Severe combined immunodeficiency diagnosis and genetic defects.

Severe combined immunodeficiency (SCID) is a rare and life-threatening genetic disorder that severely impairs the immune system's ability to defend the body against infections. Often referred to as the "bubble boy" disease, SCID gained widespread recognition due to the case of David Vetter, a young boy who lived in a sterile plastic bubble to protect him from germs. SCID is typically present at birth, and it results from genetic mutations that affect the development and function of immune cells, particularly T cells and B cells. These immune cells are essential for identifying and fighting off infections caused by viruses, bacteria, and fungi. In SCID patients, the immune system is virtually non-existent, leaving them highly susceptible to recurrent, severe infections. There are several forms of SCID, with varying degrees of severity, but all share common features. Newborns with SCID often exhibit symptoms such as chronic diarrhea, thrush, skin rashes, and persistent infections that do not respond to standard treatments. Without prompt diagnosis and intervention, SCID can lead to life-threatening complications and a high risk of mortality. There are over 20 possible affected genes. Treatment options for SCID primarily involve immune reconstitution, with the most well-known approach being hematopoietic stem cell transplantation (HSCT). Alternatively, gene therapy is also available for some forms of SCID. Once treated successfully, SCID patients can lead relatively normal lives, but they may still require vigilant infection control measures and lifelong medical follow-up to manage potential complications. In conclusion, severe combined immunodeficiency is a rare but life-threatening genetic disorder that severely compromises the immune system's function, rendering affected individuals highly vulnerable to infections. Early diagnosis and appropriate treatment are fundamental. With this respect, newborn screening is progressively and dramatically improving the prognosis of SCID.

Doença granulomatosa crônica: características clínicas, seguimento e terapêutica de cinco pacientes pediátricos / Chronic granulomatous disease: clinical characteristics, follow-up, and therapy of 5 pediatric patients

Introdução: A doença granulomatosa crônica (DGC) é caracterizada por um defeito na capacidade microbicida das células fagocíticas (monócitos e neutrófilos), com alta mortalidade se não diagnosticada precocemente. Os pacientes apresentam infecções recorrentes ou graves, suscetibilidade a granulomas em órgãos profundos, doenças autoimunes e doença inflamatória intestinal. Objetivo e Método: Relato de aspectos clínicos e do tratamento de cinco pacientes com doença granulomatosa crônica. Resultados: Cinco pacientes, três meninos, medianas de idade no início dos sintomas e diagnóstico de 8 meses e 48 meses, respectivamente, foram estudados por um período de 10 anos. Pneumonia (5/5) e doença micobacteriana (3/5) foram as manifestações iniciais mais comuns. Alterações pulmonares foram observadas em todos os casos. Mutações nos genes CYBB e NCF1 foram identificadas em três casos. Antibioticoprofilaxia foi instituída em todos os pacientes e três foram submetidos ao transplante de células tronco-hematopoiéticas (TCH), aos 7, 18 e 19 anos e com sobrevida atual entre 4 a 5 anos. Conclusão: O monitoramento cuidadoso de infecções graves com tratamento imediato foi crucial para a sobrevivência. O TCH, mesmo ao final da adolescência, promoveu a cura da DGC em três pacientes.

Introduction: Chronic granulomatous disease (CGD) is characterized by a defective microbicidal capacity of phagocytic cells (monocytes and neutrophils) with high mortality if not early diagnosed. Patients have recurrent or severe infections and are susceptible to granulomas in visceral organs, autoimmune diseases, and inflammatory bowel diseases. Objective and Method: To report the clinical features and treatment of 5 patients with CGD. Results: Five patients, 3 boys, with median ages at symptom onset and diagnosis of 8 months and 48 months, respectively, were followed for 10 years. Pneumonia (5/5) and mycobacterial disease (3/5) were the most common initial manifestations. Pulmonary changes were observed in all cases. Mutations in the CYBB and NCF1 genes were identified in 3 cases. All patients received antibiotic prophylaxis. Three patients underwent a hematopoietic stem cell transplant (HSCT) at 7, 18, and 19 years, with current survival of 4 to 5 years. Conclusion: Careful monitoring for severe infection with prompt treatment was crucial for survival. Even though HSCT was performed in late adolescence, it promoted the cure of CGD in 3 patients.

