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1.
Medicina (B Aires) ; 78(2): 123-126, 2018.
Artigo em Espanhol | MEDLINE | ID: mdl-29659363

RESUMO

WHIM syndrome is a primary autosomal dominant immuno deficiency due to CXCR4 mutations characterized by mucocutaneous warts, hypogammaglobulinemia, recurrent bacterial infections and myelokathesis. Treatment consists in prophylactic antibiotics, immunoglobulin replacement and granulocyte or granulocyte/monocyte colony stimulating factors. We present the case of a 21 year old woman who showed leukopenia at 10 months of age and one year later multiple infections with hypogammaglobulinemia requiring intravenous immunoglobulin. During follow up she developed chronic neutropenia. A bone marrow aspiration showed increased myeloid series with predominance of immature elements. On the basis of infections, low levels of IgG, IgA, IgM and lymphopenia with absent memory B cells, a diagnosis of common variable immunodeficiency was made. She started intravenous immunoglobulin replacement and prophylactic antibiotics. At age 20, small warts in hands that progressed to forearms, knees, abdomen and face were recorded. CXCR4 gene sequencing was done detecting a heterozygous p.Arg334STOP mutation, confirming WHIM syndrome. This disease is infrequent and difficult to diagnose.

2.
Medicina (B.Aires) ; 78(2): 123-126, abr. 2018. ilus, graf
Artigo em Espanhol | LILACS-Express | ID: biblio-954961

RESUMO

El síndrome WHIM es una inmunodeficiencia primaria de herencia autosómica dominante, debida a mutaciones en el gen CXCR4, que se caracteriza por verrugas cutáneo-mucosas, hipogammaglobulinemia, infecciones bacterianas recurrentes y mielocatesis. El tratamiento se basa en el uso de antibióticos profilácticos, gammaglobulina en dosis sustitutiva y factores estimulantes de colonias de granulocitos o de granulocitos y macrófagos, en forma crónica. Presentamos el caso de una mujer de 21 años que comenzó a los 10 meses de edad con leucopenia y al siguiente año múltiples infecciones con hipogammaglobulinemia requiriendo gammaglobulina endovenosa durante los episodios. Evolucionó con neutropenia crónica. Una punción aspiración de médula ósea mostró la serie mieloide aumentada con ligero predominio de elementos inmaduros. El cuadro fue interpretado como inmunodeficiencia común variable debido a la asociación de múltiples cuadros infecciosos, niveles disminuidos de IgG, IgM e IgA y linfopenia con disminución de linfocitos B de memoria, por lo que comenzó tratamiento sustitutivo con gammaglobulina endovenosa más antibióticos profilácticos. A los 20 años se registraron pequeñas verrugas en manos que progresaron hacia antebrazos, abdomen, cara y rodillas. Se realizaron estudios moleculares para la búsqueda de mutaciones en el gen CXCR4 donde se detectó la mutación p.Arg334STOP en estado heterocigota confirmando el diagnóstico de síndrome WHIM, que es una inmunodeficiencia infrecuente y de difícil diagnóstico.


WHIM syndrome is a primary autosomal dominant immuno deficiency due to CXCR4 mutations characterized by mucocutaneous warts, hypogammaglobulinemia, recurrent bacterial infections and myelokathesis. Treatment consists in prophylactic antibiotics, immunoglobulin replacement and granulocyte or granulocyte/monocyte colony stimulating factors. We present the case of a 21 year old woman who showed leukopenia at 10 months of age and one year later multiple infections with hypogammaglobulinemia requiring intravenous immunoglobulin. During follow up she developed chronic neutropenia. A bone marrow aspiration showed increased myeloid series with predominance of immature elements. On the basis of infections, low levels of IgG, IgA, IgM and lymphopenia with absent memory B cells, a diagnosis of common variable immunodeficiency was made. She started intravenous immunoglobulin replacement and prophylactic antibiotics. At age 20, small warts in hands that progressed to forearms, knees, abdomen and face were recorded. CXCR4 gene sequencing was done detecting a heterozygous p.Arg334STOP mutation, confirming WHIM syndrome. This disease is infrequent and difficult to diagnose.

