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1.
Blood Transfus ; 2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37677093

RESUMO

BACKGROUND: Immune thrombocytopenia (ITP) is an acquired immune-mediated bleeding disorder characterized by isolated thrombocytopenia. Its estimated yearly incidence in the pediatric population is 1.9-6.4/100,000. ITP in children is usually a self-limiting and benign disorder. The clinical management of children with ITP often remains controversial, as robust randomized trials on the management of this disorder are lacking. Treatments vary widely in clinical practice and existing guidelines from hematology societies on clinical management offer indications based largely on expert opinion rather than strong evidence. MATERIALS AND METHODS: The Coagulative Disorder Working Group of the Italian Association of Pediatric Hematology and Oncology (AIEOP) developed this document to collect shared expert opinions on the management of newly diagnosed ITP, updating previous guidelines and providing recommendations to pediatricians. Each statement has been given a score expressing the strength of evidence, appropriateness and agreement among participants. RESULTS: Clear-cut definitions of the clinical phases of the disease and clinical response are stated. Recommendations are given regarding the classification of bleeding symptoms, evaluation of bleeding risk, diagnosis, and prognostic factors. Specific recommendations for treatment include indications for first-line (intravenous immunoglobulins, steroids) and second-line (combined therapy, thrombopoietin receptor agonists, immunosuppressive drugs, rituximab) therapeutic agents, as well as hemorrhagic emergency and supportive treatment, including emergency splenectomy. The optimal follow-up schedule, the relation between ITP and vaccines and health-related quality-of-life issues are also discussed. DISCUSSION: The panel achieved broad consensus on issues related to how to treat children with newly diagnosed ITP, providing a comprehensive review of all relevant clinical aspects.

2.
Blood Transfus ; 18(5): 396-405, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32931416

RESUMO

BACKGROUND: The aim of the present study was to assess management strategies for immune thrombocytopenia (ITP) among Italian paediatric haematologists, and to compare these with those of recent international guidelines. Predictors of early remission or disease chronicity were also evaluated. MATERIALS AND METHODS: During a period of 1 year, 205 children (age: 1 month-18 years) with newly diagnosed ITP were prospectively enrolled by 16 centres belonging to the Italian Association of Paediatric Haematology and Oncology (AIEOP). We collected the subjects demographic data, history, clinical symptoms, platelet count and treatment at presentation and at subsequent visits. RESULTS: Of the 205 patients, 47 (23%) were initially managed with a wait-and-see approach. Compared to these patients, children administered platelet-enhancing therapies were significantly younger (median age: 4.75 vs 7.96 years; p<0.001) and had lower platelet counts. At the 3-month follow-up, 92/202 patients (46%) had persistent ITP. Recovery within 3 months was predicted by younger median age (5.3 vs 7.8 years; p<0.001), and recent viral infection (p<0.001) . At 1 year, 56 patients had chronic ITP, which was associated with older median age (7.54 vs 5.35 years; p<0.001), and a family history of autoimmunity (p<0.05; relative risk: 1.81; 95% confidence interval: 1.09-2.98). In total, 357 pharmacological treatments were recorded (216 intravenous immunoglobulins, 80 steroids). Response to intravenous immunoglobulins did not have an effect on remission rate at 12 months. DISCUSSION: Pediatric hematologists in Italian Centre treat over three-quarters of patients with newly diagnosed ITP, despite recent international guidelines. Almost 80% of patients with mild clinical symptoms received pharmacological treatment at diagnosis, which was significantly associated with younger age. Chronicity at 12 months was not affected by different therapeutic approaches at diagnosis or response to therapy.


Assuntos
Fidelidade a Diretrizes , Imunoglobulinas Intravenosas/administração & dosagem , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Imunoglobulinas Intravenosas/efeitos adversos , Lactente , Itália , Masculino , Contagem de Plaquetas , Guias de Prática Clínica como Assunto , Estudos Prospectivos , Púrpura Trombocitopênica Idiopática/sangue , Púrpura Trombocitopênica Idiopática/tratamento farmacológico
3.
Blood Transfus ; 18(2): 143-151, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31657709

RESUMO

Emicizumab has been approved in several countries for regular prophylaxis in patients with congenital haemophilia A and FVIII inhibitors because it substantially reduces their bleeding risk and improves quality of life. However, although significantly less frequent, some breakthrough bleeds may still occur while on emicizumab, requiring treatment with bypassing or other haemostatic agents. Thrombotic complications have been reported with the associated use of activated prothrombin complex concentrates. In addition, when surgery/invasive procedures are needed while on emicizumab, their management requires multidisciplinary competences and direct supervision by experts in the use of this agent. Given this, and in order to expand the current knowledge on the use of emicizumab and concomitant haemostatic agents, and reduce the risk of complications in this setting, the Italian Association of Haemophilia Centres (AICE) here provides guidance on the management of breakthrough bleeds and surgery in emergency situations in patients with haemophilia A and inhibitors on emicizumab prophylaxis. This paper has been shared with other National Scientific Societies involved in the field.