A novel insight on SARS-CoV-2 S-derived fragments in the control of the host immunity.

Despite all efforts to combat the pandemic of COVID-19, we are still living with high numbers of infected persons, an overburdened health care system, and the lack of an effective and definitive treatment. Understanding the pathophysiology of the disease is crucial for the development of new technologies and therapies for the best clinical management of patients. Since the manipulation of the whole virus requires a structure with an adequate level of biosafety, the development of alternative technologies, such as the synthesis of peptides from viral proteins, is a possible solution to circumvent this problem. In addition, the use and validation of animal models is of extreme importance to screen new drugs and to compress the organism's response to the disease. Peptides derived from recombinant S protein from SARS-CoV-2 were synthesized and validated by in silico, in vitro and in vivo methodologies. Macrophages and neutrophils were challenged with the peptides and the production of inflammatory mediators and activation profile were evaluated. These peptides were also inoculated into the swim bladder of transgenic zebrafish larvae at 6 days post fertilization (dpf) to mimic the inflammatory process triggered by the virus, which was evaluated by confocal microscopy. In addition, toxicity and oxidative stress assays were also developed. In silico and molecular dynamics assays revealed that the peptides bind to the ACE2 receptor stably and interact with receptors and adhesion molecules, such as MHC and TCR, from humans and zebrafish. Macrophages stimulated with one of the peptides showed increased production of NO, TNF-α and CXCL2. Inoculation of the peptides in zebrafish larvae triggered an inflammatory process marked by macrophage recruitment and increased mortality, as well as histopathological changes, similarly to what is observed in individuals with COVID-19. The use of peptides is a valuable alternative for the study of host immune response in the context of COVID-19. The use of zebrafish as an animal model also proved to be appropriate and effective in evaluating the inflammatory process, comparable to humans.

Improving Access to Therapy for Patients With Inborn Errors of Immunity: A Call to Action.

Breakthroughs in sequencing technology, targeted immunotherapy, and immune reconstituting treatment have increased the pool of patients with inborn errors of immunity, requiring expertise from clinical immunologists. A growing category of immunodeficiency, presenting as primary immune regulatory disorder and secondary immunodeficiency due to targeted immune therapy for cancer and autoimmunity, has added to the growing burden of patients needing access to immune-supportive therapy. The confluence of a growing population of patients needing a clinical immunologist, complex payer structures, and inadequate health care representation will exacerbate current problems with access to therapy. Patients, health care providers, researchers, public and private payers, and industry must come together to find solutions to improve access to therapy. In this article, we reviewed the major topics regarding access to therapy for patients with immunodeficiency.

SCID and Other Inborn Errors of Immunity with Low TRECs - the Brazilian Experience.

Severe combined immunodeficiency, SCID, is a pediatric emergency that represents the most critical group of inborn errors of immunity (IEI). Affected infants present with early onset life-threatening infections due to absent or non-functional T cells. Without early diagnosis and curative treatment, most die in early infancy. As most affected infants appear healthy at birth, newborn screening (NBS) is essential to identify and treat patients before the onset of symptoms. Here, we report 47 Brazilian patients investigated between 2009 and 2020 for SCID due to either a positive family history and/or clinical impression and low TRECs. Based on clinical presentation, laboratory finding, and genetic information, 24 patients were diagnosed as typical SCID, 14 as leaky SCID, and 6 as Omenn syndrome; 2 patients had non-SCID IEI, and 1 remained undefined. Disease onset median age was 2 months, but at the time of diagnosis and treatment, median ages were 6.5 and 11.5 months, respectively, revealing considerable delay which affected negatively treatment success. While overall survival was 51.1%, only 66.7% (30/45) lived long enough to undergo hematopoietic stem-cell transplantation, which was successful in 70% of cases. Forty-three of 47 (91.5%) patients underwent genetic testing, with a 65.1% success rate. Even though our patients did not come from the NBS programs, the diagnosis of SCID improved in Brazil during the pilot programs, likely due to improved medical education. However, we estimate that at least 80% of SCID cases are still missed. NBS-SCID started to be universally implemented in the city of São Paulo in May 2021, and it is our hope that other cities will follow, leading to early diagnosis and higher survival of SCID patients in Brazil.

