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1.
Int J Mol Sci ; 21(8)2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32326075

RESUMO

The genome of living cells is continuously exposed to endogenous and exogenous attacks, and this is particularly amplified at high temperatures. Alkylating agents cause DNA damage, leading to mutations and cell death; for this reason, they also play a central role in chemotherapy treatments. A class of enzymes known as AGTs (alkylguanine-DNA-alkyltransferases) protects the DNA from mutations caused by alkylating agents, in particular in the recognition and repair of alkylated guanines in O6-position. The peculiar irreversible self-alkylation reaction of these enzymes triggered numerous studies, especially on the human homologue, in order to identify effective inhibitors in the fight against cancer. In modern biotechnology, engineered variants of AGTs are developed to be used as protein tags for the attachment of chemical ligands. In the last decade, research on AGTs from (hyper)thermophilic sources proved useful as a model system to clarify numerous phenomena, also common for mesophilic enzymes. This review traces recent progress in this class of thermozymes, emphasizing their usefulness in basic research and their consequent advantages for in vivo and in vitro biotechnological applications.

2.
Sci Rep ; 10(1): 103, 2020 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-31919410

RESUMO

Fanconi Anemia is a rare genetic disease associated with DNA repair defects, congenital abnormalities and infertility. Most of FA pathway is evolutionary conserved, allowing dissection and mechanistic studies in simpler model systems such as Caenorhabditis elegans. In the present study, we employed C. elegans to better understand the role of FA group D2 (FANCD2) protein in vivo, a key player in promoting genome stability. We report that localization of FCD-2/FANCD2 is dynamic during meiotic prophase I and requires its heterodimeric partner FNCI-1/FANCI. Strikingly, we found that FCD-2 recruitment depends on SPO-11-induced double-strand breaks (DSBs) but not RAD-51-mediated strand invasion. Furthermore, exposure to DNA damage-inducing agents boosts FCD-2 recruitment on the chromatin. Finally, analysis of genetic interaction between FCD-2 and BRC-1 (the C. elegans orthologue of mammalian BRCA1) supports a role for these proteins in different DSB repair pathways. Collectively, we showed a direct involvement of FCD-2 at DSBs and speculate on its function in driving meiotic DNA repair.

3.
Extremophiles ; 24(1): 81-91, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31555904

RESUMO

The specific labelling of proteins in recent years has made use of self-labelling proteins, such as the SNAP-tag® and the Halotag®. These enzymes, by their nature or suitably engineered, have the ability to specifically react with their respective substrates, but covalently retaining a part of them in the catalytic site upon reaction. This led to the synthesis of substrates conjugated with, e.g., fluorophores (proposing them as alternatives to fluorescent proteins), but also with others chemical groups, for numerous biotechnological applications. Recently, a mutant of the OGT from Saccharolobus solfataricus (H5) very stable to high temperatures and in the presence of physical and chemical denaturing agents has been proposed as a thermostable SNAP-tag® for in vivo and in vitro harsh reaction conditions. Here, we show two new thermostable OGTs from Thermotoga neapolitana and Pyrococcus furiosus, which, respectively, display a higher catalytic activity and thermostability respect to H5, proposing them as alternatives for in vivo studies in these extreme model organisms.

5.
Biomolecules ; 9(10)2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547634

RESUMO

: Indole-3-acetic acid (IAA) is a major plant hormone that affects many cellular processes in plants, bacteria, yeast, and human cells through still unknown mechanisms. In this study, we demonstrated that the IAA-treatment of two unrelated bacteria, the Ensifer meliloti 1021 and Escherichia coli, harboring two different host range plasmids, influences the supercoiled state of the two plasmid DNAs in vivo. Results obtained from in vitro assays show that IAA interacts with DNA, leading to DNA conformational changes commonly induced by intercalating agents. We provide evidence that IAA inhibits the activity of the type IA topoisomerase, which regulates the DNA topological state in bacteria, through the relaxation of the negative supercoiled DNA. In addition, we demonstrate that the treatment of E. meliloti cells with IAA induces the expression of some genes, including the ones related to nitrogen fixation. In contrast, these genes were significantly repressed by the treatment with novobiocin, which reduces the DNA supercoiling in bacterial cells. Taking into account the overall results reported, we hypothesize that the IAA action and the DNA structure/function might be correlated and involved in the regulation of gene expression. This work points out that checking whether IAA influences the DNA topology under physiological conditions could be a useful strategy to clarify the mechanism of action of this hormone, not only in plants but also in other unrelated organisms.

