Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rheumatology (Oxford) ; 59(11): 3499-3504, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32757002

RESUMO

OBJECTIVES: SSc is an autoimmune disease characterized by fibrosis, microangiopathy and immune dysfunctions including dysregulation of proinflammatory cytokines. Clonal haematopoiesis of indeterminate potential (CHIP) is defined by the acquisition of somatic mutations in haematopoietic stem cells leading to detectable clones in the blood. Recent data have shown a higher risk of cardiovascular disease in patients with CHIP resulting from increased production of proinflammatory cytokines and accelerated atherosclerosis. Eventual links between CHIP and autoimmune diseases are undetermined. The aim of our study was to evaluate the prevalence of CHIP in SSc patients and its association with clinical phenotype. METHODS: Forty-one genes frequently mutated in myeloid malignancies were sequenced in peripheral blood mononuclear cells from 90 SSc patients and 44 healthy donors. RESULTS: A total of 15 somatic variants were detected in 13/90 SSc patients (14%) and four somatic variants in 4/44 (9%) healthy donors (HD) (P = 0.58). The prevalence of CHIP was significantly higher in younger SSc patients than in HD: 25% (6/24) vs 4% (1/26) (P = 0.045) under 50 years and 17% (7/42) vs 3% (1/38) (P = 0.065) under 60 years. The prevalence of CHIP in patients over 70 years was similar in SSc patients and healthy donors. The most common mutations occurred in DNMT3A (seven variants). No major clinical differences were observed between SSc patients with or without CHIP. CONCLUSION: Whether CHIP increases the risk to develop SSc or is a consequence of a SSc-derived modified bone marrow micro-environment remains to be explored.

2.
Blood Adv ; 4(15): 3550-3557, 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32761230

RESUMO

Clonal hematopoiesis (CH) of indeterminate potential has been described in blood samples from large series of patients. Its prevalence and consequences are still not well understood because sequencing methods vary and because most studies were performed in cohorts comprising individuals with nonhematologic diseases. Here, we investigated the frequency of CH in 82 paired bone marrow and blood samples from carefully selected healthy adult volunteers. Forty-one genes known to be mutated in myeloid malignancies were sequenced with a 1% threshold of detection. In bone marrow samples, clones were found in almost 40% of healthy volunteers more than 50 years old. The most frequent mutations were found in DNMT3A and TET2, with 1 individual carrying 3 variants. Variant allele frequencies were highly concordant between blood and bone marrow samples. Blood parameters were normal except for those in 2 individuals: 1 had a mild macrocytosis and 1 had a mild thrombocytosis. Furthermore, no morphologic abnormalities or dysplasia were detected when bone marrow smears were carefully evaluated. Individuals with CH differed from others by age (62.8 vs 38.6 years; P < .0001) and platelet count (294 vs 241 ×109/L; P = .0208), the latter being no more significant when removing the 2 individuals who carried the JAK2 p.V617F mutation. These results confirm that CH is a very common condition in healthy adults over 50 years old. Consequently, the detection of driver myeloid mutations should be interpreted with caution in the absence of cytologic abnormalities in the blood and/or the bone marrow.

3.
Mol Genet Genomic Med ; 8(6): e1237, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32281309

RESUMO

BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency disorder (PID) affecting NADPH oxidase activity. The rarest form of the disease is considered to be caused by NCF2 gene bi-allelic variant. Here, we report the clinical and molecular characterization of a patient presenting with early-onset severe disease due to bi-allelic NCF2 variant. METHODS: Gene mutational analysis was performed by whole-exome and Sanger sequencing. RESULTS: The patient presented with a history of fever and rash since the age of 1 month, followed by destructive osteomyelitis and necrotizing lymphadenopathy. The patient received the Bacillus Calmette-Guérin (BCG) vaccine at birth; she was subsequently diagnosed with disseminated BCG infection. Whole-exome sequencing identified a private (unreported) homozygous variant in NCF2 (c.290C > A) that results in a nonconservative change, p.Ala97Asp, in the p67phox protein. The variant is located in the third helix of the TRP domain, which is crucial for the binding of GTPase RAC2 to the NADPH oxidase complex. CONCLUSION: We identified a novel NCF2 variant located in the region interacting with RAC2 that is linked to a severe and early CGD phenotype in the setting of disseminated BCG infection. Our findings support postponing BCG vaccination until 6-12 months of age and after PID assessment.

