RESUMO
The linear ubiquitin assembly complex (LUBAC) consists of HOIP, HOIL-1 and SHARPIN and is essential for proper immune responses. Individuals with HOIP and HOIL-1 deficiencies present with severe immunodeficiency, autoinflammation and glycogen storage disease. In mice, the loss of Sharpin leads to severe dermatitis due to excessive keratinocyte cell death. Here, we report two individuals with SHARPIN deficiency who manifest autoinflammatory symptoms but unexpectedly no dermatological problems. Fibroblasts and B cells from these individuals showed attenuated canonical NF-κB responses and a propensity for cell death mediated by TNF superfamily members. Both SHARPIN-deficient and HOIP-deficient individuals showed a substantial reduction of secondary lymphoid germinal center B cell development. Treatment of one SHARPIN-deficient individual with anti-TNF therapies led to complete clinical and transcriptomic resolution of autoinflammation. These findings underscore the critical function of the LUBAC as a gatekeeper for cell death-mediated immune dysregulation in humans.
Assuntos
Síndromes de Imunodeficiência , Proteínas do Tecido Nervoso , Ubiquitinas , Humanos , Síndromes de Imunodeficiência/genética , Síndromes de Imunodeficiência/imunologia , Feminino , Masculino , NF-kappa B/metabolismo , Ubiquitina-Proteína Ligases/genética , Inflamação/imunologia , Inflamação/genética , Linfócitos B/imunologia , Mutação com Perda de Função , Fibroblastos/metabolismo , Fibroblastos/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Animais , Camundongos , AlelosRESUMO
BACKGROUND: Systemic allergic reactions (sARs) following coronavirus disease 2019 (COVID-19) mRNA vaccines were initially reported at a higher rate than after traditional vaccines. OBJECTIVE: We aimed to evaluate the safety of revaccination in these individuals and to interrogate mechanisms underlying these reactions. METHODS: In this randomized, double-blinded, phase 2 trial, participants aged 16 to 69 years who previously reported a convincing sAR to their first dose of COVID-19 mRNA vaccine were randomly assigned to receive a second dose of BNT162b2 (Comirnaty) vaccine and placebo on consecutive days in a blinded, 1:1 crossover fashion at the National Institutes of Health. An open-label BNT162b2 booster was offered 5 months later if the second dose did not result in severe sAR. None of the participants received the mRNA-1273 (Spikevax) vaccine during the study. The primary end point was recurrence of sAR following second dose and booster vaccination; exploratory end points included biomarker measurements. RESULTS: Of 111 screened participants, 18 were randomly assigned to receive study interventions. Eight received BNT162b2 second dose followed by placebo; 8 received placebo followed by BNT162b2 second dose; 2 withdrew before receiving any study intervention. All 16 participants received the booster dose. Following second dose and booster vaccination, sARs recurred in 2 participants (12.5%; 95% CI, 1.6 to 38.3). No sAR occurred after placebo. An anaphylaxis mimic, immunization stress-related response (ISRR), occurred more commonly than sARs following both vaccine and placebo and was associated with higher predose anxiety scores, paresthesias, and distinct vital sign and biomarker changes. CONCLUSIONS: Our findings support revaccination of individuals who report sARs to COVID-19 mRNA vaccines. Distinct clinical and laboratory features may distinguish sARs from ISRRs.
