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1.
Lancet Haematol ; 6(5): e239-e253, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30981783

RESUMO

BACKGROUND: Wiskott-Aldrich syndrome is a rare, life-threatening, X-linked primary immunodeficiency characterised by microthrombocytopenia, infections, eczema, autoimmunity, and malignant disease. Lentiviral vector-mediated haemopoietic stem/progenitor cell (HSPC) gene therapy is a potentially curative treatment that represents an alternative to allogeneic HSPC transplantation. Here, we report safety and efficacy data from an interim analysis of patients with severe Wiskott-Aldrich syndrome who received lentiviral vector-derived gene therapy. METHODS: We did a non-randomised, open-label, phase 1/2 clinical study in paediatric patients with severe Wiskott-Aldrich syndrome, defined by either WAS gene mutation or absent Wiskott-Aldrich syndrome protein (WASP) expression or a Zhu clinical score of 3 or higher. We included patients who had no HLA-identical sibling donor available or, for children younger than 5 years of age, no suitable 10/10 matched unrelated donor or 6/6 unrelated cord blood donor. After treatment with rituximab and a reduced-intensity conditioning regimen of busulfan and fludarabine, patients received one intravenous infusion of autologous CD34+ cells genetically modified with a lentiviral vector encoding for human WAS cDNA. The primary safety endpoints were safety of the conditioning regimen and safety of lentiviral gene transfer into HSPCs. The primary efficacy endpoints were overall survival, sustained engraftment of genetically corrected HSPCs, expression of vector-derived WASP, improved T-cell function, antigen-specific responses to vaccinations, and improved platelet count and mean platelet volume normalisation. This interim analysis was done when the first six patients treated had completed at least 3 years of follow-up. The planned analyses are presented for the intention-to-treat population. This trial is registered with ClinicalTrials.gov (number NCT01515462) and EudraCT (number 2009-017346-32). FINDINGS: Between April 20, 2010, and Feb 26, 2015, nine patients (all male) were enrolled of whom one was excluded after screening; the age range of the eight treated children was 1·1-12·4 years. At the time of the interim analysis (data cutoff April 29, 2016), median follow-up was 3·6 years (range 0·5-5·6). Overall survival was 100%. Engraftment of genetically corrected HSPCs was successful and sustained in all patients. The fraction of WASP-positive lymphocytes increased from a median of 3·9% (range 1·8-35·6) before gene therapy to 66·7% (55·7-98·6) at 12 months after gene therapy, whereas WASP-positive platelets increased from 19·1% (range 4·1-31·0) to 76·6% (53·1-98·4). Improvement of immune function was shown by normalisation of in-vitro T-cell function and successful discontinuation of immunoglobulin supplementation in seven patients with follow-up longer than 1 year, followed by positive antigen-specific response to vaccination. Severe infections fell from 2·38 (95% CI 1·44-3·72) per patient-year of observation (PYO) in the year before gene therapy to 0·31 (0·04-1·11) per PYO in the second year after gene therapy and 0·17 (0·00-0·93) per PYO in the third year after gene therapy. Before gene therapy, platelet counts were lower than 20 × 109 per L in seven of eight patients. At the last follow-up visit, the platelet count had increased to 20-50 × 109 per L in one patient, 50-100 × 109 per L in five patients, and more than 100 × 109 per L in two patients, which resulted in independence from platelet transfusions and absence of severe bleeding events. 27 serious adverse events in six patients occurred after gene therapy, 23 (85%) of which were infectious (pyrexia [five events in three patients], device-related infections, including one case of sepsis [four events in three patients], and gastroenteritis, including one case due to rotavirus [three events in two patients]); these occurred mainly in the first 6 months of follow-up. No adverse reactions to the investigational drug product and no abnormal clonal proliferation or leukaemia were reported after gene therapy. INTERPRETATION: Data from this study show that gene therapy provides a valuable treatment option for patients with severe Wiskott-Aldrich syndrome, particularly for those who do not have a suitable HSPC donor available. FUNDING: Italian Telethon Foundation, GlaxoSmithKline, and Orchard Therapeutics.


