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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

FATORES EPIDEMIOLÓGICOS ASSOCIADOS E NOVAS ABORDAGENS DIAGNÓSTICAS PARA LEISHMANIOSE E BABESIOSE CANINA NO MUNICÍPIO DE SÃO LUÍS-MA, BRASIL / EPIDEMIOLOGICAL FACTORS ASSOCIATED AND DIAGNOSTIC APPROACHES NEW FOR LEISHMANIASIS AND CANINE BABESIOSIS IN THE MUNICIPALITY OF SAO LUIS-MA, BRAZIL

Santana, Andressa Almeida 29 July 2011 (has links)
Made available in DSpace on 2016-08-16T18:18:41Z (GMT). No. of bitstreams: 1 Tese Andressa Almeida Santana.pdf: 1466363 bytes, checksum: ae0eefc75fb09cd9f96594f4e5656ed5 (MD5) Previous issue date: 2011-07-29 / FUNDAÇÃO DE AMPARO À PESQUISA E AO DESENVOLVIMENTO CIENTIFICO E TECNOLÓGICO DO MARANHÃO / Canine babesiosis and canine visceral leishmaniasis (CVL) are vector borne diseases, where dogs exert a play as reservoir or source for arthropods responsible by the transmission of these protozoosis. Babesia canis vogeli, is transmited by tick Rhipicephalus sanguineus while Leishmania infantum (sin. Leishmania chagasi) is transmited by sand fly (Lutzomyia longipalpis). The results showed that CVL remains endemic in São Luís Municipality. Despite that the coinfection between Leishmania and Babesia was low considering that both diseases are endemic in this tropical area. Beside that was observed that Yorkshire terrier presented higher predisposition to acquire the infection by B. canis vogeli. A remarkable result was the occurrence of ocular lesions associated to L. infantum infection. / A babesiose canina e a leishmaniose visceral canina são doenças transmitidas por vetores, sendo os cães competentes reservatórios e fonte alimentar dos artrópodes envolvidos. Babesia canis vogeli, é um parasita intraeritrocitário transmitido pelo carrapato Rhipicephalus sanguineus. Leishmania infantum (sin. Leishmania chagasi) transmitidos a mamíferos pela picada dos flebotomíneos (Lutzomyia longipalpis), infectando macrófagos do Sistema Fagocítico Mononuclear do hospedeiro. O presente trabalho é divido em capítulos e os resultados encontrados mostraram que a leishmaniose visceral canina ainda é endêmica no município de São Luís, e que apesar disso a taxa de coinfecção com Babesia foi baixa. Também foi observado que a raça Yorkshire terrier, dentre as raças estudadas, apresentou maior predisposição para contrair a infecção por B. canis vogeli. Outro resultado significativo foi a ocorrência de lesões oculares associadas à infecção por L. infantum.
82

Factores asociados a los diferentes patrones de marcadores para Virus de la Hepatitis B en pacientes peruanos viviendo con VIH, 2016-2017 / Factors associated with the different serological patterns for Hepatitis B virus infection among Peruvian patients living with HIV, 2016-2017

