Analysis of clinical phenotype and variant of RAG1 gene in a child with B-cell-negative Severe Combined Immunodeficiency / 中华医学遗传学杂志

OBJECTIVE@#To report on a child with B-cell-negative severe combined immunodeficiency (B-SCID) manifesting as fulminant myocarditis and carry out genetic testing for her.@*METHODS@#A child with B-SCID who presented at Fujian Maternity and Child Health Care Hospital on January 31, 2021 was selected as the subject. Whole exome sequencing was carried out for her. Candidate variant was verified by Sanger sequencing.@*RESULTS@#The female infant had developed recurrent skin and lung infections soon after birth, and was admitted due to fulminant myocarditis. Serological examination has disclosed a remarkable reduction in immunoglobulins. Flow cytometric analysis revealed that her peripheral blood T and B lymphocytes and NK cells were significantly reduced. Whole exome sequencing revealed that she has harbored a homozygous c.C3007T (p.Q1003X) nonsense variant of the RAG1 gene, for which both of her parents were heterozygous carriers. The variant has not been recorded in normal population databases. Based on the guidelines from the American College of Medical Genetics and Genomics, the variant was predicted to be pathogenic.@*CONCLUSION@#A case of RAG1 gene associated B-SCID has been diagnosed. Above finding has enriched the spectrum of RAG1 gene variants and enabled early diagnosis and intervention of the disease.

Inmunodeficiencia combinada grave: Presentación de un caso / Severe Combined Immunodeficiency: Case presentation

Introducción: Las inmunodeficiencias primarias son un grupo heterogéneo de trastornos hereditarios ocasionados por defectos del desarrollo o función del sistema inmunológico. Las inmunodeficiencias combinadas graves constituyen el 15 por ciento de las inmunodeficiencias primarias, son graves y los pacientes rara vez sobreviven sin tratamiento después del primer año de vida, lo que obliga a un diagnóstico y tratamiento oportuno. Objetivo: Presentar un caso con inmunodeficiencia combinada grave, condición reportada con poca frecuencia y evolución desfavorable. Presentación de caso: Lactante masculino de seis meses con antecedentes de cuatro ingresos en Unidad de Terapia Intensiva por infecciones, el último por bronconeumonía bilateral. Fue valorado por Inmunología y se diagnosticó una inmunodeficiencia combinada grave por la clínica (infecciones por gérmenes oportunistas: Candida albicans y Pneumocistys jirovecii) y estudios inmunológicos (con disminución de los anticuerpos IgG: 0,02 g/L, IgM: 0.1 g/L e IgA: 0 g/L), subpoblaciones linfocitarias disminuidas (CD3/CD4: 9,3 por ciento, CD3/CD8: 5,6 por ciento, CD19: 0 por ciento, CD 16: 0,73 por ciento), además hipoplasia tímica severa (120 mm2). Se inició tratamiento con antimicrobianos de amplio espectro e inmunoestimulantes (Hebertrans y Biomodulina T). Evolucionó desfavorablemente y falleció por shock séptico. Conclusiones: La inmunodeficiencia combinada grave es una emergencia pediátrica que debe tenerse en cuenta en pacientes con antecedentes de infecciones recurrentes, es vital conocer las manifestaciones clínicas tempranas que permitan la sospecha diagnóstica, haciendo uso de todas las herramientas disponibles para su confirmación. El diagnóstico precoz es el elemento clave para la reducción de la morbilidad y mortalidad relacionada con estas enfermedades(AU)

Introduction: Primary Immunodeficiencies are a heterogeneous group of inherited disorders caused by defects in development or function of the immune system. Severe Combined Immunodeficiencies constitute 15% of the primary immunodeficiencies, they are acute and patients rarely survive without treatment after the first year of life, requiring a quick diagnosis and treatment. Objective: To present a case on Severe Combined Immunodeficiency, a condition infrequently reported and with unfavorable evolution. Case presentation: Six-month-old male infant with a history of four admissions to the Intensive Care Unit due to infections, in the latter one due to bilateral bronchopneumonia. He was evaluated by Immunology and a Severe Combined Immunodeficiency was diagnosed by the clinic (infections by opportunistic germs: Candida albicans and Pneumocistys jirovecii) and immunological studies (with a decrease in IgG antibodies: 0.02 g/L, IgM: 0.1 g/L and IgA: 0 g/L), decreased lymphocyte subpopulations (CD3/CD4: 9.3 percent, CD3/CD8: 5.6 percent, CD19: 0 percent, CD 16: 0.73 percent), in addition to severe thymic hypoplasia (120 mm2). Treatment with broad spectrum antimicrobials and immunostimulants (Hebertrans and Biomodulin T) was started. He evolved unfavorably and died of septic shock. Conclusions: Severe Combined Immunodeficiency is a pediatric emergency that must be taken into account in patients with a history of recurrent infections, it is vital to know the early clinical manifestations that allow a suspected diagnosis, making use of all the available tools for its confirmation. Early diagnosis is the key element in reducing morbidity and mortality related to these diseases(AU)

