult worms in chronic infection. This vaccine is protective against both intestinal and urinary schistosomiasis. In this study, the longevity of Sm-p80-specific antibody responses was studied in mice and in baboons. Robust antibody titers were detected in mice for up to 60 weeks following vaccination with Sm-p80 recombinant vaccine (Sm-p80 + GLA-SE). In the follow-up experiments to our published studies, Sm-p80-specific IgG was also detected in baboons 5-8 years following the initial vaccination with an Sm-p80 DNA vaccine. In one baboon, transfer of Sm-p80-specific antibody was detected in umbilical cord blood and in the baby. These long-lasting humoral immune response data coupled with the vaccine efficacy data in rodents and nonhuman primates further strengthens the case for Sm-p80 to be moved forward through development leading to human clinical trials.

A study of the prevalence of diarrhoeagenic Escherichia coli in children from Gwagwalada, Federal Capital Territory, Nigeria

Introduction

Diarrhoeagenic Escherichia coli (DEC) are major causes of diarrhoea in Nigeria. This study was conducted to determine the prevalence of diarrhoea caused by DEC within the Federal Capital Territory, Abuja, Nigeria.

Methods

A total of 730 rectal swabs obtained from 201 children with diarrhoea and 529 healthy controls aged 0-24 months were cultured for the isolation of Escherichia coli. All E. coli isolates were investigated by PCR to determine their pathotype.

Results

A total of 61 DEC strains were recovered at a rate of 18.4% and 2.6% from children with diarrhoea and healthy controls respectively. The DEC strains recovered were Enteroaggregative Escherichia coli (34.4%), Shiga-toxin producing Escherichia coli (31.1%), Enterotoxigenic Escherichia coli(18.0%), typical enteropathogenic Escherichia coli (15.0%) and Enteroinvasive Escherichia coli (1.6%). Shiga-toxin producing Escherichia coli andEnteroinvasive Escherichia coli were recovered only from children suffering from diarrhoea and the overall prevalence of DEC strains was significantly higher among the children with diarrhoea (P < 0.0001). The number of DEC strains obtained during the dry season was significantly higher (P = 0.012) than the number obtained in the rainy season.

Conclusion

Diarrhoea caused by E. coli in the Nigerian children studied is associated with several diarrhoeagenic pathotypes and a significant proportion of the healthy children were found to harbour EAEC and ETEC strains. These asymptomatic carriers may be regarded as potential transmitters of infection to vulnerable children in the study area.

Placental transfer of (125)Iodinated humanized immunoglobulin G2Δa in the Sprague Dawley rat

Antibody-like biopharmaceuticals cross the placenta by utilizing transport pathways available for transfer of maternal antibodies to the conceptus. To characterize the timing and magnitude of this transfer in the rat, embryo/fetal biodistribution of maternally administered radiolabeled humanized IgG2 was quantified over the course of gestation using gamma counting and whole body autoradiography. The result was humanized IgG2 found in rat embryo/fetal tissues as early as gestation day 11 with a >1000-fold increase in the amount of total IgG2 by day 21. The concentration of IgG2 in rat embryo/fetal tissues generally remained unchanged from gestation day 11 to 17 with a slight increase from day 17 to 21. In addition, fetal-maternal tissue concentration ratios remained stable during organogenesis with a slight increase from gestation day 17 to 21. Based on the empirical amount of antibody present in the embryo/fetus during specific developmental windows, direct antibody binding to biological targets could potentially result in adverse developmental outcomes.

Management of a pregnant woman with common variable immunodeficiency and previous reactions to intravenous IgG administration

Common variable immunodeficiency is the most common symptomatic primary immunodeficiency in adulthood. Pregnant women with common variable immunodeficiency have different needs from other patients with the same disease. Because of immature state of the fetal and neonatal immune system, transplacental transfer of immunoglobulin G (IgG) has a relevant role in protecting the infant. We here report on a high-risk pregnant woman with common variable immunodeficiency with adverse reactions to intravenous immunoglobulin that was successfully rescued with a new Ig human intravenous, 10% liquid preparation. The treatment was tailored to the health status and characteristics of the patient. The new product was safe and well tolerated. The mother did not report any infections during pregnancy and the baby had a healthy course with 'protective' serum IgG levels. Our case is a further demonstration that intravenous immunoglobulin tolerability in patients with immunodeficiency could be linked to a product's characteristics.