4.
Nat Genet ; 49(8): 1192-1201, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28628108

RESUMO

Few monogenic causes for severe manifestations of common allergic diseases have been identified. Through next-generation sequencing on a cohort of patients with severe atopic dermatitis with and without comorbid infections, we found eight individuals, from four families, with novel heterozygous mutations in CARD11, which encodes a scaffolding protein involved in lymphocyte receptor signaling. Disease improved over time in most patients. Transfection of mutant CARD11 expression constructs into T cell lines demonstrated both loss-of-function and dominant-interfering activity upon antigen receptor-induced activation of nuclear factor-κB and mammalian target of rapamycin complex 1 (mTORC1). Patient T cells had similar defects, as well as low production of the cytokine interferon-γ (IFN-γ). The mTORC1 and IFN-γ production defects were partially rescued by supplementation with glutamine, which requires CARD11 for import into T cells. Our findings indicate that a single hypomorphic mutation in CARD11 can cause potentially correctable cellular defects that lead to atopic dermatitis.


Assuntos
Proteínas Adaptadoras de Sinalização CARD/genética , Dermatite Atópica/genética , Mutação em Linhagem Germinativa , Guanilato Ciclase/genética , Sistema ASC de Transporte de Aminoácidos/metabolismo , Estudos de Coortes , Análise Mutacional de DNA , Dermatite Atópica/imunologia , Feminino , Genes Dominantes , Glutamina/metabolismo , Humanos , Células Jurkat , Ativação Linfocitária , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Antígenos de Histocompatibilidade Menor/metabolismo , Complexos Multiproteicos/metabolismo , NF-kappa B/metabolismo , Linhagem , Linfócitos T/imunologia , Linfócitos T/metabolismo , Serina-Treonina Quinases TOR/metabolismo
5.
J Allergy Clin Immunol ; 139(3): 913-922, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27713077

RESUMO

BACKGROUND: Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by impaired immunoglobulin production and usually presents with a normal quantity of peripheral B cells. Most attempts aiming to classify these patients have mainly been focused on T- or B-cell phenotypes and their ability to produce protective antibodies, but it is still a major challenge to find a suitable classification that includes the clinical and immunologic heterogeneity of these patients. OBJECTIVE: In this study we evaluated the late stages of B-cell differentiation in a heterogeneous population of patients with pediatric-onset CVID to clinically correlate and assess their ability to perform somatic hypermutation (SHM), class-switch recombination (CSR), or both. METHODS: We performed a previously reported assay, the restriction enzyme hotspot mutation assay (IgκREHMA), to evaluate in vivo SHM status. We amplified switch regions from genomic DNA to investigate the quality of the double-strand break repairs in the class-switch recombination process in vivo. We also tested the ability to generate immunoglobulin germline and circle transcripts and to upregulate the activation-induced cytidine deaminase gene through in vitro T-dependent and T-independent stimuli. RESULTS: Our results showed that patients could be classified into 2 groups according to their degree of SHM alteration. This stratification showed a significant association between patients of group A, severe alteration, and the presence of noninfectious complications. Additionally, 60% of patients presented with increased microhomology use at switched regions. In vitro activation revealed that patients with CVID behaved heterogeneously in terms of responsiveness to T-dependent stimuli. CONCLUSIONS: The correlation between noninfectious complications and SHM could be an important tool for physicians to further characterize patients with CVID. This categorization would help to improve elucidation of the complex mechanisms involved in B-cell differentiation pathways.


