Early-Onset Autoimmune Disease as a Manifestation of Primary Immunodeficiency

Autoimmune disorders (AID) have been increasingly observed in association with primary immunodeficiencies (PIDs). Here, we discuss the interface between PID and AID, focusing on autoimmune manifestations early in life, which can be diagnostic clues for underlying PIDs. Inflammatory bowel disease in infants and children has been associated with IL-10 and IL-10R deficiencies, chronic granulomatous disease, immunedysregulation-polyendocrinopathy-enteropathy-X-linked syndrome (IPEX), autoinflammatory disorders, and others. Some PIDs have been identified as underlying defects in juvenile systemic lupus erythematosus: C1q-, IgA-, IgM deficiencies, alterations of the IFN-α pathway (in Aicardi-Goutières syndrome due to TREX1 mutation). IPEX (due to FOXP3 mutation leading to Treg cell deficiency), usually appearing in the first months of life, was recently observed in miscarried fetuses with hydrops who presented with CD3+ infiltrating lymphocytes in the pancreas. Hemophagocytic lymphohistiocytosis due to perforin deficiency was also identified as a cause of fetal hydrops. In conclusion, PID should be suspected in any infant with signs of autoimmunity after excluding transferred maternal effects, or in children with multiple and/or severe AID.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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

Avaliação da transferência materno-infantil de anticorpos em pacientes com síndrome antifosfolípide

Introdução: a síndrome antifosfolípide (SAF) é caracterizada por eventos trombóticos e perdas gestacionais de repetição sendo considerada a trombofilia adquirida mais comum. Objetivo: realizar uma revisão narrativa da passagem transplacentária de anticorpos em pacientes com SAF. Metodologia: revisão narrativa da literatura. Resultados: quando não está associada a alguma doença do tecido conectivo é dita primária e quando em associação com lúpus eritematosos sistêmico é dita secundária. A morbidade gestacional é frequente e torna-se de importância avaliar a passagem desses anticorpos transplacentariamente, desde que existem modelos animais da síndrome com transferência passiva desses anticorpos. A passagem transplacentária de anticorpos específicos já foi determinada em estudos, os quais demonstraram baixos níveis destes anticorpos no soro materno, porém uma eficiente passagemtransplacentária para o neonato. Conclusão: existem poucos estudos sobre essa passagem materno-infantil em pacientes com SAF, que são aqui revisados

Fatores nutricionais no leite de mães brasileiras de recém-nascidos de baixo peso para idade gestacional

The composition of breast milk from brazilian mothers delivering low birthweight infants and its adequacy as a source of nutrients for this group has not yet been fully elucidated. A total of 209 milk samples from 66 women were analysed. The mothers were divided into three groups: G1, mothers delivering term babies of low birthweight (TSGA, n=16); G2, mothers delivering preterm babies of appropriate birthweight (PTAGA, n=20); G3, mothers delivering term babies of appropriate birthweight (TAGA, n=30). The following factors were analysed: osmolarity, total proteins and protein fractions, creamatocrit, sodium, potassium, calcium and magnesium. Milk samples were collected 48 h and 7, 15, 30 and 60 days after delivery. The groups did not differ significantly in terms of osmolarity, total proteins and fractions, creamatocrit, calcium, magnesium or potassium throughout the study period. Sodium levels were higher in all samples from mothers of TSGA infants and in samples from mothers of PTAGA infants on the 7th, 15th and 30th days than in milk from the TAGA group. The authors consider the needs of the low birthweight and TAGA infants and that these high sodium levels may be necessary for growth of low birthweight infants.A composição do leite de mães brasileiras de lactentes de baixo peso e sua adequação como fonte de nutrientes para este grupo ainda não foi totalmente elucidada. Um total de 209 amostras de leite de 66 nutrizes foram analisadas. As mães foram divididas em três grupos: G1, mães de recém-nascidos (RN) a termo, com baixo peso (TSGA, n=16); G2, mães de RN pré-termo, com peso adequado (PTAGA, n=20); G3, mães de RN a termo e peso adequado (TAGA, n=30). Os seguintes fatores foram analisados: osmolaridade, proteínas totais e frações, crematócrito, sódio, potássio, cálcio e magnésio. As amostras foram coletadas 48 h, no 7º, 15º, 30º e 60º dias após o parto. Os grupos não diferiram em termos de osmolaridade, proteínas totais e frações, crematócrito, cálcio, magnésio ou potássio durante o estudo. Os níveis de sódio foram maiores em todas as amostras de mães de TSGA e em mães de PTAGA no 7º, 15º e 30º dias em relação a mães de TAGA. Foram consideradas as necessidades dos lactentes de baixo peso e TAGA, e estes níveis de sódio podem ser necessários para o crescimento dos RN de baixo peso

IgG Placental Transfer in Healthy and Pathological Pregnancies

Placental transfer of maternal IgG antibodies to the fetus is an important mechanism that provides protection to the infant while his/her humoral response is inefficient. IgG is the only antibody class that significantly crosses the human placenta. This crossing is mediated by FcRn expressed on syncytiotrophoblast cells. There is evidence that IgG transfer depends on the following: (i) maternal levels of total IgG and specific antibodies, (ii) gestational age, (iii) placental integrity, (iv) IgG subclass, and (v) nature of antigen, being more intense for thymus-dependent ones. These features represent the basis for maternal immunization strategies aimed at protecting newborns against neonatal and infantile infectious diseases. In some situations, such as mothers with primary immunodeficiencies, exogenous IgG acquired by intravenous immunoglobulin therapy crosses the placenta in similar patterns to endogenous immunoglobulins and may also protect the offspring from infections in early life. Inversely, harmful autoantibodies may cross the placenta and cause transitory autoimmune disease in the neonate