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1.
Pediatr Allergy Immunol ; 34(3): e13930, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36974653

RESUMO

INTRODUCTION: Children with peanut allergy are at increased risk of developing tree nut allergies, which can be severe and for most lifelong. Introduction of peanut in the first year of life can reduce the risk of peanut allergy; however, prevention strategies for tree nut allergies have not been established. We aimed to test the efficacy and safety of a novel strategy, a supervised multi-nut oral food challenge (OFC) compared with standard care for tree nut allergy prevention in infants at high risk of developing tree nut allergy, TreEAT. METHODS AND ANALYSIS: TreEAT is a 2-armed, open-label, randomized, controlled trial (RCT). Infants (n = 212) aged 4-11 months with peanut allergy will be randomized 1:1 at peanut allergy diagnosis to either a hospital-based multi-tree nut (almond, cashew, hazelnut, and walnut) OFC using multi-nut butter or standard care (home introduction of individual tree nuts). All infants will be assessed at age 18 months, with questionnaires and SPT to peanut and tree nuts. Peanut and tree nut OFCs will be performed as required to determine the allergy status for each nut. The primary outcome is tree nut allergy at age 18 months. Secondary outcomes include peanut allergy resolution, proportion, and severity of adverse events related to tree nut ingestion, number and frequency of tree nuts ingested, quality of life and parental anxiety, and allergy-related healthcare visits from randomization to 18 months of age. Analyses will be performed on an intention-to-treat basis. ETHICS AND DISSEMINATION: TreEAT was approved by the Royal Children's Hospital Human Research Ethics Committee (#70489). Outcomes will be presented at scientific conferences and disseminated through publication. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov ID: NCT04801823.


Assuntos
Juglans , Hipersensibilidade a Noz , Hipersensibilidade a Amendoim , Criança , Lactente , Humanos , Hipersensibilidade a Noz/diagnóstico , Hipersensibilidade a Noz/prevenção & controle , Nozes , Imunoglobulina E , Alérgenos , Arachis , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Ann Allergy Asthma Immunol ; 128(6): 660-668.e9, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35367346

RESUMO

BACKGROUND: Bleach bathing is frequently recommended to treat atopic dermatitis (AD), but its efficacy and safety are uncertain. OBJECTIVE: To systematically synthesize randomized controlled trials (RCTs) addressing bleach baths for AD. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and GREAT from inception to December 29, 2021, for RCTs assigning patients with AD to bleach vs no bleach baths. Paired reviewers independently and in duplicate screened records, extracted data, and assessed risk of bias (Cochrane version 2) and GRADE quality of evidence. We obtained unpublished data, harmonized individual patient data and did Frequentist and Bayesian random-effects meta-analyses. RESULTS: There were 10 RCTs that enrolled 307 participants (median of mean age 7.2 years, Eczema Area Severity Index baseline mean of means 27.57 [median SD, 10.74]) for a median of 6 weeks (range, 4-10). We confirmed that other trials registered globally were terminated. Bleach baths probably improve AD severity (22% vs 32% improved Eczema Area Severity Index by 50% [ratio of means 0.78, 95% credible interval 0.59-0.99]; moderate certainty) and may slightly reduce skin Staphylococcal aureus colonization (risk ratio, 0.89 [95% confidence interval, 0.73-1.09]; low certainty). Adverse events, mostly dry skin and irritation, along with itch, patient-reported disease severity, sleep quality, quality of life, and risk of AD flares were not clearly different between groups and of low to very low certainty. CONCLUSION: In patients with moderate-to-severe AD, bleach baths probably improve clinician-reported severity by a relative 22%. One in 10 will likely improve severity by 50%. Changes in other patient-important outcomes are uncertain. These findings support optimal eczema care and the need for additional large clinical trials. TRIAL REGISTRATION: PROSPERO Identifier: CRD42021238486.


Assuntos
Anti-Infecciosos , Dermatite Atópica , Eczema , Anti-Infecciosos/uso terapêutico , Banhos , Criança , Dermatite Atópica/tratamento farmacológico , Eczema/tratamento farmacológico , Humanos , Prurido/tratamento farmacológico , Staphylococcus aureus
3.
J Allergy Clin Immunol ; 144(1): 236-253, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30738173

