Uso de PCR digital para definir terapéuticas específicas y seguimiento en enfermedades autoinflamatorias / Use of digital PCR to define specific therapeutics and follow-up in autoinflammatory diseases

Las enfermedades autoinflamatorias (AIDs) son un grupo heterogéneo de desórdenes monogénicos o poligénicos, con características de disregulación inmune innata y/o adaptativa, cuyo mecanismo central es la autoinflamación pero también pueden presentarse con autoinmunidad e inmunodeficiencia. En estos últimos años el desarrollo de las tecnologías de secuenciación masiva han provocado una explosión en el descubrimiento de nuevos genes responsables de AIDs monogénicas. Esto remarca la importancia de implementar este tipo de estudios para llegar a un diagnóstico definitivo sobre todo en este grupo de patologías genéticamente muy diversas donde los fenotipos clínicos se solapan. Sin embargo, dada la presencia de variantes de significación incierta (VUS), los resultados pueden no ser concluyentes planteándose la necesidad de desarrollar pruebas funcionales para determinar la patogenicidad de dichas variantes genéticas. En nuestro grupo de trabajo estamos aplicando la PCR digital en gotas (ddPCR), una técnica cuantitativa de 3era generación altamente sensible, especifica y reproducible que no necesita de curvas de calibración, para desarrollar pruebas funcionales que permitan no sólo reclasificar variantes VUS para lograr diagnósticos definitivos sino también estudiar los mecanismos responsables de las principales AIDs que permitan una estratificación de las terapéuticas especificas a aplicar y de esta manera poder contribuir al diagnóstico, tratamiento y seguimiento de nuestros pacientes en forma personalizada. (AU)

Autoinflammatory diseases (AIDs) are a heterogeneous group of monogenic or polygenic disorders, with characteristics of inborn and/or adaptive immune dysregulation, whose central mechanism is autoinflammation but may also present with autoimmunity and immunodeficiency. In recent years the development of massive sequencing technologies has led to an exponential increase in the discovery of new genes responsible for monogenic AIDs. This emphasizes the importance of the implementation of this type of studies to make a definitive diagnosis, especially in this group of genetically very diverse diseases with overlapping clinical phenotypes. However, given the presence of variants of uncertain significance (VUS), the results may not be conclusive, raising the need to develop functional tests to determine the pathogenicity of these genetic variants. In our working group we are applying droplet digital PCR (ddPCR), a highly sensitive, specific and reproducible third generation quantitative technique that does not require calibration curves, to develop functional tests that allow not only to reclassify VUS variants to achieve definitive diagnoses but also to study the mechanisms responsible for the main AIDs that allow for the stratification of specific treatments to be used and thereby contribute to the individualized diagnosis, treatment, and follow-up of our patients (AU)

Enfermedades auto inflamatorias (EAI) en pediatría / Autoinflammatory diseases in children

Las enfermedades autoinmunes son un grupo de enfermedades de relativo reciente conocimiento. Muchas de ellas están genéticamente determinadas (excepto el síndrome de PFAPA). Se caracterizan por episodios recurrentes de fiebre asociada a síntomas que generalmente pueden comprometer la piel, sistema músculo esquelético y gastrointestinal. A pesar de su baja prevalencia, el descubrimiento de los genes comprometidos en algunas de ella, ha permitido una mejor comprensión de los mecanismos de la respuesta inmune innata y en especial del rol de los llamados inflamosomas. Estos avances han permitido terapias más específicas, lo que ha llevado a disminuir en forma importante la morbilidad asociada, tanto a corto como a largo plazo. En el área pediátrica, el síndrome de PFAPA debe ser incluido como alternativa en el diagnóstico diferencial.

Autoimmune diseases are an emerging group of genetically determined diseases (except PFAPA) that affect innate immune system. They are characterized by recurrent episodes of fever associated with symptoms affecting skin, musculoskeletal and gastrointestinal system. Although unfrequent, the discovery of affected genes has allowed a better understanding of molecular mechanisms of innate immune response, specially about the role of inflammasomes. Subsequent targeted therapies have allowed a great improvement in short term and long term morbidity of most of these diseases. In children, PFAPA must be included in the analysis of differential diagnosis.

retrospective review of autoinflammatory diseases in Saudi children at a rheumatology clinic

Published data from Saudi Arabia regarding autoinflammatory diseases are scarce. In this study, we describe the clinical and laboratory features of autoinflammatory diseases in Saudi children. Restrospective, hospital-based study conducted from January 2010 until June 2010.Patients with autoinflammatory disease treated at the Pediatric Rheumatology Clinic at King Faisal Specialist Hospital and Research Center, Riyadh, over the past 10 years were included. Autoinflammatory diseases included the following: familial Mediterranean fever [FMF]; chronic recurrent multifocal osteomyelitis [CRMO]; early-onset sarcoidosis [EOS]; periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome [PFAPA]; chronic infantile neurologic cutaneous and articular syndrome [CINCA]; and Muckle-Wells syndrome [MWS]. Demographic characteristics, diagnosis, age at onset, disease duration, follow-up duration, clinical and laboratory variables, and outcome data were compiled. Gathered laboratory data were part of patients usual medical care. Thirty-four patients [females, 53%] with autoinflammatory diseases were included [mean age, 151 months]. Mean disease duration was 118 months; mean age at onset was 32 months; consanguinity was present in 40%. Patients were diagnosed as follows: FMF, 50%; CRMO, 23.5%; CINCA, 8.8%; EOS, 8.8%; MWS, 6%; and PFAPA, 2.9%. The referral diagnosis was inaccurate in all patients except for FMF patients. Gene study was informative in 9 of 14 FMF patients who had molecular analyses. None of our cohort had amyloidosis. All CRMO patients had a favorable response to treatment except 1 patient, who had refractory, progressive disease. All patients with EOS had multiorgan involvement, including uveitis. All CINCA patients had a favorable response to anakinra. Our report shows that autoinflammatory diseases other than FMF may be overlooked. Increased awareness among pediatricians about these conditions will help to provide better health care to patients in the form of early diagnosis and management