HFcRn-mediated transplacental immunoglobulin G transport: protection of and threat to the human fetus and newborn

In human newborns, endogenous levels of plasma immunoglobulin G (IgG) begin to rise slowly after birth following exposure to the environment. For immunoprotection during fetal and early neonatal life, maternal IgG is provided by transplacental transport. While cellular immunoprotective IgG effects are mainly triggered by FcγRI, -RII and -RIII, transplacental IgG transfer is mediated by the MHC class I-like neonatal Fc-receptor, hFcRn. This compact review explains the mechanism of hFcRn-mediated IgG transcytosis across the placental barrier - syncytiotrophoblast and fetal endothelial cells. Restrictions of this IgG transport are summarized. These include IgG subclass discrimination and limited IgG transport before the third trimester that can cause insufficient protection from infections of preterm (≤ 35 th week) delivered babies. As hFcRn does not discriminate beneficial from hazardous IgGs, maternal auto- and alloimmune as well as therapeutic antibodies can reach the fetus. The consequences including severe diseases of the newborn are summarized in this article.

Management of granulomatous common variable immunodeficiency diagnosed in pregnancy: a case report

Common variable immunodeficiency (CVID) is a rare condition that affects women of childbearing age with important implications in pregnancy. It is characterised by low immunoglobulins (Igs), poor antibody response and a susceptibility to recurrent infections. The cornerstone of management of CVID is Ig replacement. As the transfer of IgG across the placenta in the third trimester of pregnancy is necessary for protection of the infant in the first months of life, failure to recognise this condition and treat it appropriately can have adverse consequences for the neonate, as well as the mother. Here we describe the complex perinatal medical management of a 34-year-old woman who was diagnosed with CVID in the 26th week of pregnancy.

Mother to child transfer of IgG and IgA antibodies against Dermatophagoides pteronyssinus

There is strong evidence from animal models that placental and/or breast milk-mediated transfer of maternal allergen-specific IgG prevents allergic immune responses in the progeny. Both human and animal data also point to IgA as having an important regulatory role. In contrast, little is known about maternal transfer of IgG and IgA specific for respiratory allergens in humans. Dermatophagoides pteronyssinus (Der p) is an indoor allergen that is a major cause of asthma worldwide. We analysed maternal to child Der p-specific IgG and IgA transfer in a cohort of 77 paired maternal and child samples. We found Der p-specific IgG and its IgG1, IgG2 and IgG4 subclasses in all cord blood samples. Except for IgG1, cord levels were higher in newborns from atopic mothers (n = 29) compared to non-atopic mothers (n = 48). Der p-specific IgA was found in all colostrum samples and levels were independent of maternal atopic status. Notably, anti-Der p IgG was also found in colostrum and levels were higher in atopic mothers. We believe that our work is a critical first step in the identification of early factors that may impact asthma development and should guide the development of clinical studies that assess whether Der p-specific IgG and IgA protect children from allergy as demonstrated in animal models.

Detection of infliximab in breast milk of nursing mothers with inflammatory bowel disease

INTRODUCTION

Limited data suggest the absence of infliximab in breast milk, thereby implying the safety of this drug during breast-feeding. We aimed to re-evaluate the presence of infliximab in breast milk of nursing IBD patients.

METHODS

Serum and breast milk were obtained post-partum from 3 breast-feeding patients with Crohn's disease before and after re-initiation of infliximab. ELISA assay was employed to measure infliximab level in maternal serum and in breast milk. The level of infliximab was also measured in breast milk of a control group of 8 nursing healthy mothers.

RESULTS

Infliximab was undetectable in breast milk prior to the first infusion and was also not measurable in 8 lactating women not exposed to infliximab. Infliximab levels in breast milk rose up to 101ng/ml within 2-3days of the infusion. These levels of infliximab in breast milk were roughly 1/200th of the level in blood.

CONCLUSIONS

In contrast with prior reports, infliximab can be detected in the breast milk of nursing mothers. The miniscule amounts of infliximab transferred in breast milk are unlikely to result in systemic immune-suppression of the infant. Nonetheless, local effects of this exposure on the neonates' intestine and potential immune sensitization or tolerization towards the drug can not be excluded and merit further investigations.