Assuntos
Anticorpos Biespecíficos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Hemofilia A/prevenção & controle , Hemostáticos/uso terapêutico , Anticorpos Biespecíficos/efeitos adversos , Anticorpos Monoclonais Humanizados/efeitos adversos , Fator VIII/antagonistas & inibidores , Hemorragia/prevenção & controle , Hemostáticos/efeitos adversos , Humanos , Itália , Qualidade de Vida
4.
J Pediatr Hematol Oncol ; 41(4): 275-279, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30640822

RESUMO

OBJECTIVE OF THE STUDY: In this study we aimed to retrospectively evaluate how centers, belonging to the Associazione Italiana Ematologia e Oncologia Pediatrica (AIEOP), manage severe acquired hypofibrinogenemia in children with acute lymphoblastic leukemia, particularly evaluating the therapeutic role of human fibrinogen concentrate (HFC) and fresh frozen plasma (FFP). METHODS: We conducted a survey among AIEOP centers; thereafter, we collected and analyzed data with regard to the treatment of episodes of severe acquired hypofibrinogenemia occurring during the induction and reinduction phases of the AIEOP-BFM ALL 2009 protocol. RESULTS: In total, 15 of the 37 AIEOP centers invited to join the survey agreed to collect the data, with 10 and 5 centers declaring to react to severe acquired hypofibrinogenemia (<70 mg/dL) by administering HFC or FFP, respectively. Of the 150 episodes of severe hypofibrinogenemia occurring in 101 patients, 47.3% were treated with HFC and 52.7% with FFP, with a normalization of fibrinogen levels achieved in greater proportion and in a shorter amount of time in the HFC group as compared with the FFP group. None of the patients presented with bleeding or thrombosis during the observation period. CONCLUSIONS: Even with the limitations of the retrospective nature of this study, HFC seems to be a safe and effective alternative to FFP for replacement therapy in case of severe hypofibrinogenemia in children with acute lymphoblastic leukemia.


Assuntos
Afibrinogenemia/tratamento farmacológico , Fibrinogênio/uso terapêutico , Plasma , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Adolescente , Afibrinogenemia/induzido quimicamente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos
5.
mSphere ; 3(6)2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30541782

RESUMO

Several immunodeficiencies are associated with high susceptibility to persistent and progressive human papillomavirus (HPV) infection leading to a wide range of cutaneous and mucosal lesions. However, the HPV types most commonly associated with such clinical manifestations in these patients have not been systematically defined. Here, we used virion enrichment, rolling circle amplification, and deep sequencing to identify circular DNA viruses present in skin swabs and/or wart biopsy samples from 48 patients with rare genetic immunodeficiencies, including patients with warts, hypogammaglobulinemia, infections, myelokathexis (WHIM) syndrome, or epidermodysplasia verruciformis (EV). Their profiles were compared with the profiles of swabs from 14 healthy adults and warts from 6 immunologically normal children. Individual patients were typically infected with multiple HPV types; up to 26 different types were isolated from a single patient (multiple anatomical sites, one time point). Among these, we identified the complete genomes of 83 previously unknown HPV types and 35 incomplete genomes representing possible additional new types. HPV types in the genus Gammapapillomavirus were common in WHIM patients, whereas EV patients mainly shed HPVs from the genus Betapapillomavirus. Preliminary evidence based on three WHIM patients treated with plerixafor, a leukocyte mobilizing agent, suggest that longer-term therapy may correlate with decreased HPV diversity and increased predominance of HPV types associated with childhood skin warts.IMPORTANCE Although some members of the viral family Papillomaviridae cause benign skin warts (papillomas), many human papillomavirus (HPV) infections are not associated with visible symptoms. For example, most healthy adults chronically shed Gammapapillomavirus (Gamma) virions from apparently healthy skin surfaces. To further explore the diversity of papillomaviruses, we performed viromic surveys on immunodeficient individuals suffering from florid skin warts. Our results nearly double the number of known Gamma HPV types and suggest that WHIM syndrome patients are uniquely susceptible to Gamma HPV-associated skin warts. Preliminary results suggest that treatment with the drug plerixafor may promote resolution of the unusual Gamma HPV skin warts observed in WHIM patients.