RESUMO

BACKGROUND: Gain-of-function (GOF) mutations in PIK3CD cause a primary immunodeficiency characterized by recurrent respiratory tract infections, susceptibility to herpesvirus infections, and impaired antibody responses. Previous work revealed defects in CD8+ T and B cells that contribute to this clinical phenotype, but less is understood about the role of CD4+ T cells in disease pathogenesis. OBJECTIVE: We sought to dissect the effects of increased phosphoinositide 3-kinase (PI3K) signaling on CD4+ T-cell function. METHODS: We performed detailed ex vivo, in vivo, and in vitro phenotypic and functional analyses of patients' CD4+ T cells and a novel murine disease model caused by overactive PI3K signaling. RESULTS: PI3K overactivation caused substantial increases in numbers of memory and follicular helper T (TFH) cells and dramatic changes in cytokine production in both patients and mice. Furthermore, PIK3CD GOF human TFH cells had dysregulated phenotype and function characterized by increased programmed cell death protein 1, CXCR3, and IFN-γ expression, the phenotype of a TFH cell subset with impaired B-helper function. This was confirmed in vivo in which Pik3cd GOF CD4+ T cells also acquired an aberrant TFH phenotype and provided poor help to support germinal center reactions and humoral immune responses by antigen-specific wild-type B cells. The increase in numbers of both memory and TFH cells was largely CD4+ T-cell extrinsic, whereas changes in cytokine production and TFH cell function were cell intrinsic. CONCLUSION: Our studies reveal that CD4+ T cells with overactive PI3K have aberrant activation and differentiation, thereby providing mechanistic insight into dysfunctional antibody responses in patients with PIK3CD GOF mutations.


Assuntos
Linfócitos T CD4-Positivos , Diferenciação Celular , Fosfatidilinositol 3-Quinases/genética , Animais , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Mutação com Ganho de Função , Humanos , Camundongos , Fenótipo
4.
J Allergy Clin Immunol ; 143(6): 2238-2253, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30660643

RESUMO

BACKGROUND: CD40 ligand (CD40L) deficiency, an X-linked primary immunodeficiency, causes recurrent sinopulmonary, Pneumocystis and Cryptosporidium species infections. Long-term survival with supportive therapy is poor. Currently, the only curative treatment is hematopoietic stem cell transplantation (HSCT). OBJECTIVE: We performed an international collaborative study to improve patients' management, aiming to individualize risk factors and determine optimal HSCT characteristics. METHODS: We retrospectively collected data on 130 patients who underwent HSCT for CD40L deficiency between 1993-2015. We analyzed outcome and variables' relevance with respect to survival and cure. RESULTS: Overall survival (OS), event-free survival (EFS), and disease-free survival (DFS) were 78.2%, 58.1%, and 72.3% 5 years after HSCT. Results were better in transplantations performed in 2000 or later and in children less than 10 years old at the time of HSCT. Pre-existing organ damage negatively influenced outcome. Sclerosing cholangitis was the most important risk factor. After 2000, superior OS was achieved with matched donors. Use of myeloablative regimens and HSCT at 2 years or less from diagnosis associated with higher OS and DFS. EFS was best with matched sibling donors, myeloablative conditioning (MAC), and bone marrow-derived stem cells. Most rejections occurred after reduced-intensity or nonmyeloablative conditioning, which associated with poor donor cell engraftment. Mortality occurred mainly early after HSCT, predominantly from infections. Among survivors who ceased immunoglobulin replacement, T-lymphocyte chimerism was 50% or greater donor in 85.2%. CONCLUSION: HSCT is curative in patients with CD40L deficiency, with improved outcome if performed before organ damage development. MAC is associated with better OS, EFS, and DFS. Prospective studies are required to compare the risks of HSCT with those of lifelong supportive therapy.


Assuntos
Ligante de CD40/deficiência , Transplante de Células-Tronco Hematopoéticas , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/terapia , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Resultado do Tratamento , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/mortalidade
5.
J Clin Immunol ; 39(5): 505-511, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31172381

RESUMO

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative for many patients with primary immune deficiency (PID). Haploidentical donors have historically been associated with higher rates of graft-versus-host disease (GvHD) and graft failure. Use of T cell receptor (TCR) α+ß+/CD19+-depleted grafts has resulted in improved haploidentical HSCT outcomes. We sought to evaluate outcomes of TCR α+ß+/CD19+-depleted haploidentical HSCT in pediatric patients with PID at a single center in Australia. Specifically, we evaluated immune reconstitution, looking at time to T cell and B cell reconstitution, and B cell function post-HSCT. Eleven patients with a mean age of 7.92 years (range 0.33-17.17 years) were included. The median time to B cell recovery was 93 days (range 41-205 days), and the median time to cessation of immunoglobulin replacement was 281.5 days (range 41-205 days). All patients who had ceased immunoglobulin replacement had an adequate response to pneumococcal conjugate (Prevenar 13) vaccine. The median time to CD4+ recovery was 132 days (range 30-296 days), and naive T cells were present in all surviving patients by 4 months post-HSCT. Eight of 11 patients are surviving, with six patients having whole blood chimerism greater than 95%, one patient with whole blood chimerism of 82.8%, and another with 76.0%. All of these patients clinically had no evidence of underlying immunodeficiency. Likelihood of overall survival at 2 years post-HSCT was 81.8%. Cumulative incidence of acute GvHD was 27.3%. Cumulative incidence of CMV viremia was 63.6%. All patients previously exposed to CMV had reactivation post-HSCT, but were controlled with pre-emptive CMV treatment. Assuming most children with PID have a haploidentical donor available, use of this technique is likely to result in good outcomes for patients who do not have a suitable matched sibling or matched unrelated donor.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Doenças da Imunodeficiência Primária/terapia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Adolescente , Antígenos CD19 , Linfócitos B/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Doenças da Imunodeficiência Primária/imunologia , Irmãos , Linfócitos T/imunologia , Doadores de Tecidos
6.
J Allergy Clin Immunol ; 139(3): 933-949, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27554822

