Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 127
Filtrar
Mais filtros

Coleção Fiocruz
Intervalo de ano de publicação
1.
Pediatr Res ; 95(1): 174-181, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36997691

RESUMO

BACKGROUND: Lyme disease is common among children and adolescents. Antibiotic treatment is effective, yet some patients report persistent symptoms following treatment, with or without functional impairment. This study characterized long-term outcome of pediatric patients with Lyme disease and evaluated the case definition of post-treatment Lyme disease (PTLD) syndrome. METHODS: The sample included 102 children with confirmed Lyme disease diagnosed 6 months-10 years prior to enrollment (M = 2.0 years). Lyme diagnosis and treatment information was extracted from the electronic health record; parent report identified presence, duration, and impact of symptoms after treatment. Participants completed validated questionnaires assessing health-related quality of life, physical mobility, fatigue, pain, and cognitive impact. RESULTS: Most parents reported their child's symptoms resolved completely, although time to full resolution varied. Twenty-two parents (22%) indicated their child had at least one persistent symptom >6 months post-treatment, 13 without functional impairment (PTLD symptoms) and 9 with functional impairment (PTLD syndrome). Children with PTLD syndrome had lower parent-reported Physical Summary scores and greater likelihood of elevated fatigue. CONCLUSIONS: In the current study, most children with Lyme disease experienced full resolution of symptoms, including those who initially met PTLD syndrome criteria. Effective communication about recovery rates and common symptoms that may persist post-treatment is needed. IMPACT: The majority of pediatric patients treated for all stages of Lyme disease reported full resolution of symptoms within 6 months. 22% of pediatric patients reported one or more symptom persisting >6 months, 9% with and 13% without accompanying functional impairment. Effective communication with families about recovery rates and common symptoms that may persist post-treatment of Lyme disease is needed.


Assuntos
Doença de Lyme , Qualidade de Vida , Adolescente , Humanos , Criança , Doença de Lyme/diagnóstico , Doença de Lyme/tratamento farmacológico , Antibacterianos/uso terapêutico , Dor/tratamento farmacológico , Fadiga/tratamento farmacológico
2.
Ann Intern Med ; 175(7): 969-979, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35605238

RESUMO

BACKGROUND: A substantial proportion of persons who develop COVID-19 report persistent symptoms after acute illness. Various pathophysiologic mechanisms have been implicated in the pathogenesis of postacute sequelae of SARS-CoV-2 infection (PASC). OBJECTIVE: To characterize medical sequelae and persistent symptoms after recovery from COVID-19 in a cohort of disease survivors and controls. DESIGN: Cohort study. (ClinicalTrials.gov: NCT04411147). SETTING: National Institutes of Health Clinical Center, Bethesda, Maryland. PARTICIPANTS: Self-referred adults with laboratory-documented SARS-CoV-2 infection who were at least 6 weeks from symptom onset were enrolled regardless of presence of PASC. A control group comprised persons with no history of COVID-19 or serologic evidence of SARS-CoV-2 infection, recruited regardless of their current health status. Both groups were enrolled over the same period and from the same geographic area. MEASUREMENTS: All participants had the same evaluations regardless of presence of symptoms, including physical examination, laboratory tests and questionnaires, cognitive function testing, and cardiopulmonary evaluation. A subset also underwent exploratory immunologic and virologic evaluations. RESULTS: 189 persons with laboratory-documented COVID-19 (12% of whom were hospitalized during acute illness) and 120 antibody-negative control participants were enrolled. At enrollment, symptoms consistent with PASC were reported by 55% of the COVID-19 cohort and 13% of control participants. Increased risk for PASC was noted in women and those with a history of anxiety disorder. Participants with findings meeting the definition of PASC reported lower quality of life on standardized testing. Abnormal findings on physical examination and diagnostic testing were uncommon. Neutralizing antibody levels to spike protein were negative in 27% of the unvaccinated COVID-19 cohort and none of the vaccinated COVID-19 cohort. Exploratory studies found no evidence of persistent viral infection, autoimmunity, or abnormal immune activation in participants with PASC. LIMITATIONS: Most participants with COVID-19 had mild to moderate acute illness that did not require hospitalization. The prevalence of reported PASC was likely overestimated in this cohort because persons with PASC may have been more motivated to enroll. The study did not capture PASC that resolved before enrollment. CONCLUSION: A high burden of persistent symptoms was observed in persons after COVID-19. Extensive diagnostic evaluation revealed no specific cause of reported symptoms in most cases. Antibody levels were highly variable after COVID-19. PRIMARY FUNDING SOURCE: Division of Intramural Research, National Institute of Allergy and Infectious Diseases.