4.
J Clin Invest ; 130(6): 3158-3171, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32163377

RESUMO

Mendelian susceptibility to mycobacterial disease (MSMD) is characterized by a selective predisposition to clinical disease caused by the Bacille Calmette-Guérin (BCG) vaccine and environmental mycobacteria. The known genetic etiologies of MSMD are inborn errors of IFN-γ immunity due to mutations of 15 genes controlling the production of or response to IFN-γ. Since the first MSMD-causing mutations were reported in 1996, biallelic mutations in the genes encoding IFN-γ receptor 1 (IFN-γR1) and IFN-γR2 have been reported in many patients of diverse ancestries. Surprisingly, mutations of the gene encoding the IFN-γ cytokine itself have not been reported, raising the remote possibility that there might be other agonists of the IFN-γ receptor. We describe 2 Lebanese cousins with MSMD, living in Kuwait, who are both homozygous for a small deletion within the IFNG gene (c.354_357del), causing a frameshift that generates a premature stop codon (p.T119Ifs4*). The mutant allele is loss of expression and loss of function. We also show that the patients' herpesvirus Saimiri-immortalized T lymphocytes did not produce IFN-γ, a phenotype that can be rescued by retrotransduction with WT IFNG cDNA. The blood T and NK lymphocytes from these patients also failed to produce and secrete detectable amounts of IFN-γ. Finally, we show that human IFNG has evolved under stronger negative selection than IFNGR1 or IFNGR2, suggesting that it is less tolerant to heterozygous deleterious mutations than IFNGR1 or IFNGR2. This may account for the rarity of patients with autosomal-recessive, complete IFN-γ deficiency relative to patients with complete IFN-γR1 and IFN-γR2 deficiencies.

5.
J Clin Immunol ; 40(3): 475-493, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32040803

RESUMO

PURPOSE: Chronic granulomatous disease (CGD) is a primary immunodeficiency characterized by an inability of phagocytes to produce reactive oxygen species, impairing their killing of various bacteria and fungi. We summarize here the 93 cases of CGD diagnosed in Mexico from 2011 to 2019. METHODS: Thirteen Mexican hospitals participated in this study. We describe the genetic, immunological, and clinical features of the 93 CGD patients from 78 unrelated kindreds. RESULTS: Eighty-two of the patients (88%) were male. All patients developed bacterial infections and 30% suffered from some kind of fungal infection. Fifty-four BCG-vaccinated patients (58%) presented infectious complications of BCG vaccine. Tuberculosis occurred in 29%. Granulomas were found in 56% of the patients. Autoimmune and inflammatory diseases were present in 15% of patients. A biological diagnosis of CGD was made in 89/93 patients, on the basis of NBT assay (n = 6), DHR (n = 27), and NBT plus DHR (n = 56). The deficiency was complete in all patients. The median age of biological diagnosis was 17 months (range, 0-186 months). A genetic diagnosis was made in 83/93 patients (when material was available), corresponding to CYBB (n = 64), NCF1 (n = 7), NCF2 (n = 7), and CYBA (n = 5) mutations. CONCLUSIONS: The clinical manifestations in these Mexican CGD patients were similar to those in patients elsewhere. This cohort is the largest in Latin America. Mycobacterial infections are an important cause of morbidity in Mexico, as in other countries in which tuberculosis is endemic and infants are vaccinated with BCG. X-linked CGD accounted for most of the cases in Mexico, as in other Latin American countries. However, a significant number of CYBA and NCF2 mutations were identified, expanding the spectrum of known causal mutations.

