Transfer Of Antibodies Research Articles

Myasthenia gravis-Gender aspects and family planning

There is evidence that gender-specific differences can influence the diagnostics, treatment and long-term disease course of myasthenia gravis (MG). In women the diagnosis is often made during childbearing age. Gender-specific differences in MG and relevant aspects in routine clinical practice are presented. In addition, current studies on family planning, pregnancy and childbirth in MG are highlighted and treatment recommendations are derived. Narrative literature review. In addition to sociodemographic data, gender-specific differences encompass clinical as well as paraclinical factors, such as disease severity and antibody status. With few exceptions pregnancy is possible with good maternal and neonatal outcome. During pregnancy and peripartum, children of MG patients should be closely monitored for early detection and treatment of potential syndromes caused by diaplacental transfer of maternal antibodies. Gender-specific factors can influence the course of MG. Adequate medical counselling and multidisciplinary collaboration are essential for MG patients who wish to have children.

Maternal-driven immune education in offspring.

Maternal environmental exposures, particularly during gestation and lactation, significantly influence the immunological development and long-term immunity of offspring. Mammalian immune systems develop through crucial inputs from the environment, beginning in utero and continuing after birth. These critical developmental windows are essential for proper immune system development and, once closed, may not be reopened. This review focuses on the mechanisms by which maternal exposures, particularly to pathogens, diet, and microbiota, impact offspring immunity. Mechanisms driving maternal-offspring immune crosstalk include transfer of maternal antibodies, changes in the maternal microbiome and microbiota-derived metabolites, and transfer of immune cells and cytokines via the placenta and breastfeeding. We further discuss the role of transient maternal infections, which are common during pregnancy, in providing tissue-specific immune education to offspring. We propose a "maternal-driven immune education" hypothesis, which suggests that offspring can use maternal encounters that occur during a critical developmental window to develop optimal immune fitness against infection and inflammation.

Seroprevalence and risk factors associated with Theileria parva infection among calves in Narok County, Kenya

Background and Aim: East Coast fever (ECF), caused by Theileria parva, is a devastating disease that causes significant economic losses to cattle production in sub-Saharan Africa. Prevention and control of ECF are challenging in pastoral settings due to inadequate epidemiological information. This study aimed to estimate the seroprevalence and risk factors associated with T. parva infection among calves in different production systems to help design appropriate control interventions. Materials and Methods: Blood samples were collected from 318 calves and tested using an indirect enzyme-linked immunosorbent assay targeting antibodies against polymorphic immunodominant molecules found on the surface of T. parva. Information on calf characteristics and management practices was also collected during sampling. Descriptive statistics and logistic regression were used to analyze potential risk factors, such as age and acaricide application, where p < 0.05 was considered significant Results: Of the 318 calves sampled, 41 (12.89%) were positive for T. parva, with a higher proportion in pastoral systems (36.58%) than in mixed farming systems (34.10%) and agropastoral systems (29.27%). From univariate analysis, calf age (p = 0.002), body weight (p = 0.001), suckling status (p = 0.026), rectal temperature (p = 0.06), calves on pasture (p = 0.022), other feeds (p = 0.004), feed grown within the farm (p = 0.004), acaricide application (p = 0.001), and acaricide application frequency (p = 0.001) were significantly associated with seropositivity. However, calf age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.91-0.99; p = 0.04), other feeds (OR, 8.82; 95% CI, 1.74-44.63; p = 0.009), and suckling status (OR, 0.38; 95% CI, 0.15-0.99; p = 0.05) were significantly associated with T. parva infection in the multivariable mixed logistic model. Conclusion: T. parva is circulating in young calves in the study area (and possibly in cattle populations due to maternal transfer of antibodies to the calves). There is a need for molecular surveillance to determine the presence and burden of T. parva infection. Keywords: calves, risk factors, seroprevalence, Theileria parva.

Endothelial YAP/TEAD1-CXCL17 signaling recruits myeloid-derived suppressor cells against liver ischemia-reperfusion injury.

