RESUMO
STAT3 is a cytokine-signaling transcription factor critical for gene regulation. Gain-of-function (GOF) mutations in STAT3 are associated with lymphoproliferation, autoimmune cytopenias, increased susceptibility to infection, early-onset solid-organ autoimmunity, short stature, and eczema. We studied the JAK/STAT signaling pathway gene expression and the cytokine profile in two families carrying STAT3-GOF variants to shed light on the STAT3-GOF-associated variable expressivity, including the identification of disease markers. Considering 92 target genes, KIT and IL2RA were downregulated only in patients with high clinical penetrance, while CXCL8 was markedly downregulated for all of them. Unlike previous studies, SOCS3-a STAT3 inhibitor-was not upregulated in patients. In addition, low levels of IL-2 and a reduced numbers of Tregs cells were strikingly prevalent in patients. This study shows a disruptive role of STAT3-GOF variants in the regulatory axis activities CXCL8/STAT3, KIT/STAT3, IL2/CD25/Treg, which, by slightly different mechanisms, underlie the broad clinical spectrum seen in the studied patients. In addition, we suggest the investigation of CXCL8 as a biomarker for identifying STAT3-GOF mutation.
Assuntos
Mutação com Ganho de Função , Subunidade alfa de Receptor de Interleucina-2/metabolismo , Interleucina-2/metabolismo , Interleucina-8/metabolismo , Fator de Transcrição STAT3/genética , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Adulto , Pré-Escolar , Hibridização Genômica Comparativa , Citocinas/sangue , Citocinas/metabolismo , Feminino , Regulação da Expressão Gênica , Estudo de Associação Genômica Ampla , Mutação em Linhagem Germinativa , Heterozigoto , Humanos , Imunofenotipagem , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Sequenciamento do Exoma , Sequenciamento Completo do GenomaRESUMO
BACKGROUND: Thrombocytopenia can occur in different circumstances during childhood and although immune thrombocytopenia is its most frequent cause, it is important to consider other conditions, especially when there is a persistent or recurrent low platelet count. We report two cases of intermittent thrombocytopenia, previously misdiagnosed as immune thrombocytopenia. CASES PRESENTATION: Both cases described were boys who presented with an intermittent pattern of thrombocytopenia, with a persistently low mean platelet volume. In both patients, peripheral blood smear revealed small platelets and flow cytometry showed low expression of Wiskott-Aldrich syndrome protein (WASP) in leucocytes. Molecular analysis of the first case identified a mutation in exon 2 of the gene coding for WASP, leading to a p.Thr45Met amino acid change and confirming the diagnosis of X-linked thrombocytopenia. In the second case, a novel missense mutation in exon 2 of the gene coding for WASP was detected, which resulted in a p.Pro58Leu amino acid change. CONCLUSION: These two rare presentations of thrombocytopenia highlight the importance of evaluating the peripheral blood smear in the presence of recurrent or persistent thrombocytopenia and show that failing to do so can lead to misdiagnoses. Since thrombocytopenia may be found in pediatric outpatient clinic, increased awareness among general pediatricians will help to improve the differential diagnosis of this condition.