Oré Ramos, Brunella, Patiño Espinoza, Alvaro 12 February 2021 (has links)
Introducción: La coinfección por virus de la hepatitis B (VHB) y VIH afecta a 2,7 millones de personas, que equivale a 5-10% de las personas viviendo con VIH. Esta comorbilidad cambia la historia natural de ambas patologías. En Perú, no están definidas las características de los pacientes VIH según los diferentes patrones serológicos del VHB. Métodos: Estudio transversal analítico secundario de una base de datos obtenida mediante revisión de historias clínicas en dos hospitales públicos de Lima, Perú. Se incluyeron personas con 18 años o más con diagnóstico confirmado de VIH, que iniciaron/reiniciaron tratamiento antiviral de gran actividad (TARGA) 2016-2017. Se evaluaron Antígeno de superficie (HBsAg), Anti-antígeno de superficie (anti-HBs), Anti-antígeno core, y los patrones serológicos según estos marcadores. Se obtuvieron Razones de Prevalencia crudos y ajustados (RPa) para las diferentes características usando regresión de Poisson con varianza robusta. Resultados: Se incluyeron 429 pacientes con una prevalencia de HBsAg de 4,43% (2.69%-6.83%). Existió asociación significativa entre prevalencia de HBsAg y drogas endovenosas (RPa:1,70; IC95% 1,07-2,68), transaminasemia (RPa:3,69; IC95% 2,97-4,57) y uso de TARGA (RPa:0,52; IC95% 0,35-0,77). 129 pacientes sin infección activa fueron evaluados para anti-HBs, siendo positivos 8.53% (4.33%-14.74%). Se encontró asociación con edad ≥30 años (RPa:5,09; IC95% 2,72-9,54), uso de TARGA previo (RPa:3,01; IC95% 1,84-4,93) y carga viral ≥1000 copias/ml (RPa:0,29; IC95% 0,13-0,63). Conclusiones: Uso de drogas endovenosas y transaminasemia se asociaron a mayor prevalencia de infección activa (HBsAg+), mientras que uso previo de TARGA a menor prevalencia. Edad ≥30 años y TARGA se asociaron a mayor prevalencia de anti-HBs en pacientes sin infección activa, y carga viral ≥1000 copias/ml se asoció a menor prevalencia. / Introduction: Hepatitis B virus (HBV) and HIV Co-infection affects 2.7 million people, which is equivalent to 5-10% of people living with HIV. This comorbidity changes the natural history of both pathologies. In Peru, the characteristics of HIV patients according to the different serological patterns of HBV are not well defined. Methods: Secondary analytical cross-sectional study of a database obtained by reviewing medical records in two public hospitals in Lima, Peru. People aged 18 years or older with a confirmed diagnosis of HIV who started/restarted highly active antiviral treatment (HAART) 2016-2017 were included. Surface antigen (HBsAg), Anti-surface antigen (anti-HBs), Anti-core antigen, and serological patterns according to these markers were evaluated. Crude and adjusted Prevalence Ratios (aPR) were obtained for the different characteristics using Poisson regression with robust variance. Results: 429 patients were included with a prevalence of HBsAg of 4.43% (2.69% -6.83%). There was significant association between HBsAg prevalence and intravenous drugs use (aPR: 1.70; 95% CI 1.07-2.68), transaminasemia (aPR: 3.69; 95% CI 2.97-4.57) and prior HAART use (aPR: 0.52; 95% CI 0.35-0.77). 129 patients without active infection were evaluated for anti-HBs, with 8.53% (4.33% -14.74%) being positive. Association was found with age ≥30 years (aPR: 5.09; 95% CI 2.72-9.54), previous HAART use (aPR: 3.01; 95% CI 1.84-4.93) and viral load ≥1000 copies / ml (aPR: 0.29; 95% CI 0.13-0.63). Conclusions: Intravenous drug use and transaminasemia were associated with a higher prevalence of active infection (HBsAg +), while previous use of HAART showed a lower prevalence. Age ≥30 years and HAART were associated with a higher prevalence of anti-HBs in patients without active infection, while viral load ≥1000 copies/ml was associated with lower prevalence. / Tesis
83

Detection of SARS-CoV-2 antibodies in febrile patients from an endemic region of dengue and chikungunya in Peru

Tarazona-Castro, Yordi, Troyes-Rivera, Lucinda, Martins-Luna, Johanna, Cabellos-Altamirano, Felipe, Aguilar-Luis, Miguel Angel, Carrillo-Ng, Hugo, Del Valle, Luis J., Kym, Sungmin, Miranda-Maravi, Sebastian, Silva-Caso, Wilmer, Levy-Blitchtein, Saul, del Valle-Mendoza, Juana 01 April 2022 (has links)
Introduction The rapid expansion of the novel SARS-CoV-2 virus has raised serious public health concerns due to the possibility of misdiagnosis in regions where arboviral diseases are endemic. We performed the first study in northern Peru to describe the detection of SARSCoV-2 IgM antibodies in febrile patients with a suspected diagnosis of dengue and chikungunya fever. Materials and methods A consecutive cross-sectional study was performed in febrile patients attending primary healthcare centers from April 2020 through March 2021. Patients enrolled underwent serum sample collection for the molecular and serological detection of DENV and CHIKV. Also, serological detection of IgM antibodies against SARS-CoV-2 was performed. Results 464 patients were included during the study period, of which (40.51%) were positive for one pathogen, meanwhile (6.90%) presented co-infections between 2 or more pathogens. The majority of patients with monoinfections were positive for SARS-CoV-2 IgM with (73.40%), followed by DENV 18.09% and CHIKV (8.51%). The most frequent co-infection was DENV + SARS-CoV-2 with (65.63%), followed by DENV + CHIKV and DENV + CHIKV + SARSCoV-2, both with (12.50%). The presence of polyarthralgias in hands (43.75%, p<0.01) and feet (31.25%, p = 0.05) were more frequently reported in patients with CHIKV monoinfection. Also, conjunctivitis was more common in patients positive for SARS-CoV-2 IgM (11.45%, p<0.01). The rest of the symptoms were similar among all the study groups. Conclusion SARS-CoV-2 IgM antibodies were frequently detected in acute sera from febrile patients with a clinical suspicion of arboviral disease. The presence of polyarthralgias in hands and feet may be suggestive of CHIKV infection. These results reaffirm the need to consider SARS-CoV-2 infection as a main differential diagnosis of acute febrile illness in arboviruses endemic areas, as well as to consider co-infections between these pathogens. Copyright: / Revisión por pares
84

