Niveles de IgA en adultos con enfermedad celíaca / IgA levels in adults with celiac disease

La enfermedad celíaca (EC) es una enfermedad autoinmune sistémica desencadenada por el consumo de gluten de la dieta en personas con susceptibilidad genética. Los principales test serológicos utilizados para el diagnóstico y seguimiento de la EC son pruebas basadas en anticuerpos de isotipo inmunoglobulina (Ig) A, siendo la determinación de IgA anti-transglutaminasa tisular (tTG)2 la prueba serológica inicial de elección. La deficiencia selectiva de IgA (DSIgA), es más prevalente en pacientes con EC que en la población general, dificultando el diagnostico serológico de la enfermedad. En el presente estudio observacional descriptivo, se incluyeron 74 pacientes adultos con diagnóstico confirmado de EC y se determinó IgA anti-tTG2 en suero mediante ensayo de ELISA a fin de detectar a aquellos pacientes con niveles indeterminados o negativos, los cuales podrían presentar DSIgA. Se dosó IgA total en el suero de estos pacientes por inmunodifusión radial y el promedio fue de 237,8 ± 100,6 mg/dL. En una paciente del sexo femenino fue detectada IgA total menor a 7 mg/dL, con niveles séricos de IgG e IgM normales, característicos de la DSIgA. Así, la frecuencia calculada de DSIgA fue de 1,35% en la población con EC estudiada. En conclusión, este trabajo es una primera aproximación para describir la frecuencia de DSIgA en pacientes con EC del país y reafirma la importancia de incluir el dosaje de IgA total en el caso de realizar test serológicos de la EC basados en IgA(AU)

Doenças autoimunes e autoanticorpos em pacientes pediátricos e seus parentes de primeiro grau com deficiência de imunoglobulina / Autoimmune diseases and autoantibodies in pediatric patients and their first-degree relatives with immunoglobulin A deficiency

Introdução: As manifestações clínicas da deficiência de imunoglobulina A (DIgA) incluem infecções recorrentes, atopia e doenças autoimunes. No entanto, para o nosso conhecimento, as avaliações concomitantes de doenças autoimunes e autoanticorpos em uma coorte de pacientes com DIgA com idade atual > 10 anos e seus parentes não foram feitas. Objetivos: Avaliar doenças autoimunes e presença de autoanticorpos em pacientes com DIgA e seus parentes de primeiro grau. Métodos: Estudo transversal feito em 34 pacientes com DIgA (idade atual > 10 anos) e em seus parentes de primeiro grau. Todos foram acompanhados em um centro terciário brasileiro para imunodeficiência primária: 27 crianças/adolescentes e sete de seus parentes de primeiro grau com diagnóstico tardio de DIgA. Doenças autoimunes e autoanticorpos (anticorpos antinucleares, fator reumatoide e antitireoglobulina, antitiroperoxidase e anticorpos antiendomísio da classe IgA) também foram avaliadas. Resultados: Doenças autoimunes (n = 14) e/ou autoanticorpos (n = 10, quatro deles com autoanticorpos isolados) foram observadas em 18/34 (53%) dos pacientes e seus parentes. As doenças autoimunes mais comuns encontradas foram tireoidite (18%), artrite crônica (12%) e doença celíaca (6%). Os autoanticorpos mais frequentes foram anticorpos antinucleares (2%), antitireoglobulina e/ou antitireoperoxidase (24%). Nenhuma diferença significativa foi observada no sexo feminino, idade no momento do diagnóstico e idade atual em pacientes com DIgA com e sem doenças autoimunes e/ou presença de autoanticorpos (p > 0,05). As frequências de imunodeficiência de primárias na família, autoimunidade em família, atopia e infecções recorrentes foram semelhantes em ambos os grupos (p> 0,05). Conclusão: Doenças autoimunes e autoanticorpos foram observadas em pacientes com DIgA durante o acompanhamento, o que reforça a necessidade de um acompanhamento rigoroso e contínuo durante a adolescência e a idade adulta. .