Aproximación diagnóstica ultrasonográfica prenatal al síndrome de Omenn: reporte de caso / Prenatal ultrasound diagnostic approach to Omenn syndrome: case report

Objetivo: reportar el caso de una gestante con diagnóstico ultrasonográfico de alteración del sistema tegumentario fetal y diagnóstico posnatal de síndrome de Omenn. Presentación de caso: se presenta el caso de paciente de 27 años con embarazo de 31 semanas, con exploración ultrasonográfica prenatal que evidencia feto con edema significativo del cuero cabelludo, líquido amniótico ecogénico y descamación de la piel abdominal, con aproximación diagnóstica ultrasonográfica de variante de ictiosis. El recién nacido presentó eritrodermia congénita complicada con infección de piel, con posterior choque séptico y muerte. El estudio genético y patológico concluye síndrome de Omenn. Conclusión: el síndrome de Omenn debe ser tomado en cuenta en los diagnósticos diferenciales cuando en la ultrasonografía prenatal existan hallazgos ultrasongráficos de una alteración del sistema tegumentario. Se requieren estudios que evalúen la exactitud del ultrasonido en el diagnóstico antenatal de las eritrodermias.

Objective: To report the case of a pregnant woman with ultrasound diagnosis of altered fetal tegumental system and postnatal diagnosis of Omenn syndrome. Case presentation: A 27-year-old patient who presented at 31 weeks of gestation with prenatal ultrasound evidence of a fetus with significant scalp edema, echogenic amniotic fluid and scaly abdominal skin, with ichtyosis variant impression on diagnostic ultrasound. The baby was born with congenital erythroderma complicated with skin infection, and later developed septic shock and died. The genetic and pathologic workup led to the conclusion of Omenn syndrome. Conclusion: Omenn syndrome must be considered as part of the differential diagnoses when prenatal ultrasound shows findings of altered tegument system. Studies are required to assess the accuracy of ultrasound for prenatal diagnosis of erythroderma.

Supervivenciade pacientes pediátricos con inmunodeficiencias primarias en un hospital público del occidente de México / Survival of pediatric patients with primary immunodeficiencies in a public hospital in western Mexico

Se presenta una serie de casos de inmunodeficiencias primarias y se describen las variables asociadas a supervivencia en pacientes ≤ 16 años. Los diagnósticos fueron acordes a los criterios de la Unión Internacional de las Sociedades de Inmunología. Se realizó un análisis de supervivencia mediante curvas de Kaplan-Meier.Entre los años 2004 y 2019, se diagnosticaron 40 pacientes con inmunodeficiencias primarias. Las más frecuentes fueron inmunodeficiencias que afectaban la inmunidad celular y humoral, el 32,5 %, y deficiencias predominantemente de anticuerpos, el 32,5 %. La mediana de edad al inicio de los síntomas y al momento del diagnóstico fue de 3,01 y 10,4 meses, respectivamente. Fallecieron el 35 % y el riesgo fue mayor en pacientes con inmunodeficiencias que afectaban la inmunidad celular y humoral y en quienes presentaron manifestaciones clínicas y tuvieron el diagnóstico en los primeros seis meses de vida.

A case series of primary immunodeficiencies is presented and outcome measures associated with survival among patients ≤ 16 years old are described. Diagnoses were made based on the criteria by the International Union of Immunological Societies. Survival was analyzed using Kaplan-Meier curves.Between 2004 and 2019, 40 patients were diagnosed with primary immunodeficiencies. The most common were immunodeficiencies affecting humoral and cell-mediated immunity (32.5 %) and predominantly antibody deficiencies (32.5 %). The median age at the onset of symptoms and at the time of diagnosis was 3.01 and 10.4 months, respectively. Thirty-five percent of patients died, and the risk was higher among those with immunodeficiencies affecting humoral and cell-mediated immunity and those who developed clinical manifestations and were diagnosed in the first 6 months of life

Combined immunodeficiencies

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.

Inmunodeficiencia Combinada Severa, reporte de pacientes chilenos diagnosticados durante el período 1999-2020 / Severe combined immunodeficiency, report of Chilean patients diagnosed during the 1999-2020 period

INTRODUCCIÓN: La inmunodeficiencia combinada severa (IDCS) corresponde a una de las formas más graves de inmunodeficiencia primaria, existiendo escasos datos nacionales sobre ésta. OBJETIVO: describir la epidemiología, complicaciones, pronóstico y uso de la vacuna BCG en pacientes chilenos con IDCS. PACIENTES Y MÉTODO: Estudio retrospectivo de pacientes diagnosticados con IDCS entre los años 1999 y 2020 por médicos inmunólogos a lo largo de Chile. El diagnóstico de IDCS se realizó conforme a los criterios propuestos por Shearer: linfocitos T (CD3+) < 300 células/μL y prolife ración 10% del límite de normalidad en respuesta a fitohemaglutinina o presencia de linfocitos T de origen materno. Se obtuvieron de la ficha clínica los datos correspondientes a: sexo, edad al diagnóstico, consanguinidad, región de origen, subpoblaciones linfocitarias, diagnóstico genético, complicaciones infecciosas y no infecciosas, vacunación BCG y sus complicaciones, edad de deriva ción al centro de TPH y causa de mortalidad no relacionada al TPH. RESULTADOS: se diagnosticaron 25 casos de IDCS en 22 familias entre los años 1999-2020. 78% varones, la edad media a la primera manifestación fue 2.3 meses (0-7), mientras que la edad media al diagnóstico fue de 3.4 meses (0 7). Un 16% de los casos tenía un antecedente familiar de IDCS. Un 40% de los casos fueron diag nosticados en la Región Metropolitana. El inmunofenotipo más frecuente fue T-B-NK+ (48%). Se realizaron estudios genéticos en 69,5% de los casos, siendo los defectos genéticos en RAG2 (39%) la causa más frecuente. Un 88% de los casos recibió la vacuna Bacillus Calmette-Guerin (BCG) previo al diagnóstico, incluidos 2 pacientes con historia familiar positiva, 36% de los vacunados experimentó complicaciones de la BCG. La edad media a la derivación a trasplante fue de 7,4 meses (5-16). De los 25 pacientes, 11 fallecieron previo a la derivación a un centro de trasplante. CONCLUSIÓN: En Chile existe un retraso clínicamente significativo entre las primeras manifestaciones y el diagnóstico de IDCS, así como un importante retraso en la derivación a centros de trasplante. La mayoría de los pacientes con IDCS reciben la vacuna BCG, pese a tener antecedentes familiares, y experimentan frecuentemente complicaciones de la vacuna.

INTRODUCTION: Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency. To date, there is little local information about this disease. OBJECTIVE: To describe the epidemiology, complications, prognosis, and use of the BCG vaccine in Chilean patients with SCID. PATIENTS AND METHOD: Retrospective review of the clinical records of patients diagnosed with SCID by clinical immunologists between 1999 and 2020 throughout Chile. SCID was diagnosed according to the cri teria proposed by Shearer: T lymphocytes (CD3+) < 300 cells/μL and proliferation 10% of the limit of normality in response to phytohemagglutinin or presence of T lymphocytes of maternal origin. Data collected from the clinical records were: sex, age at diagnosis, consanguinity, region of origin, lymphocyte subpopulations, genetic diagnosis, infectious and non-infectious complications, BCG vaccination and its complications, age at referral to the bone marrow transplant (BMT) center, and cause of non-BMT-related mortality. RESULTS: Between 1999 and 2020, 25 patients were diagnosed with SCID. 78% of them were male, mean age at first manifestation of the disease was 2.3 months (0-7), while the mean age at diagnosis was 3.4 months (0-7). 16% of patients had a family history of SCID. 40% of cases were diagnosed within the Metropolitan Region. The most frequent immuno- phenotype was T-B-NK+ SCID (48%). Genetic studies were done in 69.5% of cases, mutations in the RAG2 gene were the most common etiology of SCID (39%). 88% of SCID patients received the Bacillus Calmette-Guerin (BCG) vaccine before diagnosis, including 2 cases with a known family history of SCID. 36% of those who received the vaccine had BCG-related complications. The mean age at referral to a bone marrow transplant center was 7.4 months (5-16). 11/25 patients died before being transferred to a transplant center. DISCUSSION: There is a clinically significant delay between the first manifestations and the diagnosis of SCID in Chilean patients, as well as an important time gap between the diagnosis of SCID and referral to a center for BMT. Most SCID cases in Chile receive the BCG vaccine, despite a known family history of the disease, and frequently develop vaccine-related complications.

Flow Cytometry for the Diagnosis of Primary Immunodeficiency Diseases: A Single Center Experience

PURPOSE: While there is an urgent need for diagnosis and therapeutic intervention in patients with primary immunodeficiency diseases (PIDs), current genetic tests have drawbacks. We retrospectively reviewed the usefulness of flow cytometry (FCM) as a quick tool for immunophenotyping and functional assays in patients suspected to have PIDs at a single tertiary care institute.METHODS: Between January 2001 and June 2018, patients suspected of having PIDs were subjected to FCM tests, including lymphocyte subset analysis, detection of surface- or intracellular-target proteins, and functional analysis of immune cells, at Samsung Medical Center, Seoul, Korea. The genetic diagnosis was performed using Sanger or diagnostic exome sequencing.RESULTS: Of 60 patients diagnosed with definite or probable PID according to the European Society of Immune Deficiencies criteria, 24 patients were provided with useful information about immunological dysfunction after initial FCM testing. In 10 patients, the PID diagnosis was based on abnormal findings in FCM testing without genetic tests. The FCM findings provided strong evidence for the diagnosis of severe combined immunodeficiency (n = 6), X-linked chronic granulomatous diseases (CGD) (n = 6), leukocyte adhesion deficiency type 1 (n = 3), X-linked agammaglobulinemia (n = 11), autoimmune lymphoproliferative syndrome-FASLG (n = 1), and familial hemophagocytic lymphohistiocytosis type 2 (n = 1), and probable evidence for autosomal recessive-CGD (n = 2), autosomal dominant-hyper-immunoglobulin E (IgE)-syndrome (n = 1), and STAT1 gain-of-function mutation (n = 1). In PIDs derived from PIK3CD (n = 2), LRBA (n = 2), and CTLA4 mutations (n = 3), the FCM test provided useful evidence of immune abnormalities and a tool for treatment monitoring.CONCLUSIONS: The initial application of FCM, particularly with known protein targets on immune cells, would facilitate the timely diagnosis of PIDs and thus would support clinical decisions and improve the clinical outcome.

Inmunodeficiencia combinada severa: es tiempo de su detección precoz / Severe combined immunodeficiency: the time for newborn screening has come

Las inmunodeficiencias primarias (IDP) son un conjunto de cerca de 350 enfermedades genéticas que afectan el funcionamiento del sistema inmunológico. Los avances en diagnóstico genético han permitido describir nuevos defectos en el sistema inmune, ampliando el espectro de manifestaciones de las IDP más allá de la susceptibilidad a infecciones. Aunque la mayoría de las IDP se presentan con infecciones recurrentes u oportunistas, un subgrupo puede presentarse por el desarrollo precoz de fenómenos autoinflamatorios, tumorales y, paradojalmente, la coexistencia de autoinmunidad e inmunodeficiencia en un mismo paciente. Al igual que sus manifestaciones clínicas, la severidad de las IDP es variable. La inmunodeficiencia combinada severa (IDCS), caracterizada por una falla en la respuesta humoral y celular, es una de las formas más graves de IDP y el único tratamiento curativo disponible en Latino-América es el trasplante de precursores hematopoyéticos. La IDCS es 100% letal durante los dos primeros años de vida si no se diagnostica y trata oportunamente. Por el contrario, si se trasplantan precozmente, estos pacientes pueden alcanzar una sobrevida normal. Pese a los avan ces en el diagnóstico de IDP que se han observado en nuestro país en los últimos años, los recursos diagnósticos no se encuentran disponibles en todas las regiones, lo que dificulta el reconocimiento temprano de la IDCS y otras IDP en grandes áreas del país. El objetivo de esta actualización es revisar conceptos generales sobre la fisiopatología de la IDCS, diagnóstico, manejo inicial y plantear la nece sidad de la implementación del tamizaje neonatal de IDCS en Chile.

Primary immunodeficiencies (PIDs) are a set of about 350 genetic disorders that affect the normal function of the immune system. Advances in genetic diagnosis have allowed the description of new defects in the immune system, broadening the clinical spectrum of PIDs' manifestations beyond susceptibility to infection. Although most PIDs present with recurrent or opportunistic infections, a subgroup of them may be recognized by the early development of auto-inflammatory events, tumors and, paradoxically, the coexistence of autoimmunity and immunodeficiency in the same patient. As their clinical manifestations, the severity of PIDs is highly variable. Severe combined immunodefi ciency (SCID), a PID that affects cellular and humoral immunity, is one of the most severe forms of PIDs and the only available curative treatment in Latin America is hematopoietic stem cells trans plantation. All patients affected by SCID die during the first two years of life if they are not diagnosed and treated opportunely. In contrast, early transplantation of patients with SCID can lead to excellent survival outcomes. Despite recent advances in the diagnosis of PIDs in Chile, diagnostic resources are not available throughout the country, making the early diagnosis of SCID and other forms of PID difficult in big areas of Chile. The objective of this article is to review general concepts on the patho physiology, diagnosis, and initial management of SCID and raise the need for the implementation of neonatal screening for SCID in Chile.

Vacunación BCG e inmunodeficiencias primarias: ¿es momento de un cambio? / BCG vaccine administration schedule and primary immunodeficiencies: Is it time for a change?

Resumen: Los pacientes con Inmunodeficiencias primarias (IDP) tienen un riesgo elevado de complicaciones severas por la vacuna BCG, incluso mortalidad. Es necesario evaluar periódicamente el riesgo versus beneficio de la vacunación universal BCG en el periodo neonatal. Chile es un país con baja incidencia de tuberculosis (TB) pero cuya epidemiología ha cambiado recientemente con un aumento de los casos. Cambios en esquemas de vacunación BCG en países con incidencias mayores o similares de TB y con coberturas de vacunación menores han sido posibles sin aumento de los casos graves de TB que son los que previene la BCG. El cambio ha evitado complicaciones graves en pacientes con IDP. Creemos que un análisis crítico de la fecha de vacunación BCG debe realizarse hoy en Chile. Más aún dada la posibilidad técnica de realizar screening neonatal de IDP.

Abstract: Patients with Primary Immunodeficiencies (PID) are at a higher risk of developing severe morbidities and mortality due to the administration of BCG vaccine. Risk-to-benefit of universal BCG vaccina tion of newborns must be assessed periodically. Chile has a low incidence of tuberculosis (TB) but the local epidemiology has recently changed with an increase of TB cases. Changes in the BCG vaccine schedule have been made in countries with similar or higher TB incidences and lower BCG vaccine coverage, with no increase in the severe TB cases, which are prevented by BCG. These changes have prevented serious complications in PID patients. We propose a critical analysis of the BCG adminis tration date in Chile due to the technical possibility of performing neonatal PID screening.

Infección diseminada por Bacilo Calmette-Guérin en un lactante con inmunodeficiencia: reporte de caso / Disseminated infection by Bacillus Calmette-Guérin in an immunodeficient infant: case report

RESUMEN La vacuna Bacillus Calmette-Guerin (BCG) que se administra a los recién nacidos de países con alta incidencia de tuberculosis puede ocasionar reacciones locales hasta infección diseminada en pacientes inmunocomprometidos. Reportamos el caso de un lactante varón de seis meses con antecedente de haber recibido vacuna BCG al nacer, y presentar cuadros infecciosos a repetición, nódulos violáceos blandos en tronco y extremidades con presencia de bacilos ácido alcohol resistentes (BARR) en la histopatología y en cultivo de piel; el estudio molecular reportó la presencia de Micobacterium bovis BCG. En la tomografía se observó opacidades intersticiales en pulmones y en el lavado gástrico se identificó BAAR. El estudio genético del paciente y de la madre reveló la presencia de mutación en el gen IL2RG confirmando el diagnóstico de inmunodeficiencia combinada severa, recibe tratamiento con inmunoglubolina humana y esquema antituberculosis con isoniacida, rifampicina y etambutol. Presentamos el caso por la implicancia en el pronóstico de vida de estos pacientes y por la necesidad de un diagnóstico preciso y oportuno.

ABSTRACT The Bacillus Calmette-Guerin (BCG) vaccine given to newborns in countries with a high incidence of tuberculosis may cause local reactions up to disseminated infection in immunocompromised patients. We report the case of a six-monthold male infant with a history of having received the BCG vaccine at birth, and presenting repeated infectious, soft violet nodules in the trunk and extremities with the presence of acid-alcohol-resistant bacilli (BAAR) in histopathology and skin culture; the molecular study reported the presence of Mycobacterium bovis BCG. In the tomography, interstitial opacities were observed in the lungs and in the gastric lavage BAAR was identified. The genetic study of the patient and the mother revealed the presence of a mutation in the IL2RG gene confirming the diagnosis of severe combined immunodeficiency. Received treatment with human immunoglobulin and anti-tuberculosis scheme with isoniazid, rifampicin, and ethambutol. We present the case because of the implication in the life prognosis of these patients and because of the need for an accurate and timely diagnosis

Advances in newborn screening and immune system reconstitution of severe combined immunodeficiency / 浙江大学学报·医学版

Severe combined immunodeficiency disease (SCID) is a group of rare congenital diseases characterized by severe deficiencies in T lymphocyte counts and/or function. The recurrent, persistent and severe infections are its clinical manifestations. Neonatal screening and immune system reconstruction would improve the prognosis of SCID children. Newborn screening programs based on T-cell receptor excision circles (TRECs) quantitative detection have been carried out in clinical practice, however, the methods still have some limitations. Other new methods such as mass spectrometry and T lymphocyte-specific biomarker assays are still under investigation. Hematopoietic stem cell transplantation and gene therapy are the two main methods for reconstructing immune function in SCID children. Through improving the success rate of transplantation and the long-term safety and stability of viral vectors, some achievements have been made by many centers already. However, large-scale prospective studies are needed for evaluation of the long-term efficacy. In this article, the recent progress in newborn screening and immune reconstitution of SCID is reviewed.

