RESUMO
ABSTRACT: Mutations in the small Rho-family guanosine triphosphate hydrolase RAC2, critical for actin cytoskeleton remodeling and intracellular signal transduction, are associated with neonatal severe combined immunodeficiency (SCID), infantile neutrophilic disorder resembling leukocyte adhesion deficiency (LAD), and later-onset combined immune deficiency (CID). We investigated 54 patients (23 previously reported) from 37 families yielding 15 novel RAC2 missense mutations, including one present only in homozygosity. Data were collected from referring physicians and literature reports with updated clinical information. Patients were grouped by presentation: neonatal SCID (n = 5), infantile LAD-like disease (n = 5), or CID (n = 44). Disease correlated to RAC2 activity: constitutively active RAS-like mutations caused neonatal SCID, dominant-negative mutations caused LAD-like disease, whereas dominant-activating mutations caused CID. Significant T- and B-lymphopenia with low immunoglobulins were seen in most patients; myeloid abnormalities included neutropenia, altered oxidative burst, impaired neutrophil migration, and visible neutrophil macropinosomes. Among 42 patients with CID with clinical data, upper and lower respiratory infections and viral infections were common. Twenty-three distinct RAC2 mutations, including 15 novel variants, were identified. Using heterologous expression systems, we assessed downstream effector functions including superoxide production, p21-activated kinase 1 binding, AKT activation, and protein stability. Confocal microscopy showed altered actin assembly evidenced by membrane ruffling and macropinosomes. Altered protein localization and aggregation were observed. All tested RAC2 mutant proteins exhibited aberrant function; no single assay was sufficient to determine functional consequence. Most mutants produced elevated superoxide; mutations unable to support superoxide formation were associated with bacterial infections. RAC2 mutations cause a spectrum of immune dysfunction, ranging from early onset SCID to later-onset combined immunodeficiencies depending on RAC2 activity. This trial was registered at www.clinicaltrials.gov as #NCT00001355 and #NCT00001467.
Assuntos
Síndromes de Imunodeficiência , Síndrome da Aderência Leucocítica Deficitária , Doenças da Imunodeficiência Primária , Imunodeficiência Combinada Severa , Humanos , Recém-Nascido , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/metabolismo , Neutrófilos/metabolismo , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/metabolismo , Proteínas rac de Ligação ao GTP/genética , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteína RAC2 de Ligação ao GTP , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/metabolismo , Superóxidos/metabolismoRESUMO
BACKGROUND: Previous investigations pointed out a role for antigen stimulation in Sezary syndrome (SS). High-throughput sequencing of the T cell receptor (TR) offers several applications beyond diagnostic purposes, including the study of T cell pathogenesis. METHODS: We performed high-throughput RNA sequencing of the TR alpha (TRA) and beta (TRB) genes focusing on the complementarity-determining region 3 (CDR3) in 11 SS and one erythrodermic mycosis fungoides (MF) patients. Five psoriasis patients were employed as controls. Peripheral blood CD4+ cells were isolated and RNA sequenced (HiSeq2500). High-resolution HLA typing was performed in neoplastic patients. RESULTS: Highly expanded predominant TRA and TRB CDR3 were only found in SS patients (median frequency: 94.4% and 93.7%). No remarkable CDR3 expansions were observed in psoriasis patients (median frequency of predominant TRA and TRB CDR3: 0.87% and 0.69%, p < 0.001 compared to SS). CDR3 almost identical to the predominant were identified within each SS patient and were exponentially correlated with frequencies of the predominant CDR3 (R2 = 0.918, p < 0.001). Forty-six different CDR3 were shared between SS patients displaying HLA similarities, including predominant TRA and TRB CDR3 in one patient that were found in other three patients. Additionally, 351 antigen matches were detected (Cytomegalovirus, Epstein-Barr, Influenza virus, and self-antigens), and the predominant CDR3 of two different SS patients matched CDR3 with specificity for Influenza and Epstein-Barr viruses. CONCLUSIONS: Besides detecting clonality, these findings shed light on the nature of SS-related antigens, pointing to RNA sequencing as a useful tool for simultaneous clonality and biological analysis in SS.
Assuntos
Psoríase , Síndrome de Sézary , Neoplasias Cutâneas , Humanos , Síndrome de Sézary/genética , Síndrome de Sézary/patologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T/genética , Regiões Determinantes de Complementaridade/genética , Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias Cutâneas/genéticaRESUMO
Las manifestaciones clínicas de la alergia de contacto en la boca difieren de las que se presenta en la piel. Estas manifestaciones han ido aumentado en los últimos años. Cuando existe una sospecha de alergia de contacto, el paciente debe ser remitido a una Unidad de Alergia Cutánea para ser estudiado. Son muchos los alérgenos responsables que pueden estar implicados pero hay baterías estandarizadas que nos permiten realizar el sistema patch test con un buen grado de fiabilidad (AU)
The clinical manifestations of the contact allergy in the mouth differ from those that one can fine in the skin. These manifestations have increased in the last years. When we have a suspicion of contact allergy, the patient must be refer to a Cutaneous Allergy Unit to be studied. There are lots of responsible allergens who can be implied, but there are standardized batteries that allow us to realize the system patch test with a good degree of reliability (AU)
Assuntos
Humanos , Dermatite de Contato/diagnóstico , Doenças da Boca/diagnóstico , Testes Cutâneos/métodosRESUMO
Realizamos patch test con 10 colutorios para ver su capacidad irritativa en 150 pacientes voluntarios. Las lecturas se han realizado a las 49 y 96 horas. Todos los voluntarios habían utilizado colutorios de forma habitual durante los dos últimos años y fueron remitidos para estudio alérgico por presentar ardor, quemazón o síntomas de boca seca. No hemos observado ninguna reacción irritativa en los 150 pacientes estudiados por lo que deducimos que su capacidad irritativa es muy baja o nula (AU)
We have been carrying out patch test with ten mouthwashes elected among the most used in our country. The patients, who had been using mouthwashes during the last two years, showed symptoms of itch, stinging or burning sensation or dry mouth syndrome. None of the patients studied presented any irritative or allergic reaction, therefore we concluded that the moth washes tested didnt have irritative capacity (AU)