RESUMO
BACKGROUND: Approximately 5.1 million Israelis had been fully immunized against coronavirus disease 2019 (Covid-19) after receiving two doses of the BNT162b2 messenger RNA vaccine (Pfizer-BioNTech) by May 31, 2021. After early reports of myocarditis during adverse events monitoring, the Israeli Ministry of Health initiated active surveillance. METHODS: We retrospectively reviewed data obtained from December 20, 2020, to May 31, 2021, regarding all cases of myocarditis and categorized the information using the Brighton Collaboration definition. We analyzed the occurrence of myocarditis by computing the risk difference for the comparison of the incidence after the first and second vaccine doses (21 days apart); by calculating the standardized incidence ratio of the observed-to-expected incidence within 21 days after the first dose and 30 days after the second dose, independent of certainty of diagnosis; and by calculating the rate ratio 30 days after the second dose as compared with unvaccinated persons. RESULTS: Among 304 persons with symptoms of myocarditis, 21 had received an alternative diagnosis. Of the remaining 283 cases, 142 occurred after receipt of the BNT162b2 vaccine; of these cases, 136 diagnoses were definitive or probable. The clinical presentation was judged to be mild in 129 recipients (95%); one fulminant case was fatal. The overall risk difference between the first and second doses was 1.76 per 100,000 persons (95% confidence interval [CI], 1.33 to 2.19), with the largest difference among male recipients between the ages of 16 and 19 years (difference, 13.73 per 100,000 persons; 95% CI, 8.11 to 19.46). As compared with the expected incidence based on historical data, the standardized incidence ratio was 5.34 (95% CI, 4.48 to 6.40) and was highest after the second dose in male recipients between the ages of 16 and 19 years (13.60; 95% CI, 9.30 to 19.20). The rate ratio 30 days after the second vaccine dose in fully vaccinated recipients, as compared with unvaccinated persons, was 2.35 (95% CI, 1.10 to 5.02); the rate ratio was again highest in male recipients between the ages of 16 and 19 years (8.96; 95% CI, 4.50 to 17.83), with a ratio of 1 in 6637. CONCLUSIONS: The incidence of myocarditis, although low, increased after the receipt of the BNT162b2 vaccine, particularly after the second dose among young male recipients. The clinical presentation of myocarditis after vaccination was usually mild.
Assuntos
Vacina BNT162/efeitos adversos , COVID-19/prevenção & controle , Miocardite/etiologia , Adolescente , Adulto , Distribuição por Idade , Comorbidade , Ecocardiografia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Israel/epidemiologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Miocardite/epidemiologia , Gravidade do Paciente , Estudos Retrospectivos , Distribuição por Sexo , Adulto JovemRESUMO
BACKGROUND AND AIMS: We found a higher incidence of myocarditis in young males who had received at least two Pfizer-BioNTech BNT162b2 vaccinations. The human leukocyte antigens (HLA) are known to play an important role in infectious and autoinflammatory diseases. We hypothesized that certain HLA alleles might be associated with vaccination-induced myocarditis. METHODS: HLA typing was performed using next-generation sequencing technology with the Illumina Iseq100 platform. HLA class I and II loci were genotyped in 29 patients with post-vaccination myocarditis and compared with HLA data from 300 healthy controls. RESULTS: We demonstrate that the DRB1*14:01, DRB1*15:03 alleles and the motifs in HLA-A - Leu62 and Gln63, which are part of binding pocket B and HLA-DR Tyr47, His60, Arg70 and Glu74, which are part of binding pockets P4, P7 and P9, were significantly associated with disease susceptibility. CONCLUSIONS: Our findings suggest that immunogenetic fingerprints in HLA peptide-binding grooves may affect the presentation of peptides derived from the Pfizer-BioNTech BNT162b2 vaccination to T cells and induce an inflammatory process that results in myocarditis.