Síndromes autoinflamatórias hereditárias na faixa etária pediátrica / Pediatric hereditary autoinflammatory syndromes

OBJETIVO: Descrever as principais síndromes autoinflamatórias hereditárias na faixa etária pediátrica. FONTES DOS DADOS: Foi realizada uma revisão da literatura nas bases de dados PubMed e SciELO, utilizando as palavras-chave "síndromes autoinflamatórias” e "criança”, e incluindo referências bibliográficas relevantes. SÍNTESE DOS DADOS: As principais síndromes autoinflamatórias são causadas por defeitos monogênicos em proteínas da imunidade inata, sendo consideradas imunodeficiências primárias. Elas são caracterizadas clinicamente por sintomas inflamatórios sistêmicos recorrentes ou contínuos e devem ser diferenciadas das doenças infecciosas, autoimunes e outras imunodeficiências primárias. Nesta revisão, foram enfatizadas características epidemiológicas, manifestações clínicas, alterações laboratoriais, prognóstico e terapia das principais síndromes autoinflamatórias: febre familiar do Mediterrâneo; síndrome periódica associada ao receptor de fator de necrose tumoral; criopirinopatias; deficiência de mevalonato-quinase; artrite granulomatosa pediátrica; síndrome de pioderma gangrenoso, artrite piogênica e acne; síndrome de Majeed; e deficiência do antagonista do receptor de interleucina-1. As criopirinopatias discutidas foram: doença inflamatória multissistêmica de início neonatal ou síndrome neurológica, cutânea e articular crônica infantil, síndrome de Muckle-Wells e síndrome autoinflamatória familiar associada ao frio. CONCLUSÕES: É importante que o pediatra reconheça as síndromes autoinflamatórias hereditárias mais prevalentes, pois o encaminhamento ao reumatologista pediátrico pode permitir um diagnóstico precoce e uma instituição de tratamento adequado, possibilitando uma melhora da qualidade de vida dos pacientes.

OBJECTIVE: To describe the most prevalent pediatric hereditary autoinflammatory syndromes. SOURCES: A review of the literature including relevant references from the PubMed and SciELO was carried out using the keywords autoinflammatory syndromes and child. SUMMARY OF THE FINDINGS: The hereditary autoinflammatory syndromes are caused by monogenic defects of innate immunity and are classified as primary immunodeficiencies. These syndromes are characterized by recurrent or persistent systemic inflammatory symptoms and must be distinguished from infectious diseases, autoimmune diseases, and other primary immunodeficiencies. This review describes the epidemiological, clinical and laboratory features, prognosis, and treatment of the main autoinflammatory syndromes, namely: familial Mediterranean fever; TNF receptor associated periodic syndrome; the cryopyrinopathies; mevalonate kinase deficiency; pediatric granulomatous arthritis; pyogenic arthritis, pyoderma gangrenosum and acne syndrome; Majeed syndrome; and deficiency of interleukin 1 receptor antagonist. The cryopyrinopathies discussed include neonatal-onset multisystem inflammatory disease (also known as chronic infantile neurologic, cutaneous and articular syndrome) Muckle-Wells syndrome, and familial cold autoinflammatory syndrome. CONCLUSIONS: Pediatricians must recognize the clinical features of the most prevalent autoinflammatory syndromes. Early referral to a pediatric rheumatologist may allow early diagnosis and institution of treatment, with improvement in the quality of life of these patients.

Autoinflammatory syndromes: report on three cases / Síndromes auto-inflamatórias: relato de três casos

Context: Autoinflammatory syndromes are diseases manifested by recurrent episodes of fever and inflammation in multiple organs. There is no production of autoantibodies, but interleukins play an important role and acute-phase reactants show abnormalities. Our aim was to report on three cases of autoinflammatory syndromes that are considered to be rare entities. CASE REPORTS: The authors describe the clinical features of three patients whose diagnosis were the following: tumor necrosis factor receptor-associated periodic syndrome (TRAPS), chronic infantile neurological cutaneous articular (CINCA) syndrome and familial Mediterranean fever (FMF). All of the patients presented fever, joint or bone involvement and increased acute phase reactants. The genetic analysis confirmed the diagnoses of two patients. The great diversity of manifestations and the difficulties in genetic analyses make the diagnosing of these diseases a challenge.

Contexto: As síndromes auto-inflamatórias são doenças que se manifestam por surtos recorrentes de febre e inflamação em diversos órgãos. Não ocorre a formação de auto-anticorpos, as interleucinas representam um papel importante e as provas de fase aguda estão alteradas. O nosso objetivo foi relatar três casos de síndromes auto-inflamatórias consideradas como entidades raras. RELATO DE CASOS: Os autores descrevem as características clínicas de três pacientes que tiveram os seguintes diagnósticos: síndrome periódica associada ao receptor do fator de necrose tumoral α (TRAPS), síndrome articular cutânea neurológica e infantil crônica (CINCA) e febre familiar do Mediterrâneo (FFM). Todos os pacientes tiveram em comum a febre, o comprometimento articular ou ósseo e o aumento de provas de fase aguda. O estudo genético confirmou o diagnóstico em dois pacientes. A grande variedade de manifestações e a dificuldade nos estudos genéticos tornam o diagnóstico destas doenças um desafio.