Liver ischemia-reperfusion injury (IRI) is a common complication of liver transplantation and hepatectomy, and causes acute liver dysfunction and even organ failure. Myeloid-derived suppressor cells (MDSCs) accumulate and play immunosuppressive function in cancers and inflammation. However, the role of MDSCs in liver IRI has not been defined. We enrolled recipients receiving orthotopic liver transplantation (OLT) and obtained the pre-OLT/post-OLT blood and liver samples. The proportions of MDSCs were significantly elevated after OLT and negatively associated with liver damage. In single-cell RNA-sequencing analysis of liver samples during OLT, two cell clusters with MDSC-like phenotypes were identified and showed maturation and infiltration in post-OLT livers. In mice model, liver IRI mobilized MDSCs and promoted their infiltration in damaged liver, and intrahepatic MDSCs possessed with enhanced immunosuppressive function by up-regulation of STAT3 signaling. Under treatment with αGr-1 antibody or adoptive transfer MDSCs to change the proportion of MDSCs in vivo, we found that intrahepatic MDSCs alleviated liver IRI-induced inflammation and damage by inhibiting M1 macrophage polarization. Mechanistically, bulk RNA-sequencing analysis and in vivo experiments verified that CXCL17 was upregulated by YAP/TEAD1 signaling and subsequently recruited MDSCs via binding with GPR35 during liver IRI. Moreover, hepatic endothelial cells were the major cells responsible for CXCL17 expression in injured livers, among which hypoxia-reoxygenation stimulation activated YAP/TEAD1 complex to promote CXCL17 transcription. Endothelial YAP/TEAD1-CXCL17 signaling recruited MDSCs to attenuate liver IRI, providing evidence of a therapeutic potential for managing IRI in liver surgery.

Immunogenicity at delivery after Tdap vaccination in successive pregnancies.

Tetanus, diphtheria, acellular pertussis (Tdap) vaccination is recommended to be administered in every pregnancy. Although the safety of this strategy has been confirmed, the immunogenicity of Tdap vaccination in two successive pregnancies has not yet been described. This study investigated Tdap-specific immunity levels and transplacental transfer in two successive pregnancies after repeated Tdap-vaccination. Women enrolled in prior studies on Tdap vaccination during pregnancy were invited to participate in a follow-up study if they became pregnant again. Women who received a Tdap vaccine in both pregnancies were considered for this analysis. Tdap-specific total IgG and IgG subclasses were measured with a multiplex immunoassay. In total, 27 participants with a mean interval between deliveries of 2.4 years were included in the analysis. In maternal serum, Tdap-specific total IgG levels were comparable at both deliveries whereas in cord serum, all Tdap-specific total IgG antibody levels were reduced at the second compared to the first delivery. This was largely reflected in the IgG1 levels in maternal and cord serum. Transplacental transfer ratios of total IgG and IgG1 were also mostly reduced in the second compared to the first pregnancy. This study reports for the first time Tdap-specific total IgG and IgG subclass levels and transfer ratios after repeated Tdap vaccination in successive pregnancies. We found reduced transfer of most Tdap-specific IgG and IgG1 antibodies in the successive pregnancy. As pertussis-specific antibodies wane quickly, Tdap vaccination in each pregnancy remains beneficial. However, more research is needed to understand the impact of closely spaced booster doses during pregnancy on early infant protection against pertussis.

Association Between Influenza Vaccination During Pregnancy and Infant Influenza Vaccination

(Obstet Gynecol. 2023;141:563–569) Vaccines are safe and effective in preventing illness, including in mildly immunosuppressed individuals such as pregnant women. Influenza vaccines have been in use for decades and have been shown to be safe and effective at preventing illness in both mother and child, providing protection through the transplacental transfer of antibodies to infants too young to receive their own vaccination. Influenza presents increased risks to pregnant individuals as well as adverse outcomes for fetuses and infants. Annual influenza vaccinations are recommended for everyone 6 months and older, but rates of annual vaccinations are chronically low. This study was designed to evaluate the association between influenza vaccination during pregnancy and infant influenza vaccination.

Disturbances in the IgG Antibody Profile in HIV-Exposed Uninfected Infants Associated with Maternal Factors.

Over the last 20 years, the incidence of vertical HIV transmission has decreased from 25%-42% to less than 1%. Although there are no signs of infection, the health of HIV-exposed uninfected (HEU) infants is notoriously affected during the first months of life, with opportunistic infections being the most common disease. Some studies have reported effects on the vertical transfer of antibodies, but little is known about the subclass distribution of these antibodies. We proposed to evaluate the total IgG concentration and its subclasses in HIV+ mothers and HEU pairs and to determine which maternal factors condition their levels. In this study, plasma from 69 HEU newborns, their mothers, and 71 control pairs was quantified via immunoassays for each IgG isotype. Furthermore, we followed the antibody profile of HEUs throughout the first year of life. We showed that mothers present an antibody profile characterized by high concentrations of IgG1 and IgG3 but reduced IgG2, and HEU infants are born with an IgG subclass profile similar to that of their maternal pair. Interestingly, this passively transferred profile could remain influenced even during their own antibody production in HEU infants, depending on maternal conditions such as CD4+ T-cell counts and maternal antiretroviral treatment. Our findings indicate that HEU infants exhibit an altered IgG subclass profile influenced by maternal factors, potentially contributing to their increased susceptibility to infections.

Analysis of the transplacental transmission of SARS CoV-2 virus and antibody transfer according to the gestational age at maternal infection

To quantify transplacental transmission of SARS-CoV-2 virus and antibody transfer in pregnant women and their newborns according to the gestational age at maternal infection. A prospective observational multicenter study including pregnant women with a positive RT-PCR or a positive serology for SARS-CoV-2 and compatible symptoms, from April to December 2020, in 11 French maternities. The study was designed to obtain a systematic collection of mother-infant dyad’s samples at birth. SARS-CoV-2 viral load was measured by RT-PCR. IgG and IgM antibodies against the SARS-CoV-2 spike protein were measured by enzyme-linked immunosorbent assay. Antibody concentrations and transplacental transfer ratios were analyzed according to the gestational age at maternal infection. The primary outcome was the rate of SARS CoV-2 materno-fetal transmission at birth. The secondary outcome was the quantification of materno-fetal antibody transfer. Maternal and neonatal outcomes at birth were additionally assessed. Among 165 dyads enrolled, one congenital infection was confirmed {n = 1 (0.63%) IC95% [0.02%; 3.48%]}. The average placental IgG antibody transfer ratio was 1.27 (IC 95% [0.69–2.89]). The transfer ratio increased with increasing time between the onset of maternal infection and delivery (P Value = 0.0001). Maternal and neonatal outcomes were reassuring. We confirmed the very low rate of SARS-CoV-2 transplacental transmission (< 1%). Maternal antibody transfer to the fetus was more efficient when the infection occurred during the first and second trimester of pregnancy.

COVID-19 Maternal Antibody Concentrations in Small for Gestational Age Infants: Does Placental Insufficiency Impact Transplacental Antibody Transfer?

COVID-19 Maternal Antibody Concentrations in Small for Gestational Age Infants: Does Placental Insufficiency Impact Transplacental Antibody Transfer?

Recombinant Antibody Fragments for Immunotherapy of Parkinson's Disease.

Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder. Multiple genetic and environmental factors leading to progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SN) and consequent depletion of dopamine were described. Current clinical approaches, such as dopamine replacement or deep brain stimulation using surgically implanted probes, provide symptomatic relief but cannot modify disease progression. Therefore, disease-modifying therapeutic tools are urgently needed. Immunotherapy approaches, including passive transfer of protective antibodies and their fragments, have shown therapeutic efficacy in several animal models of neurodegenerative diseases, including PD. Recombinant antibody fragments are promising alternatives to conventional full-length antibodies. Modern computational approaches and molecular biology tools, directed evolution methodology, and the design of tissue-penetrating fusion peptides allowed for the development of recombinant antibody fragments with superior specificity and affinity, reduced immunogenicity, the capacity to target hidden epitopes and cross the blood-brain barrier (BBB), higher solubility and stability, the ability to refold after heat denaturation, and inexpensive large-scale production. In addition, antibody fragments do not induce microglia Fcγ receptor (FcγR)-mediated proinflammatory response and tissue damage in the central nervous system (CNS), because they lack the Fc portion of the immunoglobulin molecule. In the present review, we summarized data on recombinant antibody fragments evaluated as immunotherapeutics in preclinical models of PD and discussed their potential for developing therapeutic and preventive protocols for patients with PD.