Introduction: Clinical manifestations of Immunoglobulin A Deficiency (IgAD) include recur-rent infections, atopy and autoimmune diseases. However, to our knowledge, theconcomitant evaluations of autoimmune diseases and auto antibodies in a cohort of IgADpatients with current age >10 years and their relatives have not been assessed. Objectives: To evaluate autoimmune diseases and the presence of auto antibodies in IgADpatients and their first-degree relatives. Methods: A cross-sectional study was performed in 34 IgAD patients (current age >10years) and their first-degree relatives. All of them were followed at a tertiary Brazilianprimary immunodeficiency center: 27 children/adolescents and 7 of their first-degree rela-tives with a late diagnosis of IgAD. Autoimmune diseases and autoantibodies (antinuclearantibodies, rheumatoid factor, and anti-thyroglobulin, anti-thyroperoxidase and IgA classanti-endomysial antibodies) were also assessed. Results: Autoimmune diseases (n = 14) and/or autoantibodies (n = 10, four of them with iso-lated autoantibodies) were observed in 18/34 (53%) of the patients and their relatives. Themost common autoimmune diseases found were thyroiditis (18%), chronic arthritis (12%)and celiac disease (6%). The most frequent autoantibodies were antinuclear antibodies(2%), anti-thyroglobulin and/or anti-thyroperoxidase (24%). No significant differences wereobserved in the female gender, age at diagnosis and current age in IgAD patients with andwithout autoimmune diseases and/or presence of auto antibodies (p > 0.05). The frequen-cies of primary immunodeficiencies in family, autoimmunity in family, atopy and recurrentinfections were similar in both groups (p > 0.05). Conclusion: Autoimmune diseases and auto antibodies were observed in IgAD patients dur-ing follow-up, reinforcing the necessity of a rigorous and continuous follow-up duringadolescence and adulthood. .

IgA deficiency: clinical correlates with IgG subclass and mannan-binding lectin deficiencies

OBJECTIVE: To characterize an IgA deficient population in terms of the incidence of IgG subclass and mannose-binding lectin (MBL) deficiencies and the type and severity of infections and other associated disorders. BACKGROUND: Selective IgA deficiency is probably the commonest of the primary immunodeficiency disorders and although it may lead to an increased risk for respiratory and gastrointestinal infections and associated to various autoimmune diseases, it may also be asymptomatic. Several studies have suggested the need of a concomitant defect in order for manifestation of its symptoms. METHODS: A total of 27 patients fulfilling the diagnostic criteria of selective IgA deficiency were evaluated for IgG subclass and MBL deficiencies after a thorough medical history, physical examination and pertinent evaluation for concomitant medical conditions. RESULTS: The overall incidence of IgG subclass deficiency found in the IgA deficient group was 18.5. MBL deficiency was found to be 3.7. These frequencies may have been influenced by the age group evaluated and the size of the population studied. Severe infections were more common in patients with combined deficiencies, either IgA and any of the IgG subclasses or IgA and MBL deficiency. Atopy was widely represented in the patients studied. CONCLUSIONS: The observed relationship between combined deficiencies Ig A, IgG subclasses and MBL and the increased representation of severe infections needs to be corroborated in a larger sample of patients with an inclusion of pediatric patients.

Anaphylactoid transfusion reaction with anti-IgA antibodies in an IgA deficient patient: a case report.

A case of anaphylactoid transfusion reaction associated with anti-IgA antibodies is reported. The patient had low levels of serum IgA. She developed serious reaction characterised by erythematous rash, pruritus, cyanosis and dyspnoea after transfusion of otherwise compatible blood. Review of literature reveals that anaphylactoid transfusion reactions are very rare although frequency of anti-IgA in general population is quite high. The IgA deficient donors (aIgA) form a unique resource of blood components for the clinical management of patients with anaphylactoid reactions caused by anti-IgA.