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1.
J Infect Dis ; 223(3): 435-440, 2021 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-32614431

RESUMEN

The recent increase in babies born with brain and eye malformations in Brazil is associated with Zika virus (ZIKV) infection in utero. ZIKV alters host DNA methylation in vitro. Using genome-wide DNA methylation profiling we compared 18 babies born with congenital ZIKV microcephaly with 20 controls. We found ZIKV-associated alteration of host methylation patterns, notably at RABGAP1L which is important in brain development, at viral host immunity genes MX1 and ISG15, and in an epigenetic module containing the causal microcephaly gene MCPH1. Our data support the hypothesis that clinical signs of congenital ZIKV are associated with changes in DNA methylation.


Asunto(s)
Metilación de ADN , Inmunidad/genética , Microcefalia/virología , Neurogénesis/genética , Infección por el Virus Zika , Encéfalo/crecimiento & desarrollo , Encéfalo/virología , Brasil , Proteínas de Ciclo Celular/genética , Preescolar , Proteínas del Citoesqueleto/genética , Femenino , Humanos , Lactante , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo/virología , Virus Zika/inmunología
2.
Clin Infect Dis ; 68(12): 2036-2044, 2019 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-30239631

RESUMEN

BACKGROUND: Visceral leishmaniasis (VL), due to Leishmania infantum, is a persistent intracellular parasitic infection transmitted by the bite of infected sand flies. Symptomatic VL has been reported in U.S. soldiers with Iraq deployment. Untreated symptomatic VL can be fatal; asymptomatic VL (AVL) may establish a lifelong risk of reactivation. We report prevalence and AVL risk factors in Operation Iraqi Freedom (OIF) deployers during 2002-11. METHODS: Healthy soldiers exposed to VL endemic areas in Iraq and 50 controls who never traveled to endemic regions were recruited through military healthcare facilities (2015-17). Responses to a risk factor survey and blood samples were obtained. Leishmania research diagnostics utilized included enzyme-linked immunosorbent assay (ELISA), rk39 test strips, quantitative polymerase chain reaction (PCR), and interferon gamma release (IGRA) assays. Statistical analyses included Fisher exact test, Pearson χ2 test, Mann-Whitney U test, and logistic regression. RESULTS: 200 deployed subjects were enrolled, mostly males (84.0%), of white ethnicity (79.0%), and median age 41 (range 24-61) years. 64% were seropositive for Phlebotomus alexandri saliva antibodies. Prevalence of AVL (any positive test result) was 39/200 (19.5%, 95% confidence interval 14.4%-25.8%). Two (1.0%) PCR, 10 (5%) ELISA, and 28 (14%) IGRA samples were positive. Travel to Ninewa governorate increased risk for AVL (P = .01). CONCLUSION: AVL was identified in 19.5% of OIF deployers; travel to northwest Iraq correlated with infection. Further studies are needed to inform risk for reactivation VL in US veterans and to target additional blood safety and surveillance measures.


Asunto(s)
Infecciones Asintomáticas , Leishmania infantum , Leishmaniasis Visceral/epidemiología , Leishmaniasis Visceral/parasitología , Personal Militar , Adulto , Femenino , Geografía , Humanos , Irak/epidemiología , Leishmaniasis Visceral/diagnóstico , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Estados Unidos/epidemiología , Adulto Joven
3.
J Immunol ; 196(10): 4100-9, 2016 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-27076677

RESUMEN

During visceral leishmaniasis (VL), Th1-based inflammation is induced to control intracellular parasites. Inflammation-based pathology was shown to be dampened by IL-10 and eventual programmed death 1-mediated T cell exhaustion. Cell type(s) responsible for the initiation of T cell-produced IL-10 during VL are unknown. CD19(+), CD5(-), CD1d(-), IgD(hi) regulatory B cells from healthy controls produced IL-10 in the absence of infection or stimulation, in contrast to IgD(lo/neg) B cells. IgD(hi) B cells may have a de novo versus induced regulatory program. The population of IgD(hi) B cells increased 3-fold as VL progressed. B cells from VL dogs were necessary and sufficient to suppress Th1 cell effector function. IgD(hi) B cells induced IL-10 production by T cells and IgD(lo) B cells. Blockage of B cell-specific PD-L1 restored Th1 responses. IgD(hi) regulatory B cells represent a novel regulatory B cell that may precipitate T cell exhaustion during VL.