Assuntos
Vacina BNT162 , Vacinas contra COVID-19 , COVID-19 , Imunização Secundária , SARS-CoV-2 , Humanos , Pessoa de Meia-Idade , Masculino , Adulto , Feminino , Método Duplo-Cego , COVID-19/prevenção & controle , COVID-19/imunologia , SARS-CoV-2/imunologia , Idoso , Adolescente , Adulto Jovem , Vacinas contra COVID-19/efeitos adversos , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Recidiva , Vacinação , Vacina de mRNA-1273 contra 2019-nCoV , Estudos Cross-OverRESUMO
BACKGROUND: An elevated basal serum tryptase level is associated with severe systemic anaphylaxis, most notably caused by Hymenoptera envenomation. Although clonal mast cell disease is the culprit in some individuals, it does not fully explain this clinical association. OBJECTIVE: Our aim was to determine the prevalence and associated impact of tryptase genotypes on anaphylaxis in humans. METHODS: Cohorts with systemic mastocytosis (SM) and venom as well as idiopathic anaphylaxis from referral centers in Italy, Slovenia, and the United States, underwent tryptase genotyping by droplet digital PCR. Associated anaphylaxis severity (Mueller scale) was subsequently examined. Healthy volunteers and controls with nonatopic disease were recruited and tryptase was genotyped by droplet digital PCR and in silico analysis of genome sequence, respectively. The effects of pooled and recombinant human tryptases, protease activated receptor 2 agonist and antagonist peptides, and a tryptase-neutralizing mAb on human umbilical vein endothelial cell permeability were assayed using a Transwell system. RESULTS: Hereditary α-tryptasemia (HαT)-a genetic trait caused by increased α-tryptase-encoding Tryptase-α/ß1 (TPSAB1) copy number resulting in elevated BST level-was common in healthy individuals (5.6% [n = 7 of 125]) and controls with nonatopic disease (5.3% [n = 21 of 398]). HαT was associated with grade IV venom anaphylaxis (relative risk = 2.0; P < .05) and more prevalent in both idiopathic anaphylaxis (n = 8 of 47; [17%; P = .006]) and SM (n = 10 of 82 [12.2%; P = .03]) relative to the controls. Among patients with SM, concomitant HαT was associated with increased risk for systemic anaphylaxis (relative risk = 9.5; P = .007). In vitro, protease-activated receptor-2-dependent vascular permeability was induced by pooled mature tryptases but not α- or ß-tryptase homotetramers. CONCLUSIONS: Risk for severe anaphylaxis in humans is associated with inherited differences in α-tryptase-encoding copies at TPSAB1.
Assuntos
Anafilaxia/genética , Mastocitose Sistêmica/genética , Triptases/sangue , Adolescente , Adulto , Idoso , Venenos de Artrópodes/efeitos adversos , Criança , Variações do Número de Cópias de DNA , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Triptases/genética , Adulto JovemRESUMO
BACKGROUND: Monogenic autoinflammatory diseases (AID) are caused by mutations in innate immune genes. The effects of these mutations on allergic inflammation are unknown. OBJECTIVES: We investigated allergic, immunological and clinical phenotypes in FMF (familial Mediterranean fever), CAPS (cryopyrin-associated periodic syndrome), TRAPS (tumour necrosis factor receptor-associated periodic syndrome), HIDS (hyper-IgD syndrome), PAPA (pyogenic arthritis, pyoderma gangrenosum and acne), DADA2 (deficiency of adenosine deaminase 2), HA20 (haploinsufficiency of A20), CANDLE (chronic atypical neutrophilic dermatosis, lipodystrophy, elevated temperature) and SAVI (STING-associated vasculopathy of infancy). METHODS: In this cross-sectional study, clinical data were assessed in 425 patients with AID using questionnaires and chart reviews. Comparator data were obtained from public databases. Peripheral blood mononuclear cells obtained from 55 patients were stimulated and CD4+ cytokine production assessed. RESULTS: Clinical laboratory features of Type 2 immunity were elevated in CAPS but reduced in most AID, particularly DADA2. Physician-diagnosed allergic diseases were prevalent in multiple AID, including CAPS and DADA2. T helper 2 (Th2) cells were expanded in CAPS, TRAPS and HIDS; Th9 cells were expanded in HA20. CONCLUSIONS: CAPS is characterised by an enhanced Type 2 signature, whereas FMF and CANDLE are associated with reduced Type 2 responses. DADA2 is associated with reduced Type 2 responses but a high rate of physician-diagnosed allergy. Therefore, NLRP3-driven autoinflammation may promote Type 2 immunity, whereas AID like DADA2 may manifest clinical phenotypes that masquerade as allergic disorders. Further investigations are needed to determine the contribution of autoinflammation to allergic clinical and immunological phenotypes, to improve the treatment of patients with AID.