Evaluation of immune responses to the pulmonary pathogens Mycobacterium tuberculosis and SARS-CoV-2

Rosas Mejia, Oscar 12 September 2022 (has links)
No description available.
85

Chicken infectious anemia virus vaccination induces immune disorders and viral persistency in infectious bursal disease virus-infected young chicks

Vaziry, Asaad 08 1900 (has links)
La bursite infectieuse aviaire (IBD) est une des causes majeures de pertes économiques pour l’industrie aviaire. La vaccination est le principal outil de contrôle de cette maladie et les oiseaux susceptibles doivent être vaccinés aussitôt que le niveau des anticorps maternels (MA) anti-IBDV est suffisamment bas. L’estimation du moment de vaccination est habituellement déterminée par la formule de Deventer qui utilise le titre initial de MA anti-IBDV et la demi-vie des anticorps pour prédire l’évolution du titre. Dans la présente étude, l’effet du gain de poids sur la vitesse de disparition des MA a été étudié dans le but de l’utiliser pour prédire la détermination du moment de la vaccination. L’analyse des taux d’anticorps neutralisants par ELISA a montré que les poussins avec une forte croissance avaient un taux de disparition plus rapide des MA que ceux à faible croissance. Une formule pour la prédiction du moment de vaccination contre le IBDV, basée sur le gain de poids et le niveau des MA a été développée et vérifiée. La prédiction du moment de vaccination avec cette formule a montré une haute corrélation avec les titres de MA mesurés par ELISA. Le virus de l’anémie infectieuse aviaire (CIAV) est une cause importante d’immunosuppression chez le poulet augmentant la pathogénicité des infections secondaires et en entraînant une réponse humorale suboptimale et une forte mortalité. D’autre part, l’infections sub-clinique du au CIAV provoque une immunosuppression qui facilite la coinfection par d’autre virus tel que le IBDV. Les effets de la coinfection à J1 avec une souche vaccinale de CIAV CAV-VAC® (Intervet) et à J14 avec une souche faiblement virulente de IBDV isolée au Québec, sur l’état de santé des poussins, sur la persistance virale et sur la réponse immunitaire ont été étudiés autant chez des poussins de 1 jour d’âge exempts d’agents pathogènes specifique (SPF) que ceux provenant d’élevages commerciaux. Les résultats ont montré que l’inoculation de la souche vaccinale du CIAV a entraîné une infection sub-clinique, une persistance virale dans la rate et le thymus, une altération de la thymopoièse et une réponse humorale temporaire chez les poussins SPF. Ces effets ont aussi été mis en évidence chez des poussins d’élevage commerciaux malgré des taux élevés de MA. Lors de l’infection avec la souche de IBDV chez des poussins déjà vaccinés contre le CIAV, la persistance du CIAV dans les organes lymphoïdes a été aggravée par une présence de réponses humorales temporaires contre les deux virus et une altération des populations lymphocytaires dans les organes lymphoïdes. Par contre, la présence des MA contre le CIAV a limité temporairement ces effets. Ces travaux ont mis en évidence des désordres immunitaires cellulaires et humoraux et une persistance virale chez des poussins vaccinés contre le CIAV et co-infectés avec le IBDV. / Infectious bursal disease (IBD) is one of the major causes of economic losses in the chicken industry. Vaccination is the main tool against the disease, and the susceptible birds should be vaccinated as soon as the maternal antibody (MA) becomes low enough to allow the vaccine to break through. Estimation of vaccination time is currently performed by Deventer formula which uses initial anti-IBDV titer and antibody half-life to predict the titer. Considering the increased growth rate of chicken in the last decades and the wide variations of MA, we have examined the effects of chick’s weight gain on MA decline and the use of weight in predicting IBD vaccination time. The virus neutralization test and ELISA results demonstrated that fast-growing birds had a faster rate of antibody decline whereas slow-growing birds demonstrated a slower rate. Based on the effect of weight-gain on maternal antibody decline, a new formula for predicting IBD vaccination time was introduced and tested. The predicted IBD vaccination time made by this weight formula showed higher correlation with the measured ELISA titers in the experiment. Chicken infectious anemia virus (CIAV) is another cause of immunosuppression in chicken which is characterized by increased pathogenicity of secondary infectious agents, sub-optimal antibody responses and mortality. CIAV subclinical infections can result in immunosuppression and enhancement of pathogenicity of co-infecting agents such as infectious bursal disease virus (IBDV). Effects of pathogenic CIAV and IBDV coinfection on chick’s health and immune responses are investigated in different studies. In this study, newly hatched specific pathogen free (SPF) and commercial chicks were vaccinated with CAV-VAC® (Intervet) vaccine and /or inoculated with a low-virulent Québec isolate of IBDV at 14 days post CIAV vaccination. Inoculation of the CIAV vaccinal strain at hatch resulted in subclinical infection associated with viral persistency in spleen and thymus, alteration of thymopoiesis and transient humoral response in SPF chicks. Subclinical infection, viral persistency and lack of antibody responses were also shown in CIAV inoculated commercial chicks with high MA. Infection of the low-virulent IBDV in the CIAV vaccinated SPF chicks lead to extended viral persistence of CIAV in lymphoid organs, transient immune responses to both CIAV and IBDV, and alteration of lymphocytes subpopulation in the lymphoid organs. In the coinfected commercial chicks, presence the CIAV in the lymphoid organs was controlled by MA in the first 1-2 weeks after hatch. Thereafter, the immune disorders, viral persistence and lack of humoral responses almost similar to the coinfected SPF chicks were recorded.
86

Virus de l’hépatite C chez la femme enceinte et l’enfant : diversité, réponse neutralisante et transmission verticale

Larouche, Ariane 08 1900 (has links)
No description available.
87

Chicken infectious anemia virus vaccination induces immune disorders and viral persistency in infectious bursal disease virus-infected young chicks

Vaziry, Asaad 08 1900 (has links)
La bursite infectieuse aviaire (IBD) est une des causes majeures de pertes économiques pour l’industrie aviaire. La vaccination est le principal outil de contrôle de cette maladie et les oiseaux susceptibles doivent être vaccinés aussitôt que le niveau des anticorps maternels (MA) anti-IBDV est suffisamment bas. L’estimation du moment de vaccination est habituellement déterminée par la formule de Deventer qui utilise le titre initial de MA anti-IBDV et la demi-vie des anticorps pour prédire l’évolution du titre. Dans la présente étude, l’effet du gain de poids sur la vitesse de disparition des MA a été étudié dans le but de l’utiliser pour prédire la détermination du moment de la vaccination. L’analyse des taux d’anticorps neutralisants par ELISA a montré que les poussins avec une forte croissance avaient un taux de disparition plus rapide des MA que ceux à faible croissance. Une formule pour la prédiction du moment de vaccination contre le IBDV, basée sur le gain de poids et le niveau des MA a été développée et vérifiée. La prédiction du moment de vaccination avec cette formule a montré une haute corrélation avec les titres de MA mesurés par ELISA. Le virus de l’anémie infectieuse aviaire (CIAV) est une cause importante d’immunosuppression chez le poulet augmentant la pathogénicité des infections secondaires et en entraînant une réponse humorale suboptimale et une forte mortalité. D’autre part, l’infections sub-clinique du au CIAV provoque une immunosuppression qui facilite la coinfection par d’autre virus tel que le IBDV. Les effets de la coinfection à J1 avec une souche vaccinale de CIAV CAV-VAC® (Intervet) et à J14 avec une souche faiblement virulente de IBDV isolée au Québec, sur l’état de santé des poussins, sur la persistance virale et sur la réponse immunitaire ont été étudiés autant chez des poussins de 1 jour d’âge exempts d’agents pathogènes specifique (SPF) que ceux provenant d’élevages commerciaux. Les résultats ont montré que l’inoculation de la souche vaccinale du CIAV a entraîné une infection sub-clinique, une persistance virale dans la rate et le thymus, une altération de la thymopoièse et une réponse humorale temporaire chez les poussins SPF. Ces effets ont aussi été mis en évidence chez des poussins d’élevage commerciaux malgré des taux élevés de MA. Lors de l’infection avec la souche de IBDV chez des poussins déjà vaccinés contre le CIAV, la persistance du CIAV dans les organes lymphoïdes a été aggravée par une présence de réponses humorales temporaires contre les deux virus et une altération des populations lymphocytaires dans les organes lymphoïdes. Par contre, la présence des MA contre le CIAV a limité temporairement ces effets. Ces travaux ont mis en évidence des désordres immunitaires cellulaires et humoraux et une persistance virale chez des poussins vaccinés contre le CIAV et co-infectés avec le IBDV. / Infectious bursal disease (IBD) is one of the major causes of economic losses in the chicken industry. Vaccination is the main tool against the disease, and the susceptible birds should be vaccinated as soon as the maternal antibody (MA) becomes low enough to allow the vaccine to break through. Estimation of vaccination time is currently performed by Deventer formula which uses initial anti-IBDV titer and antibody half-life to predict the titer. Considering the increased growth rate of chicken in the last decades and the wide variations of MA, we have examined the effects of chick’s weight gain on MA decline and the use of weight in predicting IBD vaccination time. The virus neutralization test and ELISA results demonstrated that fast-growing birds had a faster rate of antibody decline whereas slow-growing birds demonstrated a slower rate. Based on the effect of weight-gain on maternal antibody decline, a new formula for predicting IBD vaccination time was introduced and tested. The predicted IBD vaccination time made by this weight formula showed higher correlation with the measured ELISA titers in the experiment. Chicken infectious anemia virus (CIAV) is another cause of immunosuppression in chicken which is characterized by increased pathogenicity of secondary infectious agents, sub-optimal antibody responses and mortality. CIAV subclinical infections can result in immunosuppression and enhancement of pathogenicity of co-infecting agents such as infectious bursal disease virus (IBDV). Effects of pathogenic CIAV and IBDV coinfection on chick’s health and immune responses are investigated in different studies. In this study, newly hatched specific pathogen free (SPF) and commercial chicks were vaccinated with CAV-VAC® (Intervet) vaccine and /or inoculated with a low-virulent Québec isolate of IBDV at 14 days post CIAV vaccination. Inoculation of the CIAV vaccinal strain at hatch resulted in subclinical infection associated with viral persistency in spleen and thymus, alteration of thymopoiesis and transient humoral response in SPF chicks. Subclinical infection, viral persistency and lack of antibody responses were also shown in CIAV inoculated commercial chicks with high MA. Infection of the low-virulent IBDV in the CIAV vaccinated SPF chicks lead to extended viral persistence of CIAV in lymphoid organs, transient immune responses to both CIAV and IBDV, and alteration of lymphocytes subpopulation in the lymphoid organs. In the coinfected commercial chicks, presence the CIAV in the lymphoid organs was controlled by MA in the first 1-2 weeks after hatch. Thereafter, the immune disorders, viral persistence and lack of humoral responses almost similar to the coinfected SPF chicks were recorded.
88

Imputation HLA et analyse génomique de la coinfection VIH/VHC / HLA imputation and genomic analysis of HIV/HCV coinfection

Jeanmougin, Marc 21 December 2017 (has links)
La génomique d'association cherche à déterminer des liens entre le génome et des traits ou phénotypes, notamment dans le contexte de maladies. Aujourd'hui, les études les plus fréquentes en génomique d’association sont les études génome entier, qui analysent autant de variants du génomes (SNPs) que possible, sans avoir de préjugé a priori sur leur fonction biologique. Cependant, les méthodes de génotypage utilisées pour ces études ne permettent pas toujours d'obtenir des informations précises dans une région hypervariable comme la région HLA, qui joue un rôle crucial dans l'immunité, et les variants génétiques de ces régions sont souvent prédits par des approches bioinformatiques. J'ai durant ma thèse créé un nouvel outil, HLA-Check, permettant d'évaluer, à partir des génotypes obtenus par puce de génotypage, la plausibilité de données d'allèles HLA d'un même individu, et démontré que cette technique permettait d'identifier plus précisément les individus dont les allèles HLA avaient été mal caractérisés afin de les retyper ou de les écarter de l'étude. Un article documentant cet outil a été publié dans BMC Bioinformatics. J'ai également effectué une étude d'association génome entier sur le déclenchement de la cirrhose chez les patients co-infectés par le VIH (virus de l'immunodéficience humaine) et le VHC (virus de l'hépatite C). La coinfection par ces deux maladies est fréquente en raison de modes d’infection similaires, et l'infection par le VIH stimule l'activité du VHC et accélère la fibrose du foie puis sa cirrhose, causant la mort des patients co-infectés. Mon étude porte sur 306 patients co-infectés issus de la cohorte ANRS CO-13 HEPAVIH. J'ai ainsi pu mettre en évidence trois signaux associés avec le déclenchement de la cirrhose, dont deux ont un lien pertinent avec les maladies hépatiques (gene CTNND2 et gene MIR7-3HG). L'identification de ces nouveaux variants devrait permettre une meilleure compréhension des mécanismes moléculaires de la cirrhose, et contribuer au développement de nouvelles stratégies diagnostiques ou thérapeutiques. L’article documentant cette étude est en cours de publication. / Association genomics aims at finding links between the genome and some traits or illnesses. Today, the most frequent studies in this field are genome wide association studies (GWAS), which analyze as many genome variants (mainly Single Nucleotide Polymorphisms) as possible, without any a priori on their biological function. However, genotyping methods used in these studies may be insufficient to get reliable information in higly variable regions such as the HLA which plays a crucial role in immunity, and the genetic variants of such regions are often predicted using bioinformatics approaches. During my PhD, I have created a new tool, HLA-Check, that allows to rate the plausibility of HLA alleles from the genotypes obtained from genotyping chips. I also assesses its performances and showed that it was able to point out individuals with a wrong HLA typing, in order to retype them or remove them from the study. An article documenting this tool was published in BMC Bioinformatics. I have also performed a genome-wide association study on cirrhosis outbreak in individuals coinfected with HIV (human immunodeficiency virus) and HCV (hepatitis C virus). Because of similar infection routes (blood-related), co-infection with those two viruses are frequent, and the infection by HIV enhances HCV activity and increases liver fibrosis leading to cirrhosis and death of co-infected patients. Our study has dealt with 306 co-infected patients from the ANRS CO-13 HEPAVIH cohort. I could point out three statistically significant signals, two of them being highly relevant for their involvement in liver diseases (gene CTNND2 and gene MIR7-3HG). The identification of these new variants should lead to a better understanding of the molecular mechanisms involved in cirrhosis, and should contribute to the rational developement of new diagnostic or therapeutic strategies. A publication is under way.
89

Phenotypic and functional characterization of cytotoxic T lymphocytes in HIV-1 infected South African adults

Pillay, Santhoshan Thiagaraj 12 1900 (has links)
Bibliography / Thesis (MScMedSc (Pathology. Medical Virology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: In just 25 years since the first reported cases in 1981, the number of Human Immunodeficiency virus (HIV) infected people has risen to 65 million, and over 25 million have died of acquired immunodeficiency syndrome (AIDS). Sub-Saharan Africa accounts for 67% of all people living with HIV and 72% of deaths in this region were AIDS related. Tuberculosis (TB) is one of the most common opportunistic infections in AIDS patients, particularly in developing countries, where 60 - 70% of TB cases occur in HIV-1-infected persons. HIV-1 is a high risk factor for the development of TB, the reactivation of a latent Mycobacterium tuberculosis infection and also progressive TB. CD8+ Cytotoxic T Lymphocytes (CTL) are pivotal in the host immune response to HIV infection. CTL are associated with resolution of acute infection and with reduction in viral load. Studies in macaques and humans indicate the importance of CTL in the control of HIV infection, where reduction in CD8+ T cell number has been correlated with progression to AIDS. The current study was a cross-sectional descriptive study of CD8+ T cells of HIV+ adult South Africans with and without TB co-infection (TB disease). The cohort consisted of anti-retroviral therapy (ART) naive patients and all CTL analyses were carried out on peripheral blood mononuclear cells (PBMCs). A total of 60 South African adults from the Western Cape were utilized in this study, including 15 healthy controls; 30 HIV+TB-individuals and 15 HIV+TB+ individuals. Expression of phenotypic, activation and functional markers were investigated by flow cytometry with the use of fluorochomeconjugated antibodies. The markers examined included the novel activation marker CD137, the CTL associated markers Perforin, Granzyme A, CD107a/b, Fas (CD95), and FasL (CD95L), intracellular cytokines IFN-y and TNF-a and the chronic HIV CTL dysfunction marker PD-1. HIV infection alone was associated with increased baseline expression of TNF-a, Perforin, Granzyme A, PD-1, Fas (CD95), and FasL (CD95L), but not CD137(4-1BB) or IFN-y as compared to uninfected controls. TB co-infection resulted in further increased baseline expression of TNF-a, perforin, PD-1, FasL (CD95L), as well as increased IFN-y. HIV-1 antigen (gag)-specific stimulation in vitro indicated that in HIV infection was associated with antigen-specific upregulation of activation and cytotoxicity markers CD137, IFN-y, TNF-a, Fas, FasL and CD107a/b. In TB co-infection a reduction in antigen-specific degranulation (CD107a/b up-regulation) and also Fas and FasL expression was observed. TB co-infection (in the form of active pulmonary TB) reduced antigen-specific CTL functional activity, but simultaneously there was an association with increased baseline PD-1 expression and also cytolytic marker expression (Fas, FasL, TNF-a). These cytolytic markers could be involved in non-antigen-specific bystander target cell death. The expression of the co-stimulatory molecule CD137 appeared to correlate with interferon-y production and levels of degranulation, confirming its usefulness as a putative surrogate marker of functional responsiveness. These data indicate that in addition to impacting on CD4 T cell function, TB co-infection leads to higher baseline expression of CTL-associated markers, but to dysfunctional antigen-specific CTL responses. / AFRIKAANSE OPSOMMING: Slegs vyf en twintig jaar na die eerste berigte van die menslike immuniteitsgebrekvirus (MIV) in 1981, het die getal MIV-geinfekteerde individue gestyg tot 65 miljoen en het meer as 25 miljoen mense alreeds gesterf aan die verworwe immuniteitsgebrek sindroom (VIGS). Sub Sahara Afrika maak 67% uit van alle HIV gevalle en het `n MIVverwante doodsyfer van 72%. Een van die algemeenste opportunistiese infeksies in VIGS pasiente is Tuberkulose (TB). In ontwikkelende lande, veral, kom 60-70% van TB gevalle voor in MIV-1 geinfekteerde individue. MIV-1 is `n hoe risiko faktor vir die ontwikkeling van TB, die heraktivering van latente Mycobacterium tuberculosis infeksie en progressiewe TB. Die CD8+ sitotoksiese T Limfosiete (STL) se immuun reaksie teen `n MIV infeksie is noodsaaklik en word geassosieer met `n resolusie van die akute infeksie en `n afname in viruslading. Studies in die mens en macaque het getoon dat sitotoksiese T limfosiete belangrik is vir die beheer van MIV infeksies aangesien die afname in CD8+ sel getalle korreleer met die verloop tot VIGS. Hierdie deursnit-beskrywende studie het die CD8+ T selle van MIV+ volwasse Suid-Afrikaners, met of sonder`n TB mede-infeksie, ondersoek. STL analise is gedoen op die perifere bloed mono-nuklere selle (PBMS) van pasiente wat geen teen-retrovirale terapie (TRT) ontvang het nie. `n Totaal van sestig Suid-Afrikaanse volwassenes van die Wes-Kaap het deelgeneem aan die studie wat 15 gesonde kontroles; 30 MIV+TBen 15 MIV+TB+ individue ingesluit het. Die uitdrukking van fenotipiese, aktiverings en funksionele merkers is ondersoek deur middel van vloeisitometrie en fluorochroomgekonjugeerde teenliggaampies. Laasgenoemde het ingesluit die nuwe aktiversingsmerker CD 137, die STL geassosieerde merkers Perforien en Gransiem A, CD 107a/b, Fas (CD95) en FasL (CD95L), intrasellulere sitokiene IFN-y en TNF-a en PD-1, die merker vir chroniese MIV CTL disfunksie. Daar is gevind dat `n TB mede-infeksie (in die vorm van aktiewe pulmonere TB) die antigeen-spesifieke STL funksie verlaag en terselftertyd `n verhoging in die uitdrukking van PD-1 en sitolitiese merkers (Fas, FasL, TNF-a) bewerkstellig. Hierdie sitolitiese basislyn merkers is moontlik betrokke by die dood van nie-antigeen-spesifieke omstander teiken selle. Die uitdrukking van die mede-stimulatoriese molekule CD 137 blyk om te korreleer met die produksie van STL IFN-y en die vlakke van degranulasie. Dit bevestig die merker se bruikbaarheid as `n gewaande surrogaat merker vir funksionele reaksies. Die data toon verder dat `n TB mede-infeksie nie net `n effek het op die CD4 T sel funksie nie, dit lei ook tot `n verhoogde basislyn uitdrukking van STLgeassosieerde merkers, maar met disfunksionele antigeen-spesifieke STL reaksies. Hierdie studie het bepaal dat `n MIV infeksie verbind word met `n toename in die basislyn uitdrukking van TNF-a, Perforien, Gransiem A, PD-1, Fas (CD95) en FasL (CD95L). Dit is egter nie die geval wanneer die uitdrukking van CD 137 (4-1BB) of IFN-y vergelyk word met nie-geinfekteerde kontroles. `n TB mede-infeksie het `n verdere toename in die uitdrukking van TNF-a, Perforien, PD-1, FasL (CD95L) getoon, asook `n verhoging in IFN-y vanaf die basislyn. In vitro MIV-1 antigeen (gag)-spesifieke stimulasies het aangedui dat `n MIV infeksie met die antigeen-spesifieke op-regulasie van aktiverings en sitotoksiese merkers CD137, IFN-y, TNF-a, Fas, FasL en CD107a/b geassosieer word. In `n TB mede-infeksie, is `n verlaging van antigeen-spesifieke degranulasie (CD 107a/b op-regulasie) asook die uitdrukking van Fas en FasL waargeneem. / The Poliomyelitis Research Foundation / The National Health Laboratory Service
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Pesquisa de marcadores sorológicos e moleculares da infecção pelo Vírus da Hepatite E (HEV) em indivíduos portadores do Vírus da Imunodeficiência Humana (HIV) / Serological and molecular markers of hepatitis E virus infection (HEV) in HIV-infected individuals

Ferreira, Ariana Carolina 28 April 2016 (has links)
A infecção pelo HEV é reconhecida como um considerável problema de saúde pública em diversas regiões do mundo. Embora caracterizada como uma infecção benigna com um curso evolutivo autolimitado, recentes estudos têm mostrado sua evolução para cronicidade em indivíduos imunocomprometidos. Além disso, tem sido verificado que nesses indivíduos a infecção crônica pelo HEV pode evoluir para fibrose hepática progressiva, culminando com o desenvolvimento de cirrose. Não existem dados acerca da prevalência da infecção pelo HEV em pacientes infectados pelo HIV no Brasil, onde a circulação deste vírus tem sido demonstrada em diversos grupos de indivíduos imunocompetentes e, até mesmo, em alguns animais provenientes de diferentes regiões do país. Com base nisso, este trabalho teve como objetivo estimar a prevalência de marcadores sorológicos e moleculares da infecção pelo HEV, bem como a padronização de uma PCR em tempo real para a detecção e quantificação da carga viral do HEV na população de soropositivos da cidade de São Paulo. Foram incluídos neste estudo soro e plasma de pacientes infectados pelo HIV (n=354), que foram divididos em grupos de acordo com a presença ou ausência de coinfecção pelos vírus das hepatites B (HBV) e C (HCV). Essas amostras foram coletadas entre 2007 e 2013. Anticorpos anti-HEV IgM e IgG foram pesquisados pela técnica de ELISA (RecomWell HEV IgM/ IgG - MIKROGEN®), e, em alguns casos, confirmados por Immunoblotting (RecomLine HEV IgM/ IgG - MIKROGEN®). Todas as amostras foram submetidas à pesquisa de HEV RNA através da PCR em tempo real padronizada. Cerca de 72% dos indivíduos avaliados pertenciam ao sexo masculino. A média de idade entre a população analisada foi de 48,4 anos. Os anticorpos anti-HEV IgM e IgG foram encontrados em 1,4% e 10,7% dos indivíduos dessa população, respectivamente. Apenas dois pacientes apresentaram positividade simultânea para anti-HEV IgM e IgG. Não houve diferença estatisticamente relevante quanto à presença de marcadores sorológicos nos grupos de estudo. Além disso, foi detectado o HEV RNA em 10,7% das amostras analisadas, entre as quais, seis apresentaram simultaneamente algum marcador sorológico (5 anti-HEV IgG e 1 IgM). A presença deste marcador foi predominante no grupo de pacientes com coinfecção pelo HCV. Através deste trabalho pôde-se constatar, portanto, que o HEV é circulante entre a população de infectados pelo HIV em São Paulo, e que o seguimento desses pacientes se faz necessário dado a possibilidade de progressão para infecção crônica e cirrose / HEV infection is recognized as a significant public health problem in different world regions. Although initially characterized as a benign infection with selflimited course, recent studies have showing its evolution to chronicity in immunocompromised individuals. Furthermore, in these individuals the chronic infection can develop progressive liver fibrosis leading to cirrhosis. There are no data regarding prevalence of HEV infections in HIV- infected patients in Brazil, where the circulation of this virus has been demonstrated in different individuals groups and in some animals from different regions of the country. Based on this, this study aimed to assess the prevalence of serological and molecular makers of HEV infection and the standardization of real-time PCR for the detection and quantification of HEV viral load in HIV-infected individuals in São Paulo. Serum and plasma samples of HIV-infected patients (n=354), collected between 2007 and 2013, were included and organized in groups of co-infection (HIV/ HBV, HIV/HCV and HIV/ HBV/ HCV) and HIV mono-infection. Antibodies anti-HEV IgM and IgG were detected by ELISA (RecomWell HEV IgM/ IgG - MIKROGEN®), and in some cases confirmed by immunoblotting (RecomLine HEV IgM/ IgG - MIKROGEN®). All samples were submitted to research HEV RNA by real-time PCR. About 72% of the patients were male. The mean age of this population was 48.4 years. The anti-HEV IgM and IgG antibodies were found in 1.4% and 10.7%, respectively. Only two patients presented simultaneous anti-HEV IgM and anti- HEV IgG. There was no statistically significant difference in the presence of serological makers among the HIV infection groups. In addition, HEV RNA was detected in 10.7% of samples and six of these samples presented simultaneously a serological maker (5 anti-HEV IgG and 1 IgM). The presence of this maker was more frequent in the co-infection HIV/ HCV group. Through this work, we observed that HEV is circulating among the HIV-infected population in São Paulo, and the monitoring these patients is necessary because of the possibility progression to chronic infection and cirrhosis

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