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Vacina BNT162 , Miocardite , Masculino , Humanos , Miocardite/induzido quimicamente , Miocardite/genética , Cadeias HLA-DRB1/metabolismo , Antígenos HLA , Suscetibilidade a Doenças , PeptídeosRESUMO
Bacteria, such as Fusobacterium nucleatum, are present in the tumor microenvironment. However, the immunological consequences of intra-tumoral bacteria remain unclear. Here, we have shown that natural killer (NK) cell killing of various tumors is inhibited in the presence of various F. nucleatum strains. Our data support that this F. nucleatum-mediated inhibition is mediated by human, but not by mouse TIGIT, an inhibitory receptor present on all human NK cells and on various T cells. Using a library of F. nucleatum mutants, we found that the Fap2 protein of F. nucleatum directly interacted with TIGIT, leading to the inhibition of NK cell cytotoxicity. We have further demonstrated that tumor-infiltrating lymphocytes expressed TIGIT and that T cell activities were also inhibited by F. nucleatum via Fap2. Our results identify a bacterium-dependent, tumor-immune evasion mechanism in which tumors exploit the Fap2 protein of F. nucleatum to inhibit immune cell activity via TIGIT.
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Adenocarcinoma/imunologia , Adenocarcinoma/microbiologia , Neoplasias do Colo/imunologia , Neoplasias do Colo/microbiologia , Fusobacterium nucleatum/imunologia , Receptores Imunológicos/imunologia , Evasão Tumoral/imunologia , Microambiente Tumoral/imunologia , Animais , Proteínas da Membrana Bacteriana Externa/imunologia , Linhagem Celular , Proliferação de Células , Humanos , Células Matadoras Naturais/imunologia , Linfócitos do Interstício Tumoral/imunologia , Camundongos , Ligação ProteicaRESUMO
BACKGROUND: Homozygous CD59-deficient patients manifest with recurrent peripheral neuropathy resembling Guillain-Barré syndrome (GBS), hemolytic anemia and recurrent strokes. Variable mutations in CD59 leading to loss of function have been described and, overall, 17/18 of patients with any mutation presented with recurrent GBS. Here we determine the localization and possible role of membrane-bound complement regulators, including CD59, in the peripheral nervous systems (PNS) of mice and humans. METHODS: We examined the localization of membrane-bound complement regulators in the peripheral nerves of healthy humans and a CD59-deficient patient, as well as in wild-type (WT) and CD59a-deficient mice. Cross sections of teased sciatic nerves and myelinating dorsal root ganglia (DRG) neuron/Schwann cell cultures were examined by confocal and electron microscopy. RESULTS: We demonstrate that CD59a-deficient mice display normal peripheral nerve morphology but develop myelin abnormalities in older age. They normally express myelin protein zero (P0), ankyrin G (AnkG), Caspr, dystroglycan, and neurofascin. Immunolabeling of WT nerves using antibodies to CD59 and myelin basic protein (MBP), P0, and AnkG revealed that CD59 was localized along the internode but was absent from the nodes of Ranvier. CD59 was also detected in blood vessels within the nerve. Finally, we show that the nodes of Ranvier lack other complement-membrane regulatory proteins, including CD46, CD55, CD35, and CR1-related gene-y (Crry), rendering this area highly exposed to complement attack. CONCLUSION: The Nodes of Ranvier lack CD59 and are hence not protected from complement terminal attack. The myelin unit in human PNS is protected by CD59 and CD55, but not by CD46 or CD35. This renders the nodes and myelin in the PNS vulnerable to complement attack and demyelination in autoinflammatory Guillain-Barré syndrome, as seen in CD59 deficiency.