RESUMO

BACKGROUND: Dedicator of cytokinesis 8 (DOCK8) deficiency is a combined immunodeficiency caused by autosomal recessive loss-of-function mutations in DOCK8. This disorder is characterized by recurrent cutaneous infections, increased serum IgE levels, and severe atopic disease, including food-induced anaphylaxis. However, the contribution of defects in CD4+ T cells to disease pathogenesis in these patients has not been thoroughly investigated. OBJECTIVE: We sought to investigate the phenotype and function of DOCK8-deficient CD4+ T cells to determine (1) intrinsic and extrinsic CD4+ T-cell defects and (2) how defects account for the clinical features of DOCK8 deficiency. METHODS: We performed in-depth analysis of the CD4+ T-cell compartment of DOCK8-deficient patients. We enumerated subsets of CD4+ T helper cells and assessed cytokine production and transcription factor expression. Finally, we determined the levels of IgE specific for staple foods and house dust mite allergens in DOCK8-deficient patients and healthy control subjects. RESULTS: DOCK8-deficient memory CD4+ T cells were biased toward a TH2 type, and this was at the expense of TH1 and TH17 cells. In vitro polarization of DOCK8-deficient naive CD4+ T cells revealed the TH2 bias and TH17 defect to be T-cell intrinsic. Examination of allergen-specific IgE revealed plasma IgE from DOCK8-deficient patients is directed against staple food antigens but not house dust mites. CONCLUSION: Investigations into the DOCK8-deficient CD4+ T cells provided an explanation for some of the clinical features of this disorder: the TH2 bias is likely to contribute to atopic disease, whereas defects in TH1 and TH17 cells compromise antiviral and antifungal immunity, respectively, explaining the infectious susceptibility of DOCK8-deficient patients.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/deficiência , Síndromes de Imunodeficiência/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , Alérgenos/imunologia , Criança , Pré-Escolar , Citocinas/imunologia , Feminino , Fatores de Troca do Nucleotídeo Guanina/imunologia , Humanos , Imunoglobulina E/sangue , Leucócitos Mononucleares/imunologia , Masculino , Adulto Jovem
7.
Eur Radiol ; 27(3): 995-1003, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27287481

RESUMO

OBJECTIVES: To explore changes in bone mineral density (BMD) measured by DEXA and MRS fat fraction (FF), Dixon FF, and ADC in lower spinal vertebral bodies in men with prostate cancer treated with androgen deprivation therapy (ADT). METHODS: Twenty-eight men were enrolled onto a clinical trial. All received ADT. DEXA imaging was performed at baseline and 12 months. L-spine MRI was done at baseline and 6 months. RESULTS: The number of patients who underwent DEXA, Dixon, ADC, and MRS at baseline/follow-up were 28/27, 28/26, 28/26, and 22/20. An increase in FF was observed from T11 to S2 (average 1 %/vertebra). There was a positive correlation between baseline MRS FF and Dixon FF (r = 0.85, p < 0.0001) and a negative correlation between MRS FF and ADC (r = -0.56, p = 0.036). Over 6 months, MRS FF increased by a median of 25 % in relative values (p = 0.0003), Dixon FF increased (p < 0.0001) and ADC values decreased (p = 0.0014). Men with >5 % BMD loss after 1 year had triple the percentage increase in MRS FF at 6 months (61.1 % vs. 20.9 %, p = 0.19). CONCLUSIONS: Changes are observed on L-spine MRI after 6 months of ADT. Further investigation is warranted of MRS change as a potential predictive biomarker for later BMD loss. KEY POINTS: • Spinal marrow fat fraction increases after 6 months of androgen deprivation therapy. • More inferior vertebral bodies tend to have higher fat fractions. • MRS fat fraction changes were associated with later changes in DEXA BMD.