Assuntos
Imunodeficiência de Variável Comum/genética , Imunodeficiência de Variável Comum/imunologia , Adolescente , Linfócitos B/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Região de Troca de Imunoglobulinas , Lactente , Leucócitos Mononucleares , Masculino , Recombinação Genética , Hipermutação Somática de Imunoglobulina
6.
J Allergy Clin Immunol ; 140(1): 232-241, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28011069

RESUMO

BACKGROUND: Germline heterozygous mutations in human signal transducer and activator of transcription 1 (STAT1) can cause loss of function (LOF), as in patients with Mendelian susceptibility to mycobacterial diseases, or gain of function (GOF), as in patients with chronic mucocutaneous candidiasis. LOF and GOF mutations are equally rare and can affect the same domains of STAT1, especially the coiled-coil domain (CCD) and DNA-binding domain (DBD). Moreover, 6% of patients with chronic mucocutaneous candidiasis with a GOF STAT1 mutation have mycobacterial disease, obscuring the functional significance of the identified STAT1 mutations. Current computational approaches, such as combined annotation-dependent depletion, do not distinguish LOF and GOF variants. OBJECTIVE: We estimated variations in the CCD/DBD of STAT1. METHODS: We mutagenized 342 individual wild-type amino acids in the CCD/DBD (45.6% of full-length STAT1) to alanine and tested the mutants for STAT1 transcriptional activity. RESULTS: Of these 342 mutants, 201 were neutral, 30 were LOF, and 111 were GOF mutations in a luciferase assay. This assay system correctly estimated all previously reported LOF mutations (100%) and slightly fewer GOF mutations (78.1%) in the CCD/DBD of STAT1. We found that GOF alanine mutants occurred at the interface of the antiparallel STAT1 dimer, suggesting that they destabilize this dimer. This assay also precisely predicted the effect of 2 hypomorphic and dominant negative mutations, E157K and G250E, in the CCD of STAT1 that we found in 2 unrelated patients with Mendelian susceptibility to mycobacterial diseases. CONCLUSION: The systematic alanine-scanning assay is a useful tool to estimate the GOF or LOF status and the effect of heterozygous missense mutations in STAT1 identified in patients with severe infectious diseases, including mycobacterial and fungal diseases.


Assuntos
Alanina/genética , Infecções por Mycobacterium/genética , Fator de Transcrição STAT1/genética , Bioensaio , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Mutagênese , Mutação , Domínios Proteicos
7.
J Allergy Clin Immunol ; 138(1): 241-248.e3, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26936803

RESUMO

BACKGROUND: Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by inborn errors of the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex. From the first year of life onward, most affected patients display multiple, severe, and recurrent infections caused by bacteria and fungi. Mycobacterial infections have also been reported in some patients. OBJECTIVE: Our objective was to assess the effect of mycobacterial disease in patients with CGD. METHODS: We analyzed retrospectively the clinical features of mycobacterial disease in 71 patients with CGD. Tuberculosis and BCG disease were diagnosed on the basis of microbiological, pathological, and/or clinical criteria. RESULTS: Thirty-one (44%) patients had tuberculosis, and 53 (75%) presented with adverse effects of BCG vaccination; 13 (18%) had both tuberculosis and BCG infections. None of these patients displayed clinical disease caused by environmental mycobacteria, Mycobacterium leprae, or Mycobacterium ulcerans. Most patients (76%) also had other pyogenic and fungal infections, but 24% presented solely with mycobacterial disease. Most patients presented a single localized episode of mycobacterial disease (37%), but recurrence (18%), disseminated disease (27%), and even death (18%) were also observed. One common feature in these patients was an early age at presentation for BCG disease. Mycobacterial disease was the first clinical manifestation of CGD in 60% of these patients. CONCLUSION: Mycobacterial disease is relatively common in patients with CGD living in countries in which tuberculosis is endemic, BCG vaccine is mandatory, or both. Adverse reactions to BCG and severe forms of tuberculosis should lead to a suspicion of CGD. BCG vaccine is contraindicated in patients with CGD.