Severe COVID-19 Shares a Common Neutrophil Activation Signature with Other Acute Inflammatory States.

Severe COVID-19 patients present a clinical and laboratory overlap with other hyperinflammatory conditions such as hemophagocytic lymphohistiocytosis (HLH). However, the underlying mechanisms of these conditions remain to be explored. Here, we investigated the transcriptome of 1596 individuals, including patients with COVID-19 in comparison to healthy controls, other acute inflammatory states (HLH, multisystem inflammatory syndrome in children [MIS-C], Kawasaki disease [KD]), and different respiratory infections (seasonal coronavirus, influenza, bacterial pneumonia). We observed that COVID-19 and HLH share immunological pathways (cytokine/chemokine signaling and neutrophil-mediated immune responses), including gene signatures that stratify COVID-19 patients admitted to the intensive care unit (ICU) and COVID-19_nonICU patients. Of note, among the common differentially expressed genes (DEG), there is a cluster of neutrophil-associated genes that reflects a generalized hyperinflammatory state since it is also dysregulated in patients with KD and bacterial pneumonia. These genes are dysregulated at the protein level across several COVID-19 studies and form an interconnected network with differentially expressed plasma proteins that point to neutrophil hyperactivation in COVID-19 patients admitted to the intensive care unit. scRNAseq analysis indicated that these genes are specifically upregulated across different leukocyte populations, including lymphocyte subsets and immature neutrophils. Artificial intelligence modeling confirmed the strong association of these genes with COVID-19 severity. Thus, our work indicates putative therapeutic pathways for intervention.

Tuberculose intratorácica na forma pseudotumoral e óssea como manifestação de doença granulomatosa crônica / Intrathoracic tuberculosis in the pseudotumoral and bone form as a manifestation of chronic granulomatous disease

A doença granulomatosa crônica (DGC) é um erro inato da imunidade de fagócitos, e ocorre em decorrência de mutações que afetam componentes da enzima NADPH oxidase. Os pacientes são suceptíveis a infecções graves e letais por fungos e bactérias. O objetivo deste trabalho é relatar o caso de um lactente com DGC que apresentou manifestação clínica de tuberculose (TB) intratorácica na forma pseudotumoral e óssea iniciada no período neonatal. O diagnóstico de DGC foi realizado através do teste de DHR e, após o início da profilaxia com sulfametoxazoltrimetroprima e itraconazol, o paciente manteve-se estável clinicamente. A mãe e a irmã também apresentaram DHR alterados, a análise genética revelou uma mutação ligada ao X no exon 2 do gene CYBB c.58G>A, levando uma alteração em G20R. É fundamental que o diagnóstico seja realizado o mais precocemente possível, a fim de instituir as orientações aos familiares e tratamento adequado, reduzindo assim complicações infecciosas e melhorando prognóstico.