Assuntos
DNA Viral/genética , Síndromes de Imunodeficiência/complicações , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , DNA Viral/química , Feminino , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Metagenômica , Pessoa de Meia-Idade , Mucosa/virologia , Técnicas de Amplificação de Ácido Nucleico , Papillomaviridae/genética , Pele/virologia , Adulto Jovem
7.
Blood Transfus ; 15(3): 259-267, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28151390

RESUMO

Autoimmune haemolytic anaemia is an uncommon disorder to which paediatric haematology centres take a variety of diagnostic and therapeutic approaches. The Red Cell Working Group of the Italian Association of Paediatric Onco-haematology (Associazione Italiana di Ematologia ed Oncologia Pediatrica, AIEOP) developed this document in order to collate expert opinions on the management of newly diagnosed childhood autoimmune haemolytic anaemia.The diagnostic process includes the direct and indirect antiglobulin tests; recommendations are given regarding further diagnostic tests, specifically in the cases that the direct and indirect antiglobulin tests are negative. Clear-cut definitions of clinical response are stated. Specific recommendations for treatment include: dosage of steroid therapy and tapering modality for warm autoimmune haemolytic anaemia; the choice of rituximab as first-line therapy for the rare primary transfusion-dependent cold autoimmune haemolytic anaemia; the indications for supportive therapy; the need for switching to second-line therapy. Each statement is provided with a score expressing the level of appropriateness and the agreement among participants.


Assuntos
Anemia Hemolítica Autoimune/diagnóstico , Anemia Hemolítica Autoimune/terapia , Anemia Hemolítica Autoimune/induzido quimicamente , Anemia Hemolítica Autoimune/epidemiologia , Transfusão de Sangue/métodos , Criança , Teste de Coombs/métodos , Gerenciamento Clínico , Hematologia/métodos , Humanos , Imunoglobulina M/análise , Itália/epidemiologia , Pediatria/métodos , Sociedades Médicas , Esteroides/uso terapêutico
8.
Sci Rep ; 7: 40136, 2017 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-28074903

RESUMO

Adenosine Deaminase (ADA) deficiency is an autosomal recessive variant of severe combined immunodeficiency (SCID) caused by systemic accumulation of ADA substrates. Neurological and behavioral abnormalities observed in ADA-SCID patients surviving after stem cell transplantation or gene therapy represent an unresolved enigma in the field. We found significant neurological and cognitive alterations in untreated ADA-SCID patients as well as in two groups of patients after short- and long-term enzyme replacement therapy with PEG-ADA. These included motor dysfunction, EEG alterations, sensorineural hypoacusia, white matter and ventricular alterations in MRI as well as a low mental development index or IQ. Ada-deficient mice were significantly less active and showed anxiety-like behavior. Molecular and metabolic analyses showed that this phenotype coincides with metabolic alterations and aberrant adenosine receptor signaling. PEG-ADA treatment corrected metabolic adenosine-based alterations, but not cellular and signaling defects, indicating an intrinsic nature of the neurological and behavioral phenotype in ADA deficiency.


Assuntos
Adenosina Desaminase/deficiência , Adenosina/metabolismo , Encéfalo/metabolismo , Doenças do Sistema Nervoso/fisiopatologia , Animais , Comportamento , Comportamento Animal , Humanos , Camundongos , Doenças do Sistema Nervoso/patologia
9.
J Clin Immunol ; 35(7): 624-37, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26376800

RESUMO

PURPOSE: We carried out a retrospective analysis of 27 patients with Adenosine Deaminase (ADA) deficiency diagnosed in a single center from 1997 to the 2013, for evaluating whether data regarding types of disease-inducing mutations, biochemical and immunological features as well as clinical outcomes of patients treated with enzyme replacement or transplantation, were comparable to those obtained in multicenter studies. METHODS: The ADA deficiency diagnosis was performed with biochemical, immunological and molecular techniques. Ten patients treated with hematopoietic stem cell transplantation and three in treatment with enzyme replacement were followed up in our center. RESULTS: Twenty-four different mutations were identified and five were not previously reported. Identical mutations were found among patients from the same Romani ethnic group or from the same geographical region. A more rapid recovery was observed in enzyme replacement treated patients in comparison with those transplanted that, however, showed a continuous and long-lasting improvement both in terms of immune and metabolic recovery. CONCLUSION: The data obtained in our single center are comparable with those that have been reported in multicenter surveys.


Assuntos
Adenosina Desaminase/deficiência , Adenosina Desaminase/metabolismo , Agamaglobulinemia/diagnóstico , Terapia de Reposição de Enzimas , Terapia Genética , Transplante de Células-Tronco Hematopoéticas , Imunodeficiência Combinada Severa/diagnóstico , Adenosina Desaminase/genética , Agamaglobulinemia/epidemiologia , Agamaglobulinemia/terapia , Pré-Escolar , Consanguinidade , Análise Mutacional de DNA , Feminino , Seguimentos , Humanos , Lactente , Itália , Masculino , Mutação/genética , Estudos Retrospectivos , Roma (Grupo Étnico) , Imunodeficiência Combinada Severa/epidemiologia , Imunodeficiência Combinada Severa/terapia , Resultado do Tratamento
10.
Br J Haematol ; 169(4): 584-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25716342

RESUMO

Sporadic essential thrombocythaemia (ET) is rare in paediatrics, and the diagnostic and clinical approach to paediatric cases cannot be simply copied from experience with adults. Here, we assessed 89 children with a clinical diagnosis of ET and found that 23 patients (25·8%) had a clonal disease. The JAK2 V617F mutation was identified in 14 children, 1 child had the MPL W515L mutation, and 6 had CALR mutations. The monoclonal X-chromosome inactivation pattern was seen in six patients (two with JAK2 V617F and two with CALR mutations). The other 66 patients (74·2%) had persistent thrombocytosis with no clonality. There were no clinical or haematological differences between the clonal and non-clonal patients. The relative proportion of ET-specific mutations in the clonal children was much the same as in adults. The higher prevalence of non-clonal cases suggests that some patients may not have myeloproliferative neoplasms, with significant implications for their treatment.


Assuntos
Neoplasias Hematológicas/genética , Janus Quinase 2/genética , Mutação de Sentido Incorreto , Proteínas de Neoplasias/genética , Trombocitemia Essencial/genética , Adolescente , Adulto , Substituição de Aminoácidos , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Neoplasias Hematológicas/terapia , Humanos , Lactente , Masculino , Trombocitemia Essencial/terapia
11.
PLoS One ; 8(11): e80131, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24302998

RESUMO

Hermansky Pudlak type 2 syndrome (HPS2) is a rare autosomal recessive primary immune deficiency caused by mutations on ß3A gene (AP3B1 gene). The defect results in the impairment of the adaptor protein 3 (AP-3) complex, responsible for protein sorting to secretory lysosomes leading to oculo-cutaneous albinism, bleeding disorders and immunodeficiency. We have studied peripheral blood and lymph node biopsies from two siblings affected by HPS2. Lymph node histology showed a nodular lymphocyte predominance type Hodgkin lymphoma (NLPHL) in both HPS2 siblings. By immunohistochemistry, CD8 T-cells from HPS2 NLPHL contained an increased amount of perforin (Prf) + suggesting a defect in the release of this granules-associated protein. By analyzing peripheral blood immune cells we found a significant reduction of circulating NKT cells and of CD56(bright)CD16(-) Natural Killer (NK) cells subset. Functionally, NK cells were defective in their cytotoxic activity against tumor cell lines including Hodgkin Lymphoma as well as in IFN-γ production. This defect was associated with increased baseline level of CD107a and CD63 at the surface level of unstimulated and IL-2-activated NK cells. In summary, these results suggest that a combined and profound defect of innate and adaptive effector cells might explain the susceptibility to infections and lymphoma in these HPS2 patients.


Assuntos
Síndrome de Hermanski-Pudlak/complicações , Síndrome de Hermanski-Pudlak/imunologia , Doença de Hodgkin/complicações , Doença de Hodgkin/imunologia , Células Matadoras Naturais/imunologia , Células T Matadoras Naturais/imunologia , Adolescente , Adulto , Idoso , Biópsia , Antígeno CD56/metabolismo , Criança , Pré-Escolar , Citotoxicidade Imunológica , Feminino , Síndrome de Hermanski-Pudlak/diagnóstico , Doença de Hodgkin/diagnóstico , Humanos , Imuno-Histoquímica , Imunofenotipagem , Interferon gama/biossíntese , Células Matadoras Naturais/metabolismo , Linfonodos/patologia , Contagem de Linfócitos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Proteína 1 de Membrana Associada ao Lisossomo/metabolismo , Masculino , Pessoa de Meia-Idade , Células T Matadoras Naturais/metabolismo , Fenótipo , Irmãos , Tetraspanina 30/metabolismo , Adulto Jovem
12.
J Allergy Clin Immunol ; 132(3): 656-664.e17, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23830146

RESUMO

BACKGROUND: Combined immunodeficiency with multiple intestinal atresias (CID-MIA) is a rare hereditary disease characterized by intestinal obstructions and profound immune defects. OBJECTIVE: We sought to determine the underlying genetic causes of CID-MIA by analyzing the exomic sequences of 5 patients and their healthy direct relatives from 5 unrelated families. METHODS: We performed whole-exome sequencing on 5 patients with CID-MIA and 10 healthy direct family members belonging to 5 unrelated families with CID-MIA. We also performed targeted Sanger sequencing for the candidate gene tetratricopeptide repeat domain 7A (TTC7A) on 3 additional patients with CID-MIA. RESULTS: Through analysis and comparison of the exomic sequence of the subjects from these 5 families, we identified biallelic damaging mutations in the TTC7A gene, for a total of 7 distinct mutations. Targeted TTC7A gene sequencing in 3 additional unrelated patients with CID-MIA revealed biallelic deleterious mutations in 2 of them, as well as an aberrant splice product in the third patient. Staining of normal thymus showed that the TTC7A protein is expressed in thymic epithelial cells, as well as in thymocytes. Moreover, severe lymphoid depletion was observed in the thymus and peripheral lymphoid tissues from 2 patients with CID-MIA. CONCLUSIONS: We identified deleterious mutations of the TTC7A gene in 8 unrelated patients with CID-MIA and demonstrated that the TTC7A protein is expressed in the thymus. Our results strongly suggest that TTC7A gene defects cause CID-MIA.


Assuntos
Síndromes de Imunodeficiência/genética , Atresia Intestinal/genética , Intestinos/anormalidades , Proteínas/genética , Animais , Pré-Escolar , Exoma/genética , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Camundongos , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/metabolismo , Timo/metabolismo , Análise Serial de Tecidos
13.
Blood ; 117(24): 6673-80, 2011 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-21467542

RESUMO

Until recently, thrombocytopenia 2 (THC2) was considered an exceedingly rare form of autosomal dominant thrombocytopenia and only 2 families were known. However, we recently identified mutations in the 5'-untranslated region of the ANKRD26 gene in 9 THC2 families. Here we report on 12 additional pedigrees with ANKRD26 mutations, 6 of which are new. Because THC2 affected 21 of the 210 families in our database, it has to be considered one of the less rare forms of inherited thrombocytopenia. Analysis of all 21 families with ANKRD26 mutations identified to date revealed that thrombocytopenia and bleeding tendency were usually mild. Nearly all patients had no platelet macrocytosis, and this characteristic distinguishes THC2 from most other forms of inherited thrombocytopenia. In the majority of cases, platelets were deficient in glycoprotein Ia and α-granules, whereas in vitro platelet aggregation was normal. Bone marrow examination and serum thrombopoietin levels suggested that thrombocytopenia was derived from dysmegakaryopoiesis. Unexplained high values of hemoglobin and leukocytes were observed in a few cases. An unexpected finding that warrants further investigation was a high incidence of acute leukemia. Given the scarcity of distinctive characteristics, the ANKRD26-related thrombocytopenia has to be taken into consideration in the differential diagnosis of isolated thrombocytopenias.


Assuntos
Família , Trombocitopenia/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Repetição de Anquirina/genética , Criança , Estudos de Coortes , Feminino , Frequência do Gene , Humanos , Padrões de Herança/genética , Masculino , Pessoa de Meia-Idade , Mutação/fisiologia , Linhagem , Fatores de Transcrição/fisiologia , Adulto Jovem
14.
J Allergy Clin Immunol ; 127(4): 998-1005.e1-2, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21376381

RESUMO

BACKGROUND: The Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) are caused by mutations in WAS, which encodes for WAS protein (WASP). The WASP-interacting protein (WIP) stabilizes WASP, as evidenced by severely decreased WASP levels in T cells from WIP-deficient mice. The majority of missense mutations in patients with WAS/XLT are located in the WIP-binding domain of WASP and might result in dissociation of the WASP-WIP complex and WASP degradation. OBJECTIVE: To restore WASP levels and correct T-cell function in WAS/XLT patients with mutations in the WIP-binding domain of WASP. METHODS: WIP, and a WIP-derived 41-amino acid-long peptide, which interacts with WASP and was designated nanoWIP (nWIP), were fused to enhanced green fluorescent protein and introduced by electroporation into EBV-transformed B cells, and by retroviral transduction into purified blood T cells from patients with WAS. WASP levels were measured by intracellular fluorescence-activated cell sorting staining. The actin cytoskeleton was visualized by intracellular phalloidin staining. RESULTS: Introduction of WIP and nWIP restored WASP levels to normal in EBV-transformed B-cell lines from XLT patients with missense mutations in the WIP-binding domain of WASP and residual WASP levels, and corrected the defective spreading and pseudopodia formation of their T cells in response to immobilized anti-CD3. CONCLUSION: A WASP-binding WIP-derived peptide stabilizes WASP in cells from XLT patients with missense mutations that disrupt WIP binding, and corrects their T-cell actin cytoskeleton defect. This may provide a novel therapeutic strategy for these patients.


Assuntos
Actinas/metabolismo , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Linfócitos T/metabolismo , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Animais , Linfócitos B/metabolismo , Western Blotting , Separação Celular , Citoesqueleto/patologia , Eletroporação , Citometria de Fluxo , Humanos , Imunoprecipitação , Células Jurkat , Camundongos , Camundongos Knockout , Microscopia de Fluorescência , Mutação de Sentido Incorreto , Peptídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/patologia , Transdução Genética , Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/metabolismo , Proteína da Síndrome de Wiskott-Aldrich/genética
15.
Blood ; 109(11): 4716-23, 2007 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-17311988

RESUMO

The treatment of children affected by severe congenital neutropenia (SCN) with G-CSF strongly reduces the risk of sepsis by reversing neutropenia. However, SCN patients who respond to the treatment with the growth factor still have an elevated risk of succumbing to sepsis. Because the disease is usually caused by heterozygous mutations of ELA2, a gene encoding for neutrophil elastase (NE), we have investigated in G-CSF-responder and nonresponder patients affected by SCN the expression of polypeptides that constitute the antimicrobial machinery of these cells. In peripheral blood-derived neutrophils of patients with heterozygous mutations of ELA2 who were treated with G-CSF, NE was nearly absent as detected by immunofluorescence and immunoblotting, suggesting that production of the mutant protein interferes with normal gene expression. This defect was associated with abnormal expression of other granule-associated proteins such as myeloperoxidase, lactoferrin, cathepsin G, and human-neutrophil-peptide. Moreover, in one patient with partial response to G-CSF, we observed an impairment of neutrophil antimicrobial activity against Candida albicans, and, to a lower extent against Escherichia coli. Thereby, we propose that the treatment with G-CSF is not sufficient to correct all of the functional deficiency of neutrophils, and this might account for the consistent risk of infections observed in SCN patients.


Assuntos
Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Elastase de Leucócito/genética , Mutação , Neutropenia/congênito , Neutropenia/tratamento farmacológico , Neutrófilos/metabolismo , Neutrófilos/microbiologia , Sepse/prevenção & controle , Candida albicans/metabolismo , Catepsina G , Catepsinas/biossíntese , Escherichia coli/metabolismo , Humanos , Lactente , Recém-Nascido , Lactoferrina/biossíntese , Peptídeos/química , Peroxidase/biossíntese , Serina Endopeptidases/biossíntese
16.
Blood ; 107(12): 4857-64, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16507770

RESUMO

Adaptor protein-3 (AP-3) is an ubiquitous cytoplasmic complex that shuttles cargo proteins from the trans-Golgi and a tubular-endosomal compartment to endosome-lysosome-related organelles. Lack of the beta3A subunit of this complex causes Hermansky-Pudlak syndrome type 2, an autosomal recessive disease characterized by partial albinism, prolonged bleeding tendency, and immunodeficiency. To investigate the pathogenesis of immunodeficiency, we studied natural killer (NK) cells and neutrophil functions in 2 previously unreported siblings affected by Hermansky-Pudlak type 2 syndrome. In both patients we observed a dramatic reduction of cytolytic activity of freshly isolated and of IL-2-activated NK cells. Levels of perforin were reduced in unstimulated NK cells, thereby accounting for the impairment of NK cytolitic activity. In addition, analysis of neutrophils in these patients demonstrated that intracellular elastase content was largely reduced while CD63 expression on plasma membrane was substantially increased. Taken together, these observations suggest that type 2 Hermansky-Pudlak syndrome is characterized by defects of innate immunity.


Assuntos
Complexo 3 de Proteínas Adaptadoras/imunologia , Subunidades beta do Complexo de Proteínas Adaptadoras/imunologia , Antígenos CD/imunologia , Síndrome de Hermanski-Pudlak/imunologia , Imunidade Inata/imunologia , Células Matadoras Naturais/imunologia , Neutrófilos/imunologia , Glicoproteínas da Membrana de Plaquetas/imunologia , Adulto , Criança , Pré-Escolar , Feminino , Regulação da Expressão Gênica/imunologia , Síndrome de Hermanski-Pudlak/patologia , Humanos , Imunidade Celular/imunologia , Síndromes de Imunodeficiência/imunologia , Síndromes de Imunodeficiência/patologia , Lactente , Células Matadoras Naturais/patologia , Elastase de Leucócito/imunologia , Masculino , Neutrófilos/patologia , Tetraspanina 30 , Rede trans-Golgi/imunologia
17.
Curr Opin Allergy Clin Immunol ; 5(6): 485-90, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16264326

RESUMO

PURPOSE OF REVIEW: This review reports on the range of clinical phenotypes that are caused by mutations in the Wiskott-Aldrich Syndrome Protein (WASP) gene. The basis of genotype-phenotype correlation in Wiskott-Aldrich syndrome (WAS) is discussed, with regard to expression of the WAS protein (WASp) and of the effects of WASP mutations on WASp function. Advances in preclinical models of gene therapy for WAS are presented. RECENT FINDINGS: Two recent studies have supported genotype-phenotype correlation in WAS and in related X-linked thrombocytopenia. Expression of the WASp was found to be the best predictor of clinical phenotype. Investigation of autoimmune manifestations associated with WAS has shown that autoimmune hemolytic anemia and elevated serum IgM associate with a more severe clinical course. Finally, while results of hematopoietic stem cell transplantation for WAS continue to improve, several studies have shown the potential benefit of novel therapeutic approaches based on gene transfer. In particular, use of lentiviral vector-driven expression of the WASP gene under autologous promoter sequences has been found to result in increased targeting of hematopoietic stem cells, higher levels of WASp expression, and improved reconstitution of immune function. SUMMARY: Availability of tools that allow analysis of WASp expression has provided evidence for a genotype-phenotype correlation in patients with WASP gene defects. Protein expression is an important prognostic indicator. The molecular and cellular abnormalities of WAS-associated defects are being identified, and significant advances in vector-mediated gene transfer have opened possibilities for the treatment of WAS based on gene therapy.


Assuntos
Proteína da Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/genética , Anemia Hemolítica Autoimune , Animais , Terapia Genética , Transplante de Células-Tronco Hematopoéticas , Humanos , Imunoglobulina M/sangue , Mutação , Linfócitos T , Síndrome de Wiskott-Aldrich/imunologia , Síndrome de Wiskott-Aldrich/terapia , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Proteína da Síndrome de Wiskott-Aldrich/fisiologia
18.
Blood ; 104(2): 444-52, 2004 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-15026312

RESUMO

The chemokine receptor CXCR4 and its functional ligand, CXCL12, are essential regulators of development and homeostasis of hematopoietic and lymphoid organs. Heterozygous truncating mutations in the CXCR4 intracellular tail cause a rare genetic disease known as WHIM syndrome (warts, hypogammaglobulinemia, infections, myelokathexis), whose pathophysiology remains unclear. We report CXCR4 function in 3 patients with WHIM syndrome carrying heterozygous truncating mutations of CXCR4. We show that CXCR4 gene mutations in WHIM patients do not affect cell surface expression of the chemokine receptor and its internalization upon stimulation with CXCL12. Moreover, no significant differences in calcium mobilization in response to CXCL12 are found. However, the chemotactic response of both polymorphonuclear cells and T lymphocytes in response to CXCL12 is increased. Furthermore, immunophenotypic analysis of circulating T and B lymphocytes reveals a decreased number of memory B cells and of naive T cells and an accumulation of effector memory T cells associated with a restricted T-cell repertoire. Based on our results, we suggest that the altered leukocyte response to CXCL12 may account for the pathologic retention of mature polymorphonuclear cells in the bone marrow (myelokathexis) and for an altered lymphocyte trafficking, which may cause the immunophenotyping abnormalities observed in WHIM patients.


Assuntos
Agamaglobulinemia/imunologia , Infecções Bacterianas/imunologia , Quimiocinas CXC/genética , Neutropenia/imunologia , Verrugas/imunologia , Adolescente , Adulto , Agamaglobulinemia/genética , Linfócitos B/citologia , Linfócitos B/imunologia , Infecções Bacterianas/genética , Medula Óssea/imunologia , Cálcio/metabolismo , Quimiocina CXCL12 , Criança , Análise Mutacional de DNA , Feminino , Citometria de Fluxo , Expressão Gênica/imunologia , Humanos , Imunofenotipagem , Neutropenia/genética , Neutrófilos/citologia , Neutrófilos/imunologia , Síndrome , Linfócitos T/citologia , Linfócitos T/imunologia , Verrugas/genética
19.
Curr Opin Allergy Clin Immunol ; 4(6): 513-21, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15640692

RESUMO

PURPOSE OF REVIEW: A decade after the availability of hematopoietic growth factors, the long-term outcome of severe congenital neutropenia has dramatically changed. The prolonged survival of neutropenic patients receiving hematopoietic growth factors has drawn attention to the heterogeneity of this disease and to the complications of treatment. The dose of granulocyte colony stimulating factor that is required to obtain normal levels of circulating neutrophils and to prevent fever and infections is quite variable among patients, but is higher in children with severe congenital neutropenia than in those with other conditions of neutropenia. Moreover, leukemic transformation during treatment is not observed in all patients, but is more typical of severe congenital neutropenia and Shwachman-Diamond patients. RECENT FINDINGS: In recent years, the converging efforts of hematologists, immunologists and geneticists have led to the discovery of the genetic and biochemical basis of severe congenital neutropenia; cyclic neutropenia; warts, hypogammaglobulinemia, immunodeficiency, myelokathexis or WHIM syndrome and other rarer conditions associated to neutropenia. SUMMARY: Although the diagnosis of congenital neutropenia includes many disorders of distinct origin and variable prognosis, their treatment is still based on granulocyte colony stimulating factor administration. Understanding the pathogenesis of these forms of neutropenia and their evolution will focus future studies on the mechanisms of normal and pathological myelopoiesis and on the development of the most appropriate treatment for each type of neutropenia.


Assuntos
Neutropenia/congênito , Cromossomos Humanos X , Doença de Depósito de Glicogênio Tipo I/complicações , Substâncias de Crescimento/uso terapêutico , Hematínicos/uso terapêutico , Síndrome de Hermanski-Pudlak/complicações , Humanos , Doenças Musculares/complicações , Neutropenia/diagnóstico , Neutropenia/etiologia , Neutropenia/terapia , Fenômeno de Shwartzman/complicações
20.
J Clin Endocrinol Metab ; 88(7): 3146-8, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12843157

RESUMO

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an autosomal-recessive syndrome defined by two of the following conditions: chronic mucocutaneous candidiasis, hypoparathyroidism, or Addison's disease. Other autoimmune conditions may be associated, such as hypothyroidism, hypogonadism, insulin-dependent diabetes mellitus, chronic active hepatitis, pernicious anemia, vitiligo, alopecia, biliary cirrhosis, and ectodermal dysplasia. APECED is caused by mutations in the autoimmune regulator gene, mapping to 21q22.3. We report on three patients whose clinical and molecular features challenge the currently used diagnostic criteria for APECED. AR presented at 15 yr of age with a history of recurrent infections and mucocutaneous candidiasis. He is now 21 yr old, and no other signs or symptoms of APECED have appeared to date. DR presented at 7 yr of age with hypocalcemia and a prolonged Q-T interval on the electrocardiogram. He also had minor facial dysmorphisms and mild mental retardation. Serum calcium levels were low, PTH levels were undetectable, and hypoparathyroidism was therefore diagnosed. All other biochemical, immunological, and endocrinological tests were normal. DR is now 8 yr old with no other signs or symptoms of APECED. ST presented at 14 yr of age for alopecia aerata and pitted nail dystrophy and goiter. Thyroid function was normal in the presence of thyroid-specific antibodies. No other signs or symptoms of APECED have appeared to date. Genetic analysis revealed a typical mutation (R257X) on a single allele in both AP and DR; in ST, heterozygosity for a novel mutation (V484M) involving one of the zinc fingers of the plant homeodomain of the protein was found. The finding of a typical APECED mutation in two patients presenting with one isolated major clinical APECED feature and of a novel mutation in a patient presenting with atypical features of APECED onset suggests that the time might have come for updating the diagnostic criteria of this syndrome.


Assuntos
Poliendocrinopatias Autoimunes/diagnóstico , Poliendocrinopatias Autoimunes/genética , Adolescente , Alopecia em Áreas/diagnóstico , Alopecia em Áreas/genética , Substituição de Aminoácidos/genética , Criança , Feminino , Heterozigoto , Humanos , Hipocalcemia/diagnóstico , Hipocalcemia/genética , Hipoparatireoidismo/diagnóstico , Hipoparatireoidismo/genética , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/genética , Masculino
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