Assuntos
Terapia Genética , Vetores Genéticos/genética , Células-Tronco Hematopoéticas/metabolismo , Lentivirus/genética , Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/terapia , Criança , Pré-Escolar , Feminino , Terapia Genética/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Humanos , Lactente , Itália , Masculino , Mutação , Linfócitos T/imunologia , Linfócitos T/metabolismo , Condicionamento Pré-Transplante/métodos , Resultado do Tratamento , Síndrome de Wiskott-Aldrich/sangue , Síndrome de Wiskott-Aldrich/diagnóstico , Proteína da Síndrome de Wiskott-Aldrich/genética
2.
J Allergy Clin Immunol Pract ; 7(6): 1970-1985.e4, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30877075

RESUMO

BACKGROUND: Although autoimmunity and hyperinflammation secondary to recombination activating gene (RAG) deficiency have been associated with delayed diagnosis and even death, our current understanding is limited primarily to small case series. OBJECTIVE: Understand the frequency, severity, and treatment responsiveness of autoimmunity and hyperinflammation in RAG deficiency. METHODS: In reviewing the literature and our own database, we identified 85 patients with RAG deficiency, reported between 2001 and 2016, and compiled the largest case series to date of 63 patients with prominent autoimmune and/or hyperinflammatory pathology. RESULTS: Diagnosis of RAG deficiency was delayed a median of 5 years from the first clinical signs of immune dysregulation. Most patients (55.6%) presented with more than 1 autoimmune or hyperinflammatory complication, with the most common etiologies being cytopenias (84.1%), granulomas (23.8%), and inflammatory skin disorders (19.0%). Infections, including live viral vaccinations, closely preceded the onset of autoimmunity in 28.6% of cases. Autoimmune cytopenias had early onset (median, 1.9, 2.1, and 2.6 years for autoimmune hemolytic anemia, immune thrombocytopenia, and autoimmune neutropenia, respectively) and were refractory to intravenous immunoglobulin, steroids, and rituximab in most cases (64.7%, 73.7%, and 71.4% for autoimmune hemolytic anemia, immune thrombocytopenia, and autoimmune neutropenia, respectively). Evans syndrome specifically was associated with lack of response to first-line therapy. Treatment-refractory autoimmunity/hyperinflammation prompted hematopoietic stem cell transplantation in 20 patients. CONCLUSIONS: Autoimmunity/hyperinflammation can be a presenting sign of RAG deficiency and should prompt further evaluation. Multilineage cytopenias are often refractory to immunosuppressive treatment and may require hematopoietic cell transplantation for definitive management.

5.
Front Immunol ; 9: 2984, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30619340

RESUMO

B cell activation via the B cell receptor (BCR) signalosome involves participation of signaling molecules such as BTK and BLNK. Genetic defects in these molecules are known to impair B cell differentiation and subsequently lead to agammaglobulinemia. Here we identified novel mutations in BTK and BLNK in two unrelated patients that perturb the intrinsic B-cell receptor signaling pathway and lead to selective IgM deficiency, whereas production of other immunoglobulin isotypes and IgG antibody response remain intact. Currently it is unknown how BCR signaling strength affects mature B cell development in humans. Both patients show reduced levels of BCR signalosome phosphorylation as well as impaired BCR-dependent Ca2+ influx, which was accompanied by a marked decrease in IgD+IgM+CD27+ MZ-like B-cells. We further describe reduced expression of essential B cell differentiation factors such as BAFF-R and T-Bet in the patients' B-cells, which might contribute to the observed deficiency of MZ-like B cells. MZ-like B cells are known to produce natural IgM antibodies that play an essential role in immune homeostasis. By using surface plasmon resonance (SPR) technology and a synthetic blood group A trisaccharide as antigen we were able to show that both patients lack the presence of anti-blood group A IgM considered to be prototypical natural antibodies whereas IgG levels were normal. Antibody binding dynamics and binding affinity of anti-blood group A IgG were comparable between patients and healthy controls. These results indicate that human IgM deficiency can be associated with signaling defects in the BCR signalosome, defective production of natural IgM antibodies in the blood group A/B/0 system and abnormalities in B cell development.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Tirosina Quinase da Agamaglobulinemia/genética , Agamaglobulinemia/genética , Linfócitos B/imunologia , Imunoglobulina M/deficiência , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adolescente , Adulto , Tirosina Quinase da Agamaglobulinemia/metabolismo , Agamaglobulinemia/imunologia , Linfócitos B/metabolismo , Humanos , Imunoglobulina M/imunologia , Masculino , Receptores de Antígenos de Linfócitos B/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/imunologia
6.
Clin Immunol ; 183: 41-45, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28705765

RESUMO

Over the past decades, a pleiotropic spectrum of B-cell intrinsic defects leading to early onset agammaglobulinemia and absent B cells has been described. Herein we report terminal 14q32.33 deletion as a novel cause of agammaglobulinemia. We describe a 20-year old man with a 1MB terminal 14q32.33 deletion resulting in a loss of the entire Immunoglobulin heavy chain gene region of chromosome 14. The patient presented with absent serum immunoglobulin levels and absent circulating B cells since age 2. The clinical picture was dominated by severe episodes of recurrent upper respiratory tract infections. In the literature, the most prevalent features of terminal 14q32.33 deletions include mental disability, facial malformation, hypotonia, seizures, and visual problems with retinal abnormalities. Neither increased susceptibility to infections nor agammaglobulinemia have been described as a manifestation of terminal 14q32.33 deletion. Thus, our findings expand the known clinical spectrum of terminal 14q32.33 deletion to include susceptibility to infections.