Assuntos
COVID-19 , Doença Aguda , Adulto , COVID-19/complicações , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Qualidade de Vida , SARS-CoV-2
3.
Clin Infect Dis ; 75(2): 342-346, 2022 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34849631

RESUMO

The role that microorganisms might have in the development of Alzheimer disease is a topic of considerable interest. In this article, we discuss whether there is credible evidence that Lyme disease is a cause of Alzheimer disease and critically review a recent publication that claimed that Borrelia burgdorferi sensu stricto infection, the primary cause of Lyme disease in the United States, may cause Lewy body dementia. We conclude that no convincing evidence exists that Lyme disease is a cause of either Alzheimer disease or Lewy body dementia.


Assuntos
Doença de Alzheimer , Grupo Borrelia Burgdorferi , Borrelia burgdorferi , Doença por Corpos de Lewy , Doença de Lyme , Doença de Alzheimer/etiologia , Humanos , Doença de Lyme/complicações , Estados Unidos
4.
Emerg Infect Dis ; 27(8): 2017-2024, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34286689

RESUMO

Lyme disease, or Lyme borreliosis, is the most common tickborne disease in the United States and Europe. In both locations, Ixodes species ticks transmit the Borrelia burgdorferi sensu lato bacteria species responsible for causing the infection. The diversity of Borrelia species that cause human infection is greater in Europe; the 2 B. burgdorferi s.l. species collectively responsible for most infections in Europe, B. afzelii and B. garinii, are not found in the United States, where most infections are caused by B. burgdorferi sensu stricto. Strain differences seem to explain some of the variation in the clinical manifestations of Lyme disease, which are both minor and substantive, between the United States and Europe. Future studies should attempt to delineate the specific virulence factors of the different species of B. burgdorferi s.l. responsible for these variations in clinical features.


Assuntos
Grupo Borrelia Burgdorferi , Borrelia , Ixodes , Doença de Lyme , Animais , Europa (Continente)/epidemiologia , Humanos , Doença de Lyme/diagnóstico , Doença de Lyme/epidemiologia , Estados Unidos/epidemiologia
5.
Proc Natl Acad Sci U S A ; 115(16): E3788-E3797, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29610317

RESUMO

Borrelia burgdorferi is one of the few extracellular pathogens capable of establishing persistent infection in mammals. The mechanisms that sustain long-term survival of this bacterium are largely unknown. Here we report a unique innate immune evasion strategy of B. burgdorferi, orchestrated by a surface protein annotated as BBA57, through its modulation of multiple spirochete virulent determinants. BBA57 function is critical for early infection but largely redundant for later stages of spirochetal persistence, either in mammals or in ticks. The protein influences host IFN responses as well as suppresses multiple host microbicidal activities involving serum complement, neutrophils, and antimicrobial peptides. We also discovered a remarkable plasticity in BBA57-mediated spirochete immune evasion strategy because its loss, although resulting in near clearance of pathogens at the inoculum site, triggers nonheritable adaptive changes that exclude detectable nucleotide alterations in the genome but incorporate transcriptional reprograming events. Understanding the malleability in spirochetal immune evasion mechanisms that ensures their host persistence is critical for the development of novel therapeutic and preventive approaches to combat long-term infections like Lyme borreliosis.


