NEONATAL IMMUNOTOLERANCE SYNDROME INDUCED BY MATERNAL MICROCHIMERISM: IMPLICATIONS FOR AUTOIMMUNE DISEASES IN CHILDHOOD

Maternal microchimerism-induced neonatal immunotolerance syndrome refers to the persistence of maternal cells in the newborn’s body, a phenomenon that can impact the regulation of the infant immune system. During pregnancy, there is a bidirectional exchange of cells between mother and fetus, which can lead to a state of prolonged immune tolerance. Evidence suggests that this maternal cellular presence can both confer protection and increase susceptibility to autoimmune diseases in childhood, such as juvenile systemic lupus erythematosus, juvenile idiopathic arthritis and type 1 diabetes mellitus. Understanding the mechanisms involved in this process is essential to assessing its impact on childhood immune development. The aim of this study is to investigate the influence of maternal microchimerism on neonatal immunotolerance and its relationship with autoimmune diseases in childhood, analyzing the underlying immunological mechanisms and their clinical implications. This study is a literature review with a qualitative approach, investigating the impact of maternal microchimerism on immune tolerance and the development of pediatric autoimmune diseases. Articles published between 2020 and 2023 were analyzed, taking into account recent advances in the field. The studies analyzed indicate that maternal microchimerism can influence the neonatal immune response, promoting greater immune tolerance. This phenomenon can reduce the incidence of some inflammatory diseases, but also predispose to certain autoimmune diseases by altering the balance between tolerance mechanisms and immune activation. The presence of maternal cells in lymphoid and peripheral tissues can modulate the activity of regulatory T lymphocytes and the production of inflammatory cytokines, impacting the development of the infant immune system. Despite advances in understanding this phenomenon, the exact mechanisms and modulating factors are still under study. Therefore, neonatal immunotolerance induced by maternal microchimerism represents a relevant immunological factor in childhood, with a potential influence on protection or predisposition to autoimmune diseases. Although studies point to a regulatory role of maternal cells in the infant immune response, the complexity of this phenomenon requires further research to elucidate its clinical implications and identify possible therapeutic strategies for pediatric autoimmune diseases.