Assuntos
Agamaglobulinemia/genética , Deleção Cromossômica , Cromossomos Humanos Par 14/genética , Agamaglobulinemia/imunologia , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Masculino , Adulto Jovem
7.
Eur J Immunol ; 47(11): 1959-1969, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28718914

RESUMO

Recent studies identified an emerging role of group 2 and 3 innate lymphoid cells (ILCs) as key players in the generation of T-dependent and T-independent antibody production. In this retrospective case-control study, CD117+ ILCs (including the majority of ILC2 and ILC3) were reduced in patients with common variable immunodeficiency (CVID). The reduction in CD117+ ILCs was distinctive to CVID and could not be observed in patients with X-linked agammaglobulinemia. Patients with a more pronounced reduction in CD117+ ILC numbers showed significantly lower numbers of peripheral MZ-like B cells and an increased prevalence of chronic, non-infectious enteropathy. Subsequent phenotyping of ILC subsets in CVID revealed that the reduction in CD117+ ILC numbers is due to a reduction in ILC2 numbers. In vitro expansion of CVID ILC2 in response to IL-2, IL-7, IL-25 and IL-33 was impaired. Furthermore, upregulation of MHCII and IL-2RA in response to IL-2, IL-7, IL-25 and IL-33 was impaired in CVID ILC2. Thus, our results indicate a dysregulation of ILC subsets with a reduction in ILC2 numbers in CVID, however, further studies are needed to explore whether ILC abnormalities are a primary finding or secondary to disease complications encountered in CVID.


Assuntos
Imunodeficiência de Variável Comum/imunologia , Subpopulações de Linfócitos/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/imunologia , Estudos Retrospectivos
8.
Front Immunol ; 7: 493, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27895641

RESUMO

HYPOTHESIS: Blood group antibodies are natural antibodies that develop early in life in response to cross-reactive environmental antigens in the absence of antigen encounter. Even later in life structural similarities in saccharide composition between environmental antigens such as bacterial polysaccharides and blood group A/B antigens could lead to changes in serum levels, IgM/IgG isotype, and affinity maturation of blood group anti-A/B antibodies. We addressed the question whether immunization with pneumococcal polysaccharide (PnP) vaccine Pneumo 23 Vaccine "Pasteur Merieux" (Pn23) could have such an effect in patients with type I diabetes mellitus (DM I), an autoimmune disease where an aberrant immune response to microbial antigens likely plays a role. METHODS: Anti-PnP IgM and IgG responses were determined by ELISA, and the DiaMed-ID Micro Typing System was used to screen anti-A/B antibody titer before and after Pn23 immunization in 28 healthy individuals and 16 patients with DM I. In addition, surface plasmon resonance (SPR) technology using the Biacore® device and a synthetic blood group A/B trisaccharide as the antigen was applied to investigate IgM and IgG anti-A/B antibodies and to measure antibody binding dynamics. RESULTS: All healthy individuals and DM I patients responded with anti-PnP IgM and IgG antibody production 4-6 weeks after Pn23 immunization, while no increase in blood group anti-A/B antibody titer was observed when measured by the DiaMed-ID Micro Typing System. Interestingly, isotype-specific testing by SPR technology revealed an increase in blood group anti-A/B IgG, but not IgM, following Pn23 immunization in both patients and controls. No change in binding characteristics of blood group anti-A/B antibodies could be detected following Pn23 vaccination, supporting the assumption of an increase in IgG antibody titer with no or very little affinity maturation. CONCLUSION: The study provides evidence for epitope sharing between pneumococcal polysaccharides and blood group ABO antigens, which leads to a booster of blood group anti-A/B antibodies of the IgG isotype after Pn23 immunization in healthy individuals. Manifest autoimmunity such as present in DM I patients has no additional effect on the cross-reactive antibody response against pneumococcal polysaccharides and blood group antigens.

9.
BMC Microbiol ; 16: 13, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26830934

RESUMO

BACKGROUND: Nosocomial infections caused by the bacterial pathogen Staphylococcus aureus can lead to serious complications due to the varying presence of secreted toxins. Comparative studies of genomic information and production rates are needed to assess the pathogenic potential of isolated strains. Genotypic and phenotypic profiling of clinical and colonising isolates of S. aureus was used to characterise the release of exotoxins. Blood isolates were compared with colonisation strains to determine similarities and differences of single strains and clusters. RESULTS: Fifty-one fresh isolates obtained from colonised individuals (n = 29) and S. aureus bacteremia (SAB) patients (n = 22) were investigated. The prevalence of genes encoding for three cytolysins (alpha/beta/gamma toxin) and twenty-four superantigens (SEA-SElX) was determined. Isolates exhibited eighteen distinct combinations of superantigens. Sequence analysis identified mutated open reading frames in hla in 13.7% of all strains, in selw (92.2%) and in selx (15.7%). All corrupted genes were associated with specific clonal complexes. Functional assessment of alpha toxin activity by a rabbit erythrocyte lysis assay revealed that supernatants lacking alpha toxin still displayed hemolysis. This was due to the presence of gamma toxin, as proven by inhibition experiments using antisera raised against the respective recombinant proteins. Alpha toxin, SEC, and TSST1 production was quantified by enzyme-linked immunosorbent assays on supernatants of all hla, sec, and tst positive isolates. Blood isolates and colonising strains showed comparable amounts of secreted proteins within a wide range. Agr types I to IV were identified, but did not allow a prediction of high or low production rates. In contrast, alpha toxin production rates between distinct clonal complexes clearly differed. Spa typing was performed and revealed thirty-two unique spa gene patterns and eight small clusters comprising nineteen isolates. Recognised spa-typing clusters displayed highly similar production rates. CONCLUSION: Production rates of the three most prevalent exotoxins varied within both groups of blood isolates and colonising strains. By comparing genotypes and secretion, we found that identical complex gene patterns did not allow predictions of toxin production and function. However, identification of spa typing clusters was suitable to predict similar quantities of released exotoxins.


Assuntos
Proteínas de Bactérias/genética , Toxinas Bacterianas/metabolismo , Hemolíticos/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Animais , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/toxicidade , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Genótipo , Hemolíticos/toxicidade , Humanos , Fenótipo , Coelhos , Staphylococcus aureus/classificação , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/metabolismo
10.
Immunotherapy ; 7(12): 1273-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26289364

RESUMO

Vaccination has been an important healthcare measure in preventing infectious diseases. The response to vaccination is reduced in immunocompromised patients, primary immune deficiency (PID) and secondary immune deficiency (SID), but vaccination studies still demonstrated a protective effect resulting in reducing complications, hospitalization, treatment costs and even mortality. The primary physician and the specialist directing patient care are responsible for vaccination. Live vaccines are contraindicated in patients with severe immune impairment, killed vaccines are highly recommended in PID and SID. Criteria have been defined to distinguish high- or low-level immune impairment in the different disease entities among PID and SID patients. For patients who do not respond to diagnostic vaccination as characterized by antibody failure immunoglobulin replacement is the mainstay of therapy.


Assuntos
Controle de Doenças Transmissíveis/normas , Hospedeiro Imunocomprometido/imunologia , Síndromes de Imunodeficiência/complicações , Síndromes de Imunodeficiência/imunologia , Vacinação/normas , Doenças Autoimunes/imunologia , Contraindicações , Pessoal de Saúde , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Neoplasias/imunologia , Transplante de Órgãos/efeitos adversos , Guias de Prática Clínica como Assunto , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Vacinas Vivas não Atenuadas/administração & dosagem , Vacinas Vivas não Atenuadas/imunologia
11.
PLoS One ; 10(7): e0133220, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26186701

RESUMO

Loss of function mutations in the recombination activating genes RAG1 and RAG2 have been reported to cause a T-B-NK+ type of severe combined immunodeficiency. In addition identification of hypomorphic mutations in RAG1 and RAG2 has led to an expansion of the spectrum of disease to include Omenn syndrome, early onset autoimmunity, granuloma, chronic cytomegalovirus- or EBV-infection with expansion of gamma/delta T-cells, idiophatic CD4 lymphopenia and a phenotype resembling common variable immunodeficiency. Herein we describe a novel presentation of leaky RAG1 and RAG2 deficiency in two unrelated adult patients with impaired antibody production against bacterial polysaccharide antigens. Clinical manifestation included recurrent pneumonia, sinusitis, otitis media and in one patient recurrent cutaneous vasculitis. Both patients harbored a combination of a null mutation on one allele with a novel hypomorphic RAG1/2 mutation on the other allele. One of these novel mutations affected the start codon of RAG1 and resulted in an aberrant gene and protein expression. The second novel RAG2 mutation leads to a truncated RAG2 protein, lacking the C-terminus with intact core RAG2 and reduced VDJ recombination capacity as previously described in a mouse model. Both patients presented with severely decreased numbers of naïve CD4+ T cells and defective T independent IgG responses to bacterial polysaccharide antigens, while T cell-dependent IgG antibody formation e.g. after tetanus or TBEV vaccination was intact. In conclusion, hypomorphic mutations in genes responsible for SCID should be considered in adults with predominantly antibody deficiency.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Homeodomínio/genética , Síndromes de Imunodeficiência/genética , Mutação , Proteínas Nucleares/genética , Adulto , Linfócitos T CD4-Positivos/imunologia , Proteínas de Ligação a DNA/metabolismo , Feminino , Proteínas de Homeodomínio/metabolismo , Humanos , Síndromes de Imunodeficiência/diagnóstico , Lipopolissacarídeos/imunologia , Proteínas Nucleares/metabolismo
12.
Front Immunol ; 6: 211, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25999949

RESUMO

BACKGROUND: Common variable immunodeficiency (CVID) is the most common clinically severe primary immunodeficiency and comprises a heterogeneous group of patients with recurrent severe bacterial infections due to the failure to produce IgG antibodies after exposure to infectious agents and immunization. Diagnostic recommendations for antibody failure include assessment of isoagglutinins. We have readdressed this four decades old but still accepted recommendation with up to date methodology. METHODS: Anti-A/B IgM- and IgG-antibodies were measured by Diamed-ID Micro Typing, surface plasmon resonance (SPR) using the Biacore(®) device and flow cytometry. RESULTS: When Diamed-ID Micro Typing was used, CVID patients (n = 34) showed IgG- and IgM-isoagglutinins that were comparable to healthy volunteers (n = 28), while all XLA patients (n = 8) had none. Anti-A/B IgM-antibodies were present in more than 2/3 of the CVID patients and showed binding kinetics comparable to anti-A/B IgM-antibodies from healthy individuals. A correlation could be found in CVID patients between levels of anti-A/B IgM-antibodies and levels of serum IgM and PnP-IgM-antibodies. In contrast in CVID patients as a group ABO antibodies were significantly decreased when assessed by SPR, which correlated with levels of switched memory, non-switched memory and naïve B cells, but all CVID patients had low/undetectable anti-A/B IgG-antibodies. CONCLUSION: These results indicate that conventional isoagglutinin assessment and assessment of anti-A/B IgM antibodies are not suited for the diagnosis of impaired antibody production in CVID. Examination of anti-A/B IgG antibodies by SPR provides a useful method for the diagnosis of IgG antibody failure in all CVID patients studied, thus indicating an important additional rationale to start immunoglobulin replacement therapy early in these patients, before post-infectious sequelae develop.

13.
Front Immunol ; 6: 32, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25699049

RESUMO

Hypogammaglobulinemia (serum IgG lower than 2 SD below the age-matched mean) and clinical symptoms such as increased susceptibility to infection, autoimmune manifestations, granulomatous disease, and unexplained polyclonal lymphoproliferation are considered to be diagnostic hallmarks in patients with common variable immunodeficiency (CVID), the most frequent clinically severe primary immunodeficiency syndrome. In the present study, we investigated patients with hypogammaglobulinemia and no clinical or immunological signs of defective cell-mediated immunity and differentiated two groups on the basis of their IgG antibody formation capacity against a variety of different antigens (bacterial toxins, polysaccharide antigens, viral antigens). Patients with hypogammaglobulinemia and intact antibody production (HIAP) displayed no or only mild susceptibility to infections, while CVID patients showed marked susceptibility to bacterial infections that normalized following initiation of IVIG or subcutaneous immunoglobulin replacement therapy. There was a substantial overlap in IgG serum levels between the asymptomatic HIAP group and the CVID patients examined before immunoglobulin treatment. HIAP patients showed normal levels of switched B-memory cells (CD19(+)CD27(+)IgD(-)), while both decreased and normal levels of switched B-memory cells could be found in CVID patients. IgG antibody response to a primary antigen, tick-borne encephalitis virus (TBEV), was defective in CVID patients, thus confirming their substantial defect in IgG antibody production. Defective IgG antibody production against multiple antigens could also be demonstrated in an adult patient with recurrent infections but normal IgG levels. To facilitate early treatment before recurrent infections may lead to organ damage, the antibody formation capacity should be examined in hypogammaglobulinemic patients and the decision to treat should be based on the finding of impaired IgG antibody production.

14.
J Clin Immunol ; 34(8): 941-53, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25205547

RESUMO

PURPOSE: Idiopathic CD4 lymphopenia constitutes a heterogeneous group of immunodeficiencies with characteristically low CD4+ T-cell counts with largely unknown genetic etiology. We here sought to determine the underlying molecular cause in an index family with two patients suffering from combined immunodeficiency that evolved into predominant CD4+ lymphopenia. The more severely affected index patient also presented with selective antibody deficiency against bacterial polysaccharide antigens. METHODS: For the genetic analysis, we used combined homozygosity mapping and exome sequencing. Functional assays included immunoblot analysis, flow cytometry and TCR Vß spectratyping. RESULTS: A novel homozygous missense mutation was revealed in the kinase domain of JAK3 (c.T3196C, p.Cys1066Arg). Further analysis showed revertant chimerism in CD8+ T-cells in both patients. The additional presence of revertant CD4+ T-cells was associated with a milder clinical and immunological phenotype in the second patient, although the role somatic chimerism plays in amelioration of disease phenotype is uncertain, as presence of revertant cells had no effect on residual CD4 cell JAK3 signaling function. Residual activity of JAK3-dependent STAT3 and STAT5 signaling was also found in immortalized B-cell lines indicating a hypomorphic nature of the described mutation which likely contributes to the milder clinical phenotype. CONCLUSIONS: We here present the first case of revertant mosaicism in JAK3 deficiency, manifesting as combined immunodeficiency evolving into predominant CD4+ lymphopenia. Revertant chimerism or hypomorphic mutations in genes typically associated with more severe T-cell deficiency should be considered when assessing patients with milder forms of combined immunodeficiencies.


Assuntos
Linfócitos T CD4-Positivos , Janus Quinase 3/genética , Linfopenia , Imunodeficiência Combinada Severa , Adolescente , Adulto , Sequência de Aminoácidos , Linfócitos T CD4-Positivos/imunologia , Células Cultivadas , Criança , Pré-Escolar , Quimerismo , Feminino , Humanos , Imunoglobulinas/sangue , Lactente , Janus Quinase 3/metabolismo , Linfopenia/genética , Masculino , Dados de Sequência Molecular , Mutação , Fator de Transcrição STAT5/metabolismo , Alinhamento de Sequência , Transdução de Sinais/genética
15.
Toxins (Basel) ; 6(6): 1724-41, 2014 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-24887085

RESUMO

Toxic shock syndrome (TSS) results from the host's overwhelming inflammatory response and cytokine storm mainly due to superantigens (SAgs). There is no effective specific therapy. Application of immunoglobulins has been shown to improve the outcome of the disease and to neutralize SAgs both in vivo and in vitro. However, in most experiments that have been performed, antiserum was either pre-incubated with SAg, or both were applied simultaneously. To mirror more closely the clinical situation, we applied a multiple dose (over five days) lethal challenge in a rabbit model. Treatment with toxic shock syndrome toxin 1 (TSST-1) neutralizing antibody was fully protective, even when administered late in the course of the challenge. Kinetic studies on the effect of superantigen toxins are scarce. We performed in vitro kinetic studies by neutralizing the toxin with antibodies at well-defined time points. T-cell activation was determined by assessing T-cell proliferation (3H-thymidine incorporation), determination of IL-2 release in the cell supernatant (ELISA), and IL-2 gene activation (real-time PCR (RT-PCR)). Here we show that T-cell activation occurs continuously. The application of TSST-1 neutralizing antiserum reduced IL-2 and TNFα release into the cell supernatant, even if added at later time points. Interference with the prolonged stimulation of proinflammatory cytokines is likely to be in vivo relevant, as postexposure treatment protected rabbits against the multiple dose lethal SAg challenge. Our results shed new light on the treatment of TSS by specific antibodies even at late stages of exposure.


Assuntos
Anticorpos Neutralizantes/uso terapêutico , Antitoxinas/uso terapêutico , Toxinas Bacterianas/antagonistas & inibidores , Modelos Animais de Doenças , Enterotoxinas/antagonistas & inibidores , Choque Séptico/tratamento farmacológico , Animais , Anticorpos Neutralizantes/farmacologia , Antitoxinas/farmacologia , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/toxicidade , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Enterotoxinas/genética , Enterotoxinas/metabolismo , Enterotoxinas/toxicidade , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-2/genética , Interleucina-2/metabolismo , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Masculino , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/metabolismo , Proteínas Mutantes/toxicidade , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/toxicidade , Choque Séptico/etiologia , Choque Séptico/imunologia , Choque Séptico/metabolismo , Superantígenos/genética , Superantígenos/metabolismo , Superantígenos/toxicidade , Análise de Sobrevida , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Toxicocinética , Fator de Necrose Tumoral alfa/metabolismo
16.
Rev Med Chil ; 137(1): 94-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19399328

RESUMO

The association of Down syndrome with mannose-binding lectin (MBL)-deficiency, recurrent infections and vasculitis has not been reported. We report a 30 year-old female with Down-syndrome associated with MBL-deficiency with the genotype LXA/HYD, IgG-deficiency, recurrent uro-genital infections, cutaneous vasculitis, G20.210A prothrombin mutation, deep venous thrombosis, and pulmonary embolism. MBL-deficiency in combination with IgG deficiency might have favored the development of recurrent uro-genital infections. Immunodeficiency might be also involved in the pathogenesis of cutaneous vasculitis. Deep venous thrombosis and pulmonary embolism were attributed to the genetically determined prothrombotic state and intake of oral contraceptives.


Assuntos
Síndrome de Down/complicações , Deficiência de IgG , Lectina de Ligação a Manose/deficiência , Protrombina/genética , Vasculite/etiologia , Adulto , Feminino , Humanos
17.
Rev. méd. Chile ; 137(1): 94-97, ene. 2009. tab
Artigo em Inglês | LILACS | ID: lil-511850

RESUMO

The association of Down syndrome with mannose-binding lectin (MBL)-deficiency, recurrent infections and vasculitis has not been reponed. We repon a 30 year-old female with Down-syndrome associated with MBL-deficiency with the genotype LXA/HYD, IgG-deficiency, recurrent uro-genital infections, cutaneous vasculitis, G20.210A prothrombin mutation, deep venous thrombosis, and pulmonary embolism. MBL-deficiency in combination with IgG deficiency might have favored the development of recurrent uro-genital infections. Immunodeficiency might be also involved in the pathogenesis of cutaneous vasculitis. Deep venous thrombosis and pulmonary embolism were attributed to the genetically determined prothrombotic state and intake of oral contraceptives.


La asociación de síndrome de Down con deficiencia de lectina de unión a manosa, infecciones recurrentes y vasculitis no ha sido informada. Presentamos una mujer de 30 años de edad con síndrome de Down asociado a deficiencia de lectina de unión a mañosa, con el genotipo LXA/HYD, deficiencia de IgG, infecciones urogenitales recurrentes, vasculitis cutánea, mutación de protrombina G20.210A, trombosis venosa profunda y embolia pulmonar. La deficiencia de lectina de unión a manosa combinada con la deficiencia de IgG puede haber favorecido las infecciones urogenitales recurrentes. La inmunodeficiencia puede también tener relación con la patogenia de la vasculitis cutánea. La trombosis venosa profunda y la embolia pulmonar pueden deberse al estado protrombótico derivado de la mutación de protrombina y el uso de contraceptivos orales.


Assuntos
Adulto , Feminino , Humanos , Síndrome de Down/complicações , Deficiência de IgG , Lectina de Ligação a Manose/deficiência , Protrombina/genética , Vasculite/etiologia
18.
AIDS ; 21(16): 2161-70, 2007 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-18090042

RESUMO

BACKGROUND: The broadly neutralizing recombinant human HIV-1 antibodies 4E10, 2F5 and Igh1b12 are reported to have autoreactive potential, which is significant for HIV-1 vaccine development and passive immunotherapy using these antibodies. OBJECTIVE: To investigate the clinical relevance of these findings in subjects receiving passive immunotherapy with these antibodies. METHODS: Four types of investigations were performed: (1) Investigation of clotting parameters in an ongoing clinical study with 4E10, 2F5 and 2G12. (2) Mixing experiments of pooled plasma with the same antibodies. (3) Retrospective analysis of serum from patients who received passive immunotherapy with 4E10, 2F5 and 2G12 either alone or in combination. (4) Assessment of clinical safety data obtained after 418 infusions with these antibodies. RESULTS: Standard clinical assays confirmed that 4E10 showed low-level cross-reactivity with cardiolipin, while previously reported cardiolipin cross-reactivity for 2F5 could not be confirmed. High serum titers of 4E10 induced mild prolongation of the activated partial thromboplastin time, which resolved with the wash out of 4E10. Neither 2F5 nor 2G12 affected coagulation. Repeated high-dose infusions of the monoclonal antibody combination were well tolerated with no incidence for thrombotic complications after 418 infusions in 39 subjects. CONCLUSIONS: Monoclonal antibody 4E10 but not 2F5 or 2G12 showed autoreactive binding specificities. Infusion of 4E10 resulted in transient low anticardiolipin titers. Although an increased thromboembolic risk cannot definitely be excluded, this risk appears to be low and likely depend on underlying disorders.