Assuntos
Proteínas de Bactérias/fisiologia , Borrelia burgdorferi/imunologia , Evasão da Resposta Imune , Lipoproteínas/fisiologia , Proteínas de Membrana/fisiologia , Animais , Antígenos de Bactérias/imunologia , Peptídeos Catiônicos Antimicrobianos/biossíntese , Peptídeos Catiônicos Antimicrobianos/genética , Vetores Aracnídeos/microbiologia , Proteínas de Bactérias/genética , Borrelia burgdorferi/genética , Borrelia burgdorferi/patogenicidade , Células Cultivadas , Proteínas do Sistema Complemento/imunologia , Citocinas/biossíntese , Citocinas/genética , Feminino , Regulação Bacteriana da Expressão Gênica , Humanos , Ixodes/microbiologia , Lipoproteínas/genética , Doença de Lyme/imunologia , Doença de Lyme/microbiologia , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos SCID , Organismos Livres de Patógenos Específicos , Virulência
6.
Clin Infect Dis ; 70(8): 1768-1773, 2020 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-31620776

RESUMO

Lyme disease, caused by some Borrelia burgdorferi sensu lato, is the most common tick-borne illness in the Northern Hemisphere and the number of cases, and geographic spread, continue to grow. Previously identified B. burgdorferi proteins, lipid immunogens, and live mutants lead the design of canonical vaccines aimed at disrupting infection in the host. Discovery of the mechanism of action of the first vaccine catalyzed the development of new strategies to control Lyme disease that bypassed direct vaccination of the human host. Thus, novel prevention concepts center on proteins produced by B. burgdorferi during tick transit and on tick proteins that mediate feeding and pathogen transmission. A burgeoning area of research is tick immunity as it can unlock mechanistic pathways that could be targeted for disruption. Studies that shed light on the mammalian immune pathways engaged during tick-transmitted B. burgdorferi infection would further development of vaccination strategies against Lyme disease.


Assuntos
Borrelia burgdorferi , Ixodes , Doença de Lyme , Carrapatos , Vacinas , Animais , Humanos , Doença de Lyme/prevenção & controle , Vacinação
7.
J Bioenerg Biomembr ; 52(1): 1-15, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31853754

RESUMO

Schizophrenia etiology is unknown, nevertheless imbalances occurring in an acute psychotic episode are important to its development, such as alterations in cellular energetic state, REDOX homeostasis and intracellular Ca2+ management, all of which are controlled primarily by mitochondria. However, mitochondrial function was always evaluated singularly, in the presence of specific respiratory substrates, without considering the plurality of the electron transport system. In this study, mitochondrial function was analyzed under conditions of isolated or multiple respiratory substrates using brain mitochondria isolated from MK-801-exposed mice. Results showed a high H2O2 production in the presence of pyruvate/malate, with no change in oxygen consumption. In the condition of multiple substrates, however, this effect is lost. The analysis of Ca2+ retention capacity revealed a significant change in the uptake kinetics of this ion by mitochondria in MK-801-exposed animals. Futhermore, when mitochondria were exposed to calcium, a total loss of oxidative phosphorylation and an impressive increase in H2O2 production were observed in the condition of multiple substrates. There was no alteration in the activity of the antioxidant enzymes analyzed. The data demonstrate for the first time, in an animal model of psychosis, two important aspects (1) mitochondria may compensate deficiencies in a single mitochondrial complex when they oxidize several substrates simultaneously, (2) Ca2+ handling is compromised in MK-801-exposed mice, resulting in a loss of phosphorylative capacity and an increase in H2O2 production. These data favor the hypothesis that disruption of key physiological roles of mitochondria may be a trigger in acute psychosis and, consequently, schizophrenia.


Assuntos
Encéfalo/patologia , Cálcio/efeitos adversos , Mitocôndrias/patologia , Transtornos Psicóticos/complicações , Doença Aguda , Animais , Humanos , Masculino , Camundongos
8.
Clin Infect Dis ; 68(6): 1052-1057, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30307486

RESUMO

Borrelia burgdorferi was discovered to be the cause of Lyme disease in 1983, leading to seroassays. The 1994 serodiagnostic testing guidelines predated a full understanding of key B. burgdorferi antigens and have a number of shortcomings. These serologic tests cannot distinguish active infection, past infection, or reinfection. Reliable direct-detection methods for active B. burgdorferi infection have been lacking in the past but are needed and appear achievable. New approaches have effectively been applied to other emerging infections and show promise in direct detection of B. burgdorferi infections.