Assuntos
Absorciometria de Fóton/métodos , Antagonistas de Androgênios/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Imageamento por Ressonância Magnética/métodos , Neoplasias da Próstata/tratamento farmacológico , Coluna Vertebral/diagnóstico por imagem , Tecido Adiposo/patologia , Idoso , Biomarcadores , Imagem de Difusão por Ressonância Magnética/métodos , Seguimentos , Humanos , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Coluna Vertebral/patologia
9.
J Allergy Clin Immunol ; 136(4): 993-1006.e1, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26162572

RESUMO

BACKGROUND: Follicular helper T (TFH) cells underpin T cell-dependent humoral immunity and the success of most vaccines. TFH cells also contribute to human immune disorders, such as autoimmunity, immunodeficiency, and malignancy. Understanding the molecular requirements for the generation and function of TFH cells will provide strategies for targeting these cells to modulate their behavior in the setting of these immunologic abnormalities. OBJECTIVE: We sought to determine the signaling pathways and cellular interactions required for the development and function of TFH cells in human subjects. METHODS: Human primary immunodeficiencies (PIDs) resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Circulating follicular helper T (cTFH) cell subsets, memory B cells, and serum immunoglobulin levels were quantified and functionally assessed in healthy control subjects, as well as in patients with PIDs resulting from mutations in STAT3, STAT1, TYK2, IL21, IL21R, IL10R, IFNGR1/2, IL12RB1, CD40LG, NEMO, ICOS, or BTK. RESULTS: Loss-of-function (LOF) mutations in STAT3, IL10R, CD40LG, NEMO, ICOS, or BTK reduced cTFH cell frequencies. STAT3 and IL21/R LOF and STAT1 gain-of-function mutations skewed cTFH cell differentiation toward a phenotype characterized by overexpression of IFN-γ and programmed death 1. IFN-γ inhibited cTFH cell function in vitro and in vivo, as corroborated by hypergammaglobulinemia in patients with IFNGR1/2, STAT1, and IL12RB1 LOF mutations. CONCLUSION: Specific mutations affect the quantity and quality of cTFH cells, highlighting the need to assess TFH cells in patients by using multiple criteria, including phenotype and function. Furthermore, IFN-γ functions in vivo to restrain TFH cell-induced B-cell differentiation. These findings shed new light on TFH cell biology and the integrated signaling pathways required for their generation, maintenance, and effector function and explain the compromised humoral immunity seen in patients with some PIDs.


Assuntos
Síndromes de Imunodeficiência/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Tirosina Quinase da Agamaglobulinemia , Linfócitos B/imunologia , Ligante de CD40/genética , Diferenciação Celular/genética , Proliferação de Células/genética , Células Cultivadas , Humanos , Quinase I-kappa B/genética , Imunidade Humoral/genética , Síndromes de Imunodeficiência/genética , Memória Imunológica , Proteína Coestimuladora de Linfócitos T Induzíveis/genética , Interferon gama/genética , Interferon gama/metabolismo , Ativação Linfocitária , Mutação/genética , Proteínas Tirosina Quinases/genética , Receptores de Citocinas/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT3/genética , Transdução de Sinais/genética , Transdução de Sinais/imunologia
10.
J Clin Immunol ; 35(4): 366-72, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25875700

RESUMO

PURPOSE: Adenosine deaminase (ADA) deficiency is a systemic disorder of purine metabolism. Deficiency of the purine salvage enzyme ADA leads to the build-up of the toxic metabolites, deoxyadenosine triphosphate and deoxyadenosine. ADA is ubiquitously expressed in all tissues of the body but most profoundly affects lymphocyte development and function leading to severe combined immunodeficiency (SCID). Unlike most other forms of SCID, ADA deficiency also results in non-immunologic manifestations. Associations between ADA deficiency and sensorineural hearing loss, behavioural abnormalities, non-infectious pulmonary disease and skeletal dysplasia are all recognised, and affect the long term outcome for these patients. Identification of new non-immunological manifestations and clinical presentations of ADA deficiency is essential to allow early optimisation of supportive care. METHODS AND RESULTS: Here we report four patients with ADA deficiency whose presenting feature was haemolytic uremic syndrome (HUS). 3 of 4 patients were diagnosed with ADA deficiency only after developing HUS, and one diagnosis was made post mortem, after a sibling was diagnosed with SCID. Shiga-toxigenic organisms were not isolated from any of the patients. 2 patients made a good recovery from their HUS with supportive treatment and initiation of PEG-ADA. Both remain well on enzyme replacement with mild or no residual renal impairment. CONCLUSIONS: Clinicians should be aware of this previously unreported non-immunologic manifestation of ADA deficiency.


Assuntos
Adenosina Desaminase/deficiência , Agamaglobulinemia/diagnóstico , Síndrome Hemolítico-Urêmica Atípica/diagnóstico , Imunodeficiência Combinada Severa/diagnóstico , Adenosina Desaminase/genética , Agamaglobulinemia/tratamento farmacológico , Criança , Diagnóstico Diferencial , Evolução Fatal , Feminino , Genótipo , Humanos , Lactente , Masculino , Mutação , Imunodeficiência Combinada Severa/tratamento farmacológico
11.
Blood ; 122(12): 2052-61, 2013 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-23929855

