Antibody deficiencies with normal IgG in adults with Non-cystic fibrosis bronchiectasis or recurrent pneumonia: Cross-sectional study / Deficiencias Predominantemente de Anticuerpos con niveles normales de IgG en adultos con bronquiectasias no fibrosis quística o neumonía recurrente en Colombia

Abstract Background: Inborn errors of immunity, mainly Predominantly Antibody deficiencies with normal IgG levels are unrecognized in adults with lung diseases such as bronchiectasis or recurrent pneumonia. Objective: To determine IgM, IgA, IgG2 subclass deficiencies, and Specific antibody deficiency (anti-pneumococcal polysaccharide antibodies) in adults with non-cystic fibrosis bronchiectasis or recurrent pneumonia. Methods: Cross-sectional study. Consecutive patients with non-cystic fibrosis bronchiectasis or recurrent pneumonia were recruited in Cali, Colombia. IgG, IgA, IgM, and IgE, IgG2subclass and IgG anti-pneumococcal serum levels were measured. Results: Among the 110 participants enrolled, Antibody deficiencies with normal serum IgG levels were found in 11(10%) cases. IgA deficiency (3 cases), IgM deficiency (2 cases) and IgG2 deficiency (2 cases) were the most frequent primary immunodeficiencies. In addition, IgG2+IgA deficiency, Ataxia-telangiectasia, Hyper-IgE syndrome and Specific Antibody Deficiency(anti-polysaccharides) were found in one case each. Conclusions: Predominantly antibody deficiencies with normal IgG levels are an important etiology of non-cystic fibrosis bronchiectasis and recurrent pneumonia in adults.

Resumen Antecedentes: Los Errores Innatos de la Inmunidad principalmente las Deficiencias Predominantemente de anticuerpos con niveles normales de IgG no se conocen en adultos con enfermedades pulmonares como las bronquiectasias o la neumonía recurrente. Objetivo: Determinar las deficiencias de IgM, IgA y de subclase de IgG2 y la Deficiencia Específica de Anticuerpos (anticuerpos antineumocócicos de polisacáridos) en adultos con Bronquiectasias no Fibrosis Quística (BQnoFQ) o neumonía recurrente. Métodos: Estudio observacional prospectivo. Se reclutaron 110 pacientes consecutivos con BQnoFQ o neumonía recurrente en Cali, Colombia. Se midieron los niveles séricos de IgG, IgA, IgM e IgE, subclase IgG2 y anticuerpos anti-neumococo. Resultados: Se encontraron deficiencias de anticuerpos con niveles normales de IgG en el 10% de los sujetos; Cuatro casos con IgG2 baja, incluido 1 caso de deficiencia de IgG2 + IgA, 1 caso de ataxia-telangiectasia, 3 deficiencias de IgA (IgAD), 2 deficiencias selectiva de IgM (IgMD), 1 síndrome de Hiper-IgE (HIES-AR) y 1 deficiencia específica de anticuerpos. Ocho pacientes fueron diagnosticados con enfermedades relacionadas con la hipogammaglobulinemia IgG. Conclusiones: Las deficiencias predominantemente de anticuerpos con niveles normales de IgG son una etiología importante de BQnoFQ y neumonía recurrente en adultos. Los sujetos con bronquiectasias o neumonía recurrente requieren una evaluación exhaustiva de la respuesta inmune humoral y clínica.

Detección de deficiencias de anticuerpos y caracterización clínico-demográfica en pacientes pediátricos con enfermedades alérgicas