Chronic granulomatous disease (CGD) is an inborn error of phagocyte immunity and occurs as a resulto f mutations that affect components of the NADPH oxidase enzyme. Patients are susceptible to serious and lethal fungal and bacterial infections. The aim of this paper is to report a case an infant with CGD who presented clinical manifestations of intrathoracic tuberculosis (TB) in the pseudotumoral and bone form, which started in the neonatal period. The diagnosis of CGD was performed using the DHR test and, after starting prophylaxis with sulfamethoxazole-trimethoprim and itraconazole, the patient remained clinically stable. The mother and sister also had altered DHR, genetic analysis revealed an X-linked mutation in exon 2 of the CYBB gene c.58G>A, leading to an alteration in G20R. It is essential that the diagnosis is made as early as possible, in order to establish guidelines for Family members and adequate treatment, thus reducing infectious complications and improving prognosis.

CD40 Ligand Deficiency in Latin America: Clinical, Immunological, and Genetic Characteristics.

CD40 ligand (CD40L) deficiency is a rare inborn error of immunity presenting with heterogeneous clinical manifestations. While a detailed characterization of patients affected by CD40L deficiency is essential to an accurate diagnosis and management, information about this disorder in Latin American patients is limited. We retrospectively analyzed data from 50 patients collected by the Latin American Society for Immunodeficiencies registry or provided by affiliated physicians to characterize the clinical, laboratory, and molecular features of Latin American patients with CD40L deficiency. The median age at disease onset and diagnosis was 7 months and 17 months, respectively, with a median diagnosis delay of 1 year. Forty-seven patients were genetically characterized revealing 6 novel mutations in the CD40LG gene. Pneumonia was the most common first symptom reported (66%). Initial immunoglobulin levels were variable among patients. Pneumonia (86%), upper respiratory tract infections (70%), neutropenia (70%), and gastrointestinal manifestations (60%) were the most prevalent clinical symptoms throughout life. Thirty-five infectious agents were reported, five of which were not previously described in CD40L deficient patients, representing the largest number of pathogens reported to date in a cohort of CD40L deficient patients. The characterization of the largest cohort of Latin American patients with CD40L deficiency adds novel insights to the recognition of this disorder, helping to fulfill unmet needs and gaps in the diagnosis and management of patients with CD40L deficiency.

The First Iranian Cohort of Pediatric Patients with Activated Phosphoinositide 3-Kinase-δ (PI3Kδ) Syndrome (APDS).

BACKGROUND: Activated phosphoinositide 3-kinase δ syndrome (APDS) is a recently defined combined primary immunodeficiency disease (PID) characterized by recurrent respiratory tract infections, lymphoproliferation, autoimmunity and lymphoma. Gain-of-function mutations in PIK3CD and loss-of-function of PIK3R1 genes lead to APDS1 and APDS2, respectively. METHODS: Demographic, clinical, immunological and genetic data were collected from medical records of 15 pediatric patients, who were genetically identified using the whole-exome sequencing method. RESULTS: Fifteen patients (6 APDS1 and 9 APDS2) were enrolled in this study. Recurrent respiratory tract infections followed by lymphoproliferation and autoimmunity were the most common manifestations (86.7%, 53.3% and 26.7%, respectively). Five patients (33.3%) had a Hyper-IgM-syndrome-like immunoglobulin profile. In the APDS1 group, splice site and missense mutations were found in half of the patients and the C-lobe domain of PIK3CD was the most affected region (50%). In the APDS2 group, splice site mutation was the most frequent mutation (77.8%) and the inter-SH2 domain was the most affected region of PIK3R1 (66.7%). Mortality rate was significantly higher in APDS2 group (P = .02) mainly due to chronic lung infections. CONCLUSION: Respiratory tract infections and humoral immunodeficiency are commonly the most important complication in pediatric APDS patients, and they can be fatal by ultimately causing catastrophic damage to the structure of lungs. Hence, physicians should be aware of its significance and further work-up of patients with recurrent respiratory tract infections especially in patients with lymphoproliferation. Moreover, delineation of genotype-phenotype associations with disease severity could be helpful in the timely application of appropriate management and patients' survival.