6.
Iran J Allergy Asthma Immunol ; 18(4): 447-451, 2019 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31522453

RESUMO

Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by defective phagocytic NADPH oxidase, causing a complete lack or significant decrease in the production of microbicidal reactive oxygen metabolites. It mainly affects male children; however, there are scarce reports of adult females diagnosed with X-linked-CGD attributed to an extremely skewed X-chromosome inactivation. This condition is characterized by severe and recurrent infections that usually develop after childhood. In clinical practice, physicians who usually confront these patients should suspect this entity and differentiate it from a secondary immunodeficiency. Here, we report a 38-year-old Mexican female with juvenile-onset X linked-CGD, caused by a de novo mutation and extremely skewed X-inactivation, whose clinical features were similar to those in patients with classic X-linked-CDG.


Assuntos
Doença Granulomatosa Crônica/diagnóstico , Doença Granulomatosa Crônica/genética , Heterozigoto , Fenótipo , Inativação do Cromossomo X , Adolescente , Biomarcadores , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Avaliação de Sintomas
9.
J Clin Immunol ; 39(3): 287-297, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30715640

RESUMO

PURPOSE: Mendelian susceptibility to mycobacterial disease (MSMD) is a rare primary immunodeficiency, triggered by non-tuberculous mycobacteria or Bacillus Calmette-Guérin (BCG) vaccines and characterized by severe diseases. All known genetic etiologies are inborn errors of IFN-γ-mediated immunity. Here, we report the molecular, cellular, and clinical features of patients from 15 Iranian families with disseminated disease without vaccination (2 patients) or following live BCG vaccination (14 patients). METHODS: We used whole blood samples from 16 patients and 12 age-matched healthy controls. To measure IL-12 and IFN-γ, samples were activated by BCG plus recombinant human IFN-γ or recombinant human IL-12. Immunological assessments and genetic analysis were also done for the patients. RESULTS: Eight patients affected as a result of parental first-cousin marriages. Seven patients originated from multiplex kindred with positive history of death because of tuberculosis or finding the MSMD-related gene mutations. Two patients died due to mycobacterial disease at the ages of 8 months and 3.7 years. The remaining patients were alive at the last follow-up and were aged between 2 and 13 years. Patients suffered from infections including chronic mucocutaneous candidiasis (n = 10), salmonellosis (n = 2), and Leishmania (responsible for visceral form) (n = 2). Thirteen patients presented with autosomal recessive (AR) IL-12Rß1 deficiency, meaning their cells produced low levels of IFN-γ. Bi-allelic IL12RB1 mutations were detected in nine of patients. Three patients with AR IL-12p40 deficiency (bi-allelic IL12B mutations) produced low levels of both IL-12 and IFN-γ. Overall, we found five mutations in the IL12RB1 gene and three mutations in the IL12B gene. Except one mutation in exon 5 (c.510C>A) of IL12B, all others were previously reported to be loss-of-function mutations. CONCLUSIONS: We found low levels of IFN-γ production and failure to respond to IL12 in 13 Iranian MSMD patients. Due to complicated clinical manifestations in affected children, early cellular and molecular diagnostics is crucial in susceptible patients.