Assuntos
Borrelia burgdorferi , Doença de Lyme/diagnóstico , Doença de Lyme/microbiologia , Borrelia burgdorferi/genética , Testes Diagnósticos de Rotina , Genômica/métodos , Ensaios de Triagem em Larga Escala , Humanos , Reação em Cadeia da Polimerase , Testes Sorológicos
9.
J Clin Microbiol ; 57(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31597750

RESUMO

Single multiplexed assays could replace the standard 2-tiered (STT) algorithm recommended for the laboratory diagnosis of Lyme disease if they perform with a specificity and a sensitivity superior or equal to those of the STT algorithm. We used human serum rigorously characterized to be sera from patients with acute- and convalescent-phase early Lyme disease, Lyme arthritis, and posttreatment Lyme disease syndrome, as well as the necessary controls (n = 241 samples), to select the best of 12 Borrelia burgdorferi proteins to improve our microfluidic assay (mChip-Ld). We then evaluated its serodiagnostic performance in comparison to that of a first-tier enzyme immunoassay and the STT algorithm. We observed that more antigens became positive as Lyme disease progressed from early to late stages. We selected three antigens (3Ag) to include in the mChip-Ld: VlsE and a proprietary synthetic 33-mer peptide (PepVF) to capture sensitivity in all disease stages and OspC for early Lyme disease. With the specificity set at 95%, the sensitivity of the mChip-Ld with 3Ag ranged from 80% (95% confidence interval [CI], 56% to 94%) and 85% (95% CI, 74% to 96%) for two panels of serum from patients with early Lyme disease and was 100% (95% CI, 83% to 100%) for serum from patients with Lyme arthritis; the STT algorithm detected early Lyme disease in the same two panels of serum from patients with early Lyme disease with a sensitivity of 48.5% and 75% and Lyme arthritis in serum from patients with Lyme arthritis with a sensitivity of 100%, and the specificity was 97.5% to 100%. The mChip-Ld platform outperformed the STT algorithm according to sensitivity. These results open the door for the development of a single, rapid, multiplexed diagnostic test for point-of-care use that can be designed to identify the Lyme disease stage.


Assuntos
Borrelia burgdorferi/imunologia , Doença de Lyme/diagnóstico , Microfluídica/métodos , Sistemas Automatizados de Assistência Junto ao Leito , Testes Sorológicos/métodos , Humanos , Sensibilidade e Especificidade
11.
Clin Infect Dis ; 66(7): 1133-1139, 2018 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-29228208

RESUMO

The cause of Lyme disease, Borrelia burgdorferi, was discovered in 1983. A 2-tiered testing protocol was established for serodiagnosis in 1994, involving an enzyme immunoassay (EIA) or indirect fluorescence antibody, followed (if reactive) by immunoglobulin M and immunoglobulin G Western immunoblots. These assays were prepared from whole-cell cultured B. burgdorferi, lacking key in vivo expressed antigens and expressing antigens that can bind non-Borrelia antibodies. Additional drawbacks, particular to the Western immunoblot component, include low sensitivity in early infection, technical complexity, and subjective interpretation when scored by visual examination. Nevertheless, 2-tiered testing with immunoblotting remains the benchmark for evaluation of new methods or approaches. Next-generation serologic assays, prepared with recombinant proteins or synthetic peptides, and alternative testing protocols, can now overcome or circumvent many of these past drawbacks. This article describes next-generation serodiagnostic testing for Lyme disease, focusing on methods that are currently available or near-at-hand.


Assuntos
Anticorpos Antibacterianos/sangue , Doença de Lyme/diagnóstico , Testes Sorológicos/métodos , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Borrelia burgdorferi/imunologia , Ensaio de Imunoadsorção Enzimática , Europa (Continente) , Humanos , Técnicas Imunoenzimáticas , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Proteínas Recombinantes , Sensibilidade e Especificidade , Testes Sorológicos/tendências , Estados Unidos
12.
J Clin Microbiol ; 56(8)2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29898997

RESUMO

Lyme disease is a tick-borne illness caused by Borreliella (Borrelia) burgdorferi, and it is the most common vector-borne disease in the United States, with an estimated incidence of 300,000 cases per year. The currently recommended approach for laboratory support of the diagnosis of Lyme disease is a standard two-tiered (STT) algorithm comprised of an enzyme-linked immunoassay (EIA) or immunofluorescence assay (IFA), followed by Western blotting (WB). The STT algorithm has low sensitivity in early infection, and there are drawbacks associated with the WB use in practice. Modified two-tiered (MTT) algorithms have been shown to improve the sensitivity of the testing in early disease while maintaining high specificity. In this issue of the Journal of Clinical Microbiology, A. Pegalajar-Jurado et al. (J Clin Microbiol 56:e01943-17, 2018, https://doi.org/10.1128/JCM.01943-17) report the results of their evaluation of the Liaison VlsE CLIA, the Captia B. burgdorferi IgG/IgM EIA, and the C6 B. burgdorferi (Lyme) EIA as MTT algorithms compared with results with the STT algorithm using the same tests as the first-tier test and the ViraStripe IgM and IgG WBs as the second-tier test. The results showed that all MTT algorithms had higher sensitivities than STT algorithms and were highly specific. These results showed that MTT approaches are a valid alternative to the currently recommended STT algorithm for serodiagnosis of Lyme disease, opening the door for the development of rapid diagnostics and point-of-care testing that can provide diagnostic information during the initial patient visit.


Assuntos
Borrelia burgdorferi/imunologia , Doença de Lyme , Algoritmos , Anticorpos Antibacterianos , Humanos , Imunoglobulina G , Sensibilidade e Especificidade , Testes Sorológicos
13.
J Med Virol ; 90(8): 1389-1397, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29704443

RESUMO

It is still not well known, in a population with high human cytomegalovirus (HCMV) seroprevalence, whether a child with congenital infection harbors multiple viral strains at birth, and whether the prolonged viral excretion in these children is secondary to the persistence of the same viral strain. To verify the genomic diversity of HCMV detected in congenitally infected children, the nucleotide viral sequences from urine and/or saliva obtained at birth from 14 newborns with congenital infection and breast milk obtained from mothers of 5 of these children were analyzed. Among the 14 children, 10 had sequential samples until the median age of 10 months. The viral nucleotide sequences in the breast milk were compared with those identified in the respective children at birth. The differentiation of viral strains was based on the variability of 3 regions of viral genes (UL55/gB, UL144, and UL73/gN). In 13/14 children (92.8%), a single genotype was observed at birth. Different viral genotypes were found in 1 child (7.2%). Among the sequential samples from 10 children, the same genotype obtained at birth was detected in 9/10 (90%), and in 1 of them (10%), a genotype change in the urine was found. More than 1 HCMV strain in milk was observed in 2 mothers (2/5, 40%). In a population with high seroprevalence, a single genotype was found in the majority of infected children. Reinfection did not frequently occur in the first months of life. Maternal reinfection does not seem to be a rare event in transmitter mothers.