Apresentação atípica de síndrome de hiper-IgM ligada ao X simulando doença inflamatória intestinal / Atypical presentation of X-linked hyper-IgM syndrome simulating inflammatory bowel disease

Relatamos o caso de um paciente do sexo masculino, que iniciou quadro de úlceras em trato gastrointestinal, associado a febre recorrente e diarreia com muco e sangue aos 10 meses de vida, suspeitado inicialmente de doença inflamatória intestinal, no entanto, não apresentou melhora do quadro com terapia imunossupressora, sendo realizada investigação para erro inato da imunidade. Nos exames laboratoriais, apresentou níveis baixos de IgG e IgA e níveis elevados de IgM e neutropenia persistente. Diante disso, foi realizado teste genético que confirmou diagnóstico de síndrome de hiper-IgM ligada ao X. Os erros inatos da imunidade podem se manifestar com doenças do trato gastrointestinal, de forma relativamente frequente, devendo entrar como diagnóstico diferencial de diarreia crônica. Inclusa nesse grupo de doenças, as síndromes de hiper-IgM constituem um grupo heterogêneo de doenças, possuindo em comum níveis significativamente baixos ou ausentes de IgG e IgA e níveis normais ou elevados de IgM, o que predispõe a infecções e febre recorrente; além de outras alterações laboratoriais, como neutropenia, que pode estar associada a úlceras no trato gastrointestinal e proctite, simulando apresentação clínica de doença inflamatória intestinal. Para o paciente relatado, foi iniciada terapia com imunoglobulinas de forma periódica, além de antibioticoprofilaxia para infecções, evoluindo com resposta clínica satisfatória. O artigo possui objetivo principal de alertar para o diagnóstico diferencial de erros inatos da imunidade diante do quadro apresentado, visando o diagnóstico precoce e a instituição da terapia adequada.

We report the case of a male patient, who started with ulcers in the gastrointestinal tract, associated with recurrent fever and diarrhea with mucus and blood at 10 months of life, initially suspected of inflammatory bowel disease, however, he did not improve the condition with immunosuppressive therapy, being investigated for inborn error of immunity. In laboratory tests, he had low levels of IgG and IgA and high levels of IgM and persistent neutropenia. Therefore, a genetic test was performed and confirmed the diagnosis of X-linked hyper IgM syndrome. Inborn errors of immunity can manifest relatively frequently with diseases of the gastrointestinal tract, and should be included as a differential diagnosis of chronic diarrhea. Included in this group of diseases, hyper-IgM syndromes constitute a heterogeneous group of diseases, having in common significantly low or absent levels of IgG and IgA and normal or high levels of IgM, which predispose to infections and recurrent fever; in addition to other laboratory alterations, such as neutropenia, which may be associated with ulcers in the gastrointestinal tract and proctitis, simulating the clinical presentation of inflammatory bowel disease. For the reported patient, therapy with immunoglobulins was started periodically, in addition to antibiotic prophylaxis for infections, evolving with a satisfactory clinical response. The main objective of the article is to alert to the differential diagnosis of inborn errors of immunity in view of the presented condition, aiming at early diagnosis and the institution of adequate therapy.

Serum Protein Electrophoresis May Be Used as a Screening Tool for Antibody Deficiency in Children and Adolescents.

Background: Patients with antibody deficiency may experience exceptionally long diagnostic delays, increasing the risk of life-threatening infections, end-organ damage, mortality, and health costs. Objective: This study aimed to analyze serum protein electrophoresis and verify the correlation between calculated globulin (CG, total protein minus albumin levels) or electrophoretically determined serum gamma globulin fraction (Gamma) with IgG levels in children and adolescents under 18 years old (yo). Methods: We analyzed serum protein electrophoresis (GC or Gamma) and IgG levels from 1215 children and adolescents under 18 yo, classified into 5 age groups. We verified the correlation between CG or Gamma with serum IgG levels. Results: Serum IgG levels varied according to age groups (from 4.3 ± 2.3 g/l in children under 6 months old to 11.4 ± 3.2 g/l in adolescents in the 10-<18 yo group). CG sensitivity and specificity to detect IgG below the reference range for all patients were 93.1% and 81.8%, respectively, and varied according to age group. Gamma sensitivity and specificity for all patients were 100% and 87.8%, respectively, and varied according to age group as well. We found serum IgG levels below the age reference level in 29 patients (2.4% of the cases) using CG or Gamma levels. Conclusion: Both CG and Gamma levels may be of utility as a screening tool for earlier diagnosis of antibody deficiency in children and adolescents under 18 yo.