RESUMO

Patients with the dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome suffer from recurrent viral and bacterial infections, hyper-immunoglobulin E levels, eczema, and greater susceptibility to cancer. Because natural killer T (NKT) cells have been implicated in these diseases, we asked if these cells were affected by DOCK8 deficiency. Using a mouse model, we found that DOCK8 deficiency resulted in impaired NKT cell development, principally affecting the formation and survival of long-lived, differentiated NKT cells. In the thymus, DOCK8-deficient mice lack a terminally differentiated subset of NK1.1(+) NKT cells expressing the integrin CD103, whereas in the liver, DOCK8-deficient NKT cells express reduced levels of the prosurvival factor B-cell lymphoma 2 and the integrin lymphocyte function-associated antigen 1. Although the initial NKT cell response to antigen is intact in the absence of DOCK8, their ongoing proliferative and cytokine responses are impaired. Importantly, a similar defect in NKT cell numbers was detected in DOCK8-deficient humans, highlighting the relevance of the mouse model. In conclusion, our data demonstrate that DOCK8 is required for the development and survival of mature NKT cells, consistent with the idea that DOCK8 mediates survival signals within a specialized niche. Accordingly, impaired NKT cell numbers and function are likely to contribute to the susceptibility of DOCK8-deficient patients to recurrent infections and malignant disease.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/genética , Células T Matadoras Naturais/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos Ly/metabolismo , Sobrevivência Celular/genética , Análise por Conglomerados , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Humanos , Receptores de Hialuronatos/metabolismo , Imunofenotipagem , Cadeias alfa de Integrinas/metabolismo , Fígado/imunologia , Fígado/metabolismo , Contagem de Linfócitos , Camundongos , Camundongos Knockout , Subfamília B de Receptores Semelhantes a Lectina de Células NK/metabolismo , Células T Matadoras Naturais/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Timo/imunologia , Timo/metabolismo
12.
Blood ; 122(24): 3940-50, 2013 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-24159173

RESUMO

B-cell responses are guided by the integration of signals through the B-cell receptor (BCR), CD40, and cytokine receptors. The common γ chain (γc)-binding cytokine interleukin (IL)-21 drives humoral immune responses via STAT3-dependent induction of transcription factors required for plasma cell generation. We investigated additional mechanisms by which IL-21/STAT3 signaling modulates human B-cell responses by studying patients with STAT3 mutations. IL-21 strongly induced CD25 (IL-2Rα) in normal, but not STAT3-deficient, CD40L-stimulated naïve B cells. Chromatin immunoprecipitation confirmed IL2RA as a direct target of STAT3. IL-21-induced CD25 expression was also impaired on B cells from patients with IL2RG or IL21R mutations, confirming a requirement for intact IL-21R signaling in this process. IL-2 increased plasmablast generation and immunoglobulin secretion from normal, but not CD25-deficient, naïve B cells stimulated with CD40L/IL-21. IL-2 and IL-21 were produced by T follicular helper cells, and neutralizing both cytokines abolished the B-cell helper capacity of these cells. Our results demonstrate that IL-21, via STAT3, sensitizes B cells to the stimulatory effects of IL-2. Thus, IL-2 may play an adjunctive role in IL-21-induced B-cell differentiation. Lack of this secondary effect of IL-21 may amplify the humoral immunodeficiency in patients with mutations in STAT3, IL2RG, or IL21R due to impaired responsiveness to IL-21.


Assuntos
Linfócitos B/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Interleucina-2/farmacologia , Interleucinas/farmacologia , Plasmócitos/efeitos dos fármacos , Fator de Transcrição STAT3/genética , Linfócitos B/citologia , Linfócitos B/metabolismo , Ligante de CD40/farmacologia , Diferenciação Celular/genética , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-10/farmacologia , Subunidade alfa de Receptor de Interleucina-2/genética , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Plasmócitos/citologia , Plasmócitos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Transcriptoma/efeitos dos fármacos
13.
J Clin Immunol ; 34(5): 551-4, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24817258

RESUMO

PURPOSE: To identify mechanisms of disease in a child born to consanguineous parents, who presented with Omenn syndrome (OS) and was found to carry a heterozygous RAG1 mutation in peripheral blood DNA. METHODS: Mutation analysis was performed on whole blood and buccal swab DNA. Recombination activity of the mutant RAG1 protein and diversity of T cell repertoire were tested. RESULTS: Apparent heterozygosity for a novel, functionally null RAG1 mutation in peripheral blood DNA from a patient with OS was shown to be secondary to true somatic reversion. Analysis of T cell repertoire demonstrated expression of various TCRBV families, but an overall restricted pattern. CONCLUSIONS: This is the first case of true somatic reversion of a RAG1 mutation in a patient with OS. The reversion event likely occurred at a stage where only a limited pool of T cell progenitors capable of performing V(D)J recombination could be generated. This work emphasizes the importance of performing functional studies to investigate the significance of novel genetic variants, and to consider somatic reversion as a possible disease modifier in SCID.