Assuntos
Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/virologia , Citomegalovirus/classificação , Citomegalovirus/genética , Variação Genética , Genótipo , Citomegalovirus/isolamento & purificação , Genes Virais , Humanos , Lactente , Recém-Nascido , Leite Humano/virologia , Saliva/virologia , Urina/virologia
14.
J Immunol ; 196(3): 1036-43, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26718339

RESUMO

Most immunogenic proteins of Borrelia burgdorferi, the causative agent of Lyme disease, are known or expected to contain multiple B cell epitopes. However, the kinetics of the development of human B cell responses toward the various epitopes of individual proteins during the course of Lyme disease has not been examined. Using the highly immunogenic VlsE as a model Ag, we investigated the evolution of humoral immune responses toward its immunodominant sequences in 90 patients with a range of early to late manifestations of Lyme disease. The results demonstrate the existence of asynchronous, independently developing, Ab responses against the two major immunogenic regions of the VlsE molecule in the human host. Despite their strong immunogenicity, the target epitopes were inaccessible to Abs on intact spirochetes, suggesting a lack of direct immunoprotective effect. These observations document the association of immune reactivity toward specific VlsE sequences with different phases of Lyme disease, demonstrating the potential use of detailed epitope mapping of Ags for staging of the infection, and offer insights regarding the pathogen's possible immune evasion mechanisms.


Assuntos
Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Linfócitos B/imunologia , Proteínas de Bactérias/imunologia , Epitopos de Linfócito B/imunologia , Lipoproteínas/imunologia , Doença de Lyme/imunologia , Adulto , Idoso , Anticorpos Antibacterianos/sangue , Borrelia burgdorferi/imunologia , Ensaio de Imunoadsorção Enzimática , Mapeamento de Epitopos , Feminino , Imunofluorescência , Humanos , Imunidade Humoral/imunologia , Immunoblotting , Doença de Lyme/sangue , Masculino , Pessoa de Meia-Idade , Adulto Jovem
16.
J Infect Dis ; 217(1): 158-167, 2017 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-29099929

RESUMO

Background: The most common clinical manifestation of early Lyme disease is the erythema migrans (EM) skin lesion that develops at the tick bite site typically between 7 and 14 days after infection with Borreliella burgdorferi. The host-pathogen interactions that occur in the skin may have a critical role in determining outcome of infection. Methods: Gene arrays were used to characterize the global transcriptional alterations in skin biopsy samples of EM lesions from untreated adult patients with Lyme disease in comparison to controls. Results: The transcriptional pattern in EM biopsies consisted of 254 differentially regulated genes (180 induced and 74 repressed) characterized by the induction of chemokines, cytokines, Toll-like receptors, antimicrobial peptides, monocytoid cell activation markers, and numerous genes annotated as interferon (IFN)-inducible. The IFN-inducible genes included 3 transcripts involved in tryptophan catabolism (IDO1, KMO, KYNU) that play a pivotal role in immune evasion by certain other microbial pathogens by driving the differentiation of regulatory T cells. Conclusions: This is the first study to globally assess the human skin transcriptional response during early Lyme disease. Borreliella burgdorferi elicits a predominant IFN signature in the EM lesion, suggesting a potential mechanism for spirochetal dissemination via IDO1-mediated localized immunosuppression.


Assuntos
Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno , Interferons/metabolismo , Doença de Lyme/patologia , Transdução de Sinais , Pele/patologia , Adulto , Idoso , Biópsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
17.
Clin Infect Dis ; 65(2): 336-337, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28379435

RESUMO

False-positive serology for Lyme disease was reported in patients with acute infectious mononucleosis. Here we describe 2 patients with early disseminated Lyme disease who were misdiagnosed with infectious mononucleosis based on false-positive tests for primary Epstein-Barr virus infection.


Assuntos
Anticorpos Antivirais/sangue , Herpesvirus Humano 4/imunologia , Mononucleose Infecciosa/diagnóstico , Doença de Lyme/diagnóstico , Adolescente , Idoso , Anticorpos Antivirais/imunologia , Antígenos Virais/imunologia , Erros de Diagnóstico , Reações Falso-Positivas , Feminino , Humanos , Imunoglobulina M/sangue , Mononucleose Infecciosa/imunologia , Doença de Lyme/imunologia , Masculino
18.
Proc Natl Acad Sci U S A ; 111(38): 13936-41, 2014 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-25205813