Hematologically important mutations: The autosomal forms of chronic granulomatous disease (third update).

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe, recurrent bacterial and fungal infections. The disease is caused by mutations in the genes encoding the components of the leukocyte NADPH oxidase. This enzyme produces superoxide, which is subsequently metabolized to hydrogen peroxide and other reactive oxygen species (ROS). These products are essential for intracellular killing of pathogens by phagocytic leukocytes (neutrophils, eosinophils, monocytes and macrophages). The leukocyte NADPH oxidase is composed of five subunits, four of which are encoded by autosomal genes. These are CYBA, encoding p22phox, NCF1, encoding p47phox, NCF2, encoding p67phox and NCF4, encoding p40phox. This article lists all mutations identified in these genes in CGD patients. In addition, cytochrome b558 chaperone-1 (CYBC1), recently recognized as an essential chaperone protein for the expression of the X-linked NADPH oxidase component gp91phox (also called Nox2), is encoded by the autosomal gene CYBC1. Mutations in this gene also lead to CGD. Finally, RAC2, a small GTPase of the Rho family, is needed for activation of the NADPH oxidase, and mutations in the RAC2 gene therefore also induce CGD-like symptoms. Mutations in these last two genes are also listed in this article.

CD40L modulates transcriptional signatures of neutrophils in the bone marrow associated with development and trafficking.

Neutrophils are produced in the BM in a process called granulopoiesis, in which progenitor cells sequentially develop into mature neutrophils. During the developmental process, which is finely regulated by distinct transcription factors, neutrophils acquire the ability to exit the BM, properly distribute throughout the body, and migrate to infection sites. Previous studies have demonstrated that CD40 ligand (CD40L) influences hematopoiesis and granulopoiesis. Here, we investigate the effect of CD40L on neutrophil development and trafficking by performing functional and transcriptome analyses. We found that CD40L signaling plays an essential role in the early stages of neutrophil generation and development in the BM. Moreover, CD40L modulates transcriptional signatures, indicating that this molecule enables neutrophils to traffic throughout the body and to migrate in response to inflammatory signals. Thus, our study provides insights into the complex relationships between CD40L signaling and granulopoiesis, and it suggests a potentially novel and nonredundant role of CD40L signaling in neutrophil development and function.

Hematologically important mutations: X-linked chronic granulomatous disease (fourth update).

Chronic granulomatous disease (CGD) is an immunodeficiency disorder affecting about 1 in 250,000 individuals. CGD patients suffer from severe bacterial and fungal infections. The disease is caused by a lack of superoxide production by the leukocyte enzyme NADPH oxidase. Superoxide and subsequently formed other reactive oxygen species (ROS) are instrumental in killing phagocytosed micro-organisms in neutrophils, eosinophils, monocytes and macrophages. The leukocyte NADPH oxidase is composed of five subunits, of which the enzymatic component is gp91phox, also called Nox2. This protein is encoded by the CYBB gene on the X chromosome. Mutations in this gene are found in about 70% of all CGD patients in Europe and in about 20% in countries with a high ratio of parental consanguinity. This article lists all mutations identified in CYBB and should therefore help in genetic counseling of X-CGD patients' families. Moreover, apparently benign polymorphisms in CYBB are also given, which should facilitate the recognition of disease-causing mutations. In addition, we also include some mutations in G6PD, the gene on the X chromosome that encodes glucose-6-phosphate dehydrogenase, because inactivity of this enzyme may lead to shortage of NADPH and thus to insufficient activity of NADPH oxidase. Severe G6PD deficiency can induce CGD-like symptoms.