Safety and Biodistribution of Human Bone Marrow-Derived Mesenchymal Stromal Cells Injected Intrathecally in Non-Obese Diabetic Severe Combined Immunodefi ciency Mice: Preclinical Study

BACKGROUND: Mesenchymal stromal cells (MSCs) have potent immunomodulatory and neuroprotective properties, and have been tested in neurodegenerative diseases resulting in meaningful clinical improvements. Regulatory guidelines specify the need to perform preclinical studies prior any clinical trial, including biodistribution assays and tumourigenesis exclusion. We conducted a preclinical study of human bone marrow MSCs (hBM-MSCs) injected by intrathecal route in Non-Obese Diabetic Severe Combined Immunodeficiency mice, to explore cellular biodistribution and toxicity as a privileged administration method for cell therapy in Friedreich's Ataxia. METHODS: For this purpose, 3 × 10⁵ cells were injected by intrathecal route in 12 animals (experimental group) and the same volume of culture media in 6 animals (control group). Blood samples were collected at 24 h (n = 9) or 4 months (n = 9) to assess toxicity, and nine organs were harvested for histology and safety studies. Genomic DNA was isolated from all tissues, and mouse GAPDH and human β2M and β-actin genes were amplified by qPCR to analyze hBM-MSCs biodistribution. RESULTS: There were no deaths nor acute or chronic toxicity. Hematology, biochemistry and body weight were in the range of normal values in all groups. At 24 h hBM-MSCs were detected in 4/6 spinal cords and 1/6 hearts, and at 4 months in 3/6 hearts and 1/6 brains of transplanted mice. No tumours were found. CONCLUSION: This study demonstrated that intrathecal injection of hBM-MSCs is safe, non toxic and do not produce tumors. These results provide further evidence that hBM-MSCs might be used in a clinical trial in patients with FRDA.

CRISPR/Cas9-mediated knockout of Rag-2 causes systemic lymphopenia with hypoplastic lymphoid organs in FVB mice / 한국실험동물학회지

Recombination activating gene-2 (RAG-2) plays a crucial role in the development of lymphocytes by mediating recombination of T cell receptors and immunoglobulins, and loss of RAG-2 causes severe combined immunodeficiency (SCID) in humans. RAG-2 knockout mice created using homologous recombination in ES cells have served as a valuable immunodeficient platform, but concerns have persisted on the specificity of RAG-2-related phenotypes in these animals due to the limitations associated with the genome engineering method used. To precisely investigate the function of RAG-2, we recently established a new RAG-2 knockout FVB mouse line (RAG-2(−/−)) manifesting lymphopenia by employing a CRISPR/Cas9 system at Center for Mouse Models of Human Disease. In this study, we further characterized their phenotypes focusing on histopathological analysis of lymphoid organs. RAG-2(−/−) mice showed no abnormality in development compared to their WT littermates for 26 weeks. At necropsy, gross examination revealed significantly smaller spleens and thymuses in RAG-2(−/−) mice, while histopathological investigation revealed hypoplastic white pulps with intact red pulps in the spleen, severe atrophy of the thymic cortex and disappearance of follicles in lymph nodes. However, no perceivable change was observed in the bone marrow. Moreover, our analyses showed a specific reduction of lymphocytes with a complete loss of mature T cells and B cells in the lymphoid organs, while natural killer cells and splenic megakaryocytes were increased in RAG-2(−/−) mice. These findings indicate that our RAG-2(−/−) mice show systemic lymphopenia with the relevant histopathological changes in the lymphoid organs, suggesting them as an improved Rag-2-related immunodeficient model.

TRIAGEM NEONATAL DE IMUNODEFICIÊNCIAS GRAVES COMBINADAS POR MEIO DE TRECS E KRECS: SEGUNDO ESTUDO PILOTO NO BRASIL / NEWBORN SCREENING FOR SEVERE COMBINED IMMUNODEFICIENCIES USING TRECS AND KRECS: SECOND PILOT STUDY IN BRAZIL

RESUMO Objetivo: Validar a quantificação de T-cell receptor excision circles (TRECs) e kappa-deleting recombination circles (KRECs) por reação em cadeia de polimerase (polymerase chain reaction, PCR) em tempo real (qRT-PCR), para triagem neonatal de imunodeficiências primárias que cursam com defeitos nas células T e/ou B no Brasil. Métodos: Amostras de sangue de recém-nascidos (RN) e controles foram coletadas em papel-filtro. O DNA foi extraído e os TRECs e KRECs foram quantificados por reação duplex de qRT-PCR. O valor de corte foi determinado pela análise de Receiver Operating Characteristics Curve, utilizando-se o programa Statistical Package for the Social Sciences (SSPS) (IBM®, Armonk, NY, EUA). Resultados: 6.881 amostras de RN foram analisadas quanto à concentração de TRECs e KRECs. Os valores de TRECs variaram entre 1 e 1.006 TRECs/µL, com média e mediana de 160 e 139 TRECs/µL, respectivamente. Três amostras de pacientes diagnosticados com imunodeficiência grave combinada (severe combined immunodeficiency, SCID) apresentaram valores de TRECs abaixo de 4/µL e um paciente com Síndrome de DiGeorge apresentou TRECs indetectáveis. Os valores de KRECs encontraram-se entre 10 e 1.097 KRECs/µL, com média e mediana de 130 e 108 KRECs/µL, e quatro pacientes com diagnóstico de agamaglobulinemia tiveram resultados abaixo de 4 KRECs/µL. Os valores de corte encontrados foram 15 TRECs/µL e 14 KRECs/µL, e foram estabelecidos de acordo com a análise da Receiver Operating Characteristics Curve, com sensibilidade de 100% para detecção de SCID e agamaglobulinemia, respectivamente. Conclusões: A quantificação de TRECs e KRECs foi capaz de diagnosticar crianças com linfopenias T e/ou B em nosso estudo, validando a técnica e dando o primeiro passo para a implementação da triagem neonatal em grande escala no Brasil.

ABSTRACT Objective: To validate the quantification of T-cell receptor excision circles (TRECs) and kappa-deleting recombination excision circles (KRECs) by real-time polymerase chain reaction (qRT-PCR) for newborn screening of primary immunodeficiencies with defects in T and/or B cells in Brazil. Methods: Blood samples from newborns and controls were collected on filter paper. DNA was extracted and TRECs, and KRECs were quantified by a duplex real-time PCR. The cutoff values were determined by receiver operating characteristic curve analysis using SPSS software (IBM®, Armonk, NY, USA). Results: Around 6,881 samples from newborns were collected and TRECs and KRECs were quantified. The TRECs values ranged between 1 and 1,006 TRECs/µL, with mean and median of 160 and 139 TRECs/µL, respectively. Three samples from patients with severe combined immunodeficiency (SCID) showed TRECs below 4/µL and a patient with DiGeorge syndrome showed undetectable TRECs. KRECs values ranged from 10 to 1,097 KRECs/µL, with mean and median of 130 and 108 KRECs/µL. Four patients with agammaglobulinemia had results below 4 KRECs/µL. The cutoff values were 15 TRECs/µL and 14 KRECs/µL and were established according to the receiver operating characteristic curve analysis, with 100% sensitivity for SCID and agammaglobulinemia detection, respectively. Conclusions: Quantification of TRECs and KRECs was able to diagnose children with T- and/or B-cell lymphopenia in our study, which validated the technique in Brazil and enabled us to implement the newborn screening program for SCID and agammaglobulinemia.

Use of Stem Cell in Fetal Therapy: Current Status and Future Perspectives

During the past decades, there has been a great evolution in the field of fetal therapy for congenital defects. Prenatal screening or diagnostic methods including non-invasive and invasive methods and fetal ultrasound have led to earlier and more accurate diagnosis of congenital anomalies. Recent advances in several therapeutic techniques including ultrasound-guided needle therapy, laser therapy or fetal endoscopy, have allowed some fetuses at risk with anatomical defects, to be corrected in utero but still, its clinical indications remain limited. Over the last 30 years, many researchers found usefulness of pluripotent stem cells from amniotic fluid and placenta because they are sources of diverse progenitor cell populations called mesenchymal stem cells. In some human conditions like severe combined immunodeficiency syndrome and chronic granulomatous disease, fetal therapy using stem cell replacement showed some promising results in researches but more studies are required to apply in clinical settings. The aim of this article is to summarize a current status and future perspective of stem cell therapy for treatment of congenital fetal anomalies.

The First Newborn Screening Study of T-Cell Receptor Excision Circle and κ- Deleting Recombination Excision Circle for Severe Combined Immunodeficiency in Korea: A Pilot Study

PURPOSE: Severe combined immunodeficiency (SCID) is the most serious form of primary immunodeficiency. Infants with SCID are susceptible to life-threatening infections. To establish newborn screening for SCID in Korea, we performed a screening test for T-cell receptor excision circle (TREC) and κ-deleting recombination excision circle (KREC) in neonates and investigated the awareness of SCID among their parents. METHODS: Collections of dried blood spots from neonates and parent surveys were performed at the Samsung Medical Center and Cheil General Hospital & Women's Healthcare Center in Korea. The amplification crossing point (Cp) value 39.0 was defined as negative. RESULTS: For TREC/KREC screening, 141 neonates were enrolled; 63 (44.7%) were male. One hundred forty neonates (99.3%) had positive TREC/KREC results at the time of the initial test; 82.3% and 75.9% were positive and 17.0% and 23.4% were weakly positive for TREC and KREC, respectively. In one neonate (0.7%), the initial TREC/KREC test result was negative. However, repeated tests obtained and confirmed a positive result. For an awareness survey, 168 parents were engaged. Only 2% of parents (3/168) knew that the newborn screening test for SCID had been introduced and performed in other countries. Eighty-four percent of parents (141/168) replied that nationwide newborn SCID screening should be performed in Korean newborns. CONCLUSIONS: In this study, newborn SCID screening was performed along with assessment of public awareness of the SCID test in Korea. The study results showed that newborn SCID screening can be readily applied for clinical use at a relatively low cost in Korea.