6.
Am J Cardiol ; 124(10): 1561-1567, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31521256

RESUMO

Red cells distribution width (RDW) is a measure of red cell size variability, but little is known about the relation between RDW and outcomes in atrial fibrillation (AF).The aims of our study were to evaluate the association between RDW values, AF patients' profile and outcomes. Consecutive patients with ECG-confirmed AF were divided in 3 groups according to tertiles of RDW values (≤13.5%, 13.6% to 14.6%, >14.6%).We enrolled 457 patients, 61.9% males, median (interquartile range) age 74 (66 to 80). Both CHA2DS2-VASc and HAS-BLED scores increased progressively according to RDW tertiles. During follow-up, there was an increased risk for all-cause death and the composite end point in the highest RDW tertile (p <0.001 for both outcomes). On multivariate Cox regression analysis, the highest RDW tertile was independently associated with all-cause death (hazard ratio [HR] 3.23, 95% confidence interval [CI] 1.04 to 10.00) and the composite end point (HR 2.04, 95% CI 1.12 to 3.70). RDW as a continuous variable was also independently associated with all cause death and the composite outcome (HR 1.16, 95% CI 1.02 to 1.31 and HR 1.16, 95% CI 1.05 to 1.27, respectively). In conclusion, in a real-life AF population, RDW is associated with clinical factors indicating a worse profile and is independently associated with increased risks of all-cause death and other clinical events.

7.
J Enzyme Inhib Med Chem ; 34(1): 946-954, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31039618

RESUMO

Carbonic anhydrases (CAs, EC 4.2.1.1) are a superfamily of ubiquitous metalloenzymes present in all living organisms on the planet. They are classified into seven genetically distinct families and catalyse the hydration reaction of carbon dioxide to bicarbonate and protons, as well as the opposite reaction. CAs were proposed to be used for biotechnological applications, such as the post-combustion carbon capture processes. In this context, there is a great interest in searching CAs with robust chemical and physical properties. Here, we describe the enhancement of thermostability of the α-CA from Sulfurihydrogenibium yellowstonense (SspCA) by using the anchoring-and-self-labelling-protein-tag system (ASLtag). The anchored chimeric H5-SspCA was active for the CO2 hydration reaction and its thermostability increased when the cells were heated for a prolonged period at high temperatures (e.g. 70 °C). The ASLtag can be considered as a useful method for enhancing the thermostability of a protein useful for biotechnological applications, which often need harsh operating conditions.


Assuntos
Anidrases Carbônicas/química , Anidrases Carbônicas/metabolismo , Bactérias Gram-Negativas Quimiolitotróficas/enzimologia , Coloração e Rotulagem/métodos , Temperatura , Estabilidade Enzimática , Modelos Moleculares , Relação Estrutura-Atividade
8.
Sci Rep ; 9(1): 6889, 2019 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-31053748

RESUMO

DNA alkylguanine DNA alkyltransferases (AGTs) are evolutionary conserved proteins that repair alkylation damage in DNA, counteracting the effects of agents inducing such lesions. Over the last years AGTs have raised considerable interest for both the peculiarity of their molecular mechanism and their relevance in cancer biology. AGT knock out mice show increased tumour incidence in response to alkylating agents, and over-expression of the human AGT protein in cancer cells is frequently associated with resistance to alkylating chemotherapy. While all data available point to a function of AGT proteins in the cell response to alkylation lesions, we report for the first time that one of the two AGT paralogs of the model organism C. elegans, called AGT-2, also plays unexpected roles in meiosis and early development under physiological conditions. Our data suggest a role for AGT-2 in conversion of homologous recombination intermediates into post-strand exchange products in meiosis, and show that agt-2 gene down-regulation, or treatment of animals with an AGT inhibitor results in increased number of germ cells that are incompatible with producing viable offspring and are eliminated by apoptosis. These results suggest possible functions for AGTs in cell processes distinct from repair of alkylating damage.