Assuntos
Anticorpos Anti-HIV/administração & dosagem , Imunização Passiva/efeitos adversos , Fatores Imunológicos/administração & dosagem , Adulto , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Especificidade de Anticorpos , Testes de Coagulação Sanguínea , Cardiolipinas/imunologia , Ensaios Clínicos como Assunto , Reações Cruzadas , Relação Dose-Resposta Imunológica , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Ensaio de Imunoadsorção Enzimática , Feminino , Anticorpos Anti-HIV/imunologia , Humanos , Imunização Passiva/métodos , Fatores Imunológicos/imunologia , Recém-Nascido , Masculino , Fosfatidilserinas/imunologia , Protrombina/imunologia
19.
J Allergy Clin Immunol ; 120(5): 1193-200, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17825894

RESUMO

BACKGROUND: Patients with common variable immunodeficiency have defective T-cell activation after stimulation via T-cell receptor (TCR)/CD28 or by recall antigens. OBJECTIVE: In the current study, we investigated whether TNF-receptor 2 (RII) costimulation, which is important for sufficient TCR/CD28 stimulation, was significantly impaired in common variable immunodeficiency (CVID). METHODS: We studied T-cell activation events such as CD69 induction, calcium flux through store operated calcium channels, protein kinase C-theta translocation, and costimulation via TNF-RII compared with costimulation via CD28. RESULTS: By measuring TNF receptor-associated factor 1 expression, which is induced by TCR alone and can be upregulated by either CD28 or TNF-RII costimulation, we show that costimulation via CD28 is intact, whereas costimulation via TNF-RII in these patients is impaired. The ras-activation pathway as tested by CD69 induction, calcium flux through store operated calcium channels, and protein kinase C-theta translocation were comparable in CVID and control T cells. CONCLUSION: Taken together, these data indicate that the primary TCR signal as well as the signal derived from CD28 are normal but that TNF-RII-supported TCR costimulation is defective, most likely leading to impairment of an important amplification loop, such as TNF-RII augmented nuclear factor-kappaB activation. CLINICAL IMPLICATIONS: The finding of defective TNF-RII cosignaling in patients with CVID may help to define the activation pathway affected, thus potentially leading to a characterization of the molecular defect and molecular diagnosis in at least some of these patients.


Assuntos
Imunodeficiência de Variável Comum/imunologia , Receptores Tipo II do Fator de Necrose Tumoral/fisiologia , Linfócitos T/imunologia , Adulto , Idoso , Antígenos CD28/fisiologia , Sinalização do Cálcio , Feminino , Humanos , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Proteína Quinase C/metabolismo , Transporte Proteico , Receptores Tipo II do Fator de Necrose Tumoral/agonistas , Proteínas ras/metabolismo
20.
Cell Immunol ; 237(1): 55-67, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16325164

RESUMO

Chronic exposure to TNF-alpha has been shown to impair T cell-activation in mice and in humans. In the present study, we investigated a possible role of TNF-RII in this long-term effect of TNF-alpha. Chronic TNF-alpha exposure led to suppression of subsequent TCR stimulation (e.g., TCR/CD28-induced proliferation, cytokine production (IFN-gamma, TNF-alpha)) but left TCR independent restimulation unaffected. Activation of T cells during TNF-alpha exposure was required for the inhibitory effect on TCR stimulation. In contrast to the mouse model, the inhibitory effect of long-term TNF-alpha exposure was mediated via TNF-RII but not TNF-receptor I, and surface expression of the TCR/CD3 complex remained unchanged. Chronic TNF-RII triggering downregulated T cell activation at an early level, as TCR-induced calcium flux and IL-2 mRNA expression were impaired after preculture in the presence of anti-TNF-RII mAbs. Furthermore, chronic TNF-RII-stimulation specifically downregulated store operated calcium channels, which contribute to sustained TCR-induced calcium influx.


Assuntos
Ativação Linfocitária/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores Tipo II do Fator de Necrose Tumoral/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/imunologia , Antígenos CD28/imunologia , Cálcio/metabolismo , Regulação para Baixo , Citometria de Fluxo , Humanos , Interleucina-2/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Fator de Necrose Tumoral alfa/metabolismo
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