Placental Transfer Efficiency of Neutralizing Antibodies on SARS-CoV-2 Vaccination before and after Pregnancy in Mexican Women.

The protection of the neonate against pathogens depends largely on the antibodies transferred placentally from the mother; for this reason, maternal vaccination against emerging viruses, such as SARS-CoV-2, is of vital importance. Knowing some of the immunogenic factors that could alter the placental transfer of antibodies could aid in understanding the immune response and neonatal protection after maternal vaccination. In this study, we analyzed the efficiency of the placental transfer of binding and neutralizing antibodies, as well as some factors that could alter the passive immune response, such as the trimester of gestation at the time of immunization, the number of doses received by the mother and the type of vaccine. Binding IgG antibodies were detected by ELISA, and the detection of neutralizing antibodies was carried out using flow cytometry. Our results show efficient transfer rates (>1), which are higher when maternal vaccination occurs during the third trimester of gestation. Antibodies are detectable in mothers and their neonates after 12 months of maternal immunization, suggesting than the vaccination against COVID-19 before and during pregnancy in the Mexican population induces a lasting neutralizing response in mothers and their newborns.

VEDOLIZUMAB DOES NOT ALTER IMMUNOGLOBULIN LEVELS IN BREASTMILK OF MOTHERS WITH IBD

Abstract Diarrheal diseases are a major cause of infant mortality worldwide. Breastfeeding helps prevent such diseases by passive transfer of maternal antibodies against gastrointestinal pathogens previously encountered by the mother. The antibody secreting cells (ASC) that populate the lactating mammary gland (LMG) are educated in gastrointestinal lymphoid tissues, thus they express integrin a4b7. To recruit these ASC, the LMG expresses MAdCAM-1 and CCL28. Vedolizumab (vedo) blocks a combinatorial epitope on integrin a4b7, interfering with lymphocyte recruitment to the gut. Given the shared homing determinants between the gut and LMG, we investigated whether vedo might interfere with ASC trafficking to the LMG, therefore decreasing immunoglobulin (Ig) levels in breast milk. We measured Ig levels by ELISA in cryopreserved breast milk from mothers enrolled in Mommy’s Milk biorepository at the University of California, San Diego without and with Ulcerative Colitis(UC) or Crohn’s Disease(CD) and lactating mothers with UC and CD treated with vedo for more than 18 months. Milk samples were collected between 1 month and 15.45 months after childbirth. The levels of secretory IgA (SIgA) in breast milk of mothers without IBD (n=45) was not different from those of mothers with CD not on vedo (n=15) (301 ± 147 ug/mL vs. 322 ± 207 ug/mL). However, milk SIgA from mothers with UC not on vedo (n=7) were lower than non-IBD controls (213 ± 149 ug/mL vs. 301 ± 147ug/mL, p&amp;lt;0.01). We then compared milk SIgA from patients with CD and UC treated with vedo (CD: n= 9; 256 ± 80ug/mL, UC: n=10; 283 ± 87 ug/mL) with those from non-IBD controls (n=45; 301 ± 147ug/mL) and found no differences. Similarly, SIgA levels were not different between CD with or without vedo (256 ± 80 ug/mL vs. 322 ± 207 ug/mL) and as compared with non-IBD controls SIgA in patients with UC with vedo were unexpectedly higher than UC without vedo (283 ±87 ug/mL vs 213 ± 149 ug/mL, p&amp;lt;0.05). The levels of secretory IgM (SIgM) in milk were not different between mothers with UC or CD treated with vedo compared with non-IBD controls (65 ± 34 ug/mL, 69 ± 32 ug/mL, and 56 ± 37 ug/mL, respectively). Similarly, no significant difference was seen between patients with UC or CD not treated with vedo compared with the non-IBD controls (58±26 ug/mL, and 46 ± 24 ug/mL respectively). We conclude that vedo does not reduce SIgA nor SIgM levels in lactating mothers with IBD. We speculate that the higher SIgA in patients with UC treated with vedo is due to the small sample size. Vedo does not interfere with passive immunity during the lactation period, thus ASC must be able to use another integrin to arrest on microvessels of the LMG during the final stages of pregnancy.

Timing of Maternal COVID-19 Vaccine and Antibody Concentrations in Infants Born Preterm

COVID-19 vaccine-derived antibodies in pregnant people may protect infants from severe infection in the first 6 months of life via transplacental antibody transfer. Few data exist on maternally derived SARS-CoV-2 antibodies in preterm compared with full-term infants in association with vaccination timing. To compare SARS-CoV-2 anti-Spike (anti-S) antibody levels in preterm and full-term infants in the context of vaccine dose timing before delivery. This prospective cohort study enrolled pregnant individuals and collected paired maternal and cord blood samples at delivery at the University of Washington between February 1, 2021, and January 31, 2023. Participants who had received at least 2 doses of a messenger RNA COVID-19 vaccine before delivery and did not have a history of prior COVID-19 infection or detectable anti-SARS-CoV-2 nucleocapsid antibodies were included. Timing of the last vaccine dose and preterm or full-term gestational age at delivery. Paired maternal and cord samples were tested for anti-S antibody, and linear regression was used to evaluate associations between preterm delivery and anti-S antibody levels. Covariates included timing of last dose, number of doses, insurance status, and immunosuppressing medications. A total of 220 participants (median [IQR] age, 34 [32-37] years; 212 [96.4%] female) with 36 preterm and 184 full-term deliveries were studied. Before delivery, 121 persons received 2 vaccine doses and 99 persons received 3 or more vaccine doses. The geometric mean concentration of maternal anti-S antibodies was 674 (95% CI, 577-787) after 2 doses and 8159 (95% CI, 6636-10 032) after 3 or more doses (P < .001). The cord anti-S antibody geometric mean concentration was 1000 (95% CI, 874-1144) after 2 doses and 9992 (95% CI, 8381-11 914) after 3 or more doses (P < .001). After adjustment for vaccine timing and number of doses before delivery, no association was found between preterm delivery and cord anti-S antibody levels (β = 0.44; 95% CI, -0.06 to 0.94). In this prospective cohort study of pregnant individuals with preterm and full-term deliveries, receipt of 3 or more compared with 2 doses of COVID-19 vaccine before delivery resulted in 10-fold higher cord anti-S antibody levels. Maternal antibody concentration appeared more important than delivery gestational age in determining cord anti-S antibody levels. The number of doses and timing considerations for COVID-19 vaccine in pregnancy should include individuals at risk for preterm delivery.

Assessing immune factors in maternal milk and paired infant plasma antibody binding to human rhinoviruses.

Before they can produce their own antibodies, newborns are protected from infections by transplacental transfer of maternal IgG antibodies and after birth through breast milk IgA antibodies. Rhinovirus (RV) infections are extremely common in early childhood, and while RV infections often result in only mild upper respiratory illnesses, they can also cause severe lower respiratory illnesses such as bronchiolitis and pneumonia. We used high-density peptide arrays to profile infant and maternal antibody reactivity to capsid and full proteome sequences of three human RVs - A16, B52, and C11. Numerous plasma IgG and breast milk IgA RV epitopes were identified that localized to regions of the RV capsid surface and interior, and also to several non-structural proteins. While most epitopes were bound by both IgG and IgA, there were several instances where isotype-specific and RV-specific binding were observed. We also profiled 62 unique RV-C protein loop sequences characteristic of this species' capsid VP1 protein. Many of the RV-C loop sequences were highly bound by IgG from one-year-old infants, indicating recent or ongoing active infections, or alternatively, a level of cross-reactivity among homologous RV-C sites.

Neonatal Fc receptor : role and implications inmaternal fetal medicine

During pregnancy, the mother's IgG immunoglobulins cross the -placenta via the neonatal Fc receptor (FcRn), enabling the fetus to acquire passive immunity. In the presence of maternal allo- or auto-antibodies, placental transfer of these pathogenic antibodies mediated by FcRn can cause diseases in the fetus and/or the newborn. FcRn blockade therefore appears to be a therapeutic strategy in these high-risk pregnancies, firstly by reducing IgG recycling, -thereby reducing its concentration in the maternal circulation, and secondly by blocking placental transfer. The promising results of a recent trial testing nipocalimab, a monoclonal antibody targeting FcRn, in very severe erythrocyte alloimmunisation, has opened the way to new targeted therapeutic approaches for perinatal diseases mediated by maternal IgG.

Сложные вопросы диагностики синдрома неонатальной волчанки

Aim. To describe a clinical case of neonatal lupus with skin syndrome, a retrospective assessment of the significance and genesis of episodes of sinus bradycardia, recorded in utero and persisted postnatally, and neutropenia in the neonatal period. Key points. Neonatal lupus is a rare syndrome characterized by transient dermatitis, various systemic disorders, hematological changes and/ or congenital fetal heart block. At its core, this is a model of a passively acquired transient immune disease of newborns, which is based on the transplacental transfer of specific maternal antibodies represented exclusively by immunoglobulin G through the Fc receptors of the trophoblast. Difficulties for diagnosis represent neonatal lupus cases with minimal clinical manifestations in a newborn from a mother without an established diagnosis of rheumatic disease. Conclusion. In the isolated cutaneous form of neonatal lupus syndrome, specific treatment is not required; observation by a pediatrician with monitoring of a blood test confirming the elimination of maternal antibodies is indicated. However, taking into account the possibility of damage to the conduction system of the heart, registration of a surface electrocardiogram and regular monitoring (at least once every 6 months) of 24-hour electrocardiogram monitoring data are necessary. Keywords: neonatal lupus, newborn, specific antibodies, differential diagnosis.

Chapter 12 - Myasthenia gravis

Myasthenia gravis (MG) is a rare neuromuscular junction disorder that is characterized by fatigable weakness of muscles. People with MG experience various clinical manifestations based on the muscles involved. MG can be autoimmune, paraneoplastic, congenital, medication-related, or transient in the neonatal period due to the passive placental transfer of antibodies from mothers with MG. Acetylcholine receptor antibodies are seen in the majority of patients with MG. However, other antibodies have been discovered in the last 20 years, including muscle-specific tyrosine kinase (MuSK) and lipoprotein-related peptide 4 (LRP4), and are now available through commercial testing. More recently, a handful of other antibodies have been associated with MG; however, they are not presently available for routine testing. A disease classification system has been developed by the Myasthenia Gravis Foundation of America (MGFA) and is commonly used worldwide. A number of objective and subjective outcome measures have been developed and validated over the years and have been proven useful for both clinical and research purposes, serving as primary and secondary outcome measures in most clinical trials. A growing number of therapies are available for both acute and chronic management of MG, with several new mechanistic approaches under investigation. An international consensus guidance for the management of MG was first published in 2016 and updated in 2020.

Effectiveness of Covid-19 Vaccine in Pregnant Women: A Systematic Review

The newly developed COVID-19 vaccine faces public's concerns in terms of its effectiveness and safety as an approach in combating COVID-19 pandemic. It is well-established that COVID-19 vaccine is effective alongside being the most promising approach against COVID-19 infection in both general and vulnerable populations. This study aims to evaluate the effectiveness of COVID-19 vaccine in pregnant women as a subgroup of vulnerable population by analysing several important immunological parameters in pregnant women. Specifically, it investigates how effective the COVID-19 vaccine will reduce the infection rate and how it will affect the mothers' antibody levels against SARS-CoV-2. In this study, the immunological parameters investigated are maternal antibody response against SARS-CoV-2 and the transplacental transfer of the antibody. To test the hypothesis that COVID-19 vaccine is effective in pregnant women, a systematic review was conducted on previous studies regarding COVID-19 vaccine and its outcomes in pregnancy. Results were narratively analysed. The results showed reduced COVID-19 infection rate, elevated maternal antibody titre against SARS-CoV-2 and positive transplacental anti-SARS-CoV-2 IgG antibody transfer in vaccinated pregnant women in comparison to unvaccinated pregnant women. These results suggest that COVID-19 vaccine is highly effective against COVID-19 infection in pregnant women. Furthermore, COVID-19 vaccine not only elicits sufficient maternal antibody response as an immunity for mothers against COVID-19 infection but also provides similar protection for infants via passive immunity by means of transplacental antibody transfer. In conclusion, the uptake of COVID-19 vaccine and future booster dose by pregnant women should be strongly encouraged due to its favourable outcomes and protection against COVID-19 disease.

Why the regeneration of immunological tolerance by vaccination is difficult

Autoimmunity, including that involved in chronic inflammatory rheumatic diseases, seems to be the price we have to pay for our efficient immune system. It has the ability to precisely recognize pathogens and tumor cells, to efficiently fight them, to adapt to their alterations and provide specific immunity for alifetime. "Inoculation", and more specifically "vaccination" takes advantage of this, either by transfer of protective antibodies (passive vaccination) or by using attenuated pathogens or parts of them by which a specific protective immunity is induced (active vaccination). The idea to use vaccination to reduce undesired (auto)immunity and chronic inflammation is nothing new in rheumatology. Many biologicals are antibodies, which specifically block the mediators of inflammation and in the broader sense are similar to a passive vaccination. The active vaccination with autoantigens using the recent mRNA/liposome technology, has shown in experimental animal models that they can prevent the formation of chronic inflammatory immune reactions, in that they strengthen the physiological tolerance and deviate the immune system to noninflammatory immune reactions against the antigen; however, there is still along way to go to achieve the actual goals of apermanent suppression of established undesired immune reactions and the regeneration of immunological tolerance.

Transplacental Transfer Efficiency of SARS-CoV-2-Specific IgG Antibodies in Iranian Seropositive Mothers: A Monocentric Study in Karaj, Iran

Background: Passively acquired maternal antibodies through the placenta and/or breastfeeding may protect neonates against SARS-CoV-2 before they are considered eligible for active immunization. Objectives: This study aimed to determine the concentration and correlation of maternal and cord blood anti-SARS-CoV-2 IgG antibodies in Iranian seropositive women. In this preliminary study, attempts were also made to assess the effects of some variables on the transplacental transfer efficiency. Methods: From September 2021 to November 2021, pregnant women presenting to Kamali Hospital in Karaj, Iran, were enrolled in this monocentric study. The maternal and neonatal demographic characteristics were collected. The maternal and cord blood spike protein-specific antibody levels, measured at delivery (119 paired samples), were evaluated by the enzyme-linked immunosorbent assay (ELISA). Results: Based on the transplacental antibody transfer ratios, the participants were divided into 2 groups: Transfer ratio ≤ 1 (n = 53) and transfer ratio &gt; 1 (n = 66). The results revealed that anti-SARS-CoV-2 IgG antibodies were transferred across the placenta in all seropositive pregnant Iranian women, and a significant correlation was found between maternal and cord blood-specific IgG antibody levels (r = 0.9646; P &lt; 0.05). A relatively efficient transplacental transfer ratio was observed in Iranian seropositive women (transfer ratio &gt; 1 in 66 out of 119 individuals; 55.46%). Although there were significant differences in the transplacental transfer ratio regarding the neonatal birth weight and maternal body mass index (BMI), more extensive investigations with a larger sample size are needed to confirm the significant association of these variables with the transplacental transfer efficiency of specific SARS-CoV-2 IgG antibodies. Conclusions: The present study highlighted the importance of vaccination during pregnancy to improve neonatal immune responses against SARS-CoV-2.