RESUMEN Introducción: Las deficiencias predominantes de anticuerpos (DPA) cursan con disminución de niveles séricos de inmunoglobulinas (hipogammaglobulinemia), infecciones recurrentes y se ha reportado su asociación con las alergias. La información sobre su frecuencia en niños alérgicos es limitada y en Paraguay no existen datos al respecto. Objetivo: Detectar DPA y establecer su frecuencia en pacientes pediátricos con enfermedades alérgicas atendidos en un hospital de referencia del país. Materiales y métodos: Fueron evaluados 64 pacientes pediátricos (1 a 17 años de edad) con diagnóstico de alergia, atendidos en la Unidad Pediátrica Ambulatoria-Especialidad Asma, Alergia e Inmunología del Hospital de Clínicas (periodo 2018-2019). Se midieron los niveles séricos de IgA, IgG e IgM por el método de inmunodifusión radial y se aplicaron criterios de diagnóstico fenotípico a los casos de hipogammaglobulinemia para definir la DPA. Resultados: La mediana de edad fue de 5 años (RIQ: 2 - 8), con predominio del sexo masculino (58%). Las alergias más frecuentes fueron asma (38%) y rinitis (34%), además predominaron las infecciones respiratorias recurrentes (80%). La frecuencia de DPA fue de 17% (11/64), detectándose 6 casos de deficiencia de inmunoglobulina A, 4 deficiencias aisladas de IgG y una inmunodeficiencia común variable. No se observaron diferencias significativas al comparar características clínico-demográficas entre pacientes alérgicos con y sin DPA. Conclusiones: La frecuencia de DPA fue elevada, por lo que se sugiere considerar el estudio de inmunoglobulinas séricas en pacientes pediátricos con enfermedades alérgicas para una detección y tratamiento oportunos.

ABSTRACT Introduction: Predominant antibody deficiencies (PAD) present with decreased serum levels of immunoglobulins (hypogammaglobulinemia), recurrent infections and their association with allergies has been reported. Information on its frequency in allergic children is limited and in Paraguay there are no data in this regard. Objective: To detect PAD and establish its frequency in pediatric patients with allergic diseases treated at a reference hospital in the country. Materials and methods: 64 pediatric patients (1 to 17 years of age) with a diagnosis of allergy, treated in the Pediatric Outpatient Unidad Pediátrica Ambulatoria-Especialidad Asma of the Hospital de Clínicas (from 2018 to 2019) were evaluated. Serum levels of IgA, IgG and IgM were measured by the radial immunodiffusion method and phenotypic diagnostic criteria were applied to hypogammaglobulinemia cases to define PAD. Results: The median age was 5 years (IQR: 2 - 8), with a predominance of males (58%). The most frequent allergies were asthma (38%) and rhinitis (34%), and recurrent respiratory infections (80%) predominated. The frequency of PAD was 17% (11/64), with 6 cases of immunoglobulin A deficiency detected, 4 isolated IgG deficiencies and a common variable immunodeficiency were also detected. No significant differences were observed when comparing clinical-demographic characteristics between allergic patients with and without PAD. Conclusions: The frequency of PAD was high, so we suggest considering serum immunoglobulins studies in pediatric patients with allergic diseases for timely detection and treatment.

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

Human Inborn Errors of Immunity (HIEI): predominantly antibody deficiencies (PADs): if you suspect it, you can detect it

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.

Deficiencia de anticuerpos específicos: inmunodeficiencia primaria asociada a alergia respiratoria / Specific antibody deficiency: primary immunodeficiency associated to respiratory allergy

La deficiencia de anticuerpos específicos con inmunoglobulinas séricas y linfocitos B normales (SAD) es una inmunodeficiencia primaria caracterizada por una capacidad alterada de responder a antígenos específicos, especialmente polisacáridos. OBJETIVO: Describir las características clínicas de pacientes con SAD y destacar la asociación entre una inmunodeficiencia primaria y enfermedades alérgicas. Pacientes y Método: Estudio descriptivo en enfermos con SAD atendidos en un hospital público entre agosto de 2007 y julio de 2015. Se descartó otra inmunodeficiencia primaria o secundaria. El diagnóstico se basó en infecciones recurrentes y una respuesta anormal a la vacuna neumocócica polisacárida con medición de IgG específica para 10 serotipos de neumococo. RESULTADOS: Se incluyeron 12 pacientes, 4 varones, con una edad promedio de 6 años; predominaron las neumonías recurrentes (91,7%) y otras infecciones respiratorias e invasivas. Los 12 enfermos con SAD tenían asma asociada; 11, rinitis alérgica y otras alergias. Tres pacientes no respondieron a ninguno de los 10 serotipos contenidos en la vacuna neumocócica polisacárida y la mayoría de los que lo hicieron fue a títulos bajos. El tratamiento con vacuna neumocócica conjugada fue favorable en 11/12 enfermos. CONCLUSIÓN: En niños mayores de 2 años con infecciones respiratorias recurrentes o infecciones invasivas por S. pneumoniae con inmunoglobulinas normales recomendamos investigar SAD, más aún si tienen enfermedad alérgica asociada.

Specific antibody deficiency (SAD) with normal immunoglobulin and normal B cells is a primary immunodeficiency characterized by reduced ability to produce antibodies to specific antigens especially polysaccharides. OBJECTIVE: To describe the characteristics of patients diagnosed with SAD emphasizing the association between primary immunodeficiency and allergic diseases. PATIENTS AND METHOD: Descriptive study showing patients with SAD treated at a public hospital between August 2007 and July 2015. Other secondary or primary immunodeficiency was discarded. The diagnosis of SAD was based on recurrent infections and abnormal response to pneumococcal polysaccharide vaccine assessed by specific IgG to 10 pneumococcal serotypes. Results: Twelve patients were included, 4 males, mean age 6 years, recurrent pneumonia predominated (91.7%) as well as other respiratory and invasive infections. All patients with SAD had associated asthma, 11 had allergic rhinitis, and other allergies. Three patients did not respond to any of the 10 serotypes contained in pneumococcal polysaccharide vaccine, and those who responded were with low titers. Treatment with conjugate pneumococcal vaccine was favorable in 11/12 patients. CONCLUSION: In children older than 2 years with recurrent respiratory infections or invasive S. pneumoniae infections with normal immunoglobulin we recommend to investigate SAD, especially if they have a concurrent allergic disease.

Rituximab e hipogammaglobulinemia / Rituximab and hypogammaglobulinemia

El rituximab (RTX), un anticuerpo quimérico anti-CD20 que induce la depleción de linfocitos B, es utilizado para el tratamiento de enfermedades linfoproliferativas y autoinmunes. La inmunodeficiencia humoral relacionada al tratamiento con RTX comenzó a ser un motivo de derivación a nuestro Servicio, por lo que decidimos analizar a los pacientes con el antecedente de haber sido tratados con RTX que consultaron por hipogammaglobulinemia o infecciones recurrentes desde noviembre de 2010 hasta diciembre de 2014. Evaluamos a ocho pacientes, siete mujeres y un varón. El tiempo promedio de seguimiento fue de 19.3 ± 18.8 meses, rango 1 a 54, con una mediana de 13. Tres tenían proteinogramas normales previo a la administración de RTX, tres hipogammaglobulinemia, y de dos no hay datos. A ninguno se le realizó una determinación cuantitativa de inmunoglobulinas previa al tratamiento. Cuatro recibieron RTX por linfoma B no Hodgkin, dos por leucemia linfocítica crónica, uno por púrpura trombocitopénica autoinmune y otro por poliangeítis microscópica. A seis se les diagnosticó hipogammaglobulinemia y a uno deficiencia de IgM, IgA e IgG2. Cinco presentaron infecciones, cuatro con buena respuesta al tratamiento de reemplazo con gammaglobulina. La inmunodeficiencia humoral relacionada a RTX es una causa de consulta cada vez más frecuente. Resulta fundamental disponer de los niveles de inmunoglobulinas previo al inicio de su administración para poder establecer una relación etiológica y durante el seguimiento, para disminuir el retraso diagnóstico. El tratamiento con gammaglobulina en dosis sustitutivas parece ser de utilidad en pacientes con infecciones graves o recurrentes.

Rituximab, a chimeric monoclonal antibody against CD20, induces the depletion of B lymphocytes. It is used for the treatment of lymphoproliferative and autoimmune diseases. Antibody immunodeficiency associated to RTX treatment is a new motif for consultation to our service. We decided to study those patients that having been treated with RTX, consulted for hypogammaglobulinemia or recurrent infections between November 2010 and December 2014. We evaluated eight patients, seven female and one male. The average follow up time was 19.3 ± 18.8 months, range 1 to 54, median 13. Three had a normal electrophoretic proteinogram before receiving RTX, three had hypogammaglobulinemia and in two data was not available. None of them had a quantitative determination of immunoglobulins before receiving RTX. Four received RTX as a treatment of non Hodking lymphoma, two as a treatment of chronic lymphocytic leukemia, one for immune thrombocytopenic purpura and other for microscopic polyangiitis. Six were diagnosed with hypogammaglobulinemia and one with combined IgM, IgA and IgG2 deficiency. Five presented infections, four of them with good response to intravenous immunoglobulin. RTX related antibody deficiency consultations are increasing. It is important to determine the immunoglobulin levels previously to RTX use in order to establish an etiologic relationship with RTX and a quick diagnosis of antibody deficiency. The substitutive treatment with gammaglobulin seems to be useful in patients with severe or recurrent infections.

Diagnostic Approach to Primary Immunodeficiency Disorders.

Primary immunodeficiency disorders (PIDs) are a heterogeneous group of inherited disorders that affect different components of the immune system. There are more than 150 different disorders which have been described till date. Despite major advances in the molecular characterization of PIDs over the last 20 years, many patients remain undiagnosed or are diagnosed too late with severe consequences. Recognizing different clinical manifestations of PID is the first most important step. It should be followed by use of appropriate diagnostic tools from a vast number of investigations available. This review will focus on important presenting features of PID and laboratory approach for diagnosis of suspected cases of PID.

Caracterização imunofenotípica de linfócitos B de memória na deficiência de IgA e imunodeficiência comum variável / Immunophenotypical characterization of memory B Iymphocytes in IgA deficiency and common variable immunodeficiency

Objetivo: A progressão da deficiência de IgA (DIgA) para imunodeficiência comum variável (ICV) tem sido relatada, embora não constitua regra geral. Postula-se que a associação com doenças autoimunes (DAIs) constitua fator de risco para tal progressão. Embora a fisiopatologia da ICV não esteja esclarecida, a redução de células B de memória class-switched (CD27+IgG-IgM-) tem sido relacionada a sua maior associação com autoimunidade. Por outro lado, na DIgA a persistência de células B imaturas IgM+ IgD+ foi associada à progressão para ICV. O objetivo foi comparar em pacientes com DIgA e ICV populações de células B de memória e correlacionar estas populações celulares à presença de DAIs em ambos grupos. Métodos: O estudo incluiu 56 pacientes adultos com DIgA ou ICV igualmente distribuídos em 4 grupos de acordo com a presença ou ausência de DAIs. As seguintes subpopulações de células B foram determinadas por citometria de fluxo de quatro cores: células B naive (CD19+IgM+), células B de memória c/ass-switched (CD27+IgM-IgD-) e células B de memória imaturas (CD27+IgM+ ou CD27+IgD+). Resultados: Os valores de células B naive e de células de memória c1ass-switched foram similares nos quatro grupos estudados. Os pacientes com DIgA ou ICV e DAIs associadas apresentaram valores igualmente aumentados de células B de memória imaturas CD27+IgM+ e CD27+IgD+ quando comparados a pacientes sem autoimunidade. Conclusões: Neste estudo foi demonstrado pela primeira vez persistência de células B de memória imaturas em pacientes adultos com DIgA e ICV associadas a doenças autoimunes. Especula-se se a persistência destas células possa constituir fator de risco para a progressão de DIgA para ICV.

Objective: Progression from IgA deficiency (IgAD) to common variable immunodeficiency (CVID) has been reported in some patients, but is not a general rule. It is postulated if association with autoimmune diseases (AIDs) could be risk factor for such progression. While the pathophysiology of CVID remains elusive, decreased numbers of classic (class-switched) memory B cells (CD27+IgG-IgM-) was correlated with increased rates of autoimmune features. By other hand, persistence of immature B cells (IgM+ IgD+) in IgA deficiency patients was correlated to progression from DIgA to CVID. The aim of this study was to compare memory B cell subpopulations in IgAD and CVID patients, and to assess the relationship between these populations and the presence of autoimmune diseases in both group of patients. Methods: This study included 56 adult patients with IgAD or CVID distributed in four groups according to the presence or absence of AIDs. The following B cell populations were determined by lymphocyte immunophenotyping by four-colour flow cytometry: narve B cells (CD19+IgM+), c1ass-switched memory B cells (CD27+IgM-IgD-) and immature B memory cells (CD27+IgM+ or CD27+IgD+). Results: Naive B cell and c1ass-switched memory B cells (CD27+IgG-IgM-) numbers were similar in all groups studied. IgAD and CVID patients with associated AIDs presented higher values of immature B cells (CD27 IgM+ and CD27+ IgD+) than patients without associated AIDs. Conclusions: This study reported for the first time the persistence of immature memory B cells in adult IgAD and CVID patients associated to autoimmune diseases. We speculate if persistence of immature B cells may constitute a rlsk factor for progression of IgAD to CVID.