10.
J Allergy Clin Immunol ; 143(6): 2215-2226.e7, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30578871

RESUMO

BACKGROUND: Inflammatory activation of CD8+ T cells can, when left unchecked, drive severe immunopathology. Hyperstimulation of CD8+ T cells through a broad set of triggering signals can precipitate hemophagocytic lymphohistiocytosis (HLH), a life-threatening systemic inflammatory disorder. OBJECTIVE: The mechanism linking CD8+ T-cell hyperactivation to pathology is controversial, with excessive production of IFN-γ and, more recently, excessive consumption of IL-2, which are proposed as competing hypotheses. We formally tested the proximal mechanistic events of each pathway in a mouse model of HLH. METHODS: In addition to reporting a complete autosomal recessive IFN-γ receptor 1-deficient patient with multiple aspects of HLH pathology, we used the mouse model of perforin (Prf1)KO mice infected with lymphocytic choriomeningitis virus to genetically eliminate either IFN-γ production or CD25 expression and assess the immunologic, hematologic, and physiologic disease measurement. RESULTS: We found a striking dichotomy between the mechanistic basis of the hematologic and inflammatory components of CD8+ T cell-mediated pathology. The hematologic features of HLH were completely dependent on IFN-γ production, with complete correction after loss of IFN-γ production without any role for CD8+ T cell-mediated IL-2 consumption. By contrast, the mechanistic contribution of the immunologic features was reversed, with no role for IFN-γ production but substantial correction after reduction of IL-2 consumption by hyperactivated CD8+ T cells. These results were complemented by the characterization of an IFN-γ receptor 1-deficient patients with HLH-like disease, in whom multiple aspects of HLH pathology were observed in the absence of IFN-γ signaling. CONCLUSION: These results synthesize the competing mechanistic models of HLH pathology into a dichotomous pathogenesis driven through discrete pathways. A holistic model provides a new paradigm for understanding HLH and, more broadly, the consequences of CD8+ T-cell hyperactivation, thereby paving the way for clinical intervention based on the features of HLH in individual patients.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Inflamação/imunologia , Interferon gama/metabolismo , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/fisiologia , Linfo-Histiocitose Hemofagocítica/imunologia , Receptores de Interferon/deficiência , Animais , Consanguinidade , Modelos Animais de Doenças , Feminino , Humanos , Lactente , Ativação Linfocitária , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/genética , Camundongos , Camundongos Knockout , Modelos Imunológicos , Marrocos , Perforina/genética , Transdução de Sinais
12.
Sci Immunol ; 3(30)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578351

RESUMO

Hundreds of patients with autosomal recessive, complete IL-12p40 or IL-12Rß1 deficiency have been diagnosed over the last 20 years. They typically suffer from invasive mycobacteriosis and, occasionally, from mucocutaneous candidiasis. Susceptibility to these infections is thought to be due to impairments of IL-12-dependent IFN-γ immunity and IL-23-dependent IL-17A/IL-17F immunity, respectively. We report here patients with autosomal recessive, complete IL-12Rß2 or IL-23R deficiency, lacking responses to IL-12 or IL-23 only, all of whom, unexpectedly, display mycobacteriosis without candidiasis. We show that αß T, γδ T, B, NK, ILC1, and ILC2 cells from healthy donors preferentially produce IFN-γ in response to IL-12, whereas NKT cells and MAIT cells preferentially produce IFN-γ in response to IL-23. We also show that the development of IFN-γ-producing CD4+ T cells, including, in particular, mycobacterium-specific TH1* cells (CD45RA-CCR6+), is dependent on both IL-12 and IL-23. Last, we show that IL12RB1, IL12RB2, and IL23R have similar frequencies of deleterious variants in the general population. The comparative rarity of symptomatic patients with IL-12Rß2 or IL-23R deficiency, relative to IL-12Rß1 deficiency, is, therefore, due to lower clinical penetrance. There are fewer symptomatic IL-23R- and IL-12Rß2-deficient than IL-12Rß1-deficient patients, not because these genetic disorders are rarer, but because the isolated absence of IL-12 or IL-23 is, in part, compensated by the other cytokine for the production of IFN-γ, thereby providing some protection against mycobacteria. These experiments of nature show that human IL-12 and IL-23 are both required for optimal IFN-γ-dependent immunity to mycobacteria, both individually and much more so cooperatively.


Assuntos
Imunidade Inata/imunologia , Interferon gama/imunologia , Interleucina-12/imunologia , Interleucina-23/imunologia , Infecções por Mycobacterium não Tuberculosas/imunologia , Mycobacterium/imunologia , Humanos , Interleucina-12/deficiência , Interleucina-12/genética , Interleucina-23/deficiência , Interleucina-23/genética , Linhagem
13.
Sci Immunol ; 3(30)2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30578352

