996 resultados para HTLV-I (Vírus)
Resumo:
Serum samples (n: 110) from blood donors and high risk individuals from Cordoba, Argentina with indeterminate HIV-1 and HTLV-I/II Wb profiles were studied for specific antibodies to HTLV-I/II and HIV-1 by indirect immunofluorescence assay (IFA) and for the presence or absence of HIV-1 and HTLV-I/II specific bands by Wb. This study was carried out in order to characterize their putative reactions with HIV-1 and HTLV-I/II proteins and to resolve the retrovirus infection status of these individuals. Results indicated that blood donors sera displaying indeterminate HIV-1 or HTLV-I/II Wb patterns were not immunoreactive to HTLV-I/II and HIV-1 on IFA. However, a high rate of indeterminate HIV-1 and HTLV-I/II Wb samples from high risk individuals had positive HTLV-I/II and HIV-1 IFA results respectively. Our study supports the growing evidence that HTLV-HIV indeterminate seroreactivity in low risk population is due to a cross reaction against nonviral antigens, and in high risk populations the indeterminate samples show serological cross-recognition between HIV-1 proteins and HTLV-I/II proteins on Wb. These results point out the necessity to investigate the HTLV-I/II reactivity in indeterminate HIV-1 samples and viceversa in order to confirm the diagnosis. Finally, this study shows the potential usefulness of IFA in elucidating the status of HIV-1 and HTLV-I/II infection of individuals with indeterminate Wb profiles, thus enabling resolution of retrovirus infection status.
Resumo:
The most frequent pathway of vertical transmission of HTLV-I is breast-feeding, however bottle fed children may also become infected in a frequency varying from 4 to 14%. In these children the most probable routes of infection are transplacental or contamination in the birth canal. Forty-one bottle-fed children of HTLV-I seropositive mothers in ages varying from three to 39 months (average age of 11 months) were submitted to nested polymerase chain reaction analysis (pol and tax genes). 81.5% of the children were born by an elective cesarean section. No case of infection was detected. The absence of HTLV-I infection in these cases indicates that transmission by transplacental route may be very infrequent.
Resumo:
Limited and contradictory information exists regarding the prognosis of HIV/HTLV-I co-infection. Our goal was to estimate the effect of HTLV-I infection on mortality in HIV-infected patients at a HIV reference center in Peru. We studied a retrospective cohort of HIV-infected patients, who were exposed or unexposed to HTLV-I. Exposed patients were Western Blot (WB) positive for both retroviruses. Unexposed patients were WB positive for HIV, and had least one negative EIA for HTLV-I. These were selected among patients who entered our Program immediately before and after each exposed patient, between January 1990 and June 2004. Survival time was considered between the diagnosis of exposure to HTLV-I and death or censoring. Confounding variables were age, gender, baseline HIV clinical stage, baseline CD4+ T cell count, and antiretroviral therapy. We studied 50 exposed, and 100 unexposed patients. Exposed patients had a shorter survival compared to unexposed patients [median survival: 47 months (95% CI: 17-77) vs. 85 months (95% CI: 70-100), unadjusted p = 0.06]. Exposed patients had a higher rate of mortality compared to unexposed patients (HIV/HTLV-I (24/50 [48%]) vs. HIV only (37/100 [37%]), univariable p = 0.2]. HTLV-I exposure was not associated to a higher risk of death in the adjusted analysis: HR: 1.2 (0.4-3.5). AIDS clinical stage and lack of antiretroviral therapy were associated to a higher risk of dying. In conclusions, HTLV-I infection was not associated with a higher risk of death in Peruvian HIV-infected patients. Advanced HIV infection and lack of antiretroviral therapy may explain the excess of mortality in this population.
Resumo:
A cidade do Salvador, capital do Estado da Bahia, apresenta a população com maior prevalência da infecção pelo HTLV-I no Brasil. Todavia, somente um estudo incluiu uma cidade do interior deste Estado, mesmo assim com número amostral pequeno. O objetivo foi o de avaliar a prevalência de anticorpos anti-HTLV-I/II na população de quatro cidades do interior do Estado da Bahia. As amostras de soro proveninentes de 1.539 indivíduos residentes em Catolândia, Ipupiara, Jacobina e Prado foram triadas através do ELISA, e a confirmação dos resultados nas amostras repetidamente positivas foi realizada através do "Western blot". Quarenta e sete (3,1%) amostras foram positivas pelo ELISA, e 44 destas foram submetidas ao Western blot, com 5 resultados positivos (0,3%), 8 (0,5%) indeterminados (todos da cidade de Jacobina) e 31 negativos. A prevalência geral de anticorpos anti-HTLV-I, nas cidades estudadas, foi de 0,3%. Esta prevalência variou de 0,0% (Prado) a 0,7% (Jacobina), porém não houve diferença estatisticamente significante (p > 0,21). Nenhum indivíduo apresentou anticorpos anti-HTLV-II. Em conclusão, a prevalência da infecção pelo HTLV-I no interior do Estado da Bahia foi baixa, contudo, a população da cidade de Jacobina apresentou a maior prevalência. No entanto, outros estudos epidemiológicos, clínicos e virológicos serão necessários para a melhor compreensão da história natural desta infecção em Jacobina.
Resumo:
Sabida la importante seroprevalencia en la Isla de Margarita para el HIV-1 nos propusimos conocer la seroprevalencia de HTLV-I/II en muestras de grupos epidemiologicamente importantes en su transmisión. El estudio se desarrolló con 141 trabajadoras sexuales y 40 hombres gays entre 1994 y 1997. Nuestros resultados permitieron establecer infección por HTLV-I en un hombre. Este es el primer reporte conocido sobre pesquisa epidemiológica de la infección por HTLV-I/II en la Isla de Margarita.
Resumo:
The purpose of this study was to determine the seroprevalence of human immunodeficiency virus (HIV-1/2), human T-cell lymphotropic virus (HTLV-I/II), hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum and Trypanosoma cruzi among 63 male prisoners in Manhuaçu, Minas Gerais, Brazil and to compare this with data from eligible blood donors. The positive results were as follows: 11/63 (17.5%) for HBV, 5/63 (7.4%) for syphilis, 4/63 (6.3%) for HCV, 3/63 (4.8%) for Chagas' disease, 2/63 (3.2%) for HIV-1/2 and 1/63 (1.6%) for HTLV-I/II. The seroprevalence in prisoners was higher than among blood donors, mainly for antibodies to HIV-1/2, HCV and HBV. This is probably due to low social economic level, illiteracy, higher proportion with a prior history of intravenous drug use and/or unsafe sexual behavior. Therefore, these prisoners constitute a high risk group and routine screening and counseling are recommended.
Resumo:
Three patients (males, black, ages 37, 40 and 57) attended a university clinic with a progressive paraparesis of obscure origin. One patient who referred disease duration of more than 16 years, showed diminished deep reflexes, bilateral Babinski's sign, diminished sensation of vibration, abnormal bladder function and back pain. The other two patients (with one and six years of disease duration) complained of weakness in one leg, increased deep reflexes and back pain. Babinski's sign and bladder disturbance were also present in the patient with six years of disease. Blood samples tested by an enzyme immune assay and a discriminatory Western blot were positive for HTLV-I. The familial analysis of one patient showed a possible pattern of sexual and vertical transmission of the virus. To the best of our knowledge, these are the first cases of a proven association between HTLV-I and TSP/HAM in Belem, Para, and emphasize the need to actively look for cases of neurological disease associated to the virus.
Resumo:
To investigate epidemiological and pathogenetic features of HTLV-I infection, a cohort of carriers has been followed at the USP Teaching Hospital since 1991. This study describes the establishment of cell lines from peripheral blood mononuclear cells (PBMC) of infected subjects. Ex vivo PBMC were cultured with those from a seronegative donor and morphologic evidence of cell transformation was obtained after 90 days with detection of multinucleated cells exhibiting cerebriform nuclei. Integration of HTLV-I proviral DNA and expression of viral antigens was demonstrated in culture by PCR and immunofluorescence. Cell lines were maintained for 240 days, gradually weaned from exogenous IL-2. Immunophenotyping of cell lines on flow cytometry yielded evidence of cell activation. Establishment of HTLV-I-infected cell lines from ex vivo PBMC is feasible and may be useful for studies on lymphocyte phenotypic changes and on mechanisms of HTLV-induced cell proliferation. Moreover they may be used with diagnostic purposes in immunofluorescence tests.
Resumo:
Introduction: Human T cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) can impact the independence and motricity of patients. The aims of this study were to estimate the effects of physiotherapy on the functionality of patients with HAM/TSP during the stable phase of the disease using proprioceptive neuromuscular facilitation (PNF) and to compare two methods of treatment delivery. Methods: Fourteen patients with human T cell lymphotropic virus type I (HTLV-I) were randomly allocated into two groups. In group I (seven patients), PNF was applied by the therapist, facilitating the functional activities of rolling, sitting and standing, walking and climbing and descending stairs. In group II (seven patients), PNF was self-administered using an elastic tube, and the same activities were facilitated. Experiments were conducted for 1h twice per week for 12 weeks. Low-back pain, a modified Ashworth scale, the functional independence measure (FIM) and the timed up and go test (TUG) were assessed before and after the interventions. Results: In the within-group evaluation, low-back pain was significantly reduced in both groups, the FIM improved in group II, and the results of the TUG improved in group I. In the inter-group analysis, only the tone was lower in group II than in group I. Conclusions: Both PNF protocols were effective in treating patients with HAM/TSP.
Resumo:
Forty-tree (31.4%) out of 137 serum samples obtained from two Indian communities living in the Amazon region were found to be positive for HTLV-I antibody, as tested by enzyme-linked immunosorbent assay (Elisa). Eighty-two sera were collected from Mekranoiti Indians, yielding 39% of positivity, whereas 11 (20.0%) or the 55 Tiriyo serum samples had antibody to HTLV-I. In addition, positive results occurred in 10 (23.2%) out of 43 sera obtained from patients living in the Belem area, who were suffering from cancer affecting different organs. Five (16.7%) out of 30 Elisa positive specimens were also shown to be positive by either Western blot analysis (WB) or indirect immunogold electron microscopy (IIG-EM).
Resumo:
We have previously demonstrated that the bZIP transcription factor CREB-2, also called ATF-4, trans-activates, in association with the viral protein Tax, the human T-cell leukemia virus type I (HTLV-I) promoter. In this study, we have examined whether CREB-2 acetylation affects transcriptional activation mediated by Tax. We present evidence that CREB-2 is acetylated in vitro and in vivo. CREB-2 is acetylated in two regions: the basic domain of the bZIP (from amino acid residue 270 to 300) and the short basic domain (from 342 to 351) located downstream from the bZIP. We also demonstrate that CREB-2 is acetylated by p300/CBP but not by p/CAF. Moreover, replacement of lysine by arginine in the basic domains decreases the trans-activating capacity of CREB-2. However, in the presence of Tax, the HTLV-I transcription remains fully activated by these CREB-2 mutants. Although we cannot totally exclude that the mutations could also affect CREB-2 structure and activity independent of acetylation, our results suggest that activation of the viral promoter in the presence of Tax is independent of the CREB-2 acetylation.
Resumo:
A case of a 20-years-old black man from Salvador, Bahia with HTLV-I associated T cell lymphoma is presented. In spite of the absence of splenomegaly and leukemia, the patient had a marked cephalic tumoral infiltrationassociated with axillary tumors in a pattern not yet described in adult T cell lymphoma. Peripheral blood involvement was observed later on in the course of thedisease. The patient underwent chemotherapy but died seven monts after diagnosis.
Resumo:
The occurrence of HTLV-I/II and HIV-1 coinfections have been shown to be frequent, probably in consequence of their similar modes of transmission. This paper presents the prevalence of coinfection of HTLV among HIV-1 infected and AIDS patients in Belém, State of Pará, Brazil. A group of 149 patients attending the AIDS Reference Unit of the State Department of Health was tested for the presence of antibodies to HTLV-I/II using an enzyme immunoassay and the positive reactions were confirmed with a Western blot that discriminates between HTLV-I and HTLV-II infections. Four patients (2.7%) were positive to HTLV-I, seven (4.7%) to HTLV-II and one (0.7%) showed an indeterminate pattern of reaction. The present results show for the first time in Belém not only the occurrence of HTLV-II/HIV-1 coinfections but also a higher prevalence of HTLV-II in relation to HTLV-I. Furthermore, it also enlarges the geographical limits of the endemic area for HTLV-II in the Amazon region of Brazil.