ARTHUR MAIA PAIVA
Projetos de Pesquisa
Unidades Organizacionais
LIM/56 - Laboratório de Investigação em Dermatologia e Imunodeficiências, Hospital das Clínicas, Faculdade de Medicina
5 resultados
Resultados de Busca
Agora exibindo 1 - 5 de 5
- ORIGIN AND PREVALENCE OF HUMAN T-LYMPHOTROPIC VIRUS TYPE 1 (HTLV-1) AND TYPE 2 (HTLV-2) AMONG INDIGENOUS POPULATIONS IN THE AMERICAS(2015) PAIVA, Arthur; CASSEB, JorgeHuman T-lymphotropic virus type 1 (HTLV-1) is found in indigenous peoples of the Pacific Islands and the Americas, whereas type 2 (HTLV-2) is widely distributed among the indigenous peoples of the Americas, where it appears to be more prevalent than HTLV-1, and in some tribes of Central Africa. HTLV-2 is considered ancestral in the Americas and is transmitted to the general population and injection drug users from the indigenous population. In the Americas, HTLV-1 has more than one origin, being brought by immigrants in the Paleolithic period through the Bering Strait, through slave trade during the colonial period, and through Japanese immigration from the early 20(th) century, whereas HTLV-2 was only brought by immigrants through the Bering Strait. The endemicity of HTLV-2 among the indigenous people of Brazil makes the Brazilian Amazon the largest endemic area in the world for its occurrence. A review of HTLV-1 in all Brazilian tribes supports the African origin of HTLV-1 in Brazil. The risk of hyperendemicity in these epidemiologically closed populations and transmission to other populations reinforces the importance of public health interventions for HTLV control, including the recognition of the infection among reportable diseases and events.
- Polymorphisms in HLA-C and KIR alleles are not associated with HAM/TSP risk in HTLV-1-infected subjects(2018) ASSONE, Tatiane; MALTA, Fernanda M.; BAKKOUR, Sonia; MONTALVO, Leilani; PAIVA, Arthur M.; SMID, Jerusa; OLIVEIRA, Augusto Cesar Penalva de; GONCALVES, Fernanda de Toledo; LUIZ, Olinda do Carmo; FONSECA, Luiz Augusto M.; NORRIS, Philip J.; CASSEB, JorgeIntroduction: Several genetic polymorphisms may be related to susceptibility or resistance to viral disease outcomes. Immunological or genetic factors may act as major triggers of the immune pathogenesis of HAM/TSP. This study investigated the association of immune related genetic polymorphisms with viral and immunological markers. Methods: 247 HTLV-1-infected volunteers, drawn from a larger group of HTLV-infected subjects followed at the Institute of Infectious Diseases ""Emilio Ribas"" (IIER) for up to 19 years, participated in this study, which ran from June 2011 to July 2016. The subjects were classified according to their neurological status into two groups: Group 1 (160 asymptomatic individuals) and Group 2 (87 HAM/TSP patients). Samples were tested for spontaneous lymphocyte proliferation (LPA) and HTLV-1 proviral load (PVL) and for IFN-lambda 4, HLA-C and KIR genotypes using qPCR. Results: We found associations between LPA (p = 0.0001) with HAM/TSP and confirmed the IFN-lambda 4 polymorphism rs8099917, allele GG, as a protective factor using a recessive model (OR = 3.22, CI = 1.10-9.47). Polymorphisms in HLA-C and KIR alleles were not associated with risk of developing HAM/TSP. Conclusion: We demonstrated that age, LPA and an IFN-lambda 4 polymorphism were associated with progression to HAM/TSP. Understanding HAM/TSP pathogenesis can provide important markers of prognostic value for clinical management, and contribute to the discovery of new therapeutic interventions in the future.
- Genetic Markers of the Host in Persons Living with HTLV-1, HIV and HCV Infections(2016) ASSONE, Tatiane; PAIVA, Arthur; FONSECA, Luiz Augusto M.; CASSEB, JorgeHuman T-cell leukemia virus type 1 (HTLV-1), hepatitis C virus (HCV) and human immunodeficiency virus type 1 (HIV-1) are prevalent worldwide, and share similar means of transmission. These infections may influence each other in evolution and outcome, including cancer or immunodeficiency. Many studies have reported the influence of genetic markers on the host immune response against different persistent viral infections, such as HTLV-1 infection, pointing to the importance of the individual genetic background on their outcomes. However, despite recent advances on the knowledge of the pathogenesis of HTLV-1 infection, gaps in the understanding of the role of the individual genetic background on the progress to disease clinically manifested still remain. In this scenario, much less is known regarding the influence of genetic factors in the context of dual or triple infections or their influence on the underlying mechanisms that lead to outcomes that differ from those observed in monoinfection. This review describes the main factors involved in the virus-host balance, especially for some particular human leukocyte antigen (HLA) haplotypes, and other important genetic markers in the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and other persistent viruses, such as HIV and HCV.
- Sexual transmission of human T-cell lymphotropic virus type 1(2014) PAIVA, Arthur; CASSEB, JorgeHuman T-cell lymphotropic virus type 1 (HTLV-1) is endemic in many parts of the world and is primarily transmitted through sexual intercourse or from mother to child. Sexual transmission occurs more efficiently from men to women than women to men and might be enhanced by sexually transmitted diseases that cause ulcers and result in mucosal ruptures, such as syphilis, herpes simplex type 2 (HSV-2), and chancroid. Other sexually transmitted diseases might result in the recruitment of inflammatory cells and could increase the risk of HTLV-1 acquisition and transmission. Additionally, factors that are associated with higher transmission risks include the presence of antibodies against the viral oncoprotein Tax (anti-Tax), a higher proviral load in peripheral blood lymphocytes, and increased cervicovaginal or seminal secretions. Seminal fluid has been reported to increase HTLV replication and transmission, whereas male circumcision and neutralizing antibodies might have a protective effect. Recently, free virions were discovered in plasma, which reveals a possible new mode of HTLV replication. It is unclear how this discovery might affect the routes of HTLV transmission, particularly sexual transmission, because HTLV transmission rates are significantly higher from men to women than women to men.
- Risk factors associated with HTLV-1 vertical transmission in Brazil: longer breastfeeding, higher maternal proviral load and previous HTLV-l-infected offspring(2018) PAIVA, Arthur M.; ASSONE, Tatiane; HAZIOT, Michel E. J.; SMID, Jerusa; FONSECA, Luiz Augusto M.; LUIZ, Olinda do Carmo; OLIVEIRA, Augusto Cesar Penalva de; CASSEB, JorgeHTLV-1 is transmitted primarily either through sexual intercourse or from mother to child. The mother/child pairs were classified as seroconcordant or serodiscordant. We analyzed mother to child transmission (MTCT) according to sociodemographic, clinical and epidemiological characteristics of the mother, child's gender and duration of breastfeeding. Between June 2006 and August 2016 we followed 192 mothers with HTLV-1 infection (mean age 41 years old), resulting in 499 exposed offspring, 288 (57.7%) of whom were tested for HTLV-1, making up the final sample for the study, along with their 134 respective mothers. Among the tested mother/child pairs, 41 (14.2%) were HTLV-1 positive, highlighted that seven of 134 family clusters concentrated 48.8% of positive cases. Variables associated with a positive child: breastfeeding duration >= 12 months, maternal PVL >= 100 copies/10(4) PBMC, mother's age at delivery >26 years old, and HTLV-1 in more than one child of the same mother. In a multiple logistic regression, breastfeeding >= 12 months, higher maternal PVL and >= 2 previous HTLV-l-infected children remained independently associated with the outcome. Thus, high maternal PVL and breastfeeding beyond 12 months were independently associated with MTCT of the HTLV-1 infection. Our results reinforce the need for both prenatal HTLV screening in endemic areas and for advising mothers on breastfeeding.