Assuntos
Síndrome de Guillain-Barré , Proteínas de Membrana , Camundongos , Humanos , Animais , Nós Neurofibrosos , Proteínas do Sistema Complemento , Antígenos CD59/genética , Antígenos CD55/genéticaRESUMO
OBJECTIVE: To investigate phenotypic and molecular characteristics of a consanguineous family with autosomal-recessive, polyarticular, juvenile isiopathic arthriris (JIA) with extra-articular manifestations, including renal amyloidosis and Crohn's disease, associated with a novel homozygous truncating variant in LACC1. METHODS: Whole exome sequencing (WES) or targeted Sanger verification were performed in 15 participants. LACC1 expression and cytokine array were analysed in patient-derived and CRISPR/Cas9-generated LACC1-knockout macrophages (MÏ). RESULTS: A homozygous truncating variant (p.Glu348Ter) in LACC1 was identified in three affected and one asymptomatic family member, and predicted harmful by causing premature stop of the LACC1 protein sequences, and by absence from ethnically-matched controls and public variation databases. Expression studies in patient-derived macrophages (MÏ) showed no endogenous p.Glu348Ter-LACC1 RNA transcription or protein expression, compatible with nonsense-mediated mRNA decay. WES analysis in the asymptomatic homozygous subject for p. Glu348Ter-LACC1 detected an exclusive heterozygous variant (p.Arg928Gln) in complement component C5. Further complement activity analysis suggested a protective role for the p.Arg928Gln-C5 variant as a phenotypic modifier of LACC1-associated disease. Finally, cytokine profile analysis indicated increased levels of pro-inflammatory cytokines in LACC1-disrupted as compared with wild-type MÏ. CONCLUSIONS: Our findings reinforce the role of LACC1 disruption in autosomal-recessive JIA, extend the clinical spectrum and intra-familial heterogeneity of the disease-associated phenotype, indicate a modulatory effect of complement factor C5 on phenotypic severity, and suggest an inhibitory role for wild-type LACC1 on pro-inflammatory pathways.
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Artrite Juvenil/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Mutação com Perda de Função/genética , Adolescente , Adulto , Artrite Juvenil/patologia , Proteína 9 Associada à CRISPR , Sistemas CRISPR-Cas , Citocinas/sangue , Feminino , Citometria de Fluxo , Edição de Genes , Humanos , Immunoblotting , Masculino , Linhagem , Sequenciamento do Exoma , Adulto JovemRESUMO
Anti-RhD antibodies are widely used in clinical practice to prevent immunization against RhD, principally in hemolytic disease of the fetus and newborn. Intriguingly, this disease is induced by production of the very same antibodies when an RhD negative woman is pregnant with an RhD positive fetus. Despite over five decades of use, the mechanism of this treatment is, surprisingly, still unclear. Here we show that anti-RhD antibodies induce human natural killer (NK) cell degranulation. Mechanistically, we demonstrate that NK cell degranulation is mediated by binding of the Fc segment of anti-RhD antibodies to CD16, the main Fcγ receptor expressed on NK cells. We found that this CD16 activation is dependent upon glycosylation of the anti-RhD antibodies. Furthermore, we show that anti-RhD antibodies induce NK cell degranulation in vivo in patients who receive this treatment prophylactically. Finally, we demonstrate that the anti-RhD drug KamRho enhances the killing of dendritic cells. We suggest that this killing leads to reduced activation of adaptive immunity and may therefore affect the production of anti-RhD antibodies.
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Células Matadoras Naturais , Receptores de IgG , Feminino , Feto/metabolismo , Glicosilação , Humanos , Recém-Nascido , Ativação Linfocitária , Gravidez , Receptores de IgG/metabolismoAssuntos
Vacina BNT162/efeitos adversos , Hospitalização/estatística & dados numéricos , Imunização Secundária/efeitos adversos , Miocardite/epidemiologia , Adolescente , Criança , Feminino , Humanos , Incidência , Israel/epidemiologia , Masculino , Miocardite/induzido quimicamente , Risco , Distribuição por SexoAssuntos
Anticorpos , Vacinas contra COVID-19 , COVID-19 , Proteína Antagonista do Receptor de Interleucina 1 , Miocardite , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , Proteína Antagonista do Receptor de Interleucina 1/imunologia , Miocardite/etiologia , Miocardite/imunologia , SARS-CoV-2 , VacinaçãoRESUMO
BACKGROUND: Fetal complete atrioventricular block (CAVB) is usually autoimmune mediated. The risk of developing CAVB is 2% to 3% in anti-Ro/SS-A seropositive pregnancies and it increases 10 times after previous CAVB in siblings. Despite being a rare complication, CAVB carries a 20% mortality rate and substantial morbidity, as about 65% of newborns will eventually need life-long pacing. Once found, fetal CAVB is almost always irreversible, despite aggressive immunotherapy. This poor outcome prompted some research groups to address this situation. All groups followed anti-Ro/SS-A seropositive pregnancies on a weekly basis during the second trimester of pregnancy and tried to detect first degree atrioventricular block (AVB) using accurate echocardiographic tools, assuming they may characterize the initiation of the immune damage to the A-V conduction system, at which point the process might still be reversible. Some of the groups treated fetuses with first degree AVB with maternal oral fluorinated steroids. We summarized the results of all groups, including our group. We describe a case of a fetus that developed CAVB 6 days after normal sinus rhythm (NSR), who under aggressive dexamethasone therapy gradually reverted to NSR. This fetus had a previous sibling with CAVB. We assumed the immune damage to the conduction system in this small group of fetuses with a previous CAVB sibling may have occurred more quickly than usual. We therefore recommend a twice-weekly follow-up with these fetuses.
Assuntos
Bloqueio Atrioventricular/tratamento farmacológico , Dexametasona/administração & dosagem , Doenças Fetais/tratamento farmacológico , Adulto , Bloqueio Atrioventricular/diagnóstico , Bloqueio Atrioventricular/imunologia , Feminino , Doenças Fetais/diagnóstico , Doenças Fetais/imunologia , Glucocorticoides/administração & dosagem , Humanos , Recém-Nascido , Gravidez , Segundo Trimestre da Gravidez , Diagnóstico Pré-Natal/métodos , Resultado do TratamentoRESUMO
BACKGROUND: Tocilizumab is an interleukin 6 (IL-6) receptor antagonist used treat moderate to severe active rheumatoid arthritis (RA). Both intravenous (IV) and subcutaneous (SC) routes are approved for the treatment of adults with RA. OBJECTIVES: To evaluate SC tocilizumab in a real-life clinical setting. METHODS: Our study was a multi-center, open-label, single-arm study. Participants were adults with a diagnosis of active RA, previously treated with disease-modifying antirheumatic drugs (DMARDs), with or without biologic agents. Participants received a weekly SC injection of tocilizumab 162 mg as monotherapy or in combination with methotrexate or DMARDs for 24 weeks. Efficacy, safety, and immunogenicity were assessed. RESULTS: Treatment of 100 patients over 24 weeks resulted in improvement in all efficacy parameters assessed: Clinical Disease Activity Index, Disease Activity Score using 28 joint counts and erythrocyte sedimentation rate, American College of Rheumatology response scores, Simplified Disease Activity Index, tender and swollen joint counts, and patient-reported outcomes including fatigue, global assessment of disease activity, pain, and Health Assessment Quality of Life Disease Index. Improvement was achieved as early as the second week of treatment. There were 473 adverse events (AEs)/100 patient-years (PY) and 16.66 serious AEs/100 PY. The most common AEs were neutropenia (12%), leukopenia (11%), and increased hepatic enzymes (11%). Of a total of 42 PY, the rates of serious infections and AEs leading to discontinuation were 4.8, and 11.9 events/100 PY, respectively. CONCLUSIONS: The safety, tolerability, and efficacy profile of tocilizumab SC were comparable to those reported in other studies evaluating the IV and SC routes of administration.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antirreumáticos/administração & dosagem , Artrite Reumatoide/tratamento farmacológico , Anticorpos Monoclonais Humanizados/efeitos adversos , Antirreumáticos/efeitos adversos , Esquema de Medicação , Quimioterapia Combinada , Feminino , Humanos , Injeções Subcutâneas , Masculino , Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Pessoa de Meia-Idade , Medidas de Resultados Relatados pelo PacienteRESUMO
OBJECTIVES: Group A streptococcal (GAS) tonsillitis is reported as an uncommon cause of acute non-rheumatic fever (non-RF) myocarditis. The aim of this research was to study the occurrence, diagnosis, management and prognosis of this condition. METHODS: We conducted a retrospective computerised search through medical records of patients admitted to our tertiary medical center between 1998-2016 with the diagnosis of either acute rheumatic fever or non-RF streptococcal myocarditis based on criteria we developed and review the relevant literature from 1973-2016. RESULTS: We identified 283 cases diagnosed with acute myocarditis. Eight patients with non-RF GAS-myocarditis were identified, 7 of whom were men. Average age was 28.5 (22-35) years, and average latency period between onset of sore throat and chest pain 4.8 (3-10) days. Most patients presented with ST-segment elevations on the ECG and 2 underwent coronary catheterisation with presumed diagnosis of myocardial infarction. Three patients had heart failure, as documented by echocardiogram. All patients were treated with antibiotics and 6 patients received non-steroidal anti-inflammatory drugs (NSAIDs). All patients recovered with no evidence of heart failure a few months after the initial infection. One patient had a recurrent episode. CONCLUSIONS: Non-RF GAS myocarditis typically affects healthy young males and represents about 3% of all hospitalised patients with myocarditis. These patients may be mistakenly diagnosed with an acute rheumatic fever or myocardial infarction. The prognosis in generally good following treatment with antibiotics and possibly NSAIDs.
Assuntos
Miocardite , Infecções Estreptocócicas , Tonsilite/complicações , Adulto , Eletrocardiografia , Feminino , Humanos , Masculino , Miocardite/etiologia , Estudos Retrospectivos , Febre Reumática , Infecções Estreptocócicas/complicações , Tonsilite/microbiologiaRESUMO
OBJECTIVES: Loss of the complement inhibitor CD55 leads to a syndrome of early-onset protein-losing enteropathy (PLE), associated with intestinal lymphangiectasia and susceptibility to large-vein thrombosis. The in vitro and short-term treatment benefits of eculizumab (C5-inhibitor) therapy for CD55-deficiency have been previously demonstrated. Here we present the 18-months treatment outcomes for 3 CD55-deficiency patients with sustained therapeutic response. METHODS: Three CD55-deficiency patients received off-label eculizumab treatment. Clinical and laboratory treatment outcomes included frequency and consistency of bowl movements, weight, patient/parent reports of overall well-being, and serum albumin and total protein levels. Membrane attack complex deposition on leukocytes was tested by flow cytometry, before and during eculizumab treatment. RESULTS: Marked clinical improvement was noted in all 3 patients with resolution of PLE manifestations, that is, diarrhea, edema, malabsorption, overall well-being, growth, and quality of life. In correlation with the clinical observations, we observed progress in all laboratory outcome parameters, including increase in albumin and total protein levels, and up to 80% reduction in membrane attack complex deposition on leukocytes (P < 0.001). The progress persisted over 18 months of treatment without any severe adverse events. CONCLUSIONS: CD55-deficiency patients present with early-onset diarrhea, edema, severe hypoalbuminemia, abdominal pain, and malnutrition. Targeted therapy with the terminal complement inhibitor eculizumab has positive clinical and laboratory outcomes in PLE related to CD55 loss-of-function mutations, previously a life-threatening condition. Our results demonstrate the potential of genetic diagnosis to guide tailored treatment, and underscore the significant role of the complement system in the intestine.
Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antígenos CD55/deficiência , Inativadores do Complemento/administração & dosagem , Enteropatias Perdedoras de Proteínas/tratamento farmacológico , Adulto , Criança , Pré-Escolar , Ensaios de Uso Compassivo , Relação Dose-Resposta a Droga , Esquema de Medicação , Seguimentos , Humanos , Infusões Intravenosas , Linfangiectasia Intestinal/complicações , Linfangiectasia Intestinal/patologia , Uso Off-Label , Estudos Prospectivos , Enteropatias Perdedoras de Proteínas/etiologia , Qualidade de Vida , Indução de RemissãoRESUMO
INTRODUCTION: Hadassah-Hebrew University Medical Center is regaining its lead in Israeli public medicine with clinical excellence, state-of-the art technology, high achievement in research, and outstanding medical education for students and trainees. Hadassah has two campuses at Ein Kerem and Mount Scopus that together offer 1200-hospital beds and 40 hybrid and advanced operating rooms. Hadassah Medical Center, an initiative of Hadassah organization led by Henrietta Szold, is one of the foremost health care providers in Israel. Together, the Hebrew University and Hadassah are home to Schools of Medicine, Pharmacy, Nursing, Public Health, Occupational Therapy, and Dental Medicine. The medical school enrolls over 1000 medical students including a special track for military physicians. Hadassah opened the new Davidson medical tower in 2012 and the development of new infrastructure continues for Centers of Excellence in Surgery, Oncology, Hematology, and Medicine, for the benefit of the public in greater Jerusalem and all of Israel. In this journal, we will present 12 articles that represent the integration of state-of-the-art clinical medicine and research technologies, all dedicated to advancing medicine for the people of Israel.
Assuntos
Centros Médicos Acadêmicos , Educação Médica , Faculdades de Medicina/normas , Humanos , Israel , MedicinaRESUMO
INTRODUCTION: Sir William Osler is considered to be one of the fathers of modern medicine who pioneered the practice of bedside teaching of clinical medicine for medical students and residents. Osler was well known as a diagnostician and outstanding therapist with a humanized approach and rare didactic capabilities. Medical training at Hadassah is built on the central tenets of Osler's approach, incorporating the tremendous advances in science and medicine. Training for residents in Internal Medicine is designed to develop a broad base of medical and, if possible, scientific knowledge, as well as skills and competencies to deliver a high standard of patient care. In the past 7 years, 28 residents have undergone specialist training in Internal Medicine B. Among them, 71% were Israeli medical school graduates; 36% were women;18% were recent immigrants to Israel; 78% were Jewish. Among Jewish residents, 32% were religiously observant. Besides the usual assignments of the internal medicine ward, the medical staff of Internal Medicine B excelled in diagnosis of hard to diagnose diseases as described in eleven cases. The diagnosis in some of those cases was a result of listening to the patient, education on clinical reasoning and the use advanced diagnostic tools. The basic unit of the residency is the clinical mission with an emphasis on exposure to novel modalities such as the use of bedside ultra sound along with dealing with end-of-life dilemmas, the management of complex situations and development of communication and interpersonal skills needed to work with close relatives and families facing critical times. The medical training in the internal ward is not just the sum of arbitrary care of the hospitalized patients, but a well-structured plan with gradually increasing demands. Over the past 7 years, residents in Internal Medicine B have achieved successful passing grades of 38/38 on the first attempt oral and written board examinations, a record that attests to the quality of the trainees and the training process. Hadassah has a long history of providing state-of-the-art patient care, and training young physicians to maintain this high standard - but the education process necessitates longstanding efforts and continuous striving for excellence.
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Medicina Interna , Internato e Residência , Competência Clínica , Comunicação , Currículo , Feminino , Humanos , Israel , Masculino , Faculdades de MedicinaRESUMO
OBJECTIVE: The objective of this work was to report on the outcome of eculizumab treatment in pediatric patients with recurrent acute predominantly motor, demyelinating neuropathy with conduction block, and chronic hemolysis attributed to p.Cys89Tyr mutation in the CD59 gene. METHODS: Four patients were recruited from our new registry of patients with homozygosity for the p.Cys89Tyr mutation on CD59. Participants received repeated intravenous eculizumab. In this 24-month open-label phase IIa study, we aimed to determine whether eculizumab reduces chronic hemolysis, and cumulative doses of steroids and intravenous immunoglobulin (IVIG), and ameliorates neurological deficits, compared to pretreatment status. Treatment response was evaluated every 2 to 4 weeks over 104 weeks and included examination with gross motor scoring by American Spinal Injury Association Impairment Scale and Inflammatory Neuropathy Cause and Treatment disability score, laboratory examination, well-being [12-item Short Form Health Survey; SF-12]). Neurological relapses and cumulative dose of IVIGs and/or corticosteroids before and after treatment were documented. Red blood cells (RBCs) and neutrophils were stained to evaluate C5b-9 deposition. ClinicalTrials.gov: NCT01579838. RESULTS: Dramatic and significant neurological amelioration in the upper limbs and trunk with more-modest amelioration in the lower limbs was observed in all patients. Corticosteroid and IVIG treatment was completely stopped. No patient relapsed during treatment despite infections, and there were no hospital admissions. Decreased C3bi and C5b-9 deposition on RBCs and neutrophils was documented (p < 0.0001). The SF-12 health questionnaires indicated significant improvement (p < 0.003). INTERPRETATION: Eculizumab was safely administered to these patients. Marked clinical improvement suggests that eculizumab may be a life-saving treatment for patients with acute predominantly motor, demyelinating neuropathy with conduction block, and secondary axonal damage attributed to primary p.Cys89Tyr mutation in the CD59 gene. Ann Neurol 2016;80:708-717.
Assuntos
Anemia Hemolítica/complicações , Anticorpos Monoclonais Humanizados/farmacologia , Antígenos CD59/genética , Hemoglobinúria/complicações , Hemólise/efeitos dos fármacos , Polirradiculoneuropatia , Sistema de Registros , Anticorpos Monoclonais Humanizados/administração & dosagem , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Mutação , Polirradiculoneuropatia/tratamento farmacológico , Polirradiculoneuropatia/etiologia , Polirradiculoneuropatia/fisiopatologia , Resultado do TratamentoAssuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antígenos CD55/genética , Mutação da Fase de Leitura , Enteropatias Perdedoras de Proteínas/tratamento farmacológico , Enteropatias Perdedoras de Proteínas/genética , Criança , Pré-Escolar , Ensaios de Uso Compassivo , Ativação do Complemento , Complexo de Ataque à Membrana do Sistema Complemento/metabolismo , Diarreia/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Análise de Sequência de DNA , Albumina Sérica/metabolismo , Adulto JovemRESUMO
Severe congenital neutropenia as well as primary myelofibrosis are rare in infancy. Elucidation of the underlying mechanism is important because it extends our understanding of the more common adult forms of these disorders. Using homozygosity mapping followed by exome sequencing, we identified a Thr224Asn mutation in the VPS45 gene in infants from consanguineous families who suffered from life-threatening neutropenia, which was refractory to granulocyte CSF, from defective platelet aggregation and myelofibrosis. The mutation segregated in the families, was not present in controls, affected a highly conserved codon, and apparently destabilized the Vps45 protein, which was reduced in the patients' leukocytes. Introduction of the corresponding mutation into yeast resulted in reduced cellular levels of Vps45 and also of the cognate syntaxin Tlg2, which is required for membrane traffic through the endosomal system. A defect in the endosomal-lysosomal pathway, the homologous system in humans, was suggested by the absence of lysosomes in the patients' fibroblasts and by the depletion of α granules in their platelets. Importantly, accelerated apoptosis was observed in the patients' neutrophils and bone marrow. This is the first report of a Vps45-related disease in humans, manifesting by neutropenia, thrombasthenia, myelofibrosis, and progressive bone marrow failure.
Assuntos
Mutação , Neutropenia/congênito , Mielofibrose Primária/genética , Proteínas de Transporte Vesicular/genética , Sequência de Bases , Western Blotting , Síndrome Congênita de Insuficiência da Medula Óssea , Consanguinidade , Feminino , Imunofluorescência , Humanos , Lactente , Recém-Nascido , Masculino , Dados de Sequência Molecular , Neutropenia/genética , LinhagemRESUMO
CD59 deficiency is a common finding in RBCs and WBCs in patients with chronic hemolysis suffering from paroxysmal nocturnal hemoglobinuria in which the acquired mutation in the PIGA gene leads to membrane loss of glycosylphosphatidylinositol-anchored membrane proteins, including CD59. The objective of the present study was to elucidate the molecular basis of childhood familial chronic Coombs-negative hemolysis and relapsing polyneuropathy presenting as chronic inflammatory demyelinating polyradiculoneuropathy in infants of North-African Jewish origin from 4 unrelated families. A founder mutation was searched for using homozygosity mapping followed by exome sequencing. The expression of CD59, CD55, and CD14 was examined in blood cells by flow cytometry followed by Western blot of the CD59 protein. A homozygous missense mutation, p.Cys89Tyr in CD59, was identified in all patients. The mutation segregated with the disease in the families and had a carrier rate of 1:66 among Jewish subjects of North-African origin. The mutated protein was present in the patients' cells in reduced amounts and was undetectable on the membrane surface. Based on the results of the present study, we conclude that the Cys89Tyr mutation in CD59 is associated with a failure of proper localization of the CD59 protein in the cell surface. This mutation is manifested clinically in infancy by chronic hemolysis and relapsing peripheral demyelinating disease.