Assuntos
Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Trombocitopenia/diagnóstico , Proteína da Síndrome de Wiskott-Aldrich/genética , Pré-Escolar , Erros de Diagnóstico , Doenças Genéticas Ligadas ao Cromossomo X/sangue , Doenças Genéticas Ligadas ao Cromossomo X/genética , Marcadores Genéticos , Humanos , Lactente , Masculino , Mutação , Contagem de Plaquetas , Trombocitopenia/sangue , Trombocitopenia/genéticaRESUMO
Most cases of autoimmune lymphoproliferative syndrome (ALPS) have an inherited genetic defect involving apoptosis-related genes of the FAS pathway. MicroRNAs (miRNAs) are a class of small non-coding regulatory RNAs playing a role in the control of gene expression. This is the first report on miRNAs in ALPS patients. We studied a mother and son carrying the same FAS cell surface death receptor (FAS) mutation, but with only the son manifesting the signs and symptoms of ALPS-FAS. The aim was to analyse, by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), the peripheral blood mononuclear cells (PBMC) relative expression of miR-146a and miR-21, including their passenger strands and respective targets (FAS and FASLG). In comparison with healthy matched control individuals, miR-21-3p was over-expressed significantly (P = 0·0313) in the son, with no significant change in the expression of miR-146a, miR-146a-3p and miR-21. In contrast, the mother had a slight under-expression of the miR-146a pair and miR-21-3p (P = 0·0625). Regarding the miRNA targets, FAS was up-regulated markedly for the mother (P = 0·0078), but down-regulated for the son (P = 0·0625), while FASLG did not have any significant alteration. Taken together, our finding clearly suggests a role of the miR-146a/FAS axis in ALPS-FAS variable expressivity in which FAS haploinsufficiency seems to be compensated only in the mother who had the miR-146a pair down-regulated. As only the son had the major clinical manifestations of ALPS-FAS, miR-21-3p should be investigated as playing a critical role in ALPS physiopathology, including the development of lymphoma.
Assuntos
Síndrome Linfoproliferativa Autoimune/genética , Proteína Ligante Fas/genética , MicroRNAs/genética , Mutação , Receptor fas/genética , Adulto , Apoptose , Síndrome Linfoproliferativa Autoimune/fisiopatologia , Regulação para Baixo , Feminino , Regulação da Expressão Gênica , Humanos , Leucócitos Mononucleares , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Regulação para CimaRESUMO
Hyper-IgM (HIGM) syndrome is a heterogeneous group of disorders characterized by normal or elevated serum IgM levels associated with absent or decreased IgG, IgA and IgE. Here we summarize data from the HIGM syndrome Registry of the Latin American Society for Immunodeficiencies (LASID). Of the 58 patients from 51 families reported to the registry with the clinical phenotype of HIGM syndrome, molecular defects were identified in 37 patients thus far. We retrospectively analyzed the clinical, immunological and molecular data from these 37 patients. CD40 ligand (CD40L) deficiency was found in 35 patients from 25 families and activation-induced cytidine deaminase (AID) deficiency in 2 unrelated patients. Five previously unreported mutations were identified in the CD40L gene (CD40LG). Respiratory tract infections, mainly pneumonia, were the most frequent clinical manifestation. Previously undescribed fungal and opportunistic infections were observed in CD40L-deficient patients but not in the two patients with AID deficiency. These include the first cases of pneumonia caused by Mycoplasma pneumoniae, Serratia marcescens or Aspergillus sp. and diarrhea caused by Microsporidium sp. or Isospora belli. Except for four CD40L-deficient patients who died from complications of presumptive central nervous system infections or sepsis, all patients reported in this study are alive. Four CD40L-deficient patients underwent successful bone marrow transplantation. This report characterizes the clinical and genetic spectrum of HIGM syndrome in Latin America and expands the understanding of the genotype and phenotype of this syndrome in tropical areas.
Assuntos
Síndrome de Imunodeficiência com Hiper-IgM/epidemiologia , Ligante de CD40/deficiência , Ligante de CD40/genética , Pré-Escolar , Comorbidade , Citidina Desaminase/deficiência , Citidina Desaminase/genética , Feminino , Hispânico ou Latino , Humanos , Síndrome de Imunodeficiência com Hiper-IgM/complicações , Síndrome de Imunodeficiência com Hiper-IgM/diagnóstico , Síndrome de Imunodeficiência com Hiper-IgM/terapia , Lactente , Recém-Nascido , Infecções/diagnóstico , Infecções/etiologia , Pulmão/patologia , Masculino , Sistema de Registros , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
INTRODUCTION: Adherence, which is crucial to the success of antiretroviral therapy (HAART), is currently a major challenge in the care of children and adolescents living with HIV/AIDS. OBJECTIVE: To evaluate the prevalence of nonadherence to HAART using complementary instruments in a cohort of children and adolescents with HIV/AIDS followed in a reference service in Campinas, Brazil. METHODS: The level of adherence of 108 patients and caregivers was evaluated by an adapted standardized questionnaire and pharmacy dispensing records (PDR). Non-adherence was defined as a drug intake lower than 95% (on 24-hour or seven-day questionnaires), or as an interval of 38 days or more for pharmacy refills. The association between adherence and clinical, immunological, virological, and psychosocial characteristics was assessed by multivariate analysis. RESULTS: Non-adherence prevalence varied from 11.1% (non-adherent in three instruments), 15.8% (24-hour self-report), 27.8% (seven-day self-report), 45.4% (PDR), and 56.3% (at least one of the outcomes). 24-hour and seven-day self-reports, when compared to PDR, showed low sensitivity (29% and 43%, respectively) but high specificity (95% and 85%, respectively). In multivariate analysis, medication intolerance, difficulty of administration by caregiver, HAART intake by the patient, lower socioeconomical class, lack of virological control, missed appointments in the past six months, and lack of religious practice by caregiver were significantly associated with non-adherence. CONCLUSION: A high prevalence of HAART non-adherence was observed in the study population, and PDR was the most sensitive of the tested instruments. The instruments employed were complementary in the identification of non-adherence.
Assuntos
Terapia Antirretroviral de Alta Atividade/estatística & dados numéricos , Prescrições de Medicamentos/estatística & dados numéricos , Infecções por HIV/tratamento farmacológico , Adesão à Medicação/estatística & dados numéricos , Farmácias/estatística & dados numéricos , Adolescente , Terapia Antirretroviral de Alta Atividade/psicologia , Cuidadores , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Adesão à Medicação/psicologia , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto JovemRESUMO
Apocynin is widely used as an inhibitor of the NADPH oxidase. Since myeloperoxidase (MPO) has been considered as essential for the mechanism of action of apocynin, here we used cells with different levels of MPO and compared their sensitivity to apocynin. HL-60 cells were differentiated with DMSO or IFN γ /TNF α and compared with peripheral mononuclear (PBMC) and polymorphonuclear cells (PMN). The relative MPO activity was PBMC = HL60 DMSO < HL60 IFN γ < PMN. Apocynin inhibited the intracellular reactive oxygen species production by PMN (80%) and IFN γ /TNF α -differentiated HL-60 cells (45%) but showed a minor effect in PBMC and DMSO differentiated HL-60 cells (20%). The addition of azide decreased the efficiency of apocynin in PMN and the addition of peroxidase increased the inhibition in PBMC. We also determined the gene expression of the components gp91phox, p47phox, p22phox and p67phox in the resting cells. Apocynin did not change gp91phox, p47phox or p22phox gene expression in nonstimulated PBMC, HL60 DMSO, HL60 IFN γ /TNF α , and PMN and has a subtle increase in p67phox in HL60 IFN γ /TNF α . The results from this work suggest that a rational search for better inhibitors of NADPH oxidase in leukocytes should include a correlation with their affinity as substrates for MPO.
RESUMO
Little is known about the vaccine protective response for infants born from HIV-infected mothers. We evaluated the antibody response to hepatitis B, tetanus, and diphtheria vaccine in vertically HIV-exposed uninfected infants and compared them to those of control infants not exposed to the virus. The quantitative determination of specific neutralizing antibodies against hepatitis B, diphtheria, and tetanus were performed blindly on serum samples. The results showed that 6.7% of the HIV-exposed uninfected individuals were nonresponders to hepatitis B vaccine (anti-HBs titer, <10 mIU/ml), and 64.4% were very good responders (anti-HBs titer, ≥1,000 mIU/ml), whereas only 3.6% of the nonexposed infants were nonresponders (χ(2)=10.93; 1 df). The HIV-exposed uninfected infants showed protective titers for diphtheria and tetanus but lower geometric mean anti-tetanus titers compared to those of the HIV-unexposed infants. Our data point to the necessity of evaluating vaccine immune responses in these children and reinforced that alterations in lymphocyte numbers and functions reported for newborns from HIV-infected mothers interfere with the vaccine response.