Assuntos
Síndromes Periódicas Associadas à Criopirina , Febre Familiar do Mediterrâneo , Doenças Hereditárias Autoinflamatórias , Hipersensibilidade , Dermatopatias , Adenosina Desaminase , Estudos Transversais , Síndromes Periódicas Associadas à Criopirina/genética , Doenças Hereditárias Autoinflamatórias/diagnóstico , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/uso terapêutico , Leucócitos Mononucleares , Dermatopatias/genéticaRESUMO
Eosinophilic leukocytes develop in the bone marrow and migrate from peripheral blood to tissues, where they maintain homeostasis and promote dysfunction via release of preformed immunomodulatory mediators. In this study, we explore human eosinophil heterogeneity with a specific focus on naturally occurring variations in cytokine content. We found that human eosinophil-associated cytokines varied on a continuum from minimally (coefficient of variation [CV] ≤ 50%) to moderately variable (50% < CV ≤ 90%). Within the moderately variable group, we detected immunoreactive IL-27 (953 ± 504 pg/mg lysate), a mediator not previously associated with human eosinophils. However, our major finding was the distinct and profound variability of eosinophil-associated IL-16 (CV = 103%). Interestingly, eosinophil IL-16 content correlated directly with body mass index (R 2 = 0.60, ***p < 0.0001) in one donor subset. We found no direct correlation between eosinophil IL-16 content and donor age, sex, total leukocytes, lymphocytes, or eosinophils (cells per microliter), nor was there any relationship between IL-16 content and the characterized -295T/C IL-16 promoter polymorphism. Likewise, although eosinophil IL-1ß, IL-1α, and IL-6 levels correlated with one another, there was no direct association between any of these cytokines and eosinophil IL-16 content. Finally, a moderate increase in total dietary fat resulted in a 2.7-fold reduction in eosinophil IL-16 content among C57BL/6-IL5tg mice. Overall, these results suggest that relationships between energy metabolism, eosinophils, and IL-16 content are not direct or straightforward. Nonetheless, given our current understanding of the connections between asthma and obesity, these findings suggest important eosinophil-focused directions for further exploration.
Assuntos
Citocinas/imunologia , Eosinófilos/imunologia , Interleucina-16/imunologia , Adulto , Idoso , Animais , Asma/imunologia , Medula Óssea/imunologia , Feminino , Humanos , Contagem de Leucócitos/métodos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Adulto JovemRESUMO
Extracellular vesicles (EVs) have been implicated in the development and progression of hematological malignancies. We thus examined serum samples from patients with systemic mastocytosis (SM) and found EVs with a mast cell signature including the presence of tryptase, FcεRI, MRGX2, and KIT. The concentration of these EVs correlated with parameters of disease including levels of serum tryptase, IL-6, and alkaline phosphatase and physical findings including hepatosplenomegaly. Given reports that EVs from one cell type may influence another cell's behavior, we asked whether SM-EVs might affect hepatic stellate cells (HSCs), based on the abnormal liver pathology associated with mastocytosis. We found that KIT was transferred from SM-EVs into an HSC line eliciting proliferation, cytokine production, and differentiation, processes that have been associated with liver pathology. These effects were reduced by KIT inhibition or neutralization and recapitulated by enforced expression of KIT or constitutively active D816V-KIT, a gain-of-function variant associated with SM. Furthermore, HSCs in liver from mice injected with SM-EVs had increased expression of α-SMA and human KIT, particularly around portal areas, compared with mice injected with EVs from normal individuals, suggesting that SM-EVs can also initiate HSC activation in vivo. Our data are thus consistent with the conclusion that SM-EVs have the potential to influence cells outside the hematological compartment and that therapeutic approaches for treatment of SM may be effective in part through inhibition of effects of EVs on target tissues, findings important both to understanding complex disease pathology and in developing interventional agents for the treatment of hematologic diseases.
Assuntos
Vesículas Extracelulares/metabolismo , Mastócitos/metabolismo , Mastocitose/patologia , Fator de Células-Tronco/metabolismo , Diferenciação Celular , Proliferação de Células , Feminino , Humanos , Mastocitose/metabolismoRESUMO
Persistent dysregulation of IL-6 production and signaling have been implicated in the pathology of various cancers. In systemic mastocytosis, increased serum levels of IL-6 associate with disease severity and progression, although the mechanisms involved are not well understood. Since systemic mastocytosis often associates with the presence in hematopoietic cells of a somatic gain-of-function variant in KIT, D816V-KIT, we examined its potential role in IL-6 upregulation. Bone marrow mononuclear cultures from patients with greater D816V allelic burden released increased amounts of IL-6 which correlated with the percentage of mast cells in the cultures. Intracellular IL-6 staining by flow cytometry and immunofluorescence was primarily associated with mast cells and suggested a higher percentage of IL-6 positive mast cells in patients with higher D816V allelic burden. Furthermore, mast cell lines expressing D816V-KIT, but not those expressing normal KIT or other KIT variants, produced constitutively high IL-6 amounts at the message and protein levels. We further demonstrate that aberrant KIT activity and signaling are critical for the induction of IL-6 and involve STAT5 and PI3K pathways but not STAT3 or STAT4. Activation of STAT5A and STAT5B downstream of D816V-KIT was mediated by JAK2 but also by MEK/ERK1/2, which not only promoted STAT5 phosphorylation but also its long-term transcription. Our study thus supports a role for mast cells and D816V-KIT activity in IL-6 dysregulation in mastocytosis and provides insights into the intracellular mechanisms. The findings contribute to a better understanding of the physiopathology of mastocytosis and suggest the importance of therapeutic targeting of these pathways.
Assuntos
Mastócitos , Mastocitose Sistêmica , Humanos , Interleucina-6/genética , Mastocitose Sistêmica/diagnóstico , Mastocitose Sistêmica/genética , Mutação , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-kit/genéticaRESUMO
Patients with autosomal dominant vibratory urticaria have localized hives and systemic manifestations in response to dermal vibration, with coincident degranulation of mast cells and increased histamine levels in serum. We identified a previously unknown missense substitution in ADGRE2 (also known as EMR2), which was predicted to result in the replacement of cysteine with tyrosine at amino acid position 492 (p.C492Y), as the only nonsynonymous variant cosegregating with vibratory urticaria in two large kindreds. The ADGRE2 receptor undergoes autocatalytic cleavage, producing an extracellular subunit that noncovalently binds a transmembrane subunit. We showed that the variant probably destabilizes an autoinhibitory subunit interaction, sensitizing mast cells to IgE-independent vibration-induced degranulation. (Funded by the National Institutes of Health.).
Assuntos
Mutação de Sentido Incorreto , Receptores Acoplados a Proteínas G/genética , Urticária/genética , Vibração/efeitos adversos , Biópsia , Degranulação Celular/genética , Feminino , Histamina/sangue , Humanos , Líbano , Masculino , Mastócitos/fisiologia , Pessoa de Meia-Idade , Linhagem , Receptores Acoplados a Proteínas G/metabolismo , Pele/patologia , Urticária/sangue , Urticária/etiologiaRESUMO
BACKGROUND: Clonal mast cell disorders are known to occur in a subset of patients with systemic reactions to Hymenoptera stings. This observation has prompted the question of whether clonal mast cell disorders also occur in patients with idiopathic anaphylaxis (IA). OBJECTIVE: We sought to determine the prevalence of clonal mast cell disorders among patients with IA, criteria to identify those patients who require a bone marrow biopsy, and whether the pathogenesis of IA involves a hyperresponsive mast cell compartment. METHODS: We prospectively enrolled patients with IA (≥3 episodes/y) who then underwent a medical evaluation that included a serum tryptase determination, allele-specific quantitative PCR (ASqPCR) for the KIT D816V mutation, and a bone marrow examination. Mast cells were cultured from peripheral blood CD34+ cells and examined for releasability after FcεRI aggregation. RESULTS: Clonal mast cell disease was diagnosed in 14% of patients referred with IA. ASqPCR for the KIT D816V mutation was a useful adjunct in helping identify those with systemic mastocytosis but not monoclonal mast cell activation syndrome. A modified overall clonal prediction model was developed by using clinical findings, a serum tryptase determination, and ASqPCR. There was no evidence of a hyperresponsive mast cell phenotype in patients with IA. CONCLUSION: Patients with clonal mast cell disease can present as having IA. Distinct clinical and laboratory features can be used to select those patients more likely to have an underlying clonal mast cell disorder (monoclonal mast cell activation syndrome or systemic mastocytosis) and thus candidates for a bone marrow biopsy.
Assuntos
Anafilaxia/genética , Anafilaxia/imunologia , Mastócitos/imunologia , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/imunologia , Mutação de Sentido Incorreto , Proteínas Proto-Oncogênicas c-kit , Adolescente , Adulto , Idoso , Substituição de Aminoácidos , Anafilaxia/patologia , Feminino , Humanos , Masculino , Mastócitos/patologia , Mastocitose Sistêmica/patologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/genética , Proteínas Proto-Oncogênicas c-kit/imunologiaRESUMO
OBJECTIVE: To provide a clinical rationale for including impulse oscillometry (IOS) as a part of standard office-based asthma assessment. DATA SOURCES: PubMed and Google search, limited to English language and human disease, with the keywords IOS and asthma. STUDY SELECTIONS: Articles included in this review were based on the expert opinion and previous publications by the authors. RESULTS: In children, IOS was more useful than spirometry in identifying asthma and uncontrolled asthma and predicting loss of control and exacerbations. IOS predicts young children at risk for loss of lung function with age and the potential for early intervention to prevent further sequelae. In adults, peripheral airway impairment detected by IOS or spirometry (ie, forced expiratory flow between 25% and 75%) commonly occurs across severity, and each measure may be complementary in predicting loss of control even with normal forced expiratory volume in 1 second. Extrafine inhaled corticosteroids with or without long-acting ß-agonists proved superior to standard particle aerosols in improving IOS-detected peripheral airway obstruction. Our data also suggest that currently available commercial reference values for lung resistance at 5 Hz and lung reactance at 5 Hz are applicable across diverse populations, but further studies are needed. CONCLUSION: The findings of this review suggest that IOS can add value to traditional clinical and spirometric assessment and thus improve management of asthma in children and adults, as well as have the potential to detect early dysfunction of the peripheral airways, which may result in better outcomes.
Assuntos
Asma/diagnóstico , Oscilometria/métodos , Corticosteroides/uso terapêutico , Adulto , Asma/tratamento farmacológico , Asma/fisiopatologia , Testes de Provocação Brônquica , Criança , Humanos , Valores de Referência , EspirometriaAssuntos
Translocação Bacteriana , Proteínas de Ligação a Ácido Graxo/metabolismo , Haptoglobinas/metabolismo , Mucosa Intestinal/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/metabolismo , Mastocitose/metabolismo , Permeabilidade , Precursores de Proteínas/metabolismo , Adulto , Idoso , Biomarcadores/metabolismo , Diarreia/fisiopatologia , Feminino , Refluxo Gastroesofágico/fisiopatologia , Humanos , Masculino , Mastocitose/genética , Mastocitose/microbiologia , Mastocitose/fisiopatologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/genética , Triptases/metabolismo , Vômito/fisiopatologia , Adulto JovemRESUMO
BACKGROUND: The management of children with pediatric mastocytosis poses a challenge. This is because there is limited information as to the application of clinical and laboratory findings and bone marrow histopathology as they relate to medical intervention and communication. OBJECTIVE: We sought to examine clinical aspects of pediatric mastocytosis in relationship to serum tryptase levels and bone marrow pathology to provide practical guidance for management. METHODS: Between 1986 and 2012, 105 children were evaluated at the National Institutes of Health. Organomegaly was confirmed by means of ultrasound. Baseline tryptase levels and at least 1 subsequent tryptase measurement was available in 84 and 37 of these children, respectively. Fifty-three children underwent a bone marrow examination. These data were used to examine relationships between clinical findings, tryptase levels, and marrow histopathology. RESULTS: In patients with high tryptase levels and severe mediator symptoms, all with organomegaly had systemic disease, and none without organomegaly had systemic disease. Serum tryptase levels differed significantly between patients with urticaria pigmentosa and those with diffuse cutaneous (P < .0001) and systemic mastocytosis (P < .0001) and in all 3 categories versus control subjects (P < .0001). Tryptase levels and symptoms decreased over time in most patients, and tryptase levels correlated with bone marrow mast cell burden in patients with systemic mastocytosis (P < .0001). There was a significant relationship between clinical resolution and the percentage decrease in tryptase levels (P = .0014). CONCLUSIONS: The majority of children experienced major or complete disease resolution (57%), whereas the remainder exhibited partial improvement. Organomegaly was a strong indicator of systemic disease. Serum tryptase levels furthered classification and reflected clinicopathologic findings, while sequential tryptase measurements were useful in supplementing clinical judgment as to disease course.
Assuntos
Medula Óssea/patologia , Mastocitose Cutânea , Mastocitose Sistêmica , Triptases/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Imunoglobulina E/sangue , Lactente , Masculino , Mastócitos/imunologia , Mastocitose Cutânea/sangue , Mastocitose Cutânea/diagnóstico por imagem , Mastocitose Cutânea/imunologia , Mastocitose Cutânea/patologia , Mastocitose Sistêmica/sangue , Mastocitose Sistêmica/diagnóstico por imagem , Mastocitose Sistêmica/imunologia , Mastocitose Sistêmica/patologia , Prognóstico , Ultrassonografia , Adulto JovemRESUMO
The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.
Assuntos
Síndromes de Imunodeficiência/diagnóstico , Síndromes de Imunodeficiência/terapia , Comitês Consultivos , Animais , Ensaios Clínicos como Assunto , Gerenciamento Clínico , Medicina Baseada em Evidências , HumanosRESUMO
BACKGROUND: Mendelian analysis of disorders of immune regulation can provide insight into molecular pathways associated with host defense and immune tolerance. METHODS: We identified three families with a dominantly inherited complex of cold-induced urticaria, antibody deficiency, and susceptibility to infection and autoimmunity. Immunophenotyping methods included flow cytometry, analysis of serum immunoglobulins and autoantibodies, lymphocyte stimulation, and enzymatic assays. Genetic studies included linkage analysis, targeted Sanger sequencing, and next-generation whole-genome sequencing. RESULTS: Cold urticaria occurred in all affected subjects. Other, variable manifestations included atopy, granulomatous rash, autoimmune thyroiditis, the presence of antinuclear antibodies, sinopulmonary infections, and common variable immunodeficiency. Levels of serum IgM and IgA and circulating natural killer cells and class-switched memory B cells were reduced. Linkage analysis showed a 7-Mb candidate interval on chromosome 16q in one family, overlapping by 3.5 Mb a disease-associated haplotype in a smaller family. This interval includes PLCG2, encoding phospholipase Cγ(2) (PLCγ(2)), a signaling molecule expressed in B cells, natural killer cells, and mast cells. Sequencing of complementary DNA revealed heterozygous transcripts lacking exon 19 in two families and lacking exons 20 through 22 in a third family. Genomic sequencing identified three distinct in-frame deletions that cosegregated with disease. These deletions, located within a region encoding an autoinhibitory domain, result in protein products with constitutive phospholipase activity. PLCG2-expressing cells had diminished cellular signaling at 37°C but enhanced signaling at subphysiologic temperatures. CONCLUSIONS: Genomic deletions in PLCG2 cause gain of PLCγ(2) function, leading to signaling abnormalities in multiple leukocyte subsets and a phenotype encompassing both excessive and deficient immune function. (Funded by the National Institutes of Health Intramural Research Programs and others.).
Assuntos
Doenças Autoimunes/genética , Síndromes Periódicas Associadas à Criopirina/genética , Síndromes de Imunodeficiência/genética , Fosfolipase C gama/genética , Deleção de Sequência , Temperatura Baixa/efeitos adversos , DNA Complementar/análise , DNA Complementar/isolamento & purificação , Feminino , Humanos , Masculino , Linhagem , Fenótipo , Fosfolipase C gama/metabolismo , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNARESUMO
Atopic dermatitis (AD) has long been associated with Staphylococcus aureus skin colonization or infection and is typically managed with regimens that include antimicrobial therapies. However, the role of microbial communities in the pathogenesis of AD is incompletely characterized. To assess the relationship between skin microbiota and disease progression, 16S ribosomal RNA bacterial gene sequencing was performed on DNA obtained directly from serial skin sampling of children with AD. The composition of bacterial communities was analyzed during AD disease states to identify characteristics associated with AD flares and improvement post-treatment. We found that microbial community structures at sites of disease predilection were dramatically different in AD patients compared with controls. Microbial diversity during AD flares was dependent on the presence or absence of recent AD treatments, with even intermittent treatment linked to greater bacterial diversity than no recent treatment. Treatment-associated changes in skin bacterial diversity suggest that AD treatments diversify skin bacteria preceding improvements in disease activity. In AD, the proportion of Staphylococcus sequences, particularly S. aureus, was greater during disease flares than at baseline or post-treatment, and correlated with worsened disease severity. Representation of the skin commensal S. epidermidis also significantly increased during flares. Increases in Streptococcus, Propionibacterium, and Corynebacterium species were observed following therapy. These findings reveal linkages between microbial communities and inflammatory diseases such as AD, and demonstrate that as compared with culture-based studies, higher resolution examination of microbiota associated with human disease provides novel insights into global shifts of bacteria relevant to disease progression and treatment.
Assuntos
Dermatite Atópica/microbiologia , Metagenoma , Pele/microbiologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Bases de Dados Genéticas , Dermatite Atópica/patologia , Humanos , Tipagem Molecular , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de RNA , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Staphylococcus/genética , Estatísticas não ParamétricasAssuntos
Deficiência de GATA2 , Hipersensibilidade Imediata , Imunoglobulina E/imunologia , Feminino , Deficiência de GATA2/genética , Deficiência de GATA2/imunologia , Deficiência de GATA2/patologia , Humanos , Hipersensibilidade Imediata/genética , Hipersensibilidade Imediata/imunologia , Hipersensibilidade Imediata/patologia , MasculinoRESUMO
Activating mutations in KIT, particularly D816V, have been associated with mastocytosis. Additionally, expression of heterozygous KIT M541L has been primarily reported in patients with pediatric mastocytosis. We thus examined the prevalence of this variant in pediatric and adult patients with mastocytosis (n = 100) compared to ancestry-matched 1000 genomes controls (n = 500) and patients with idiopathic anaphylaxis (n = 23). We then compared clinical symptoms and laboratory data on patients with systemic and cutaneous mastocytosis and bone marrow histopathology on a matched cohort with and without the KIT M541L variant. Overall, the KIT M541L variant was identified in 19 individuals; the majority were diagnosed with systemic mastocytosis (89.4%) with an associated KIT D816V mutation. There were no significant differences in peripheral blood parameters between groups. Patients with mastocytosis carrying the KIT M541L variant did not demonstrate significant differences in symptomatology compared to a matched reference cohort (n = 13/81) without KIT M541L. In patients with idiopathic anaphylaxis, no significant associations were observed. This study uniquely examines the prevalence and impact of the KIT M541L variant in both adult and pediatric patients with mastocytosis further stratified by disease variant. To our knowledge, this is the first case/control study to show a significant genetic association with mastocytosis at the KIT M541L locus.
Assuntos
Proteínas Proto-Oncogênicas c-kit , Humanos , Proteínas Proto-Oncogênicas c-kit/genética , Masculino , Feminino , Adulto , Criança , Pessoa de Meia-Idade , Prevalência , Estudos de Casos e Controles , Adolescente , Mutação , Mastocitose/genética , Mastocitose/epidemiologia , Idoso , Adulto Jovem , Pré-Escolar , Anafilaxia/genética , Anafilaxia/epidemiologia , Predisposição Genética para Doença , Mastocitose Sistêmica/genética , Mastocitose Sistêmica/epidemiologiaRESUMO
Background: Symptoms in patients with systemic mastocytosis (SM) are associated with an increase in mast cell burden and release of mast cell-derived mediators. The most frequent presentation of SM is indolent SM (ISM), with moderate symptoms and prognosis. Basophil numbers in these patients are generally normal. However, when examining basophil activation in patients with ISM, we noted an abnormal response to N-formylmethione-leucyl-phenylalanine (fMLP). Objective: Our aim was to compare basophil responsiveness to fMLP and anti-IgE in healthy volunteers and patients with ISM and relate the findings to fMLP receptor (FPR) expression. Methods: Basophils isolated from peripheral blood of 15 patients with ISM and 14 healthy volunteers were stimulated with fMLP or anti-IgE. CD63 expression to assess basophil activation and expression of FPRs were assessed by flow cytometry. Results: Baseline expression of CD63 on basophils was similar between the healthy volunteers and patients with ISM. fMLP induced higher expression of CD63 on basophils from patients with ISM, whereas responses to anti-IgE were similar between groups. Basophils from patients with ISM also had higher fMLP1 receptor (FPR1) expression, wheresas FPR2 and FPR3 were not detected. fMLP blocked the binding of anti-FPR1 antibody to FPR1, consistent with the conclusion that fMLP signals through FPR1. Conclusions: Level of fMLP-induced basophil activation is higher in patients with ISM, which is associated with an increase in FPR1 expression. Further investigation is needed to determine why FPR1 expression is elevated, whether such expression might serve as an additional surrogate marker in the diagnosis of ISM, and whether enhanced responses of basophils to fMPL might have some relationship to unexplained episodes of mediator release.