Asunto(s)
Antígenos de Protozoos/inmunología , Linfocitos B Reguladores/inmunología , Antígeno B7-H1/metabolismo , Interleucina-10/metabolismo , Leishmania infantum/inmunología , Leishmaniasis Visceral/inmunología , Proteínas Protozoarias/inmunología , Células TH1/inmunología , Animales , Anticuerpos Bloqueadores/metabolismo , Anticuerpos Antiprotozoarios/metabolismo , Linfocitos B Reguladores/parasitología , Antígeno B7-H1/inmunología , Células Cultivadas , Progresión de la Enfermedad , Perros , Femenino , Humanos , Tolerancia Inmunológica , Inmunoglobulina D/metabolismo , Masculino , Células TH1/parasitología
4.
Acta Neurol Scand ; 138(5): 459-462, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30003535

RESUMEN

OBJECTIVE: The Erasmus Guillain Barre Outcome Score (EGOS) is a prognostic model that predicts the chance of being able to walk independently at 6 months after Guillain Barré syndrome (GBS). This study was conducted aiming to determine the validity of EGOS in a Brazilian population. MATERIAL AND METHODS: Data collected from GBS patients in Rio Grande do Norte, Brazil, were used to determine the validity of EGOS. GBS disability score was assessed in the second week of disease and at 6 months. RESULTS: A total of 206 subjects were studied. The Brazilian patients were younger, with a more severe clinical presentation, with higher percentage of cranial nerve involvement and upper respiratory infection. There was no difference relative to sex or presence of anti-gangliosides antibodies. The demyelinating variant was more common (73.9%). However, only 24% of the Brazilians with EGOS 5.5-7 were not able to walk after 6 months, compared to 52% to European Group. Nine patients (3.8%) presented nodopathies, of these four had an EGOS >5, but only one of the latter group was unable to walk after 6 months of GBS. CONCLUSIONS: Erasmus Guillain Barre Outcome Score was not a good predictor for the ability to walk after 6 months of GBS in Rio Grande do Norte, Brazil. Differences could be that the Brazilian GBS were younger, or alternatively, it could be due to a different infection profile or in the incidence of nodopathies.


Asunto(s)
Síndrome de Guillain-Barré/complicaciones , Recuperación de la Función , Índice de Severidad de la Enfermedad , Adulto , Brasil/epidemiología , Femenino , Síndrome de Guillain-Barré/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Pronóstico , Caminata
5.
Ann Hum Genet ; 81(1): 41-48, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28054334

RESUMEN

Genetic risk factors contribute to asymptomatic versus symptomatic visceral leishmaniasis (VL) outcomes following infection with Leishmania infantum. We therefore carried out a family-based (n = 918 post-quality control fully genotyped and phenotyped individuals) candidate gene study for symptomatic VL or asymptomatic delayed-type hypersensitivity (DTH) skin test phenotypes in highly endemic neighborhoods of northeast Brazil. A total of 248 SNPs were genotyped in 42 genes selected as candidates on the basis of prior genetic, immunological, and transcriptional profiling studies. The most significant association with the VL phenotype was with SNP rs6785358 (P = 5.7e-04; pcorrected = 0.026) 3.8 kb upstream of TGFBR2, the gene encoding the type 2 receptor for transforming growth factor beta (TGFß). A second inhibitory member of the TGBß superfamily signaling pathway, SMAD7, was associated with the DTH phenotype (SNP rs7238442: P = 0.001; pcorrected = 0.051). The most significant association for the DTH phenotype was with SNP rs10800309 (P = -8.4e-06; pcorrected = 3.9e-04) situated 3.1 kb upstream of FCGR2A, the gene encoding the low-affinity IIa receptor for the Fc fragment of IgG. Overall, our results imply a role for IgG-mediated inflammation in determining DTH associated with asymptomatic infection and contribute to growing evidence that the TGFß pathway is important in the immunopathogenesis of VL.