Neonatal screening for severe combined immunodeficiency in Brazil / Triagem neonatal para imunodeficiência combinada grave no Brasil

Abstract Objective To apply, in Brazil, the T-cell receptor excision circles (TRECs) quantification technique using real-time polymerase chain reaction in newborn screening for severe combined immunodeficiency and assess the feasibility of implementing it on a large scale in Brazil. Methods 8715 newborn blood samples were collected on filter paper and, after DNA elution, TRECs were quantified by real-time polymerase chain reaction. The cutoff value to determine whether a sample was abnormal was determined by ROC curve analysis, using SSPS. Results The concentration of TRECs in 8,682 samples ranged from 2 to 2,181 TRECs/µL of blood, with mean and median of 324 and 259 TRECs/µL, respectively. Forty-nine (0.56%) samples were below the cutoff (30 TRECs/µL) and were reanalyzed. Four (0.05%) samples had abnormal results (between 16 and 29 TRECs/µL). Samples from patients previously identified as having severe combined immunodeficiency or DiGeorge syndrome were used to validate the assay and all of them showed TRECs below the cutoff. Preterm infants had lower levels of TRECs than full-term neonates. The ROC curve showed a cutoff of 26 TRECs/µL, with 100% sensitivity for detecting severe combined immunodeficiency. Using this value, retest and referral rates were 0.43% (37 samples) and 0.03% (3 samples), respectively. Conclusion The technique is reliable and can be applied on a large scale after the training of technical teams throughout Brazil.

Resumo Objetivo Aplicar no Brasil a técnica de quantificação de T-cell Receptor Excision Circles (TRECs) por PCR em tempo real para triagem neonatal de imunodeficiência combinada grave (SCID) e avaliar se é possível fazê-la em grande escala em nosso país. Métodos Foram coletadas em papel filtro 8.715 amostras de sangue de recém-nascidos e, após eluição do DNA, os TRECs foram quantificados por PCR em tempo real. O valor de corte para determinar se uma amostra é anormal foi determinado pela análise de curva ROC com o programa SSPS. Resultados A concentração de TRECs em 8.682 amostras analisadas variou entre 2 e 2.181 TRECs/µL de sangue, com média e mediana de 324 e 259 TRECs/µL, respectivamente. Das amostras, 49 (0,56%) ficaram abaixo do valor de corte (30 TRECs/µL) e foram requantificadas. Quatro (0,05%) mantiveram resultados anormais (entre 16 e 29 TRECs/µL). Amostras de pacientes com diagnóstico clínico prévio de SCID e síndrome de DiGeorge foram usadas para validar o ensaio e todas apresentaram concentração de TRECs abaixo do valor de corte. Recém-nascidos prematuros apresentaram menores níveis de TRECs comparados com os nascidos a termo. Com o uso da curva ROC em nossos dados, chegamos ao valor de corte de 26 TRECs/µL, com sensibilidade de 100% para detecção de SCID. Com o uso desse valor, as taxas de repetição e encaminhamento ficaram em 0,43% (37 amostras) e 0,03% (3 amostras), respectivamente. Conclusão A técnica é factível e pode ser implantada em grande escala, após treinamento técnico das equipes envolvidas.

Analysis of genetic mutations and pathogenesis for two children with Omenn syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the clinical characteristics and genetic mutations in two children with Omenn syndromes.</p><p><b>METHODS</b>Peripheral venous blood samples were collected from 2 children suspected with severe combined immunodeficiency (SCID) and their family members. The samples were subjected to RAG1 and RAG2 gene sequencing and TCR Vβ subclone analysis.</p><p><b>RESULTS</b>Both patients had recurrent infections, erythroderma rashes and alopecia baldness. One patient has fit with immunophenotype T-B-NK+, while another was consistent with typical Omenn syndrome combined with T+B-NK+ immunophenotype, IgE and eosinophil increase. Both children have carried compound heterozygous mutations of the RAG1 gene. The first patient carried c.1328 G>A (p.R443K) and c.2486-2490delGGAAA (p.R829fsX869) mutations, both were of de novel type. The second patient has carried c.1209C>T (p.R403W) and c.2892delT (p.ASN964LYSfs*14), with c.2892delT (p.ASN964LYSfs*14) being a de novel mutation. The parents of both patients were heterozygous carriers. The same mutations were not found in 100 healthy children. Both patients' 24 TCR Vβ subfamilies have presented monoclonal or oligoclonal peaks, with TCR Vβ polymorphism being severely disrupted.</p><p><b>CONCLUSION</b>Three novel mutations have been identified in two children with Omenn syndrome, which featured early onset and rapid progression. Early recognition of the disease and prompt treatment may reduce the mortality.</p>