RESUMO

CXCR6-GFP(+) cells, which encompass 70% invariant natural killer T cells (iNKT cells), have been found primarily patrolling inside blood vessels in the liver. Although the iNKT cells fail to interact with live pathogens, they do respond to bacterial glycolipids presented by CD1d on liver macrophage that have caught the microbe. In contrast, in this study using dual laser multichannel spinning-disk intravital microscopy of joints, the CXCR6-GFP, which also made up 60-70% iNKT cells, were not found in the vasculature but rather closely apposed to and surrounding the outside of blood vessels, and to a lesser extent throughout the extravascular space. These iNKT cells also differed in behavior, responding rapidly and directly to joint-homing pathogens like Borrelia burgdorferi, which causes Lyme disease. These iNKT cells interacted with B. burgdorferi at the vessel wall and disrupted dissemination attempts by these microbes into joints. Successful penetrance of B. burgdorferi out of the vasculature and into the joint tissue was met by a lethal attack by extravascular iNKT cells through a granzyme-dependent pathway, an observation also made in vitro for iNKT cells from joint but not liver or spleen. These results suggest a novel, critical extravascular iNKT cell immune surveillance in joints that functions as a cytotoxic barrier and explains a large increase in pathogen burden of B. burgdorferi in the joint of iNKT cell-deficient mice, and perhaps the greater susceptibility of humans to this pathogen because of fewer iNKT cells in human joints.


Assuntos
Borrelia burgdorferi/imunologia , Imunidade Celular , Artropatias/imunologia , Articulações/imunologia , Doença de Lyme/imunologia , Células T Matadoras Naturais/imunologia , Animais , Granzimas/genética , Granzimas/imunologia , Humanos , Artropatias/genética , Artropatias/microbiologia , Artropatias/patologia , Articulações/microbiologia , Articulações/patologia , Fígado/imunologia , Fígado/patologia , Doença de Lyme/genética , Doença de Lyme/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Células T Matadoras Naturais/patologia , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , Baço/imunologia , Baço/patologia
20.
Clin Infect Dis ; 63(11): 1399-1404, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27585799

RESUMO

BACKGROUND: Infection with Borrelia burgdorferi, the causative agent of Lyme disease, triggers host immune responses that affect the clinical outcome and are a source of biomarkers with diagnostic utility. Although adaptive immunity to B. burgdorferi has been extensively characterized, considerably less information is available about the development of innate acute-phase responses in Lyme disease. Our aim in this study was to evaluate the expression of C-reactive protein (CRP) and serum amyloid A (SAA), the prototype acute-phase response proteins, in the context of the varying manifestations associated with Lyme borreliosis. METHODS: Circulating concentrations of CRP and SAA in patients with a range of early to late objective manifestations of Lyme disease and in individuals with post-treatment Lyme disease syndrome were compared with those in healthy control groups. RESULTS: CRP and SAA levels were significantly elevated in early localized and early disseminated Lyme disease but not in the later stages of active infection. Levels of CRP, but not SAA, were also found to be significantly increased in patients with antibiotic-refractory Lyme arthritis and in those with post-treatment Lyme disease syndrome. CONCLUSIONS: These findings indicate that circulating CRP and SAA levels are highest when the concentration of spirochetes is greatest in skin and/or blood and that levels decline after the dissemination of the organism to extracutaneous sites in subsequent stages of infection. The data also suggest that antibiotic-refractory Lyme arthritis and post-treatment Lyme disease syndrome are associated with elevated CRP responses that are driven by inflammatory mechanisms distinct from those in active infection.


Assuntos
Proteína C-Reativa/análise , Doença de Lyme/sangue , Proteína Amiloide A Sérica/análise , Adulto , Idoso , Antibacterianos/uso terapêutico , Anticorpos Antibacterianos/sangue , Biomarcadores/sangue , Borrelia burgdorferi/imunologia , Borrelia burgdorferi/isolamento & purificação , Proteína C-Reativa/genética , Feminino , Humanos , Imunidade Inata , Inflamação , Doença de Lyme/tratamento farmacológico , Doença de Lyme/imunologia , Doença de Lyme/microbiologia , Masculino , Pessoa de Meia-Idade , Proteína Amiloide A Sérica/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA