Resumo em Inglês:

Abstract Objectives: To rescue medical genetics concepts that are necessary to understand the advances in the genetic-molecular characterization of primary immunodeficiencies, to help in the understanding and adequate interpretation of their results. Source of data: Non-systematic literature review, searching for articles since 2000 on PubMed using the terms “genetic evaluation” OR “whole exome sequence” or “whole genome sequence” OR “next generation sequence” AND “immunologic deficiency syndromes” OR “Immune deficiency disease” OR “immune deficiency” NOT HIV. Summary of the data: Knowledge of medical genetics is essential for the understanding of the principles of heredity and disease inheritance patterns, types of genetic variants, types of genetic sequencing and interpretation of their results. The clinical and immunophenotypic evaluation of each patient is essential for the correlation with the genetic variants observed in the genetic study of patients with primary immunodeficiencies. The discussion of the benefits and limitations of genetic tests should always guide the performance of genetic tests. Conclusions: There are many evident benefits of genetic analysis, such as the definitive diagnosis of the disease, family genetic counseling, and the possibility of a more adequate and accurate management. Cost, access and interpretation of genetic test results are limitations that need continuous improvement. The understanding of the benefits and limits of the several genetic assessment methodologies related to primary immunodeficiencies is essential to obtain more effective results from the sequencing.

Resumo em Inglês:

Abstract Objectives: To describe the hereditary angioedema to improve awareness of this condition and reduce diagnostic delay. Data sources: Relevant articles in the MEDLINE database through PubMed. Data synthesis: Hereditary angioedema is rare and has an autosomal dominant pattern of inheritance. Its onset occurs mainly in childhood, but there is an important delay in the diagnosis. In the most frequent phenotype, there is a quantitative and/or functional deficiency in the C1esterase inhibitor protein, which regulates the activation of the complement, contact and fibrinolysis systems with greater formation of bradykinin, the main mediator of angioedema. There is a third type, the hereditary angioedema with a normal C1 inhibitor level, which is rare in children. Clinical manifestations are characterized by recurrent angioedema attacks, mainly in the extremities, abdomen and upper airways, which can progress to asphyxia and death. The main triggers are mechanical trauma, infections and stress. The diagnosis is attained by patient clinical picture and decreased serum levels of C4 and C1esterase inhibitor or its function. In hereditary angioedema with a normal C1 inhibitor, there is no change in these parameters, thus requiring a genetic study. Treatment is based on the use of attack medications and long and short-term prophylaxis. Conclusions: Hereditary angioedema is little known by pediatricians due to the significant delay in diagnosis of this condition, whose onset usually begins in childhood. The presence of recurrent angioedema that does not respond to treatment with antihistamines, corticosteroids and adrenaline should increase the diagnostic suspicion.

Resumo em Inglês:

Abstract Objectives: To provide an overview of drug treatment, transplantation, and gene therapy for patients with primary immunodeficiencies. Source of data: Non-systematic review of the literature in the English language carried out at PubMed. Synthesis of data: The treatment of patients with primary immunodeficiencies aims to control their disease, especially the treatment and prevention of infections through antibiotic prophylaxis and/or immunoglobulin replacement therapy. In several diseases, it is possible to use specific medications for the affected pathway with control of the condition, especially in autoimmune or autoinflammatory processes associated with inborn immunity errors. In some diseases, treatment can be curative through hematopoietic stem cell transplantation (HSCT); more recently, gene therapy has opened new horizons through new technologies. Conclusions: Immunoglobulin replacement therapy remains the main therapeutic tool. Precision medicine with specific drugs for altered immune pathways is already a reality for several immune defects. Advances in the management of HSCT and gene therapy have expanded the capacity for curative treatments in patients with primary immunodeficiencies.

Resumo em Inglês:

Abstract Objectives: Classical immunodeficiencies are mainly characterized by infectious conditions. In recent years, manifestations related to allergy, inflammation, autoimmunity, lymphoproliferation, and malignancies related to this group of diseases have been described. The text intends to make an update on the non-infectious manifestations of the primary defects of the immune system. Source of data: Searches were carried out in the PubMed database for review articles published in the last five years, in English, French, or Spanish, using the terms “allergy,” “inflammation,” “autoimmunity,” “lymphoproliferation,” “cancer,” AND “immunodeficiency” or “primary immunodeficiency” or “inborn errors of immunity” NOT “HIV”. Synthesis of data: Non-infectious manifestations characterize the primary defects in which there is dysregulation of the immune system. The most common manifestations of autoimmunity in this group of diseases are autoimmune cytopenias. Exacerbated inflammatory processes, benign lymphoproliferation, and propensity to malignancy of the lymphoreticular system are related to several diseases in this group. Severe manifestations of atopy or food allergy characterize some immunodeficiencies. Disorders of inborn immunity of the autoinflammatory type are characterized by an aseptic inflammatory process in the absence of autoimmunity, with fever and recurrent manifestations in different organs. Conclusions: Not only infectious conditions should raise the suspicion of immunodeficiencies, but also manifestations of allergy, inflammation, autoimmunity, lymphoproliferation, or cancer, especially if they are recurrent, associated to each other, affecting young patients, or in severe and/or difficult to treat conditions.

Resumo em Inglês:

Abstract Objectives: To draw physicians' attention to the different warning signs of diseases of inborn errors of immunity. Data sources: A non-systematic review of the literature was carried out in the PubMed, LILACS, and SciELO databases, in addition to consultation of reference textbooks. Summary of the findings: It is known that the lack of immunological competence observed in patients with inborn errors of immunity diseases causes particularly serious and/or recurrent infections. However, manifestations related to autoimmunity, inflammation, allergies, and malignancy can also occur. Aiming at the early identification of these patients, a list of warning signs for inborn errors of immunity was created, in which the need for intravenous antibiotics or prolonged antibiotics use to control infection, failure to thrive, and positive family history for this group of diseases are considered the most sensitive. Regarding non-infectious manifestations, early onset, difficulty in controlling with the usual treatments, atypical presentations or association with other warning signs are noteworthy, and investigation for inborn errors of immunity in these situations is recommended. Conclusions: This article highlights the importance of considering this group of diseases even in the face of patients with non-infectious manifestations. Disclosure of inborn errors of immunity diseases, especially to non-specialists, is essential for early diagnosis and, consequently, for the reduction of these patients' morbidity and mortality.

Resumo em Inglês:

Abstract Objectives: Inborn Errors of Immunity (IEI), also known as primary immunodeficiencies, correspond to a heterogeneous group of congenital diseases that primarily affect immune response components. The main clinical manifestations comprise increased susceptibility to infections, autoimmunity, inflammation, allergies and malignancies. The aim of this article is to review the literature on combined immunodeficiencies (CIDs) focusing on the diagnosis and treatment and the particularities of the clinical management of these patients. Source of data: Critical integrative review, aimed to present articles related to primary immunodeficiencies combined with a searchin the PubMed and SciELO databases, with evaluation of publications from the last twenty years that were essential for the construction of knowledge on this group of diseases. Summary of data: We highlight the main characteristics of CIDs, dividing them according to their pathophysiological mechanisms, such as defects in the development of T cells, TCR signaling, co-stimulatory pathways, cytokine signaling, adhesion, migration and organization of the cytoskeleton, apoptosis pathways, DNA replication and repair and metabolic pathways. In CIDs, clinical manifestations vary widely, from sinopulmonary bacterial infections and diarrhea to opportunistic infections, caused by mycobacteria and fungi. Neonatal screening makes it possible to suspect these diseases before clinical manifestations appear. Conclusions: The CIDs or IEI constitute a complex group of genetic diseases with T-cell involvement. Neonatal screening for these diseases has improved the prognosis of these patients, especially in severe ones, known as SCIDs.

Resumo em Inglês:

Abstract Objective: A review article was carried out, addressing the clinical and epidemiological characteristics of immune system deficiencies, which are associated with or predispose to recurrent infectious processes, autoimmune diseases, auto inflammatory diseases, or neoplasms, and which are classified as inborn errors of immunity (IEI) and secondary immunodeficiencies (SID). Emphasis was placed on the classification of the main signs and symptoms for each organ and system, which will serve as warning signs, to guide the pediatrician in the investigation of the main IEI. In addition, the main secondary changes in the immune system triggered by infections (with emphasis on COVID-19), drugs, chronic diseases, metabolic and nutritional disorders were identified. Sources of data: This review included articles published in the last five years and that were identified in the MEDLINE platform (PubMed). Summary of findings: The recurrence of infectious processes, associated with the severity of the condition and/or unusual profile of the infectious agent, always related to the age range of symptom onset, are the most important findings for suspected diagnosis. Conclusions: Considering this scenario, immunity disorders should be part of the investigation carried out by the general pediatrician, whether they are the innate errors of immunity (primary immunodeficiencies) or secondary immunodeficiencies, so that the diagnosis is attained as early as possible and therapeutic measures are implemented, reducing the morbidity and mortality of these patients.

Resumo em Inglês:

Abstract Objectives: To describe the ontogeny of the immune system and the adaptive mechanisms of the immune system in the neonatal period, with an emphasis on transplacental antibody transport and breastfeeding. Source of data: Non-systematic literature review in the PubMed database. Summary of the findings: The last two decades have witnessed a great advance in the knowledge of the immune system since conception. Several investigation tools have provided insight on phenomena that were previously inadequately understood. Still expanding, the functional and molecular investigation of various aspects of the immune system will make it possible to understand how intra-uterus maternal-fetal exchanges, the maternal microbiota interacting with the fetus and newborn, and the acquisition of immunological competence occur in healthy and disease scenarios. Conclusions: In-depth knowledge of the development of the immune system and of the adaptive mechanisms that allow a safer transition to the extrauterine environment are fundamental components of optimizing maternal and young infant vaccination, as well as the strategies associated with full postnatal development, and the early diagnosis and treatment of innate errors of immunity.

Resumo em Inglês:

Abstract Objective: This minireview gathers the scientific foundations of the literature on genetic errors in the development of the humoral immune system to help pediatricians suspect these defects. Sources: A systemic search using the PubMed MEDLINE database was performed for all Predominantly Antibody Deficiencies (PADs) described in the 2020 IUIS Expert Committee for PID classification system, combined with terms for hypogammaglobulinemia. Search terms for PADs were based on the listed names and affected genes as classified by the IUIS 2020. Abstracts of the results were reviewed to find relevant case series, review articles of PADs associated with infection, opportunistic infection, autoimmunity, cytopenias, malignancies, inflammatory diseases, neurological and respiratory diseases. References from relevant articles were further reviewed for additional references. Relevant findings were grouped in accordance with the IUIS 2020 classification system. Clinical and genetic features, if known, were described. Data synthesis: PADs refer to impaired antibody production due to molecular defects intrinsic to B cells or a failure of interaction between B and T cells. The patients develop recurrent or chronic infection or respond to the antigens with dysregulation of the immune function, causing severe allergy, autoimmunity, inflammation, lymphoproliferation and malignancy. The diagnosis is a combined exercise of clinical and laboratory investigation similar to that performed by Bruton (1952). In the context of SARS-CoV-2 infection, the experience of XLA and CVID patients has been surprising. Variants in 39 genes were reported as causing PADs, but the clinical heterogeneity within each variant is not clear. Conclusion: Bruton (1952) used clinical expertise and protein electrophoresis to identify XLA. The IUIS (2020) committee used immunoglobulins and B lymphocyte to characterize PADs. Pediatricians should suspect it to detect it and prevent morbidities that can have an astonishing and irreversible impact on the child's life.

Resumo em Inglês:

Abstract Objectives: The aim of the report is to describe the main immunodeficiencies with syndromic characteristics according to the new classification of Inborn Errors of Immunity. Data source: The data search was centered on the PubMed platform on review studies, meta-analyses, systematic reviews, case reports and a randomized study published in the last 10 years that allowed the characterization of the several immunological defects included in this group. Data synthesis: Immunodeficiencies with syndromic characteristics include 65 immunological defects in 9 subgroups. The diversity of clinical manifestations is observed in each described disease and may appear early or later, with variable severity. Congenital thrombocytopenia, syndromes with DNA repair defect, immuno-osseous dysplasias, thymic defects, Hyper IgE Syndrome, anhidrotic ectodermal dysplasia with immunodeficiency and purine nucleoside phosphorylase deficiency were addressed. Conclusions: Immunological defects can present with very different characteristics; however, the occurrence of infectious processes, autoimmune disorders and progression to malignancy may suggest diagnostic research. In the case of diseases with gene mutations, family history is of utmost importance.

Resumo em Inglês:

Abstract Objectives: Inborn Errors of Immunity are characterized by infectious conditions and manifestations of immune dysregulation. The diversity of clinical phenotypes can make it difficult to direct the laboratory investigation. This article aims to update the investigation of immunological competence in the context of primary defects of the immune system. Source of data: Searches were carried out on Pubmed to review articles published in the last five years, in English, French or Spanish, using the terms “diagnosis” OR “investigation” AND “immunodeficiency” or “primary immunodeficiency” or “inborn errors of immunity” NOT “HIV”. Recent textbook editions have also been consulted. Summary of findings: The immune system competence investigation should be started based on clinical phenotypes. Relevant data are: characterization of infectious conditions (location, recurrence, types of infectious agents, response to treatment), age during symptom onset and associated manifestations (growth impairment, allergy, autoimmunity, malignancies, fever and signs of inflammation without the identification of infection or autoimmunity) and family history. These data contribute to the selection of tests to be performed. Conclusions: The diagnostic investigation of Inborn Errors of Immunity should be guided by the clinical characterization of patients, aiming to optimize the use of complementary tests. Many diagnoses are attained only through genetic tests, which are not always available. However, the absence of a diagnosis of certainty should never delay the implementation of therapeutic measures that preserve patient life and health.