Assuntos
Proteínas de Homeodomínio/genética , Mosaicismo , Imunodeficiência Combinada Severa/genética , Transposases/genética , Linfócitos B/imunologia , Linfócitos B/patologia , Análise Mutacional de DNA , Genótipo , Transplante de Células-Tronco Hematopoéticas , Heterozigoto , Proteínas de Homeodomínio/sangue , Humanos , Lactente , Masculino , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , Imunodeficiência Combinada Severa/terapia , Linfócitos T/imunologia , Linfócitos T/patologia , Transposases/sangue
14.
Blood ; 119(17): 3997-4008, 2012 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-22403255

RESUMO

T follicular helper (Tfh) cells are critical for providing the necessary signals to induce differentiation of B cells into memory and Ab-secreting cells. Accordingly, it is important to identify the molecular requirements for Tfh cell development and function. We previously found that IL-12 mediates the differentiation of human CD4(+) T cells to the Tfh lineage, because IL-12 induces naive human CD4(+) T cells to acquire expression of IL-21, BCL6, ICOS, and CXCR5, which typify Tfh cells. We have now examined CD4(+) T cells from patients deficient in IL-12Rß1, TYK2, STAT1, and STAT3 to further explore the pathways involved in human Tfh cell differentiation. Although STAT1 was dispensable, mutations in IL12RB1, TYK2, or STAT3 compromised IL-12-induced expression of IL-21 by human CD4(+) T cells. Defective expression of IL-21 by STAT3-deficient CD4(+) T cells resulted in diminished B-cell helper activity in vitro. Importantly, mutations in STAT3, but not IL12RB1 or TYK2, also reduced Tfh cell generation in vivo, evidenced by decreased circulating CD4(+)CXCR5(+) T cells. These results highlight the nonredundant role of STAT3 in human Tfh cell differentiation and suggest that defective Tfh cell development and/or function contributes to the humoral defects observed in STAT3-deficient patients.


Assuntos
Diferenciação Celular , Interleucina-12/farmacologia , Mutação/genética , Receptores de Interleucina-12/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT3/genética , Linfócitos T Auxiliares-Indutores/citologia , TYK2 Quinase/genética , Animais , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Citocinas/metabolismo , Humanos , Hospedeiro Imunocomprometido , Ativação Linfocitária , Camundongos , Receptores de Interleucina-12/deficiência , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT3/deficiência , Transdução de Sinais , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , TYK2 Quinase/metabolismo , Fatores de Transcrição/metabolismo
15.
J Allergy Clin Immunol ; 132(2): 400-11.e9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23830147

RESUMO

BACKGROUND: The capacity of CD8(+) T cells to control infections and mediate antitumor immunity requires the development and survival of effector and memory cells. IL-21 has emerged as a potent inducer of CD8(+) T-cell effector function and memory development in mouse models of infectious disease. However, the role of IL-21 and associated signaling pathways in protective CD8(+) T-cell immunity in human subjects is unknown. OBJECTIVE: We sought to determine which signaling pathways mediate the effects of IL-21 on human CD8(+) T cells and whether defects in these pathways contribute to disease pathogenesis in patients with primary immunodeficiencies caused by mutations in components of the IL-21 signaling cascade. METHODS: Human primary immunodeficiencies resulting from monogenic mutations provide a unique opportunity to assess the requirement for particular molecules in regulating human lymphocyte function. Lymphocytes from patients with loss-of-function mutations in signal transducer and activator of transcription 1 (STAT1), STAT3, or IL-21 receptor (IL21R) were used to assess the respective roles of these genes in human CD8(+) T-cell differentiation in vivo and in vitro. RESULTS: Mutations in STAT3 and IL21R, but not STAT1, led to a decrease in multiple memory CD8(+) T-cell subsets in vivo, indicating that STAT3 signaling, possibly downstream of IL-21R, regulates the memory cell pool. Furthermore, STAT3 was important for inducing the lytic machinery in IL-21-stimulated naive CD8(+) T cells. However, this defect was overcome by T-cell receptor engagement. CONCLUSION: The IL-21R/STAT3 pathway is required for many aspects of human CD8(+) T-cell behavior but in some cases can be compensated by other signals. This helps explain the relatively mild susceptibility to viral disease observed in STAT3- and IL-21R-deficient subjects.