Freqüência de inadequação do estado nutricional em pacientes com deficiência de anticorpo / Frequency of inadequate nutritional status in patients with antibody deficiency

Pacientes com imunodeficiência primária (IOP) que necessitam de reposição regular de imunoglobulinas podem cursar com distúrbios inflamatórios, endócrinos e com exacerbação do estresse oxidativo, resultando em alterações do estado nutricional (EN) e maior risco de desenvolvimento de outras doenças crônicas. Objetivou-se nesse estudo descrever o EN de pacientes com agamaglobulinemia congênita ligada ao X (XLA), imunodeficiência comum variável (ICV) e deficiência de anticorpo a antígenos polissacarídeos (DAAP). Foram avaliados pacientes em uso regular de imunoglobulina, atendidos na Universidade Federal de São Paulo em 2009. O diagnóstico de IOP seguiu os critérios do PAGID-ESID. Avaliou-se o estado nutricional através do índice de massa corporal (IMC) e índice de estatura por idade (E/I), adotando-se os pontos de corte propostos pela Sociedade Brasileira de Pediatria (crianças e adolescentes) e Organização Mundial da Saúde (adultos). Foram avaliados 52 pacientes, sendo 14 com XLA, 33 com ICV e 5 DAAP; 63,5% do sexo masculino e 61,5% (32/50) com menos de 20 anos. A mediana de idade foi de 14 anos (1,6 - 53). Nos adultos, observou-se 20% de desnutrição e 25% excesso de peso e nas crianças e adolescentes, 21,8%, 15,6% e 25% de desnutrição, excesso de peso e baixa estatura grave, respectivamente. Observou-se comprometimento pulmonar em 45% dos adultos e 34% entre crianças e adolescentes. O grupo estudado demonstrou alta frequência de inadequação do EN, ressaltando-se a desnutrição em adultos e desnutrição e baixa estatura em crianças e adolescentes. A desnutrição e a baixa estatura, crianças e adolescentes, apresentou relação com o comprometimento pulmonar.

Patients with primary immunodeficiency (PIO) receive immunoglobulin replacement therapy, and as with other chronic diseases, may present inflammatory and endocrine complications and exacerbation of oxidative stress leading to an altered nutritional status (NS) and to a greater risk of developing other chronic diseases. This study aimed to describe the NS in patients with congenital X-linked agammaglobulinemia (XLA), common variable immunodeficiency (CVIO) and antibody deficiency to polysaccharide antigens (DAAP). We assessed patients with regular use of immunoglobulin, attended at Federal São Paulo University in 2009. These diseases were classified according to the PAGID-ESID criteria. Nutritional status was evaluated by body mass index and height for age. The values were expressed in z score and the cutoff points for diagnosis were adopted according to World Health Organization and Brazilian Society of Pediatrics. We evaluated 52 patients (63.5% male, median age= 14 years, age range= 1,6-53 years, 61.5% (32/50) with less than 20 years), 14 with XLA, 33 with CVIO and 5 DAAP. In adults, there was 20% for malnutrition and 25% and overweight, and in children and adolescents, 21.8%, 15.6% and 25% of malnutrition, overweight and severe short stature, respectively. Pulmonary sequel was observed in 45% of adults and in 34% of children and adolescents. We observed a high frequency of inadequate nutritional status, especialIy malnutrition in adults and malnutrition and severe short stature in children and adolescents. Malnutrition and severe short stature.