RESUMO

Inherited IL-12Rß1 and TYK2 deficiencies impair both IL-12- and IL-23-dependent IFN-γ immunity and are rare monogenic causes of tuberculosis, each found in less than 1/600,000 individuals. We show that homozygosity for the common TYK2 P1104A allele, which is found in about 1/600 Europeans and between 1/1000 and 1/10,000 individuals in regions other than East Asia, is more frequent in a cohort of patients with tuberculosis from endemic areas than in ethnicity-adjusted controls (P = 8.37 × 10-8; odds ratio, 89.31; 95% CI, 14.7 to 1725). Moreover, the frequency of P1104A in Europeans has decreased, from about 9% to 4.2%, over the past 4000 years, consistent with purging of this variant by endemic tuberculosis. Surprisingly, we also show that TYK2 P1104A impairs cellular responses to IL-23, but not to IFN-α, IL-10, or even IL-12, which, like IL-23, induces IFN-γ via activation of TYK2 and JAK2. Moreover, TYK2 P1104A is properly docked on cytokine receptors and can be phosphorylated by the proximal JAK, but lacks catalytic activity. Last, we show that the catalytic activity of TYK2 is essential for IL-23, but not IL-12, responses in cells expressing wild-type JAK2. In contrast, the catalytic activity of JAK2 is redundant for both IL-12 and IL-23 responses, because the catalytically inactive P1057A JAK2, which is also docked and phosphorylated, rescues signaling in cells expressing wild-type TYK2. In conclusion, homozygosity for the catalytically inactive P1104A missense variant of TYK2 selectively disrupts the induction of IFN-γ by IL-23 and is a common monogenic etiology of tuberculosis.


Assuntos
Interferon gama/imunologia , Interleucina-23/imunologia , Mutação de Sentido Incorreto/genética , TYK2 Quinase/genética , Tuberculose/imunologia , Células Cultivadas , Homozigoto , Humanos , Interleucina-23/deficiência , TYK2 Quinase/imunologia
14.
J Clin Immunol ; 38(7): 787-793, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30255293

RESUMO

PURPOSE: Inborn errors of IFN-γ-mediated immunity underlie Mendelian Susceptibility to Mycobacterial Disease (MSMD), which is characterized by an increased susceptibility to severe and recurrent infections caused by weakly virulent mycobacteria, such as Bacillus Calmette-Guérin (BCG) vaccines and environmental, nontuberculous mycobacteria (NTM). METHODS: In this study, we investigated four patients from four unrelated consanguineous families from Isfahan, Iran, with disseminated BCG disease. We evaluated the patients' whole blood cell response to IL-12 and IFN-γ, IL-12Rß1 expression on T cell blasts, and sequenced candidate genes. RESULTS: We report four patients from Isfahan, Iran, ranging from 3 months to 26 years old, with impaired IL-12 signaling. All patients suffered from BCG disease. One of them presented mycobacterial osteomyelitis. By Sanger sequencing, we identified three different types of homozygous mutations in IL12RB1. Expression of IL-12Rß1 was completely abolished in the four patients with IL12RB1 mutations. CONCLUSIONS: IL-12Rß1 deficiency was found in the four MSMD Iranian families tested. It is the first report of an Iranian case with S321* mutant IL-12Rß1 protein. Mycobacterial osteomyelitis is another type of location of BCG infection in an IL-12Rß1-deficient patient, notified for the first time in this study.


Assuntos
Suscetibilidade a Doenças , Interleucina-12/metabolismo , Interleucina-23/metabolismo , Infecções por Mycobacterium/etiologia , Infecções por Mycobacterium/metabolismo , Receptores de Interleucina-12/deficiência , Adolescente , Adulto , Alelos , Vacina BCG/imunologia , Biomarcadores , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Imunofenotipagem , Lactente , Irã (Geográfico)/epidemiologia , Masculino , Mutação , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/prevenção & controle , Prognóstico , Adulto Jovem
15.
Nat Immunol ; 19(9): 973-985, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30127434

RESUMO

Human inborn errors of IFN-γ immunity underlie mycobacterial diseases. We describe patients with Mycobacterium bovis (BCG) disease who are homozygous for loss-of-function mutations of SPPL2A. This gene encodes a transmembrane protease that degrades the N-terminal fragment (NTF) of CD74 (HLA invariant chain) in antigen-presenting cells. The CD74 NTF therefore accumulates in the HLA class II+ myeloid and lymphoid cells of SPPL2a-deficient patients. This toxic fragment selectively depletes IL-12- and IL-23-producing CD1c+ conventional dendritic cells (cDC2s) and their circulating progenitors. Moreover, SPPL2a-deficient memory TH1* cells selectively fail to produce IFN-γ when stimulated with mycobacterial antigens in vitro. Finally, Sppl2a-/- mice lack cDC2s, have CD4+ T cells that produce small amounts of IFN-γ after BCG infection, and are highly susceptible to infection with BCG or Mycobacterium tuberculosis. These findings suggest that inherited SPPL2a deficiency in humans underlies mycobacterial disease by decreasing the numbers of cDC2s and impairing IFN-γ production by mycobacterium-specific memory TH1* cells.