Treatment of patients with immunodeficiency: Medication, gene therapy, and transplantation

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.

Vacinas contra a COVID-19 e os erros inatos da imunidade (ou imunodeficiências primárias) / COVID-19 vaccines and inborn errors of immunity (or primary immunodeficiencies)

Desde o início da pandemia de COVID-19 iniciou-se a corrida por uma imunização ativa, eficaz e segura. Todas as vacinas desenvolvidas até o momento vêm demostrando boa eficácia na prevenção de casos graves de COVID-19, de hospitalizações e mortes. Muitos pacientes com erros inatos da imunidade (EII) não terão capacidade de desenvolver uma resposta imune semelhante ao indivíduo imunocompetente. Esses pacientes foram incluídos nos grupos prioritários definidos pelo Ministério da Saúde, como pessoas entre 18 a 59 anos com uma ou mais das comorbidades, incluindo as imunodeficiências primárias. Eles podem e devem receber as vacinas em uso contra o SARS-CoV-2, mas nem sempre apresentarão uma resposta imunológica satisfatória e protetora, e, portanto, seus contactantes também devem ser vacinados.

Since the beginning of the COVID-19 pandemic, the race for an active, effective, and safe immunization has started. All vaccines developed to date have shown good efficacy in preventing serious cases of COVID-19, hospitalization, and death. Many patients with inborn errors of immunity will not be able to develop an immune response similar to that of immunocompetent individuals. These patients were included in the priority groups defined by the Brazilian Ministry of Health, as people between 18 and 59 years of age with one or more comorbidities, including primary immunodeficiencies. They can and should receive the vaccines in use against SARS-CoV-2, but they will not always have a satisfactory and protective immune response, and, therefore, those in direct contact with them should also be vaccinated.

Inherited GATA2 Deficiency Is Dominant by Haploinsufficiency and Displays Incomplete Clinical Penetrance.

PURPOSE: Germline heterozygous mutations of GATA2 underlie a variety of hematological and clinical phenotypes. The genetic, immunological, and clinical features of GATA2-deficient patients with mycobacterial diseases in the familial context remain largely unknown. METHODS: We enrolled 15 GATA2 index cases referred for mycobacterial disease. We describe their genetic and clinical features including their relatives. RESULTS: We identified 12 heterozygous GATA2 mutations, two of which had not been reported. Eight of these mutations were loss-of-function, and four were hypomorphic. None was dominant-negative in vitro, and the GATA2 locus was found to be subject to purifying selection, strongly suggesting a mechanism of haploinsufficiency. Three relatives of index cases had mycobacterial disease and were also heterozygous, resulting in 18 patients in total. Mycobacterial infection was the first clinical manifestation in 11 patients, at a mean age of 22.5 years (range: 12 to 42 years). Most patients also suffered from other infections, monocytopenia, or myelodysplasia. Strikingly, the clinical penetrance was incomplete (32.9% by age 40 years), as 16 heterozygous relatives aged between 6 and 78 years, including 4 older than 60 years, were completely asymptomatic. CONCLUSION: Clinical penetrance for mycobacterial disease was found to be similar to other GATA2 deficiency-related manifestations. These observations suggest that other mechanisms contribute to the phenotypic expression of GATA2 deficiency. A diagnosis of autosomal dominant GATA2 deficiency should be considered in patients with mycobacterial infections and/or other GATA2 deficiency-related phenotypes at any age in life. Moreover, all direct relatives should be genotyped at the GATA2 locus.

Treatment of patients with immunodeficiency: Medication, gene therapy, and transplantation.

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.