Assuntos
Linfócitos T CD8-Positivos/citologia , Diferenciação Celular , Memória Imunológica , Síndrome de Job/genética , Mutação , Fator de Transcrição STAT3/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Humanos , Interleucinas/genética , Interleucinas/imunologia , Interleucinas/metabolismo , Síndrome de Job/imunologia , Síndrome de Job/patologia , Receptores de Interleucina-21/genética , Receptores de Interleucina-21/imunologia , Receptores de Interleucina-21/metabolismo , Fator de Transcrição STAT3/genética
16.
J Exp Med ; 204(10): 2407-22, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17893200

RESUMO

Human interleukin (IL) 1 receptor-associated kinase 4 (IRAK-4) deficiency is a recently discovered primary immunodeficiency that impairs Toll/IL-1R immunity, except for the Toll-like receptor (TLR) 3- and TLR4-interferon (IFN)-alpha/beta pathways. The clinical and immunological phenotype remains largely unknown. We diagnosed up to 28 patients with IRAK-4 deficiency, tested blood TLR responses for individual leukocyte subsets, and TLR responses for multiple cytokines. The patients' peripheral blood mononuclear cells (PBMCs) did not induce the 11 non-IFN cytokines tested upon activation with TLR agonists other than the nonspecific TLR3 agonist poly(I:C). The patients' individual cell subsets from both myeloid (granulocytes, monocytes, monocyte-derived dendritic cells [MDDCs], myeloid DCs [MDCs], and plasmacytoid DCs) and lymphoid (B, T, and NK cells) lineages did not respond to the TLR agonists that stimulated control cells, with the exception of residual responses to poly(I:C) and lipopolysaccharide in MDCs and MDDCs. Most patients (22 out of 28; 79%) suffered from invasive pneumococcal disease, which was often recurrent (13 out of 22; 59%). Other infections were rare, with the exception of severe staphylococcal disease (9 out of 28; 32%). Almost half of the patients died (12 out of 28; 43%). No death and no invasive infection occurred in patients older than 8 and 14 yr, respectively. The IRAK-4-dependent TLRs and IL-1Rs are therefore vital for childhood immunity to pyogenic bacteria, particularly Streptococcus pneumoniae. Conversely, IRAK-4-dependent human TLRs appear to play a redundant role in protective immunity to most infections, at most limited to childhood immunity to some pyogenic bacteria.


Assuntos
Infecções Bacterianas/imunologia , Infecções Bacterianas/metabolismo , Quinases Associadas a Receptores de Interleucina-1/deficiência , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Receptores Toll-Like/metabolismo , Adolescente , Adulto , Infecções Bacterianas/patologia , Diferenciação Celular/imunologia , Células Cultivadas , Criança , Pré-Escolar , Citocinas/biossíntese , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Lactente , Quinases Associadas a Receptores de Interleucina-1/genética , Leucócitos/citologia , Leucócitos/imunologia , Leucócitos/metabolismo , Masculino , Mutação/genética , Células Mieloides/imunologia , Células Mieloides/metabolismo , Linhagem , Receptores Toll-Like/agonistas
17.
Blood ; 118(26): 6824-35, 2011 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-22039266

RESUMO

SCID resulting from mutations in IL2RG or JAK3 is characterized by lack of T and natural killer cells; B cells are present in normal number, but antibody responses are defective. Hematopoietic cell transplantation (HCT) is curative for SCID. However, B-cell dysfunction persists in a substantial proportion of patients. We hypothesized that impaired B-cell responses after HCT in IL2RG/JAK3 deficiency results from poor donor B-cell engraftment and defective γc-dependent cytokine signaling in host B cells. To test this, and to identify which γc cytokine(s) is critical for humoral immunity, we studied 28 transplanted patients with IL2RG/JAK3 deficiency. Lack of donor B-cell engraftment associated with persistent humoral dysfunction and significantly reduced memory B cells. B-cell proliferation induced by CD40L alone or together with CpG, anti-Ig, IL-4, IL-10, or IL-13 was comparable in healthy controls and in post-HCT SCID patients, irrespective of their chimerism status. However, in vitro stimulation with CD40L/IL-21 induced B-cell proliferation, plasmablast differentiation, and antibody secretion in patients with donor B cells, but not in patients with autologous B cells. These data imply that IL-21-mediated signaling is critical for long-lived humoral immunity and to restore antibody responses in IL2RG/JAK3-deficient patients after HCT. Furthermore, in vitro stimulation with CD40L/IL-21 can predict in vivo B-cell immunity in IL2RG/JAK3 SCID after transplantation.


Assuntos
Linfócitos B/imunologia , Diferenciação Celular/imunologia , Subunidade gama Comum de Receptores de Interleucina/imunologia , Interleucinas/imunologia , Linfócitos B/metabolismo , Ligante de CD40/imunologia , Ligante de CD40/metabolismo , Células Cultivadas , Citometria de Fluxo , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Memória Imunológica/imunologia , Subunidade gama Comum de Receptores de Interleucina/genética , Subunidade gama Comum de Receptores de Interleucina/metabolismo , Interleucinas/metabolismo , Janus Quinase 3/genética , Janus Quinase 3/imunologia , Janus Quinase 3/metabolismo , Mutação , Ligação Proteica , Imunodeficiência Combinada Severa/genética , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/metabolismo , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/metabolismo
18.
Blood ; 117(1): 53-62, 2011 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-20926771

RESUMO

X-linked lymphoproliferative disease (XLP1) is a rare immunodeficiency characterized by severe immune dysregulation and caused by mutations in the SH2D1A/SAP gene. Clinical manifestations are varied and include hemophagocytic lymphohistiocytosis (HLH), lymphoma and dysgammaglobulinemia, often triggered by Epstein-Barr virus infection. Historical data published before improved treatment regimens shows very poor outcome. We describe a large cohort of 91 genetically defined XLP1 patients collected from centers worldwide and report characteristics and outcome data for 43 patients receiving hematopoietic stem cell transplant (HSCT) and 48 untransplanted patients. The advent of better treatment strategies for HLH and malignancy has greatly reduced mortality for these patients, but HLH still remains the most severe feature of XLP1. Survival after allogeneic HSCT is 81.4% with good immune reconstitution in the large majority of patients and little evidence of posttransplant lymphoproliferative disease. However, survival falls to 50% in patients with HLH as a feature of disease. Untransplanted patients have an overall survival of 62.5% with the majority on immunoglobulin replacement therapy, but the outcome for those untransplanted after HLH is extremely poor (18.8%). HSCT should be undertaken in all patients with HLH, because outcome without transplant is extremely poor. The outcome of HSCT for other manifestations of XLP1 is very good, and if HSCT is not undertaken immediately, patients must be monitored closely for evidence of disease progression.


Assuntos
Antígenos CD/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Linfo-Histiocitose Hemofagocítica/genética , Transtornos Linfoproliferativos/genética , Mutação/genética , Receptores de Superfície Celular/genética , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/patologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Transplante de Células-Tronco Hematopoéticas , Herpesvirus Humano 4/genética , Humanos , Lactente , Recém-Nascido , Linfo-Histiocitose Hemofagocítica/patologia , Linfo-Histiocitose Hemofagocítica/terapia , Transtornos Linfoproliferativos/patologia , Transtornos Linfoproliferativos/terapia , Masculino , Pessoa de Meia-Idade , Proteína Associada à Molécula de Sinalização da Ativação Linfocitária , Membro 1 da Família de Moléculas de Sinalização da Ativação Linfocitária , Taxa de Sobrevida , Adulto Jovem
19.
Hum Mutat ; 33(3): 471-5, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22125116

RESUMO

Chronic granulomatous disease (CGD) is mainly caused by mutations in X-linked CYBB that encodes gp91. We have identified two novel mutations in CYBB resulting in the rare X91(+)-CGD variant, c.1500T>G (p.Asp500Glu) in two male siblings and c.1463C>A (p.Ala488Asp) in an unrelated male. Zymosan and/or PMA (Phorbol 12-myristate 13-acetate)-induced recruitment of p47(phox) and p67(phox) to the membrane fraction was normal for both mutants. Cell-free assays using recombinant wild-type and the mutant proteins revealed that these mutants were not activated by NADPH (nicotinamide adenine dinucleotide phosphate). Interestingly, the Ala488Asp mutant was activated by NADPH in the presence of glutathione. These data suggest that the mutations prevented NADPH from binding to gp91(phox) and the requirement of a negative charge at residue 500 in gp91(phox) for NADPH oxidase assembly, in contrast to a previously described Asp500Gly change. These mutations and the effect of glutathione provide a unique insight into disease pathogenesis and potential therapy in variant X91(+)-CGD.


Assuntos
Doença Granulomatosa Crônica/etiologia , Doença Granulomatosa Crônica/genética , Glicoproteínas de Membrana/genética , NADPH Oxidases/genética , Humanos , Masculino , Mutação , NADP/metabolismo , NADPH Oxidase 2 , Ligação Proteica , Estrutura Secundária de Proteína
20.
J Clin Immunol ; 32(5): 897-906, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22526590

RESUMO

This phase III, open-label, multi-centre study investigated the efficacy, safety, pharmacokinetics and quality of life impact of Evogam(®), a new chromatographically fractionated 16% subcutaneous immunoglobulin, utilising a 1:1 dose transition ratio from previous immunoglobulin therapy. Thirty-five previously treated patients with primary immunodeficiency received weekly Evogam over 36 weeks. Primary endpoints were rate of serious bacterial infections (SBIs) and steady-state serum immunoglobulin G (IgG) trough concentrations. No SBIs were reported during the study. Evogam produced significantly higher mean trough IgG concentrations with 1:1 dose conversion compared to previous immunoglobulin treatment (8.94 versus 8.27 g/L, p = 0.0063). Evogam was efficacious in the prevention of infections and maintenance of trough levels using a 1:1 dose conversion. It was well tolerated with no withdrawals due to adverse events and was preferred to IVIg by the majority of patients.


Assuntos
Imunoglobulina G/administração & dosagem , Síndromes de Imunodeficiência/tratamento farmacológico , Fatores Imunológicos/administração & dosagem , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/farmacologia , Síndromes de Imunodeficiência/sangue , Fatores Imunológicos/sangue , Fatores Imunológicos/farmacologia , Injeções Subcutâneas , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Adulto Jovem
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