Assuntos
Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Células Dendríticas/imunologia , Proteínas de Membrana/metabolismo , Infecções por Mycobacterium/imunologia , Mycobacterium bovis/fisiologia , Mycobacterium tuberculosis/fisiologia , Células Th1/imunologia , Tuberculose/imunologia , Animais , Antígenos de Diferenciação de Linfócitos B/metabolismo , Células Cultivadas , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Imunidade , Memória Imunológica , Lactente , Interferon gama/metabolismo , Linfadenopatia , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação/genética , Infecções por Mycobacterium/genética , Vacinação
16.
J Clin Immunol ; 38(5): 617-627, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29995221

RESUMO

PURPOSE: Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Autosomal recessive complete IL-12Rß1 deficiency is the most frequent genetic etiology of MSMD. Only two of the 84 known mutations are copy number variations (CNVs), identified in two of the 213 IL-12Rß1-deficient patients and two of the 164 kindreds reported. These two CNVs are large deletions found in the heterozygous or homozygous state. We searched for novel families with IL-12Rß1 deficiency due to CNVs. METHODS: We studied six MSMD patients from five unrelated kindreds displaying adverse reactions to BCG vaccination. Three of the patients also presented systemic salmonellosis, two had mucocutaneous candidiasis, and one had disseminated histoplasmosis. We searched for CNVs and other variations by IL12RB1-targeted next-generation sequencing (NGS). RESULTS: We identified six new IL-12Rß1-deficient patients with a complete loss of IL-12Rß1 expression on phytohemagglutinin-activated T cells and/or EBV-transformed B cells. The cells of these patients did not respond to IL-12 and IL-23. Five different CNVs encompassing IL12RB1 (four deletions and one duplication) were identified in these patients by NGS coverage analysis, either in the homozygous state (n = 1) or in trans (n = 4) with a single-nucleotide variation (n = 3) or a small indel (n = 1). Seven of the nine mutations are novel. Interestingly, four of the five CNVs were predicted to be driven by nearby Alu elements, as well as the two previously reported large deletions. The IL12RB1 locus is actually enriched in Alu elements (44.7%), when compared with the rest of the genome (10.5%). CONCLUSION: The IL12RB1 locus is Alu-enriched and therefore prone to rearrangements at various positions. CNVs should be considered in the genetic diagnosis of IL-12Rß1 deficiency.


Assuntos
Elementos Alu , Variações do Número de Cópias de DNA , Estudos de Associação Genética , Predisposição Genética para Doença , Subunidade beta 1 de Receptor de Interleucina-12/deficiência , Alelos , Sequência de Bases , Mapeamento Cromossômico , Feminino , Expressão Gênica , Humanos , Interferon gama , Masculino , Mutação , Infecções por Mycobacterium/diagnóstico , Infecções por Mycobacterium/etiologia , Infecções por Mycobacterium/metabolismo , Linhagem , Fenótipo
17.
J Clin Invest ; 128(9): 3957-3975, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-29969437

RESUMO

Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40phox-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another. When overexpressed in NB4 neutrophil-like cells and EBV-transformed B cells in vitro, the mutant alleles were found to be LOF, with the exception of the p.R58C and c.120_134del alleles, which were hypomorphic. Particle-induced NADPH oxidase activity was severely impaired in the patients' neutrophils, whereas PMA-induced dihydrorhodamine-1,2,3 (DHR) oxidation, which is widely used as a diagnostic test for chronic granulomatous disease (CGD), was normal or mildly impaired in the patients. Moreover, the NADPH oxidase activity of EBV-transformed B cells was also severely impaired, whereas that of mononuclear phagocytes was normal. Finally, the killing of Candida albicans and Aspergillus fumigatus hyphae by neutrophils was conserved in these patients, unlike in patients with CGD. The patients suffer from hyperinflammation and peripheral infections, but they do not have any of the invasive bacterial or fungal infections seen in CGD. Inherited p40phox deficiency underlies a distinctive condition, resembling a mild, atypical form of CGD.


Assuntos
Doença Granulomatosa Crônica/genética , Mutação com Perda de Função , Fosfoproteínas/deficiência , Fosfoproteínas/genética , Adolescente , Adulto , Alelos , Criança , Pré-Escolar , Feminino , Técnicas de Inativação de Genes , Doença Granulomatosa Crônica/diagnóstico , Doença Granulomatosa Crônica/metabolismo , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , NADPH Oxidases/genética , NADPH Oxidases/metabolismo , Linhagem , Fagócitos/imunologia , Fagócitos/metabolismo , Fagócitos/microbiologia , Fenótipo , Fosfoproteínas/metabolismo , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transdução Genética , Adulto Jovem
18.
Elife ; 72018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29537367

RESUMO

Most humans are exposed to Tropheryma whipplei (Tw). Whipple's disease (WD) strikes only a small minority of individuals infected with Tw (<0.01%), whereas asymptomatic chronic carriage is more common (<25%). We studied a multiplex kindred, containing four WD patients and five healthy Tw chronic carriers. We hypothesized that WD displays autosomal dominant (AD) inheritance, with age-dependent incomplete penetrance. We identified a single very rare non-synonymous mutation in the four patients: the private R98W variant of IRF4, a transcription factor involved in immunity. The five Tw carriers were younger, and also heterozygous for R98W. We found that R98W was loss-of-function, modified the transcriptome of heterozygous leukocytes following Tw stimulation, and was not dominant-negative. We also found that only six of the other 153 known non-synonymous IRF4 variants were loss-of-function. Finally, we found that IRF4 had evolved under purifying selection. AD IRF4 deficiency can underlie WD by haploinsufficiency, with age-dependent incomplete penetrance.


Assuntos
Haploinsuficiência/genética , Fatores Reguladores de Interferon/genética , Tropheryma/genética , Doença de Whipple/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Predisposição Genética para Doença/genética , Humanos , Leucócitos/microbiologia , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Penetrância , Tropheryma/patogenicidade , Doença de Whipple/microbiologia , Doença de Whipple/patologia
19.
J Clin Immunol ; 38(3): 278-282, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29589181

RESUMO

PURPOSE: Mendelian susceptibility to mycobacterial disease (MSMD) is a rare primary immunodeficiency predisposing congenitally affected individuals to diseases caused by weakly virulent mycobacteria, such as Bacillus Calmette-Guérin (BCG) vaccine strains and environmental mycobacteria. IL-12p40 deficiency is a genetic etiology of MSMD resulting in impaired IL-12- and IL-23-dependent IFN-γ immunity. Most of the reported patients with IL-12p40 deficiency originate from Saudi Arabia (30 of 52) and carry the recurrent IL12B mutation c.315insA (27 of 30). METHODS: Whole-exome sequencing was performed on three patients from two unrelated kindreds from Saudi Arabia with disseminated disease caused by a BCG vaccine substrain. RESULTS: Genetic analysis revealed a homozygous mutation, p.W60X, in exon 3 of the IL12B gene, resulting in complete IL12p40 deficiency. This mutation is recurrent due to a new founder effect. CONCLUSIONS: This report provides evidence for a second founder effect for recurrent mutations of IL12B in Saudi Arabia.


Assuntos
Efeito Fundador , Estudos de Associação Genética , Predisposição Genética para Doença , Subunidade p40 da Interleucina-12/genética , Mutação , Infecções por Mycobacterium/etiologia , Pré-Escolar , Análise Mutacional de DNA , Exoma , Feminino , Humanos , Lactente , Masculino , Infecções por Mycobacterium/diagnóstico , Infecções por Mycobacterium/terapia , Linhagem , Arábia Saudita , Sequenciamento Completo do Exoma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA