Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Arthritis Rheumatol ; 74(1): 150-162, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34196496

RESUMO

OBJECTIVE: Antinuclear antibody (ANA)-positive juvenile idiopathic arthritis (JIA) is characterized by synovial B cell hyperactivity, but the precise role of CD4+ T cells in promoting local B cell activation is unknown. This study was undertaken to determine the phenotype and function of synovial CD4+ T cells that promote aberrant B cell activation in JIA. METHODS: Flow cytometry was performed to compare the phenotype and cytokine patterns of PD-1high CD4+ T cells in the synovial fluid (SF) of patients with JIA and T follicular helper cells in the tonsils of control individuals. TCRVB next-generation sequencing was used to analyze T cell subsets for signs of clonal expansion. The functional impact of these T cell subsets on B cells was examined in cocultures in vitro. RESULTS: Multidimensional flow cytometry revealed the expansion of interleukin-21 (IL-21) and interferon-γ (IFNγ)-coexpressing PD-1high CXCR5-HLA-DR+CD4+ T cells that accumulate in the joints of ANA-positive JIA patients. These T cells exhibited signs of clonal expansion with restricted T cell receptor clonotypes. The phenotype resembled peripheral T helper (Tph) cells with an extrafollicular chemokine receptor pattern and high T-bet and B lymphocyte-induced maturation protein 1 expression, but low B cell lymphoma 6 expression. SF Tph cells, by provision of IL-21 and IFNy, skewed B cell differentiation toward a CD21low/- CD11c+ phenotype in vitro. Additionally, SF Tph cell frequencies correlated with the appearance of SF CD21low/- CD11c+CD27-IgM- double-negative (DN) B cells in situ. CONCLUSION: Clonally expanded CD4+ Tph cells accumulate in the joints of ANA-positive JIA patients and, in particular, promote CD21low/- CD11c+ DN B cell differentiation. The expansion of Tph cells and DN B cells might reflect the autoimmune response in the joints of ANA-positive JIA patients.


Assuntos
Anticorpos Antinucleares , Artrite Juvenil/imunologia , Linfócitos B/imunologia , Linfócitos T CD4-Positivos/imunologia , Articulações/citologia , Receptor de Morte Celular Programada 1/imunologia , Receptores CXCR5/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Diferenciação Celular , Humanos , Ativação Linfocitária
2.
Front Pediatr ; 9: 635815, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33937147

RESUMO

Juvenile idiopathic arthritis (JIA) encompasses a heterogeneous group of diseases. The appearance of antinuclear antibodies (ANAs) in almost half of the patients suggests B cell dysregulation as a distinct pathomechanism in these patients. Additionally, ANAs were considered potential biomarkers encompassing a clinically homogenous subgroup of JIA patients. However, in ANA+ JIA patients, the site of dysregulated B cell activation as well as the B cell subsets involved in this process is still unknown. Hence, in this cross-sectional study, we aimed in an explorative approach at characterizing potential divergences in B cell differentiation in ANA+ JIA patients by assessing the distribution of peripheral blood (PB) and synovial fluid (SF) B cell subpopulations using flow cytometry. The frequency of transitional as well as switched-memory B cells was higher in PB of JIA patients than in healthy controls. There were no differences in the distribution of B cell subsets between ANA- and ANA+ patients in PB. However, the composition of SF B cells was different between ANA- and ANA+ patients with increased frequencies of CD21lo/-CD27-IgM- "double negative" (DN) B cells in the latter. DN B cells might be a characteristic subset expanding in the joints of ANA+ JIA patients and are potentially involved in the antinuclear immune response in these patients. The results of our explorative study might foster further research dissecting the pathogenesis of ANA+ JIA patients.

3.
Transfusion ; 61(6): 1916-1922, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33734454

RESUMO

BACKGROUND: CD177 is a surface protein on neutrophils and a main mediator for the surface expression of proteinase 3 (PR3). Its functions are largely unknown. At least three types of antibodies have been described to target CD177: isoantibodies, which are formed in CD177-null individuals as a result of an immune reaction following transfusion or pregnancy; autoantibodies present in sera from patients with autoimmune neutropenia; and antineutrophil cytoplasmic antibodies in sera from patients with glomerulonephritis with polyangiitis. In this study, we aimed to compare the binding characteristics of auto- and iso-antibodies to optimize their detectability in the neutrophil serology laboratory. STUDY DESIGN AND METHODS: The reactivity of iso- and auto-antibodies against CD177 was studied using granulocytes, "native" CD177/PR3 complex, and recombinant CD177 or PR3. RESULTS: All iso- and auto-antibodies were reactive with CD177/PR3 when immobilized with monoclonal antibody (moab) 7D8. Seventy-five percent of autoantibodies, but none of the isoantibodies, did not react with CD177/PR3 immobilized with moab MEM166. The majority of autoantibodies did not react with recombinant CD177, whereas most isoantibodies tested positive. DISCUSSION: Our results suggest that iso- and auto-antibodies against CD177 target different epitopes. Isoantibodies mainly target CD177 alone, while the majority of autoantibodies target a native epitope present on the neutrophil surface, but absent from recombinant CD177 which lacks PR3. Moab MEM166 binds to the native epitope and hinders the binding of CD177 autoantibodies. The results may help to design diagnostic strategies, especially for the identification of autoantibodies.


Assuntos
Autoanticorpos/imunologia , Isoantígenos/imunologia , Receptores de Superfície Celular/imunologia , Células Cultivadas , Proteínas Ligadas por GPI/imunologia , Humanos , Isoanticorpos/imunologia , Neutropenia/imunologia , Neutrófilos/imunologia
4.
Biomolecules ; 10(12)2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33302551

RESUMO

Tissue-nonspecific alkaline phosphatase (TNAP) is a ubiquitously expressed enzyme that is best known for its role during mineralization processes in bones and skeleton. The enzyme metabolizes phosphate compounds like inorganic pyrophosphate and pyridoxal-5'-phosphate to provide, among others, inorganic phosphate for the mineralization and transportable vitamin B6 molecules. Patients with inherited loss of function mutations in the ALPL gene and consequently altered TNAP activity are suffering from the rare metabolic disease hypophosphatasia (HPP). This systemic disease is mainly characterized by impaired bone and dental mineralization but may also be accompanied by neurological symptoms, like anxiety disorders, seizures, and depression. HPP characteristically affects all ages and shows a wide range of clinical symptoms and disease severity, which results in the classification into different clinical subtypes. This review describes the molecular function of TNAP during the mineralization of bones and teeth, further discusses the current knowledge on the enzyme's role in the nervous system and in sensory perception. An additional focus is set on the molecular role of TNAP in health and on functional observations reported in common laboratory vertebrate disease models, like rodents and zebrafish.


Assuntos
Fosfatase Alcalina/genética , Ansiedade/genética , Osso e Ossos/enzimologia , Depressão/genética , Hipofosfatasia/genética , Convulsões/genética , Dente/enzimologia , Fosfatase Alcalina/deficiência , Animais , Ansiedade/enzimologia , Ansiedade/patologia , Osso e Ossos/patologia , Calcificação Fisiológica/genética , Depressão/enzimologia , Depressão/patologia , Difosfatos/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Humanos , Hipofosfatasia/enzimologia , Hipofosfatasia/patologia , Mutação , Convulsões/enzimologia , Convulsões/patologia , Índice de Gravidade de Doença , Dente/crescimento & desenvolvimento , Vitamina B 6/metabolismo
5.
Orphanet J Rare Dis ; 15(1): 212, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811521

RESUMO

BACKGROUND: Hypophosphatasia (HPP) is a rare, inherited metabolic disorder caused by loss-of-function mutations in the ALPL gene that encodes the tissue-nonspecific alkaline phosphatase TNAP (ORPHA 436). Its clinical presentation is highly heterogeneous with a remarkably wide-ranging severity. HPP affects patients of all ages. In children HPP-related musculoskeletal symptoms may mimic rheumatologic conditions and diagnosis is often difficult and delayed. To improve the understanding of HPP in children and in order to shorten the diagnostic time span in the future we studied the natural history of the disease in our large cohort of pediatric patients. This single centre retrospective chart review included longitudinal data from 50 patients with HPP diagnosed and followed at the University Children's Hospital Wuerzburg, Germany over the last 25 years. RESULTS: The cohort comprises 4 (8%) perinatal, 17 (34%) infantile and 29 (58%) childhood onset HPP patients. Two patients were deceased at the time of data collection. Diagnosis was based on available characteristic clinical symptoms (in 88%), low alkaline phosphatase (AP) activity (in 96%), accumulating substrates of AP (in 58%) and X-ray findings (in 48%). Genetic analysis was performed in 48 patients (31 compound heterozygous, 15 heterozygous, 2 homozygous mutations per patient), allowing investigations on genotype-phenotype correlations. Based on anamnestic data, median age at first clinical symptoms was 3.5 months (min. 0, max. 107), while median time to diagnosis was 13 months (min. 0, max. 103). Common symptoms included: impairment of motor skills (78%), impairment of mineralization (72%), premature loss of teeth (64%), musculoskeletal pain and craniosynostosis (each 64%) and failure to thrive (62%). Up to now 20 patients started medical treatment with Asfotase alfa. CONCLUSIONS: Reported findings support the clinical perception of HPP being a chronic multi-systemic disease with often delayed diagnosis. Our natural history information provides detailed insights into the prevalence of different symptoms, which can help to improve and shorten diagnostics and thereby lead to an optimised medical care, especially with promising therapeutic options such as enzyme-replacement-therapy with Asfotase alfa in mind.


Assuntos
Hipofosfatasia , Fosfatase Alcalina/genética , Fosfatase Alcalina/uso terapêutico , Criança , Terapia de Reposição de Enzimas , Alemanha , Humanos , Hipofosfatasia/diagnóstico , Hipofosfatasia/tratamento farmacológico , Hipofosfatasia/genética , Mutação , Estudos Retrospectivos
6.
Clin Immunol ; 217: 108484, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32485239

RESUMO

Juvenile Idiopathic Arthritis (JIA) is currently classified into seven subgroups. Recently, antinuclear antibody (ANA) positive JIA patients were suggested to encompass a clinically homogenous new subgroup. CD4+ T helper (Th) cells play an essential role in JIA pathogenesis. Herein, we analyzed cytokine expression in synovial fluid (SF) CD4+ Th cells of JIA patients by using flow cytometry and compared cytokine patterns between JIA subgroups. We could show increased frequencies of IL-21 expressing CD4+ Th cells in the joints of ANA+ Oligo-/Poly-JIA patients, which co-expressed the Th-1 cytokines IFN-γ/TNF-α. In contrast, frequencies of IL-17 expressing cells were lowest in the joints of ANA+ Oligo-/Poly-JIA but enriched in that of ERA-JIA patients. This is the first description of a diverse SF Th cell cytokine pattern in different JIA subgroups. Additionally, we could define IL-21 as an effector cytokine expressed in SF Th cell in a significant proportion of ANA+ JIA patients.


Assuntos
Anticorpos Antinucleares/imunologia , Artrite Juvenil/imunologia , Interferon gama/metabolismo , Líquido Sinovial/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Artrite Juvenil/patologia , Criança , Pré-Escolar , Feminino , Humanos , Interleucina-17/metabolismo , Interleucinas/metabolismo , Masculino
7.
Pediatr Rheumatol Online J ; 18(1): 11, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32014003

RESUMO

Following publication of the original article [1], we have been notified that the authors' first names and last names are presented in wrong order. The presentation of names, thus, should be as follows.

8.
Z Rheumatol ; 78(7): 636-644, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31338681

RESUMO

BACKGROUND: In juvenile idiopathic arthritis and related chronic inflammatory diseases, proinflammatory cytokines inhibit bone formation and stimulate bone resorption. Anti-inflammatory drugs, such as glucocorticoids and nonsteroidal antirheumatic drugs (NSARD) have as a side effect the potential to inhibit growth and maintenance of bone. These issues are of particular importance for the growing skeleton in childhood and adolescence. OBJECTIVE: This article presents a narrative overview about the dimension of the problem, a critical evaluation of diagnostic procedures and a discussion of available countermeasures. METHODS: A systematic literature search was carried out and the available evidence was evaluated based on the authors' knowledge and clinical experience as experts in the field. RESULTS AND CONCLUSION: In recent years solid data have been accumulated with respect to the interpretation of bone mineral density (BMD) measurements in children and adolescents. Based on these data from the literature and given that the radiation exposure is also very low, it is now possible to clinically apply BMD measurements in this population using dual energy X­ray absorption (DXA) technology for risk evaluation and diagnosis, taking the respective phase of development and body length into consideration. Dynamic measurements over time appear to be especially valuable in the context of individual clinical data. Hence, BMD measurements can be helpful in monitoring bone health, especially in juvenile idiopathic arthritis and other related inflammatory diseases. Apart from the specific indications for extended diagnostics and bone targeted pharmacological treatment, this method can also contribute to the management of preventive measures, such as sufficient calcium and vitamin D intake and targeted exercise interventions. Even in times of extremely effective antirheumatic drugs, children with chronic inflammatory diseases still bear a risk for bone health.


Assuntos
Artrite Juvenil , Densidade Óssea , Osso e Ossos/efeitos dos fármacos , Glucocorticoides/efeitos adversos , Absorciometria de Fóton , Adolescente , Artrite Juvenil/complicações , Artrite Juvenil/tratamento farmacológico , Osso e Ossos/fisiologia , Criança , Fraturas Ósseas , Glucocorticoides/uso terapêutico , Humanos , Radiografia
9.
J Pediatr ; 209: 116-124.e4, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30979546

RESUMO

OBJECTIVE: To report clinical characteristics and medical history data obtained retrospectively for a large cohort of pediatric patients with perinatal and infantile hypophosphatasia. STUDY DESIGN: Medical records from academic medical centers known to diagnose and/or treat hypophosphatasia were reviewed. Patients born between 1970 and 2011 with hypophosphatasia and any of the following signs/symptoms at age <6 months were eligible: vitamin B6-dependent seizures, respiratory compromise, or rachitic chest deformity (NCT01419028). Patient demographics and characteristics, respiratory support requirements, invasive ventilator-free survival, and further complications of hypophosphatasia were followed for up to the first 5 years of life. RESULTS: Forty-eight patients represented 12 study sites in 7 countries; 13 patients were alive, and 35 were dead (including 1 stillborn). Chest deformity, respiratory distress, respiratory failure (as conditioned by the eligibility criteria), failure to thrive, and elevated calcium levels were present in >70% of patients between birth and age 5 years. Vitamin B6-dependent seizures and respiratory distress and failure were associated significantly (P < .05) with the risk of early death. Serum alkaline phosphatase activity in all 41 patients tested (mean [SD]: 18.1 [15.4] U/L) was below the mean lower limit of normal of the reference ranges of the various laboratories (88.2 U/L). Among the 45 patients with relevant data, 29 had received respiratory support, of whom 26 had died at the time of data collection. The likelihood of invasive ventilator-free survival for this cohort decreased to 63% at 3 months, 54% at 6 months, 31% at 12 months, and 25% at 5 years. CONCLUSIONS: Patients with perinatal or infantile hypophosphatasia and vitamin B6-dependent seizures, with or without significant respiratory distress or chest deformities, have high morbidity and mortality in the first 5 years of life. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01419028.


Assuntos
Fosfatase Alcalina/sangue , Causas de Morte , Terapia de Reposição de Enzimas/métodos , Hipofosfatasia/mortalidade , Hipofosfatasia/terapia , Fosfatase Alcalina/uso terapêutico , Estudos de Coortes , Progressão da Doença , Intervalo Livre de Doença , Terapia de Reposição de Enzimas/mortalidade , Feminino , Seguimentos , Humanos , Hipofosfatasia/sangue , Hipofosfatasia/diagnóstico , Lactente , Internacionalidade , Estimativa de Kaplan-Meier , Masculino , Gravidez , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Análise de Sobrevida , Fatores de Tempo
10.
J Clin Endocrinol Metab ; 104(7): 2735-2747, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30811537

RESUMO

CONTEXT: Long-term data on enzyme replacement treatment of hypophosphatasia (HPP) are limited. OBJECTIVE: To evaluate efficacy and safety of asfotase alfa in patients aged ≤5 years with HPP followed for up to 6 years. DESIGN: Phase 2 open-label study (July 2010 to September 2016). SETTING: Twenty-two sites; 12 countries. PARTICIPANTS: Sixty-nine patients [median (range) age: 16.0 (0.02 to 72) months] with severe HPP and sign/symptom onset before age 6 months. INTERVENTION: Asfotase alfa 2 mg/kg three times/week or 1 mg/kg six times/week subcutaneously. MAIN OUTCOME MEASURES: Primary efficacy measure: Radiographic Global Impression of Change (RGI-C) score [-3 (severe worsening) to +3 (complete/near-complete healing)]. Additional outcome measures: respiratory status, growth, and safety. Post hoc analysis: characteristics of radiographic responders vs nonresponders at Year 1 (RGI-C: ≥+2 vs <+2). RESULTS: During median (minimum, maximum) 2.3 (0.02, 5.8) years of treatment, RGI-C scores improved significantly at Month 6 [+2.0 (-1.7, +3.0)], Year 1 [+2.0 (-2.3, +3.0)], and Last Assessment [+2.3 (-2.7, +3.0); P < 0.0001 all]. Of 24 patients requiring respiratory support at Baseline, 11 (46%) no longer needed support. Height/weight z scores generally increased. Nine patients died (13%). All patients experienced at least one adverse event; pyrexia was most common. Compared with responders [n = 50 (72%)], nonresponders [n = 19 (28%)] had more severe disease at Baseline and a higher rate of neutralizing antibodies (NAbs) at Last Assessment. CONCLUSIONS: Most infants/young children given asfotase alfa showed early radiographic and clinical improvement sustained up to 6 years; radiographic nonresponders had more severe disease and more frequent NAbs at Last Assessment.