Assuntos
Doença Granulomatosa Crônica/complicações , Infecções por Mycobacterium/diagnóstico , Infecções por Mycobacterium/etiologia , Vacina BCG/administração & dosagem , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/epidemiologia , Infecções Bacterianas/etiologia , Infecções Bacterianas/mortalidade , Criança , Pré-Escolar , Feminino , Doença Granulomatosa Crônica/epidemiologia , Doença Granulomatosa Crônica/mortalidade , Doença Granulomatosa Crônica/terapia , Humanos , Lactente , Masculino , Infecções por Mycobacterium/epidemiologia , Infecções por Mycobacterium/mortalidade , Micoses/diagnóstico , Micoses/epidemiologia , Micoses/etiologia , Micoses/mortalidade , Avaliação de Resultados da Assistência ao Paciente , Estudos Retrospectivos , Tuberculose/diagnóstico , Tuberculose/etiologia
8.
J Clin Immunol ; 35(8): 769-76, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26563159

RESUMO

Mutations in the FAS gene are the most common cause of Autoimmune Lymphoproliferative Syndrome (ALPS), and the majority of them affect the intracellular domain of FAS protein, particularly the region termed death domain. However, approximately one third of these mutations affect the extracellular region of FAS and most are stop codons, with very few missense changes having been described to date. We previously described 7 patients with a FAS missense extracellular mutation, C107Y, two in homozygozity and 5 in heterozygosity. We investigated here the mechanistic effects of this mutation and observed that the homozygous patients did not show any FAS surface expression, while the heterozygous patients had diminished receptor expression. Aiming to understand why a missense mutation was abolishing receptor expression, we analyzed intracellular FAS protein trafficking using fluorescent fusion proteins of wild type FAS, two missense extracellular mutants (FAS-C107Y and FAS-C104Y) and one missense change localized in the intracellular region, FAS-D260E. The FAS-C107Y and FAS-C104Y mutants failed to reach the cell surface, being retained at the endoplasmic reticulum, unlike the WT or the FAS-D260E which were clearly expressed at the plasma membrane. These results support haploinsufficiency as the underlying mechanism involved in the pathogenesis of ALPS caused by extracellular FAS missense mutations.


Assuntos
Síndrome Linfoproliferativa Autoimune/genética , Mutação de Sentido Incorreto/genética , Estrutura Terciária de Proteína/genética , Proteínas Recombinantes de Fusão/genética , Receptor fas/metabolismo , Alelos , Apoptose/genética , Argentina , Espaço Extracelular , Células HEK293 , Haploinsuficiência , Humanos , Linhagem , Engenharia de Proteínas , Transporte Proteico/genética , Receptor fas/genética
9.
Pediatr Blood Cancer ; 62(12): 2101-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26185101

RESUMO

AIM: We analyzed data from 71 patients with chronic granulomatous disease (CGD) with a confirmed genetic diagnosis, registered in the online Latin American Society of Primary Immunodeficiencies (LASID) database. RESULTS: Latin American CGD patients presented with recurrent and severe infections caused by several organisms. The mean age at disease onset was 23.9 months, and the mean age at CGD diagnosis was 52.7 months. Recurrent pneumonia was the most frequent clinical condition (76.8%), followed by lymphadenopathy (59.4%), granulomata (49.3%), skin infections (42%), chronic diarrhea (41.9%), otitis (29%), sepsis (23.2%), abscesses (21.7%), recurrent urinary tract infection (20.3%), and osteomyelitis (15.9%). Adverse reactions to bacillus Calmette-Guérin (BCG) vaccination were identified in 30% of the studied Latin American CGD cases. The genetic diagnoses of the 71 patients revealed 53 patients from 47 families with heterogeneous mutations in the CYBB gene (five novel mutations: p.W361G, p.C282X, p.W483R, p.R226X, and p.Q93X), 16 patients with the common deletion c.75_76 del.GT in exon 2 of NCF1 gene, and two patients with mutations in the CYBA gene. CONCLUSION: The majority of Latin American CGD patients carry a hemizygous mutation in the CYBB gene. They also presented a wide range of clinical manifestations most frequently bacterial and fungal infections of the respiratory tract, skin, and lymph nodes. Thirty percent of the Latin American CGD patients presented adverse reactions to BCG, indicating that this vaccine should be avoided in these patients.


Assuntos
Doença Granulomatosa Crônica , Glicoproteínas de Membrana/genética , Mutação , NADPH Oxidases/genética , Sistema de Registros , Abscesso/epidemiologia , Abscesso/etiologia , Abscesso/genética , Adolescente , Idade de Início , Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia/etiologia , Diarreia/genética , Feminino , Doença Granulomatosa Crônica/complicações , Doença Granulomatosa Crônica/epidemiologia , Doença Granulomatosa Crônica/genética , Hispano-Americanos , Humanos , Lactente , Recém-Nascido , Doenças Linfáticas/epidemiologia , Doenças Linfáticas/etiologia , Doenças Linfáticas/genética , Masculino , NADPH Oxidase 2 , Osteomielite/epidemiologia , Osteomielite/etiologia , Osteomielite/genética , Otite/epidemiologia , Otite/etiologia , Otite/genética , Pneumonia/epidemiologia , Pneumonia/etiologia , Pneumonia/genética , Sepse/epidemiologia , Sepse/etiologia , Sepse/genética , Dermatopatias/epidemiologia , Dermatopatias/etiologia , Dermatopatias/genética , Infecções Urinárias/epidemiologia , Infecções Urinárias/etiologia , Infecções Urinárias/genética
10.
Rev Alerg Mex ; 61(3): 219-23, 2014 Jul-Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-25177856

RESUMO

Wiskott-Aldrich syndrome was first reported clinically in 1937, and in 1954 the classic triad was identified: eccema, recurrent infections and thrombocytopenia with an X-linked transmission. Its incidence is estimated at 1 to 10 in one million live births per year. Wiskott Aldrich syndrome is caused by mutations in a gene in the short arm of chromosome X that encodes the Wiskott-Aldrich syndrome protein (WASp), which identification and sequencing was first performed in 1994, and since then about 300 mutations have been reported. This paper describes the case of a boy with Wiskott-Aldrich syndrome, with clinical and genetic diagnosis, with a considerable diagnostic delay attributable to an atypical presentation misdiagnosed as immune thrombocytopenia.

12.
Eur J Immunol ; 43(3): 805-14, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23225259

RESUMO

Mutations in the transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI) were previously found to be associated with hypogammaglobulinemia in humans. It has been shown that proliferation inducing ligand (APRIL) elicits class switch recombination (CSR) by inducing recruitment of MyD88 to a TACI highly conserved cytoplasmic domain (THC). We have identified a patient with hypogammaglobulinemia carrying a missense mutation (S231R) predicted to affect the THC. Aiming to evaluate the relevance of this novel mutation of TACI in CSR induction, we tested the ability of TACI, TLR9, or/and CD40 ligands to trigger CSR in naive B cells and B-cell lines carrying S231R. IgG secretion was impaired when triggered by TACI or/and TLR9 ligands on S231R-naive B cells. Likewise, these stimuli induced less expression of activation-induced cytidine deaminase, I(γ)1-C(µ), and I(γ)1-C(µ), while induction by optimal CD40 stimulation was indistinguishable from controls. These cells also showed an impaired cooperation between TACI and TLR9 pathways, as well as a lack of APRIL-mediated enhancement of CD40 activation in suboptimal conditions. Finally, after APRIL ligation, S231R-mutated TACI failed to colocalize with MyD88. Collectively, these results highlight the requirement of an intact MyD88-binding site in TACI to trigger CSR.


Assuntos
Switching de Imunoglobulina/genética , Mutação , Fator 88 de Diferenciação Mieloide/metabolismo , Proteína Transmembrana Ativadora e Interagente do CAML/genética , Recombinação V(D)J , Adolescente , Linfócitos B/imunologia , Linfócitos B/metabolismo , Sítios de Ligação , Antígenos CD40/metabolismo , Células Cultivadas , Imunodeficiência de Variável Comum/genética , Imunodeficiência de Variável Comum/imunologia , Humanos , Ligação Proteica , Transdução de Sinais , Proteína Transmembrana Ativadora e Interagente do CAML/química , Proteína Transmembrana Ativadora e Interagente do CAML/metabolismo
13.
J Clin Immunol ; 32(6): 1197-203, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22752343

RESUMO

UNLABELLED: Mutations in the Fas gene (TNFRSF6) are the most common causes of Autoimmune Lymphoproliferative Syndrome (ALPS-FAS). PURPOSE: In Argentina almost a third of patients with ALPS-FAS present a missense mutation affecting the extracellular cysteine rich domain 2 of Fas, p.Cys107Tyr (C107Y). This change was found in homozygous state in 2 patients from a consanguineous family, and heterozygously, in 3 other patients from 3 unrelated families. In these families, 12 relatives were identified as healthy carriers of the mutation. We sought to test the hypothesis that this mutation actually represents a single haplotype of TNFRSF6. METHODS: DNAs from ALPS-C107Y patients and their families, as well as from 150 Argentinean control subjects were sequenced for the known higher frequency single nucleotide polymorphisms (SNPs) of TNFRSF6. The C107Y-carriers were also genotyped at 5 microsatellites proximal to the Fas gene locus. RESULTS: All C107Y alleles presented a unique intragenic haplotype that could be restricted to this group. Extent of haplotype sharing and variability of microsatellite alleles in C107Y chromosomes support the presence of a single haplotype block including the mutation and encompassing 2.395 Mb. CONCLUSIONS: A founder effect for C107Y has been evidenced in this work and the most common recent ancestor to the patients probably lived 350 years ago. This constitutes the first report of a founder event in ALPS.


Assuntos
Síndrome Linfoproliferativa Autoimune/genética , Efeito Fundador , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único , Receptor fas/genética , Adolescente , Adulto , Alelos , Argentina , Síndrome Linfoproliferativa Autoimune/patologia , Sequência de Bases , Estudos de Casos e Controles , Criança , Feminino , Haplótipos , Heterozigoto , Homozigoto , Humanos , Masculino , Repetições de Microssatélites , Dados de Sequência Molecular , Linhagem , Estrutura Terciária de Proteína , Análise de Sequência de DNA
14.
J Clin Immunol ; 32(1): 89-97, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22076597

RESUMO

Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by impaired immunoglobulin production. Mutations in the gene encoding TACI (TNFRSF13B) were previously found to be associated with CVID. Previous studies have identified a variety of sequence variants in TACI where A181E and C104R were the most common, with variable frequencies in different ethnic populations. So far, no mutations were identified in the recently reported "TACI highly conserved" (THC) cytoplasmic domain, important for the induction of class switch recombination. Our study evaluated immunological and clinical data on a cohort of 28 Argentinean pediatric CVID patients and allowed the identification of two novel mutations in TNFRSF13B, including one, S231R, affecting the highly conserved THC domain. In contrast, none of the patients presented with A181E and C104R mutations.


Assuntos
Imunodeficiência de Variável Comum/genética , Imunodeficiência de Variável Comum/imunologia , Mutação , Proteína Transmembrana Ativadora e Interagente do CAML/genética , Adolescente , Substituição de Aminoácidos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Sequência de Bases , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Ordem dos Genes , Humanos , Masculino , Linhagem , RNA Mensageiro/metabolismo
15.
Rev Alerg Mex ; 59(1): 41-5, 2012 Jan-Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-24007933

RESUMO

Wiskott Aldrich syndrome (WAS) is an X-linked primary immunodeficiency, associated with WASP gene mutation that causes severe immunological abnormalities and alterations in platelet function. A seven year old male patient with WASP, began with acute abdominal pain, fever and knee swelling. The diagnosis of septic arthritis was made, and he was treated with broad-spectrum antibiotics and human gammaglobulin. During treatment he presented digestive tract bleeding with hypovolemic shock; after 72 hours palpable purpura in upper and lower extremities appeared. Then Henoch-Schönlein purpura with abdominal vasculitis was suspected, and later confirmed by histopathology. Methylprednisolone pulses were initiated, showing improvement within 24 hours. The patient had a severe inflammatory reaction, caused by a serious infectious disease, but the clinical evolution suggested an autoimmune disease such as Henoch-Schönlein purpura. Up to 20% of patients with WAS have autoimmune manifestations of vasculitis. An early diagnosis of autoimmunity in WAS is important for a favorable clinical outcome.


Assuntos
Púrpura de Schoenlein-Henoch , Síndrome de Wiskott-Aldrich , Dor Abdominal , Humanos , Vasculite , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X
16.
J Clin Immunol ; 30(2): 330-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19967551

RESUMO

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease with major diagnostic and therapeutic difficulties, basically comprising two different conditions: primary and secondary forms. Recent advances regarding molecular diagnosis may be useful to distinguish from one another, especially in sporadic cases starting in early infancy. MATERIALS AND METHODS: In this report, we evaluated three Argentinean patients with clinical suspicion of HLH, but without family history. We excluded mutations in the perforin gene but identified in the three patients a novel homozygous deletion (c. 581_584delTGCC; p.Leu194ProfsX2) in the gene-encoding syntaxin 11 (STX11), causing a premature termination codon. RESULTS AND CONCLUSION: Each parent from the three unrelated families resulted heterozygous for this deletion confirming the diagnosis of familial hemophagocytic lymphohistiocytosis type 4. Patients shared the same single-nucleotide polymorphism profile in STX11 gene, and genotyping at ten microsatellites surrounding this gene support the presence of a single-haplotype block carrying the novel mutation.


Assuntos
Família , Linfo-Histiocitose Hemofagocítica/diagnóstico , Linfo-Histiocitose Hemofagocítica/genética , Proteínas Qa-SNARE/genética , Deleção de Sequência/genética , Argentina , Análise Mutacional de DNA , Diagnóstico Diferencial , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Transplante de Células-Tronco Hematopoéticas , Humanos , Lactente , Infecção , Linfo-Histiocitose Hemofagocítica/fisiopatologia , Neutropenia , Linhagem , Polimorfismo de Nucleotídeo Único
17.
J Clin Immunol ; 29(1): 123-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18677443

RESUMO

INTRODUCTION: Argentina has a large number of patients with definite diagnosis of X-linked agammaglobulinemia reported in the Latin-American registry. Forty-nine of them were seen in our referral pediatric hospital, between 1987 and 2005. RESULTS AND DISCUSSION: A retrospective study of clinical, laboratory, and molecular data showed that respiratory tract infections were the most frequent initial clinical presentation and the most common among all manifestations prior to diagnosis (69%). Up to diagnosis, we found a high frequency of severe infections (sepsis, 14% and meningitis, 16%) and a high proportion of patients with chronic lung disease. During follow-up, the development of chronic lung disease was significantly related with age at diagnosis and inappropriate treatment. CONCLUSION: Although molecular diagnosis has been available in our center for the past 10 years, there is no doubt that awareness for early recognition of immunodeficiency should be improved through broader and more comprehensive education programs emphasizing characteristics of patients with immunodeficiencies.


Assuntos
Agamaglobulinemia/diagnóstico , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Adolescente , Tirosina Quinase da Agamaglobulinemia , Agamaglobulinemia/complicações , Agamaglobulinemia/tratamento farmacológico , Agamaglobulinemia/genética , Agamaglobulinemia/terapia , Argentina , Criança , Pré-Escolar , Doença Crônica , Diagnóstico Precoce , Feminino , Seguimentos , Doenças Genéticas Ligadas ao Cromossomo X/complicações , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/terapia , Humanos , Imunoglobulinas/sangue , Imunoglobulinas Intravenosas/uso terapêutico , Lactente , Pneumopatias/diagnóstico , Pneumopatias/etiologia , Pneumopatias/imunologia , Masculino , Mutação/genética , Proteínas Tirosina Quinases/genética , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/etiologia , Infecções Respiratórias/imunologia , Estudos Retrospectivos
18.
J Clin Immunol ; 27(4): 455-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17351759

RESUMO

CD40 ligand (CD40L) deficiency is an X-linked combined immunodeficiency characterized by impaired class switch recombination. We analyzed clinical and molecular findings in 11 Argentinian patients from seven unrelated families. The mean age at onset of symptoms was 1.1 years (0.5-3.0 years) and the 10 alive patients have a median age of 17 years. We identified two nonsense mutations, including R11X reported as a "hypomorphic" defect, four missense mutations, and one point deletion. Although R11X was associated herein with parvovirus B19-anemia and higher Igs levels as previously described, histoplasmosis and Pneumocystis jiroveci pneumonia were also present. Other so-called "milder" mutation, T254M, was present in three related patients clinically and immunologically undistinguishable from the rest of the cohort. Furthermore, 10 of the 11 patients, having heterogeneous mutations, never had persistent neutropenia, none presented Cryptosporidium sp. infection nor developed liver-biliary tract disease, highlighting the debatable concept of "milder" mutations.


Assuntos
Ligante de CD40/deficiência , Ligante de CD40/genética , Mutação , Adolescente , Adulto , Idade de Início , Argentina , Criança , Demografia , Seguimentos , Triagem de Portadores Genéticos , Humanos , Masculino , Análise de Sequência de DNA
19.
J Clin Virol ; 31(1): 58-65, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15288615

RESUMO

BACKGROUND: Post-transplant lymphoproliferative disease (PTLD) is a frequent and severe Epstein-Barr virus (EBV)-associated complication in transplant recipients that is caused by suppression of T-cell function. OBJECTIVE: Evaluation of the diagnostic value of EBV DNA load in non-fractionated whole blood samples (n = 297) from 110 pediatric transplant patients by real-time PCR. RESULTS AND CONCLUSIONS: Patients with PTLD had a median viral load of 1.08 x 10(5) copies/ml blood (n = 24), which was significantly higher compared with patients without PTLD (median: 50 copies/ml blood, n = 273, P < 0.0001). From receiver operating characteristic (ROC) curve analysis we obtained a cut-off value of 6215 copies/ml blood with a sensitivity of 95.8%, specificity of 71.4%, negative predictive value (NPV) of 99.5% and positive predictive value (PPV) of 22.8%. Thus, real-time PCR proved to be more useful in ruling out than in indicating the presence of PTLD. Further analysis showed that patients without PTLD but developing a post-transplant EBV-primary infection had associated high viral loads that were indistinguishable from those of the PTLD group (statistically not significant). Similarly, the presence of clinical symptoms of disease in patients without PTLD was associated with higher viral loads than in patients that were asymptomatic (P < 0.0001), but the difference was much less significant when compared with the PTLD group of patients (P = 0.0391). These patients who had a high viral load may benefit from a close follow-up of the viral burden.


Assuntos
Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/isolamento & purificação , Transtornos Linfoproliferativos/virologia , Transplante de Órgãos , Adolescente , Argentina , Criança , Pré-Escolar , DNA Viral/sangue , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Carga Viral
20.
Hum Mutat ; 21(4): 451, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12655572

RESUMO

The block in differentiation from pro-B to pre-B cells results in a selective defect in the humoral immune response characteristic of human X-linked agammaglobulinemia (XLA). Mutations of Bruton tyrosine kinase (BTK) gene have been identified as the cause of XLA. Mutation detection is the most reliable method for making a definitive diagnosis, except when clinical and laboratory findings are distinctive and coupled with history of X-linked inheritance. To provide a definitive diagnosis to 40 families incorporated in the Argentinian Primary Immunodeficiencies Registry we analysed the BTK gene by SSCP analysis as screening method for XLA, followed by direct sequencing. The molecular defect was localized in 45 patients from 34 unrelated families. From the 34 independent mutations identified, 16 were previously undescribed, 31 were unique mutations, 22 were exonic single nucleotide changes (16 missense and 6 nonsense) and four intronic mutations. Because five families had clinical, immunological and inheritance data sufficient for a definitive diagnosis, our study allowed 37 patients from 29 families previously categorized probable/ possible XLA, have now definitive diagnosis leading to appropriate genetic counseling.


Assuntos
Agamaglobulinemia/enzimologia , Agamaglobulinemia/genética , Mutação , Proteínas Tirosina Quinases/genética , Tirosina Quinase da Agamaglobulinemia , Agamaglobulinemia/diagnóstico , Agamaglobulinemia/epidemiologia , Argentina/epidemiologia , Triagem de Portadores Genéticos/métodos , Testes Genéticos/métodos , Humanos , Masculino , Polimorfismo Conformacional de Fita Simples
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