9.
Int J Cardiol ; 282: 60-65, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30773267

RESUMO

BACKGROUND: Data concerning idiopathic recurrent pericarditis in pregnancy are scarce. OBJECTIVES: To evaluate the management and outcome of idiopathic recurrent pericarditis during pregnancy. METHODS AND RESULTS: Twenty-one pregnancies were evaluated in fourteen women with a history of recurrent idiopathic pericarditis (mean maternal age 31.5 years, mean gestational age 39.0 weeks), and subdivided in 2 cohorts: eight pregnancies were analyzed retrospectively (2002-2010), thirteen (2011-2017) prospectively and followed according a predefined management protocol. Ten pregnancies were uneventful, three ended in spontaneous early abortion, one fetal death occurred at 19 weeks. Recurrences of pericarditis occurred in eight and were treated by adding NSAIDs in two cases; in five cases the dose of corticosteroids was increased and in two cases aspirin was started/increased; paracetamol was always allowed. Colchicine was used in two cases in the prospective cohort. HELLP syndrome occurred in one patient, which resolved after delivery, and one patient experienced arterial hypertension and elevated transaminase. All infants had a good outcome (mean birth weight 3114 g, 10 males). Birth weight was significantly lower in the retrospective cohort (respectively 2806 g vs. 3320 g, p-value 0.017) in which higher doses of corticosteroids were used (median dose respectively 10.0 mg vs. 2.5 mg, p-value 0.048). Five recurrences of pericarditis occurred after delivery, easily treated with standard therapy. CONCLUSION: General outcomes of pregnancy in patients with idiopathic recurrent pericarditis is good, especially when patients are carefully followed by multidisciplinary teams according to standardized protocols.


Assuntos
Gerenciamento Clínico , Pericardite/diagnóstico , Pericardite/terapia , Complicações Cardiovasculares na Gravidez/diagnóstico , Complicações Cardiovasculares na Gravidez/terapia , Adulto , Anti-Inflamatórios não Esteroides/administração & dosagem , Aspirina/administração & dosagem , Estudos de Coortes , Feminino , Seguimentos , Humanos , Gravidez , Recidiva , Estudos Retrospectivos
10.
J Enzyme Inhib Med Chem ; 34(1): 490-499, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30724623

RESUMO

The use of natural systems, such as outer membrane protein A (OmpA), phosphoporin E (PhoE), ice nucleation protein (INP), etc., has been proved very useful for the surface exposure of proteins on the outer membrane of Gram-negative bacteria. These strategies have the clear advantage of unifying in a one-step the production, the purification and the in vivo immobilisation of proteins/biocatalysts onto a specific biological support. Here, we introduce the novel Anchoring-and-Self-Labelling-protein-tag (ASLtag), which allows the in vivo immobilisation of enzymes on E. coli surface and the labelling of the neosynthesised proteins with the engineered alkylguanine-DNA-alkyl-transferase (H5) from Sulfolobus solfataricus. Our results demonstrated that this tag enhanced the overexpression of thermostable enzymes, such as the carbonic anhydrase (SspCA) from Sulfurihydrogenibium yellowstonense and the ß-glycoside hydrolase (SsßGly) from S. solfataricus, without affecting their folding and catalytic activity, proposing a new tool for the improvement in the utilisation of biocatalysts of biotechnological interest.


Assuntos
Proteínas da Membrana Bacteriana Externa/metabolismo , Enzimas Imobilizadas/metabolismo , Escherichia coli/enzimologia , Transferases/metabolismo , Enzimas Imobilizadas/química , Escherichia coli/metabolismo , Humanos , Coloração e Rotulagem , Propriedades de Superfície , Transferases/química
11.
Heart ; 105(6): 477-481, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30274986

RESUMO

OBJECTIVE: Aim of this paper is to evaluate the outcomes of 'idiopathic' chronic large pericardial effusions without initial evidence of pericarditis. METHODS: All consecutive cases of idiopathic chronic large pericardial effusions evaluated from 2000 to 2015 in three Italian tertiary referral centres for pericardial diseases were enrolled in a prospective cohort study. The term 'idiopathic' was applied to cases that performed a complete diagnostic evaluation to exclude a specific aetiology. A clinical and echocardiographic follow-up was performed every 3-6 months. RESULTS: 100 patients were included (mean age 61.3±14.6 years, 54 females, 44 patients were asymptomatic according to clinical evaluation) with a mean follow-up of 50 months. The baseline median size of the effusion (evaluated as the largest end-diastolic echo-free space) was 25 mm (IQR 8) and decreased to a mean value of 7 mm (IQR 19; p<0.0001) with complete regression in 39 patients at the end of follow-up. There were no new aetiological diagnoses. Adverse events were respectively: cardiac tamponade in 8 patients (8.0%), pericardiocentesis in 30 patients (30.0%), pericardial window in 12 cases (12.0%) and pericardiectomy in 3 patients (3.0%). Recurrence-free survival and complications-free survival was better in patients treated without interventions (log rank p=0.0038). CONCLUSIONS: The evolution of 'idiopathic' chronic large pericardial effusions is usually benign with reduction of the size of the effusion in the majority of cases, and regression in about 40% of cases. The risk of cardiac tamponade is 2.2%/year and recurrence/complications survival was better in patients treated conservatively without interventions.


Assuntos
Doenças Assintomáticas/epidemiologia , Tamponamento Cardíaco , Derrame Pericárdico , Pericardiectomia , Pericardiocentese , Pericardite , Idoso , Tamponamento Cardíaco/diagnóstico , Tamponamento Cardíaco/epidemiologia , Tamponamento Cardíaco/etiologia , Ecocardiografia/métodos , Feminino , Seguimentos , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Derrame Pericárdico/complicações , Derrame Pericárdico/diagnóstico , Derrame Pericárdico/epidemiologia , Pericardiectomia/métodos , Pericardiectomia/estatística & dados numéricos , Pericardiocentese/métodos , Pericardiocentese/estatística & dados numéricos , Pericardite/complicações , Pericardite/diagnóstico , Pericardite/epidemiologia , Estudos Prospectivos , Recidiva , Fatores de Risco , Índice de Gravidade de Doença , Análise de Sobrevida
12.
Sci Rep ; 8(1): 6163, 2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29670174

RESUMO

Topology affects physical and biological properties of DNA and impacts fundamental cellular processes, such as gene expression, genome replication, chromosome structure and segregation. In all organisms DNA topology is carefully modulated and the supercoiling degree of defined genome regions may change according to physiological and environmental conditions. Elucidation of structural properties of DNA molecules with different topology may thus help to better understand genome functions. Whereas a number of structural studies have been published on highly negatively supercoiled DNA molecules, only preliminary observations of highly positively supercoiled are available, and a description of DNA structural properties over the full range of supercoiling degree is lacking. Atomic Force Microscopy (AFM) is a powerful tool to study DNA structure at single molecule level. We here report a comprehensive analysis by AFM of DNA plasmid molecules with defined supercoiling degree, covering the full spectrum of biologically relevant topologies, under different observation conditions. Our data, supported by statistical and biochemical analyses, revealed striking differences in the behavior of positive and negative plasmid molecules.


Assuntos
DNA Super-Helicoidal/ultraestrutura , DNA/química , DNA/ultraestrutura , Microscopia de Força Atômica , Plasmídeos/química , Plasmídeos/genética , Plasmídeos/ultraestrutura
13.
Biochem Biophys Res Commun ; 500(3): 698-703, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29684348

RESUMO

The self-labeling protein tags are robust and versatile tools for studying different molecular aspects of cell biology. In order to be suitable for a wide spectrum of experimental conditions, it is mandatory that these systems are stable after the fluorescent labeling reaction and do not alter the properties of the fusion partner. SsOGT-H5 is an engineered variant alkylguanine-DNA-alkyl-transferase (OGT) of the hyperthermophilic archaeon Sulfolobus solfataricus, and it represents an alternative solution to the SNAP-tag® technology under harsh reaction conditions. Here we present the crystal structure of SsOGT-H5 in complex with the fluorescent probe SNAP-Vista Green® (SsOGT-H5-SVG) that reveals the conformation adopted by the protein upon the trans-alkylation reaction with the substrate, which is observed covalently bound to the catalytic cysteine residue. Moreover, we identify the amino acids that contribute to both the overall protein stability in the post-reaction state and the coordination of the fluorescent moiety stretching-out from the protein active site. We gained new insights in the conformational changes possibly occurring to the OGT proteins upon reaction with modified guanine base bearing bulky adducts; indeed, our structural analysis reveals an unprecedented conformation of the active site loop that is likely to trigger protein destabilization and consequent degradation. Interestingly, the SVG moiety plays a key role in restoring the interaction between the N- and C-terminal domains of the protein that is lost following the new conformation adopted by the active site loop in the SsOGT-H5-SVG structure. Molecular dynamics simulations provide further information into the dynamics of SsOGT-H5-SVG structure, highlighting the role of the fluorescent ligand in keeping the protein stable after the trans-alkylation reaction.


Assuntos
Corantes Fluorescentes/metabolismo , O(6)-Metilguanina-DNA Metiltransferase/química , O(6)-Metilguanina-DNA Metiltransferase/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Coloração e Rotulagem , Sulfolobus solfataricus/enzimologia , Sequência de Aminoácidos , Domínio Catalítico , Cristalografia por Raios X , Corantes Fluorescentes/química , Metilação , Simulação de Dinâmica Molecular , Mutação/genética , Análise de Componente Principal , Conformação Proteica , Sulfolobus solfataricus/química , Sulfolobus solfataricus/genética
14.
Int J Mol Sci ; 18(12)2017 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-29206193

RESUMO

O6-DNA-alkyl-guanine-DNA-alkyl-transferases (OGTs) are evolutionarily conserved, unique proteins that repair alkylation lesions in DNA in a single step reaction. Alkylating agents are environmental pollutants as well as by-products of cellular reactions, but are also very effective chemotherapeutic drugs. OGTs are major players in counteracting the effects of such agents, thus their action in turn affects genome integrity, survival of organisms under challenging conditions and response to chemotherapy. Numerous studies on OGTs from eukaryotes, bacteria and archaea have been reported, highlighting amazing features that make OGTs unique proteins in their reaction mechanism as well as post-reaction fate. This review reports recent functional and structural data on two prokaryotic OGTs, from the pathogenic bacterium Mycobacterium tuberculosis and the hyperthermophilic archaeon Sulfolobus solfataricus, respectively. These studies provided insight in the role of OGTs in the biology of these microorganisms, but also important hints useful to understand the general properties of this class of proteins.


Assuntos
Reparo do DNA/fisiologia , Síncrotrons , Alquil e Aril Transferases/genética , Reparo do DNA/genética , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/metabolismo , Estabilidade Proteica , Sulfolobus solfataricus/enzimologia , Sulfolobus solfataricus/metabolismo
15.
PLoS One ; 12(10): e0185791, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28973046

RESUMO

Protein imaging, allowing a wide variety of biological studies both in vitro and in vivo, is of great importance in modern biology. Protein and peptide tags fused to proteins of interest provide the opportunity to elucidate protein location and functions, detect protein-protein interactions, and measure protein activity and kinetics in living cells. Whereas several tags are suitable for protein imaging in mesophilic organisms, the application of this approach to microorganisms living at high temperature has lagged behind. Archaea provide an excellent and unique model for understanding basic cell biology mechanisms. Here, we present the development of a toolkit for protein imaging in the hyperthermophilic archaeon Sulfolobus islandicus. The system relies on a thermostable protein tag (H5) constructed by engineering the alkylguanine-DNA-alkyl-transferase protein of Sulfolobus solfataricus, which can be covalently labeled using a wide range of small molecules. As a suitable host, we constructed, by CRISPR-based genome-editing technology, a S. islandicus mutant strain deleted for the alkylguanine-DNA-alkyl-transferase gene (Δogt). Introduction of a plasmid-borne H5 gene in this strain led to production of a functional H5 protein, which was successfully labeled with appropriate fluorescent molecules and visualized in cell extracts as well as in Δogt live cells. H5 was fused to reverse gyrase, a peculiar thermophile-specific DNA topoisomerase endowed with positive supercoiling activity, and allowed visualization of the enzyme in living cells. To the best of our knowledge, this is the first report of in vivo imaging of any protein of a thermophilic archaeon, filling an important gap in available tools for cell biology studies in these organisms.


Assuntos
Archaea/metabolismo , Proteínas Arqueais/metabolismo , Sulfolobus solfataricus/metabolismo , Sulfolobus/metabolismo , DNA Topoisomerases Tipo I/metabolismo , Temperatura Alta
17.
Biochim Biophys Acta Gen Subj ; 1861(2): 86-96, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27777086

RESUMO

BACKGROUND: Alkylated DNA-protein alkyltransferases (AGTs) are conserved proteins that repair alkylation damage in DNA by using a single-step mechanism leading to irreversible alkylation of the catalytic cysteine in the active site. Trans-alkylation induces inactivation and destabilization of the protein, both in vitro and in vivo, likely triggering conformational changes. A complete picture of structural rearrangements occurring during the reaction cycle is missing, despite considerable interest raised by the peculiarity of AGT reaction, and the contribution of a functional AGT in limiting the efficacy of chemotherapy with alkylating drugs. METHODS: As a model for AGTs we have used a thermostable ortholog from the archaeon Sulfolobus solfataricus (SsOGT), performing biochemical, structural, molecular dynamics and in silico analysis of ligand-free, DNA-bound and mutated versions of the protein. RESULTS: Conformational changes occurring during lesion recognition and after the reaction, allowed us to identify a novel interaction network contributing to SsOGT stability, which is perturbed when a bulky adduct between the catalytic cysteine and the alkyl group is formed, a mandatory step toward the permanent protein alkylation. CONCLUSIONS: Our data highlighted conformational changes and perturbation of intramolecular interaction occurring during lesion recognition and catalysis, confirming our previous hypothesis that coordination between the N- and C-terminal domains of SsOGT is important for protein activity and stability. GENERAL SIGNIFICANCE: A general model of structural rearrangements occurring during the reaction cycle of AGTs is proposed. If confirmed, this model might be a starting point to design strategies to modulate AGT activity in therapeutic settings.


Assuntos
Alquil e Aril Transferases/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Alquilantes/metabolismo , Alquilação/fisiologia , Catálise , Reparo do DNA/fisiologia , Domínios Proteicos , Estabilidade Proteica , Sulfolobus solfataricus/metabolismo
19.
JAMA ; 316(18): 1906-1912, 2016 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-27825009

RESUMO

Importance: Anakinra, an interleukin 1ß recombinant receptor antagonist, may have potential to treat colchicine-resistant and corticosteroid-dependent recurrent pericarditis. Objective: To determine the efficacy of anakinra for colchicine-resistant and corticosteroid-dependent recurrent pericarditis. Design, Setting, and Participants: The Anakinra-Treatment of Recurrent Idiopathic Pericarditis (AIRTRIP) double-blind, placebo-controlled, randomized withdrawal trial (open label with anakinra followed by a double-blind withdrawal step with anakinra or placebo until recurrent pericarditis occurred) conducted among 21 consecutive patients enrolled at 3 Italian referral centers between June and November 2014 (end of follow-up, October 2015). Included patients had recurrent pericarditis (with ≥3 previous recurrences), elevation of C-reactive protein, colchicine resistance, and corticosteroid dependence. Interventions: Anakinra was administered at 2 mg/kg per day, up to 100 mg, for 2 months, then patients who responded with resolution of pericarditis were randomized to continue anakinra (n = 11) or switch to placebo (n = 10) for 6 months or until a pericarditis recurrence. Main Outcomes and Measures: The primary outcomes were recurrent pericarditis and time to recurrence after randomization. Results: Eleven patients (7 female) randomized to anakinra had a mean age of 46.5 (SD, 16.3) years; 10 patients (7 female) randomized to placebo had a mean age of 44 (SD, 12.5) years. All patients were followed up for 12 months. Median follow-up was 14 (range, 12-17) months. Recurrent pericarditis occurred in 9 of 10 patients (90%; incidence rate, 2.06% of patients per year) assigned to placebo and 2 of 11 patients (18.2%; incidence rate, 0.11% of patients per year) assigned to anakinra, for an incidence rate difference of -1.95% (95% CI, -3.3% to -0.6%). Median flare-free survival (time to flare) was 72 (interquartile range, 64-150) days after randomization in the placebo group and was not reached in the anakinra group (P <.001). During anakinra treatment, 20 of 21 patients (95.2%) experienced transient local skin reactions: 1 (4.8%) herpes zoster, 3 (14.3%) transaminase elevation, and 1 (4.8%) ischemic optic neuropathy. No patient permanently discontinued the active drug. No adverse events occurred during placebo treatment. Conclusion and Relevance: In this preliminary study of patients with recurrent pericarditis with colchicine resistance and corticosteroid dependence, the use of anakinra compared with placebo reduced the risk of recurrence over a median of 14 months. Larger studies are needed to replicate these findings as well as to assess safety and longer-term efficacy. Trial Registration: clinicaltrials.gov Identifier: NCT02219828.


Assuntos
Desenvolvimento Infantil , Cognição , Fórmulas Infantis , Recém-Nascido de muito Baixo Peso/crescimento & desenvolvimento , Leite Humano , Método Duplo-Cego , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Desenvolvimento da Linguagem , Masculino , Ontário
20.
J Cardiovasc Med (Hagerstown) ; 17(9): 707-12, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27467459

RESUMO

OBJECTIVE: Limited data are available about recurrent pericarditis in children. We sought to explore contemporary causes, characteristics, therapies and outcomes of recurrent pericarditis in paediatric patients. METHODS: A multicentre (eight sites) cohort study of 110 consecutive cases of paediatric patients with at least two recurrences of pericarditis over an 11-year period (2000-2010) [median 13 years, interquartile range (IQR) 5, 69 boys]. RESULTS: Recurrences were idiopathic or viral in 89.1% of cases, followed by postpericardiotomy syndrome (9.1%) and familial Mediterranean fever (0.9%). Recurrent pericarditis was treated with nonsteroidal anti-inflammatory drugs (NSAIDs) in 80.9% of cases, corticosteroids in 64.8% and colchicine was added in 61.8%. Immunosuppressive therapies were administered in 15.5% of patients after subsequent recurrences. After a median follow-up of 60th months, 528 subsequent recurrences were recorded (median 3, range 2-25). Corticosteroid-treated patients experienced more recurrences (standardized risk of recurrence per 100 person-years was 93.2 for patients treated with corticosteroids and 45.2 for those without), side effects and disease-related hospitalizations (for all P < 0.05). Adjuvant therapy with colchicine was associated with a decrease in the risk of recurrence from 3.74 per year before initiation of colchicine to 1.37 per year after (P < 0.05). Anakinra therapy (n = 12) was associated with a drop in the number of recurrences from 4.29 per year before to 0.14 per year after (P < 0.05). Transient constrictive pericarditis developed in 2.7% of patients. CONCLUSION: Recurrent pericarditis has an overall favourable prognosis in children, although it may require frequent readmissions and seriously affect the quality of life, especially in patients treated with corticosteroids. Colchicine or anakinra therapies were associated with significant decrease in the risk of recurrence.


Assuntos
Pericardite/diagnóstico , Pericardite/tratamento farmacológico , Adolescente , Anti-Inflamatórios não Esteroides/uso terapêutico , Criança , Pré-Escolar , Estudos de Coortes , Colchicina/uso terapêutico , Seguimentos , Glucocorticoides/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Lactente , Recém-Nascido , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Pericardite/etiologia , Prognóstico , Recidiva , Fatores de Tempo , Resultado do Tratamento
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