Asunto(s)
Leishmania infantum , Leishmaniasis Visceral/genética , Proteínas Serina-Treonina Quinasas/genética , Receptores de IgG/genética , Receptores de Factores de Crecimiento Transformadores beta/genética , Adolescente , Infecciones Asintomáticas , Brasil , Niño , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Leishmaniasis Visceral/parasitología , Desequilibrio de Ligamiento , Masculino , Polimorfismo de Nucleótido Simple , Receptor Tipo II de Factor de Crecimiento Transformador beta
6.
PLoS Genet ; 10(7): e1004445, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25033443

RESUMEN

Approaches based on linear mixed models (LMMs) have recently gained popularity for modelling population substructure and relatedness in genome-wide association studies. In the last few years, a bewildering variety of different LMM methods/software packages have been developed, but it is not always clear how (or indeed whether) any newly-proposed method differs from previously-proposed implementations. Here we compare the performance of several LMM approaches (and software implementations, including EMMAX, GenABEL, FaST-LMM, Mendel, GEMMA and MMM) via their application to a genome-wide association study of visceral leishmaniasis in 348 Brazilian families comprising 3626 individuals (1972 genotyped). The implementations differ in precise details of methodology implemented and through various user-chosen options such as the method and number of SNPs used to estimate the kinship (relatedness) matrix. We investigate sensitivity to these choices and the success (or otherwise) of the approaches in controlling the overall genome-wide error-rate for both real and simulated phenotypes. We compare the LMM results to those obtained using traditional family-based association tests (based on transmission of alleles within pedigrees) and to alternative approaches implemented in the software packages MQLS, ROADTRIPS and MASTOR. We find strong concordance between the results from different LMM approaches, and all are successful in controlling the genome-wide error rate (except for some approaches when applied naively to longitudinal data with many repeated measures). We also find high correlation between LMMs and alternative approaches (apart from transmission-based approaches when applied to SNPs with small or non-existent effects). We conclude that LMM approaches perform well in comparison to competing approaches. Given their strong concordance, in most applications, the choice of precise LMM implementation cannot be based on power/type I error considerations but must instead be based on considerations such as speed and ease-of-use.


Asunto(s)
Estudio de Asociación del Genoma Completo , Leishmaniasis Visceral/genética , Modelos Lineales , Modelos Teóricos , Brasil , Humanos , Leishmaniasis Visceral/patología , Linaje , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Programas Informáticos
7.
Am J Pathol ; 185(8): 2105-17, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26079813

RESUMEN

Chronic kidney disease is a major contributor to human and companion animal morbidity and mortality. Renal complications are sequelae of canine and human visceral leishmaniasis (VL). Despite the high incidence of infection-mediated glomerulonephritis, little is known about pathogenesis of VL-associated renal disease. Leishmania infantum-infected dogs are a naturally occurring model of VL-associated glomerulonephritis. Membranoproliferative glomerulonephritis type I [24 of 25 (96%)], with interstitial lymphoplasmacytic nephritis [23 of 25 (92%)], and glomerular and interstitial fibrosis [12 of 25 (48%)] were predominant lesions. An ultrastructural evaluation of glomeruli from animals with VL identified mesangial cell proliferation and interposition. Immunohistochemistry demonstrated significant Leishmania antigen, IgG, and C3b deposition in VL dog glomeruli. Asymptomatic and symptomatic dogs had increased glomerular nucleotide-binding domain leucine-rich repeat-containing-like receptor family, pyrin domain containing 3 and autophagosome-associated microtubule-associated protein 1 light chain 3 associated with glomerular lesion severity. Transcriptional analyses from symptomatic dogs confirmed induction of autophagy and inflammasome genes within glomeruli and tubules. On the basis of temporal VL staging, glomerulonephritis was initiated by IgG and complement deposition. This deposition preceded presence of nucleotide-binding domain leucine-rich repeat-containing-like receptor family, pyrin domain containing 3-associated inflammasomes and increased light chain 3 puncta indicative of autophagosomes in glomeruli from dogs with clinical VL and renal failure. These findings indicate potential roles for inflammasome complexes in glomerular damage during VL and autophagy in ensuing cellular responses.


Asunto(s)
Autofagia/fisiología , Proteínas Portadoras/metabolismo , Glomerulonefritis/veterinaria , Inflamasomas/metabolismo , Leishmania infantum , Leishmaniasis Visceral/veterinaria , Animales , Perros , Glomerulonefritis/metabolismo , Glomerulonefritis/parasitología , Glomérulos Renales/metabolismo , Glomérulos Renales/parasitología , Glomérulos Renales/patología , Leishmaniasis Visceral/complicaciones , Leishmaniasis Visceral/metabolismo
8.
J Infect Dis ; 211(10): 1658-76, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25398459

RESUMEN

BACKGROUND: Leprosy morbidity is increased by 2 pathologic immune reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL). METHODS: To discover host factors related to immune reactions, global transcriptional profiles of peripheral blood mononuclear cells were compared between 11 RR, 11 ENL, and 19 matched control patients, with confirmation by quantitative polymerase chain reaction. Encoded proteins were investigated in skin biopsy specimens by means of immunohistochemistry. RESULTS: There were 275 genes differentially expressed in RR and 517 differentially expressed in ENL on the microarray. Pathway analysis showed immunity-related pathways represented in RR and ENL transcriptional profiles, with the "complement and coagulation" pathway common to both. Interferon γ was identified as a significant upstream regulator of the expression changes for RR and ENL. Immunohistochemical staining of skin lesions showed increased C1q in both RR and ENL. CONCLUSIONS: These data suggest a previously underrecognized role for complement in the pathogenesis of both RR and ENL, and we propose new hypotheses for reaction pathogenesis.


Asunto(s)
Perfilación de la Expresión Génica , Lepra/genética , Lepra/inmunología , Adulto , Anciano , Estudios de Casos y Controles , Proteínas del Sistema Complemento/inmunología , Femenino , Humanos , Inmunohistoquímica , Lepra/patología , Leucocitos Mononucleares/inmunología , Masculino , Análisis por Micromatrices , Persona de Mediana Edad , Reacción en Cadena en Tiempo Real de la Polimerasa , Piel/patología , Adulto Joven
9.
J Med Entomol ; 51(1): 237-44, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24605474

RESUMEN

Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in Brazil, is spread mostly by the bite of the sand fly Lutzomyia longipalpis (Lutz & Neiva). We trapped sand flies in endemic neighborhoods near Natal, Brazil, where cases of human and dog VL were documented. Amplification of species-specific cytochrome b (Cyt b) genes by polymerase chain reaction revealed that sand flies from rural and periurban areas harbored blood from different sources. The most common source ofbloodmeal was human, but blood from dog, chicken, and armadillo was also present. We tested the preference for a source of bloodmeal experimentally by feeding L. longipalpis F1 with blood from different animals. There were significant differences between the proportion of flies engorged and number of eggs laid among flies fed on different sources, varying from 8.4 to 19 (P < 0.0001). Blood from guinea pig or horse was best to support sand fly oviposition, but human blood also supported sand fly oviposition well. No sand flies fed on cats, and sand flies feeding on the opossum Monodelphis domestica Wagner produced no eggs. These data support the hypothesis that L. longipalpis is an eclectic feeder, and humans are an important source of blood for this sand fly species in periurban areas of Brazil.


Asunto(s)
Preferencias Alimentarias , Especificidad del Huésped , Insectos Vectores/fisiología , Psychodidae/fisiología , Animales , Biodiversidad , Brasil , Citocromos b/genética , Perros , Femenino , Humanos , Leishmania infantum , Leishmaniasis Visceral/transmisión , Oviposición , Reacción en Cadena de la Polimerasa , Temperatura
10.
Vet Parasitol Reg Stud Reports ; 49: 100988, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38462297

RESUMEN

The incidence of human Visceral Leishmaniasis (VL) has decreased in Brazil; however, the number of areas reporting human and canine cases has increased, with Leishmania infantum usually preceding human infection. This study aimed to analyze the profile of infectious diseases that are endemic for both human and canine VL, in dogs housed in a shelter located in the state of Rio Grande do Norte, Northeast Brazil. Data was obtained between November/2021 to April/2022. All dogs residing at the shelter (98 dogs) were examined and blood was collected for testing for L. infantum, Ehrlichia canis, and Babesia sp. Statistical analyses considered the clinical and laboratory findings. Of the 98 animals, approximately 43% were positive for L. infantum antibodies, 19% were positive for L. infantum kDNA, and 18% were L. infantum positive by culture. Greater levels of anti-leishmania antibodies were observed in dogs with symptoms suggestive of VL. The dogs tested positive for E. canis (19/98) and B. canis (18/98). Lutzomyia longipalpis was captured inside the shelter, representing 74.25% (n = 225) of whole sandflies in the dog shelter. Concomitant infection by L. infantum and E. canis increased the odds of death. Treatment of VL included the use of allopurinol (n = 48) and miltefosine (n = 8). Treated animals showed more signs of Leishmania infection. Tickborn parasites and Leishmania were prevalent in sheltered dogs in a VL-endemic area, which increases the odds of death and poses an additional challenge for caring for abandoned dogs and at the same time setting protocols to manage reservoirs of L. infantum.


Asunto(s)
Babesia , Enfermedades de los Perros , Leishmania infantum , Leishmaniasis Visceral , Leishmaniasis , Psychodidae , Humanos , Animales , Perros , Leishmaniasis Visceral/parasitología , Leishmaniasis Visceral/veterinaria , Leishmaniasis/tratamiento farmacológico , Leishmaniasis/veterinaria , Leishmania infantum/genética , Psychodidae/parasitología , Enfermedades de los Perros/epidemiología
11.
PLoS Negl Trop Dis ; 17(4): e0011206, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37011128

RESUMEN

Visceral leishmaniasis (VL) is a neglected tropical disease that is globally distributed and has the potential to cause very serious illness. Prior literature highlights the emergence and spread of VL is influenced by multiple factors, such as socioeconomic status, sanitation levels or animal and human reservoirs. The study aimed to retrospectively investigate the presence and infectiousness of VL in Rio Grande do Norte (RN), Brazil between 2007 and 2020. We applied a hierarchical Bayesian approach to estimate municipality-specific relative risk of VL across space and time. The results show evidence that lower socioeconomic status is connected to higher municipality-specific VL risk. Overall, estimates reveal spatially heterogeneous VL risks in RN, with a high probability that VL risk for municipalities within the West Potiguar mesoregion are more than double the expected VL risk. Additionally, given the data available, results indicate there is a high probability of increasing VL risk in the municipalities of Natal, Patu and Pau dos Ferros. These findings demonstrate opportunities for municipality-specific public health policy interventions and warrant future research on identifying epidemiological drivers in at-risk regions.


Asunto(s)
Leishmaniasis Visceral , Animales , Humanos , Leishmaniasis Visceral/epidemiología , Estudios Retrospectivos , Brasil/epidemiología , Teorema de Bayes , Ciudades , Enfermedades Desatendidas
12.
Dis Model Mech ; 16(7)2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37458166

RESUMEN

An outbreak of births of microcephalic patients in Brazil motivated multiple studies on this incident. The data left no doubt that infection by Zika virus (ZIKV) was the cause, and that this virus promotes reduction in neuron numbers and neuronal death. Analysis of patients' characteristics revealed additional aspects of the pathology alongside the decrease in neuronal number. Here, we review the data from human, molecular, cell and animal model studies attempting to build the natural history of ZIKV in the embryonic central nervous system (CNS). We discuss how identifying the timing of infection and the pathways through which ZIKV may infect and spread through the CNS can help explain the diversity of phenotypes found in congenital ZIKV syndrome (CZVS). We suggest that intraneuronal viral transport is the primary mechanism of ZIKV spread in the embryonic brain and is responsible for most cases of CZVS. According to this hypothesis, the viral transport through the blood-brain barrier and cerebrospinal fluid is responsible for more severe pathologies in which ZIKV-induced malformations occur along the entire anteroposterior CNS axis.


Asunto(s)
Microcefalia , Infección por el Virus Zika , Virus Zika , Animales , Humanos , Infección por el Virus Zika/complicaciones , Microcefalia/etiología , Microcefalia/patología , Sistema Nervioso Central/patología , Barrera Hematoencefálica/patología , Encéfalo/patología
13.
J Infect Dis ; 204(3): 467-77, 2011 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-21742847

RESUMEN

BACKGROUND: Visceral leishmaniasis (VL) is caused by Leishmania donovani and Leishmania infantum chagasi. Genome-wide linkage studies from Sudan and Brazil identified a putative susceptibility locus on chromosome 6q27. METHODS: Twenty-two single-nucleotide polymorphisms (SNPs) at genes PHF10, C6orf70, DLL1, FAM120B, PSMB1, and TBP were genotyped in 193 VL cases from 85 Sudanese families, and 8 SNPs at genes PHF10, C6orf70, DLL1, PSMB1, and TBP were genotyped in 194 VL cases from 80 Brazilian families. Family-based association, haplotype, and linkage disequilibrium analyses were performed. Multispecies comparative sequence analysis was used to identify conserved noncoding sequences carrying putative regulatory elements. Quantitative reverse-transcription polymerase chain reaction measured expression of candidate genes in splenic aspirates from Indian patients with VL compared with that in the control spleen sample. RESULTS: Positive associations were observed at PHF10, C6orf70, DLL1, PSMB1, and TBP in Sudan, but only at DLL1 in Brazil (combined P = 3 × 10(-4) at DLL1 across Sudan and Brazil). No functional coding region variants were observed in resequencing of 22 Sudanese VL cases. DLL1 expression was significantly (P = 2 × 10(-7)) reduced (mean fold change, 3.5 [SEM, 0.7]) in splenic aspirates from patients with VL, whereas other 6q27 genes showed higher levels (1.27 × 10(-6) < P < .01) than did the control spleen sample. A cluster of conserved noncoding sequences with putative regulatory variants was identified in the distal promoter of DLL1. CONCLUSIONS: DLL1, which encodes Delta-like 1, the ligand for Notch3, is strongly implicated as the chromosome 6q27 VL susceptibility gene.


Asunto(s)
Cromosomas Humanos Par 6 , Predisposición Genética a la Enfermedad , Péptidos y Proteínas de Señalización Intercelular/genética , Leishmaniasis Visceral/genética , Proteínas de la Membrana/genética , Polimorfismo de Nucleótido Simple , Proteínas de Unión al Calcio , Genotipo , Haplotipos , Humanos , Péptidos y Proteínas de Señalización Intercelular/fisiología , Proteínas de la Membrana/fisiología
14.
Infect Genet Evol ; 106: 105379, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36280088

RESUMEN

Genome-wide association studies (GWASs) are a research approach used to identify genetic variants associated with common diseases, like COVID-19. The lead genetic variants (n = 41) reported by the eleven largest COVID-19 GWASs are mapped to 22 different chromosomal regions. The loci 3q21.31 (LZTFL1 and chemokine receptor genes) and 9q34.2 (ABO), associated with disease severity and susceptibility to infection, respectively, were the most replicated findings across studies. Genes involved with mucociliary clearance (CEP97, FOXP4), viral-entry (ACE2, SLC6A20) and mucosal immunity (MIR6891) are associated with the risk of SARS-CoV-2 infection while genes of antiviral immune response (IFNAR2, OAS1), leukocyte trafficking (CCR9, CXCR6) and lung injury (DPP9, NOTCH4) are associated with severe disease. The biological processes underlying the risk of infection occur prominently, but not exclusively, in the upper airways whereas the severe COVID-19-associated processes in alveolar-capillary interface. The COVID-19 GWASs has unraveled key genetic mechanisms of SARS-CoV-2 pathogenesis, although the genetic basis of other COVID-19 related phenotypes (long COVID and neurological impairment) remains to be elucidated.


Asunto(s)
COVID-19 , Humanos , COVID-19/genética , SARS-CoV-2/genética , Estudio de Asociación del Genoma Completo , Síndrome Post Agudo de COVID-19 , Antivirales , Proteínas de Transporte de Membrana
15.
PLoS Negl Trop Dis ; 16(10): e0010337, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36191040

RESUMEN

BACKGROUND: The first case of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in Rio Grande do Norte, northeastern Brazil, was diagnosed on March 12, 2020; thereafter, multiple surges of infection occurred, similar to what was seen elsewhere. These surges were mostly due to SARS-CoV-2 mutations leading to emergence of variants of concern (VoC). The introduction of new VoCs in a population previously exposed to SARS-CoV-2 or after vaccination has been a challenge to understanding the kinetics of the protective immune response against this virus. The aim of this study was to investigate the outbreak of SARS-CoV-2 reinfections observed in mid-January 2022 in Rio Grande do Norte state, Brazil. It describes the clinical and genomic characteristics of nine cases of reinfection that occurred coincident with the introduction of the omicron variant. METHODOLOGY/PRINCIPAL FINDINGS: Of a total of 172,965 individuals with upper respiratory symptoms tested for SARS-CoV-2, between March 2020 through mid-February 2022, 58,097 tested positive. Of those, 444 had documented a second SARS-CoV-2 infection and nine reinfection cases were selected for sequencing. Genomic analysis revealed that virus lineages diverged between primary infections and the reinfections, with the latter caused by the Omicron (BA.1) variant among individuals fully vaccinated against SARS-CoV-2. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that the Omicron variant is able to evade both natural and vaccine-induced immunity, since all nine cases had prior natural infection and, in addition, were fully vaccinated, emphasizing the need to develop effective blocking vaccines.


Asunto(s)
COVID-19 , Vacunas Virales , Brasil/epidemiología , COVID-19/epidemiología , COVID-19/prevención & control , Humanos , Reinfección , SARS-CoV-2/genética
16.
J Exp Med ; 201(5): 747-54, 2005 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-15753208

RESUMEN

We examined the role of immunoglobulin (Ig)G antibodies in mediating host defense to the intracellular parasite, Leishmania. We show that IgG not only fails to provide protection against this intracellular pathogen, but it actually contributes to disease progression. The J(H) strain of BALB/c mice, which lack IgG because they have a targeted deletion in the Ig heavy chain (J) locus, were more resistant to infection with Leishmania major than were normal BALB/c mice. However, the passive administration of anti-Leishmania IgG caused J(H) mice to develop large lesions containing high numbers of parasites. Antibody administration correlated with an increase in interleukin (IL) 10 production in lesions, and blocking the murine IL-10 receptor prevented antibody-mediated disease exacerbation. In human patients with active visceral leishmaniasis, high IgG levels are predictive of disease. Patients with ongoing disease had high IgG antibody titers and no delayed-type hypersensitivity (DTH) responses to Leishmania antigens. This pattern was reversed upon disease resolution after treatment, resulting in a decrease in total IgG, which was accompanied by a progressive increase in DTH responsiveness. We conclude that IgG can cause a novel form of immune enhancement due to its ability to induce IL-10 production from macrophages.


Asunto(s)
Complejo Antígeno-Anticuerpo/inmunología , Inmunoglobulina G/inmunología , Leishmania major/inmunología , Leishmaniasis/inmunología , Animales , Células Cultivadas , Humanos , Hipersensibilidad Tardía/inmunología , Interleucina-10/biosíntesis , Interleucina-10/inmunología , Leishmaniasis/metabolismo , Leishmaniasis/patología , Ratones , Ratones Endogámicos BALB C , Monocitos/metabolismo , Monocitos/parasitología
17.
J Clin Microbiol ; 49(11): 3892-904, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22042830

RESUMEN

The Leishmania species cause a variety of human disease syndromes. Methods for diagnosis and species differentiation are insensitive and many require invasive sampling. Although quantitative PCR (qPCR) methods are reported for leishmania detection, no systematic method to quantify parasites and determine the species in clinical specimens is established. We developed a serial qPCR strategy to identify and rapidly differentiate Leishmania species and quantify parasites in clinical or environmental specimens. SYBR green qPCR is mainly employed, with corresponding TaqMan assays for validation. The screening primers recognize kinetoplast minicircle DNA of all Leishmania species. Species identification employs further qPCR set(s) individualized for geographic regions, combining species-discriminating probes with melt curve analysis. The assay was sufficient to detect Leishmania parasites, make species determinations, and quantify Leishmania spp. in sera, cutaneous biopsy specimens, or cultured isolates from subjects from Bangladesh or Brazil with different forms of leishmaniasis. The multicopy kinetoplast DNA (kDNA) probes were the most sensitive and useful for quantification based on promastigote standard curves. To test their validity for quantification, kDNA copy numbers were compared between Leishmania species, isolates, and life stages using qPCR. Maxicircle and minicircle copy numbers differed up to 6-fold between Leishmania species, but the differences were smaller between strains of the same species. Amastigote and promastigote leishmania life stages retained similar numbers of kDNA maxi- or minicircles. Thus, serial qPCR is useful for leishmania detection and species determination and for absolute quantification when compared to a standard curve from the same Leishmania species.


Asunto(s)
Técnicas de Laboratorio Clínico/métodos , Leishmania/clasificación , Leishmania/aislamiento & purificación , Leishmaniasis/diagnóstico , Leishmaniasis/parasitología , Parasitología/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Bangladesh , Benzotiazoles , Brasil , Cartilla de ADN/genética , Diaminas , Microbiología Ambiental , Humanos , Leishmania/genética , Compuestos Orgánicos/metabolismo , Quinolinas , Coloración y Etiquetado/métodos
18.
Drug Dev Res ; 72(6): 451-462, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25821334

RESUMEN

Visceral leishmaniasis [VL] represents a major public health problem in many areas of the world. This review focuses on the impact of periurbanization on the epidemiology and treatment of VL, using Brazil as an example. VL continues to be mostly a disease of poverty with impact on families. However, the disease has expanded in Latin America, with foci reported as far south as Argentina. There is an increasing overlap of Leishmania infantum chagasi and HIV infections and other immunosuppressive conditions, resulting in VL emerging as an opportunistic infection. This new setting poses new challenges for VL disease control and patient management.

19.
Pregnancy Hypertens ; 23: 56-58, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33249328

RESUMEN

The role of Renin-Angiotensin-System (RAS) in the pathogenesis of preeclampsia and eclampsia is still unclear. Our aim was to investigate plasma angiotensin II concentration [Ang II] in women with normotensive pregnancies (NP, n = 22) and severe preeclampsia in use of magnesium sulfate (SPE, n = 29). Despite no difference between the groups (SPE: 47.8 pg/ml vs NP: 39.7 pg/ml, p = 0.195), lower maternal age (p = 0.007) and primigravida (p = 0.028) were associated with lower [Ang II]. Plasma [Ang II] increased over the 24 h of magnesium sulfate administration (r = 0.48, p = 0.009). Our findings suggest that RAS may be involved with the mechanism of magnesium protection against eclamptic seizure.


Asunto(s)
Angiotensina II/efectos de los fármacos , Sulfato de Magnesio/farmacología , Preeclampsia/tratamiento farmacológico , Factores de Edad , Angiotensina II/sangre , Estudios de Casos y Controles , Femenino , Humanos , Sulfato de Magnesio/administración & dosificación , Preeclampsia/sangre , Embarazo , Convulsiones/prevención & control
20.
Sci Rep ; 11(1): 12565, 2021 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-34131209

RESUMEN

Accurate designing of polymerase chain reaction (PCR) primers targeting conserved segments in viral genomes is desirable for preventing false-negative results and decreasing the need for standardization across different PCR protocols. In this work, we designed and described a set of primers and probes targeting conserved regions identified from a multiple sequence alignment of 2341 Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) genomes from the Global Initiative on Sharing All Influenza Data (GISAID). We subsequently validated those primers and probes in 211,833 SARS-CoV-2 whole-genome sequences. We obtained nine systems (forward primer + reverse primer + probe) that potentially anneal to highly conserved regions of the virus genome from these analyses. In silico predictions also demonstrated that those primers do not bind to nonspecific targets for human, bacterial, fungal, apicomplexan, and other Betacoronaviruses and less pathogenic sub-strains of coronavirus. The availability of these primer and probe sequences will make it possible to validate more efficient protocols for identifying SARS-CoV-2.


Asunto(s)
Prueba de Ácido Nucleico para COVID-19/métodos , Reacción en Cadena de la Polimerasa/métodos , SARS-CoV-2/genética , Simulación por Computador , Cartilla de ADN , Genoma Viral , Humanos , SARS-CoV-2/aislamiento & purificación , Secuenciación Completa del Genoma
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