Assuntos
Fosfatase Alcalina/uso terapêutico , Osso e Ossos/diagnóstico por imagem , Terapia de Reposição de Enzimas , Hipofosfatasia/tratamento farmacológico , Imunoglobulina G/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Fosfatase Alcalina/sangue , Criança , Desenvolvimento Infantil , Pré-Escolar , Pressão Positiva Contínua nas Vias Aéreas , Feminino , Fraturas Ósseas/etiologia , Transtornos do Crescimento/etiologia , Humanos , Hipercalcemia/etiologia , Hipercalcemia/metabolismo , Hipofosfatasia/complicações , Hipofosfatasia/diagnóstico por imagem , Hipofosfatasia/metabolismo , Lactente , Recém-Nascido , Joelho/diagnóstico por imagem , Masculino , Nefrocalcinose/etiologia , Oxigenoterapia , Radiografia Torácica , Respiração Artificial , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapia , Caixa Torácica/anormalidades , Convulsões/etiologia , Taxa de Sobrevida , Resultado do Tratamento , Punho/diagnóstico por imagem
11.
Transfusion ; 58(1): 200-207, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29210081

RESUMO

BACKGROUND: Currently, the gold standard for the identification of antibodies against human neutrophil antigens (HNAs) is the monoclonal antibody-immobilized granulocyte antigen (MAIGA) assay. However, the handling of this assay is laborious and therefore cumbersome for the rapid screening of neutrophil antibodies. STUDY DESIGN AND METHODS: In this study, we simplified the performance of the conventional MAIGA procedure and approved it for the identification of anti-HNA-1 with HNA-1-typed neutrophils and stable transfected (HEK293) cell line expressing HNA-1a, -1b, and -1c. RESULTS: In contrast to the conventional MAIGA, all working steps including the incubation of antibodies with cells, washings, cell lysis, and subsequent antibody detection could be performed on microtiter plates. This modification accelerates the work schedule of MAIGA and reduces pipetting errors. Comparison between both assay performances using neutrophils as target showed concordant results. Subsequently, stable mammalian cell lines were tested. In comparison to neutrophils, cell lines were stable for a longer period of time (>4 weeks) and results obtained with these cell lines showed better interassay precision. Analysis of different FcγRIIIb capture monoclonal antibodies (MoAbs) for the MAIGA assay showed that MoAb LNK16 is superior for the detection of anti-HNA-1a, -1b, and -1c, whereas MoAb 3G8 showed false-negative results, caused by competitive inhibition of anti-HNA-1c alloantibodies. CONCLUSION: The modification of MAIGA and the use of transfected HEK293 cells improve the detection of anti-HNA-1 alloantibodies that may allow screening analysis in large cohort of samples.


Assuntos
Anticorpos Monoclonais/imunologia , Testes Imunológicos , Isoanticorpos/sangue , Isoantígenos/imunologia , Neutrófilos/imunologia , Especificidade de Anticorpos , Reações Antígeno-Anticorpo , Ligação Competitiva , Linhagem Celular , Epitopos/imunologia , Reações Falso-Negativas , Proteínas Ligadas por GPI/sangue , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/genética , Células HEK293 , Humanos , Isoanticorpos/imunologia , Modelos Moleculares , Conformação Proteica , Domínios Proteicos , Receptores de IgG/sangue , Receptores de IgG/química , Receptores de IgG/genética , Proteínas Recombinantes/imunologia
12.
J Clin Invest ; 127(6): 2148-2158, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28436937

RESUMO

BACKGROUND: Hypophosphatasia (HPP) is a rare genetic disorder resulting in variable alterations of bone formation and mineralization that are caused by mutations in the ALPL gene, encoding the tissue-nonspecific alkaline phosphatase (ALP) enzyme. METHODS: In this phase IIA open-label, single-center, intra-patient, dose-escalating study, adult patients with HPP received 3 ascending intravenous doses of 5, 10, and 20 mg/kg BPS804, a fully human anti-sclerostin monoclonal antibody, on days 1, 15, and 29, respectively. Patients were followed for 16 weeks after the last dose. We assessed the pharmacodynamics, pharmacokinetics, preliminary efficacy, and safety of BPS804 administrations at specified intervals during treatment and follow-up. RESULTS: Eight patients (mean age 47.8 years) were enrolled in the study (6 females, 2 males). BPS804 treatment increased mean ALP and bone-specific ALP enzymatic activity between days 2 and 29. Transient increases in the bone formation markers procollagen type-I N-terminal propeptide (PINP), osteocalcin, and parathyroid hormone as well as a transient decrease in the bone resorption marker C-telopeptide of type I collagen (CTX-1) were observed. Lumbar spine bone mineral density showed a mean increase by day 85 and at end of study. Treatment-associated adverse events were mild and transient. CONCLUSION: BPS804 treatment was well tolerated and resulted in increases in bone formation biomarkers and bone mineral density, suggesting that sclerostin inhibition could be applied to enhance bone mineral density, stability, and regeneration in non-life-threatening clinical situations in adults with HPP. TRIAL REGISTRATION: Clinicaltrials.gov NCT01406977. FUNDING: Novartis Institutes for BioMedical Research, Basel, Switzerland.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Hipofosfatasia/tratamento farmacológico , Proteínas Adaptadoras de Transdução de Sinal , Adulto , Idoso , Anticorpos Monoclonais/farmacocinética , Densidade Óssea/efeitos dos fármacos , Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Esquema de Medicação , Feminino , Marcadores Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
13.
Bone ; 94: 75-83, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27777120

RESUMO

Hypophosphatasia (HPP) is a multi-systemic inborn disease with an extraordinary spectrum of severity, ranging from the absence of mineralization to high lethality and it involves different organs including bone, muscle, kidney, lung, gastrointestinal tract and the nervous system. The disease is characterized by low levels of serum alkaline phosphatase, caused by loss-of-function mutations within the ALPL gene that encodes the tissue-nonspecific alkaline phosphatase TNAP. Here we present the functional characterization of a gene mutation, detected in intron 7 of the ALPL gene of a boy with infantile HPP in whom routine sequencing of the coding region failed to detect any mutation. The homozygous c.793del-14_33 mutation results in the loss of the branch-point motif, relevant for correct ALPL pre-mRNA splicing. The main transcript skips exon 8 and codes for a C-terminally truncated TNAP protein of 275 amino acids, which was detected in peripheral blood mononuclear cells and serum from the patient. The functional characterization of recombinant TNAP275 revealed no enzymatic activity nor any dominant-negative effect, relevant for the heterozygous parents. Nevertheless correct pre-mRNA splicing can take place without the branch-point sequence to a limited extend, as concluded from the ALPL cDNA, obtained from patient's PBMC, and from the low serum AP activity. These data reaffirm that in clear cut clinical cases, where conventional sequencing including the coding sequence and direct exon-intron-boundaries fails to detect mutations, deeper analyses of regulatory important motifs like branch-point sequences are required to establish a genetic diagnosis.


Assuntos
Fosfatase Alcalina/genética , Hipofosfatasia/enzimologia , Hipofosfatasia/genética , Íntrons/genética , Deleção de Sequência/genética , Adulto , Processamento Alternativo/genética , Sequência de Bases , Membrana Celular/metabolismo , Pré-Escolar , DNA/genética , Regulação da Expressão Gênica , Homozigoto , Humanos , Lactente , Recém-Nascido , Masculino , Nucleotídeos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
14.
Angew Chem Int Ed Engl ; 55(8): 2719-23, 2016 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-26804727

RESUMO

Here we report the development of the first enantioselective Dakin-West reaction, yielding α-acetamido methylketones with up to 58 % ee with good yields. Two of the obtained products were recrystallized once to achieve up to 84 % ee. The employed methylimidazole-containing oligopeptides catalyze both the acetylation of the azlactone intermediate and the terminal enantioselective decarboxylative protonation. We propose a dispersion-controlled reaction path that determines the asymmetric reprotonation of the intermediate enolate after the decarboxylation.

15.
J Clin Endocrinol Metab ; 101(1): 334-42, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26529632

RESUMO

CONTEXT: Hypophosphatasia (HPP) is an inborn error of metabolism that, in its most severe perinatal and infantile forms, results in 50-100% mortality, typically from respiratory complications. OBJECTIVES: Our objective was to better understand the effect of treatment with asfotase alfa, a first-in-class enzyme replacement therapy, on mortality in neonates and infants with severe HPP. DESIGN/SETTING: Data from patients with the perinatal and infantile forms of HPP in two ongoing, multicenter, multinational, open-label, phase 2 interventional studies of asfotase alfa treatment were compared with data from similar patients from a retrospective natural history study. PATIENTS: Thirty-seven treated patients (median treatment duration, 2.7 years) and 48 historical controls of similar chronological age and HPP characteristics. INTERVENTIONS: Treated patients received asfotase alfa as sc injections either 1 mg/kg six times per week or 2 mg/kg thrice weekly. MAIN OUTCOME MEASURES: Survival, skeletal health quantified radiographically on treatment, and ventilatory status were the main outcome measures for this study. RESULTS: Asfotase alfa was associated with improved survival in treated patients vs historical controls: 95% vs 42% at age 1 year and 84% vs 27% at age 5 years, respectively (P < .0001, Kaplan-Meier log-rank test). Whereas 5% (1/20) of the historical controls who required ventilatory assistance survived, 76% (16/21) of the ventilated and treated patients survived, among whom 75% (12/16) were weaned from ventilatory support. This better respiratory outcome accompanied radiographic improvements in skeletal mineralization and health. CONCLUSIONS: Asfotase alfa mineralizes the HPP skeleton, including the ribs, and improves respiratory function and survival in life-threatening perinatal and infantile HPP.


Assuntos
Fosfatase Alcalina/uso terapêutico , Hipofosfatasia/tratamento farmacológico , Imunoglobulina G/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Fatores Etários , Fosfatase Alcalina/administração & dosagem , Densidade Óssea , Pré-Escolar , Terapia de Reposição de Enzimas , Feminino , Humanos , Hipofosfatasia/mortalidade , Hipofosfatasia/terapia , Imunoglobulina G/administração & dosagem , Lactente , Recém-Nascido , Injeções Subcutâneas , Estimativa de Kaplan-Meier , Masculino , Proteínas Recombinantes de Fusão/administração & dosagem , Respiração Artificial , Testes de Função Respiratória , Análise de Sobrevida , Resultado do Tratamento
16.
Phys Chem Chem Phys ; 17(47): 31769-79, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26563563

RESUMO

The development of aprotic lithium-oxygen (Li-O2) batteries suffers from high charging overvoltages. Dissolved redox mediators, like nitroxides, providing increased energy efficiency and longer lifetime are promising tools to overcome this challenge. Since this auspicious concept is still in its infancy, the underlying chemical reactions as well as the impact of the different (electro)chemical parameters are poorly understood. Herein, we derive an electrochemical model for the charging reactions, which is validated by potentiostatic measurements. The model elucidates the impact of the major factors including basic cell parameters and the chemical properties of the redox mediator. The model is applied to the promising class of nitroxides, which is systematically investigated by using derivatives of TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy), AZADO (2-azaadamantane-N-oxyl), and an azaphenalene based nitroxide. The nitroxides are electrochemically characterized by cyclic voltammetry and their performance as redox mediators is studied in Li-O2 batteries with an ether-based electrolyte. Based on the presented model, the charging profiles of the different nitroxide redox mediators are correlated with their molecular structures.

17.
Subcell Biochem ; 76: 323-41, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26219718

RESUMO

Hypophosphatasia (HPP) is a rare monogenetic and multisystemic disease with involvement of different organs, including bone, muscle, kidney, lung, gastrointestinal tract and the nervous system. The exact metabolic mechanisms of the effects of TNAP deficiency in different tissues are not understood in detail. There is no approved specific treatment for HPP; therefore symptomatic treatment in order to improve the clinical features is of major interest. Enzyme replacement therapy (ERT) is a relatively new type of treatment based on the principle of administering a medical treatment replacing a defective or absent enzyme. Recently ERT with a bone targeted recombinant human TNAP molecule has been reported to be efficient in ten severely affected patients and improved survival of life threatening forms. These results are very promising especially with regard to the skeletal phenotype but it is unclear whether ERT also has beneficial effects for craniosynostosis and in other affected tissues in HPP such as brain and kidney. Long-term data are not yet available and further systematic clinical trials are needed. It is also necessary to establish therapeutic approaches to help patients who are affected by less severe forms of HPP but also suffer from a significant reduction in quality of life. Further basic research on TNAP function and role in different tissues and on its physiological substrates is critical to gain a better insight in the pathogenesis in HPP. This and further experiences in new therapeutic strategies may improve the prognosis and quality of life of patients with all forms of HPP.


Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/uso terapêutico , Terapia de Reposição de Enzimas , Hipofosfatasia/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Fosfatase Alcalina/administração & dosagem , Fosfatase Alcalina/uso terapêutico , Animais , Proteínas de Transporte/administração & dosagem , Sistemas de Liberação de Medicamentos , Avaliação Pré-Clínica de Medicamentos , Terapia de Reposição de Enzimas/métodos , Humanos , Imunoglobulina G/administração & dosagem , Imunoglobulina G/uso terapêutico , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/uso terapêutico
18.
Bone ; 79: 150-61, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26032516

RESUMO

Patients suffering from the rare hereditary disease hypophosphatasia (HPP), which is based on mutations in the ALPL gene, tend to develop central nervous system (CNS) related issues like epileptic seizures and neuropsychiatric illnesses such as anxiety and depression, in addition to well-known problems with the mineralization of bones and teeth. Analyses of the molecular role of tissue-nonspecific alkaline phosphatase (TNAP) in transgenic SH-SY5Y(TNAPhigh) neuroblastoma cells compared to SH-SY5Y(TNAPlow) cells indicate that the enzyme influences the expression levels of neuronal marker genes like RNA-binding protein, fox-1 homolog 3 (NEUN) and enolase 2, gamma neuronal (NSE) as well as microtubule-binding proteins like microtubule-associated protein 2 (MAP2) and microtubule-associated protein tau (TAU) during neurogenic differentiation. Fluorescence staining of SH-SY5Y(TNAPhigh) cells reveals TNAP localization throughout the whole length of the developed projection network and even synapsin Ι co-localization with strong TNAP signals at some spots at least at the early time points of differentiation. Additional immunocytochemical staining shows higher MAP2 expression in SH-SY5Y(TNAPhigh) cells and further a distinct up-regulation of tau and MAP2 in the course of neurogenic differentiation. Interestingly, transgenic SH-SY5Y(TNAPhigh) cells are able to develop longer cellular processes compared to control cells after stimulation with all-trans retinoic acid (RA). Current therapies for HPP prioritize improvement of the bone phenotype. Unraveling the molecular role of TNAP in extraosseous tissues, like in the CNS, will help to improve treatment strategies for HPP patients. Taking this rare disease as a model may also help to dissect TNAP's role in neurodegenerative diseases and even improve future treatment of common pathologies.


Assuntos
Fosfatase Alcalina/metabolismo , Diferenciação Celular/genética , Neurônios/enzimologia , Western Blotting , Linhagem Celular Tumoral , Humanos , Hipofosfatasia/genética , Imuno-Histoquímica , Neurônios/citologia , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Transgenes
19.
J Org Chem ; 80(3): 1972-8, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25569106

RESUMO

We present an organocatalytic C-O-bond cross-coupling strategy to kinetically resolve racemic diols with aromatic and aliphatic alcohols, yielding enantioenriched esters. This one-pot protocol utilizes an oligopeptide multicatalyst, m-CPBA as the oxidant, and N,N'-diisopropylcarbodiimide as the activating agent. Racemic acyclic diols as well as trans-cycloalkane-1,2-diols were kinetically resolved, achieving high selectivities and good yields for the products and recovered diols.

20.
Clin Exp Rheumatol ; 32(4): 604-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25065777

RESUMO

OBJECTIVES: Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory disorder of the skeletal system. Treatment with NSAIDs is generally effective in the majority of patients, however, a sizeable proportion of patients have persistent disease and subsequent treatment strategies are required. The aim of this study was to characterise the clinical and radiological disease course in CNO patients treated with the bisphosphonate pamidronate (PAM). METHODS: Eight CNO patients refractory to NSAIDs, glucocorticoids and sulfasalazine were treated with 6 cycles of PAM in four-weekly intervals. The disease course was assessed by clinical examination and whole-body (WB) MRI at standardised time points during the treatment phase and in a 6 months follow-up. RESULTS: Seven patients were in complete clinical remission after 6 applications of PAM. WB MRIs showed regression of inflammatory lesions in 7 patients with complete remission in only one patient and partial remission in 6 patients. One patient developed radiological progression despite a marked improvement of clinical symptoms. In the follow-up after PAM therapy, 3 patients developed MRI confirmed relapse. Additional applications of PAM induced a sustained clinical remission and partial radiological response in two of them. Mild temporary adverse effects were noted in 5 patients. CONCLUSIONS: Our study highlights that PAM is effective in controlling clinical symptoms (e.g. pain) in CNO patients. However, subclinical bone inflammation was still detectable by MRI in most of the patients and disease progression was noticed in some patients after cessation of PAM.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Osso e Ossos/efeitos dos fármacos , Difosfonatos/uso terapêutico , Osteomielite/tratamento farmacológico , Adolescente , Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/efeitos adversos , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/patologia , Criança , Pré-Escolar , Doença Crônica , Difosfonatos/administração & dosagem , Difosfonatos/efeitos adversos , Progressão da Doença , Esquema de Medicação , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Osteomielite/complicações , Osteomielite/diagnóstico , Dor/diagnóstico , Dor/etiologia , Dor/prevenção & controle , Medição da Dor , Pamidronato , Radiografia , Indução de Remissão , Fatores de Tempo , Resultado do Tratamento , Imagem Corporal Total
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA