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Search Results: 1 - 10 of 21561 matches for " Ricardo Sobhie Diaz "
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Analysis of the Origin and Evolutionary History of HIV-1 CRF28_BF and CRF29_BF Reveals a Decreasing Prevalence in the AIDS Epidemic of Brazil
Natalia Ristic,Jean Zukurov,Wagner Alkmim,Ricardo Sobhie Diaz,Luiz Mario Janini,Mario P. S. Chin
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017485
Abstract: HIV-1 subtype B and subtype F are prevalent in the AIDS epidemic of Brazil. Recombinations between these subtypes have generated at least four BF circulating recombinant forms (CRFs). CRF28_BF and CRF29_BF are among the first two BF recombinants being identified in Brazil and they contributed significantly to the epidemic. However, the evolution and demographic histories of the CRFs are unclear.
Relaxation of Adaptive Evolution during the HIV-1 Infection Owing to Reduction of CD4+ T Cell Counts
élcio Leal, Jorge Casseb, Michael Hendry, Michael P. Busch, Ricardo Sobhie Diaz
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039776
Abstract: Background The first stages of HIV-1 infection are essential to establish the diversity of virus population within host. It has been suggested that adaptation to host cells and antibody evasion are the leading forces driving HIV evolution at the initial stages of AIDS infection. In order to gain more insights on adaptive HIV-1 evolution, the genetic diversity was evaluated during the infection time in individuals contaminated by the same viral source in an epidemic cluster. Multiple sequences of V3 loop region of the HIV-1 were serially sampled from four individuals: comprising a single blood donor, two blood recipients, and another sexually infected by one of the blood recipients. The diversity of the viral population within each host was analyzed independently in distinct time points during HIV-1 infection. Results Phylogenetic analysis identified multiple HIV-1 variants transmitted through blood transfusion but the establishing of new infections was initiated by a limited number of viruses. Positive selection (dN/dS>1) was detected in the viruses within each host in all time points. In the intra-host viruses of the blood donor and of one blood recipient, X4 variants appeared respectively in 1993 and 1989. In both patients X4 variants never reached high frequencies during infection time. The recipient, who X4 variants appeared, developed AIDS but kept narrow and constant immune response against HIV-1 during the infection time. Conclusion Slowing rates of adaptive evolution and increasing diversity in HIV-1 are consequences of the CD4+ T cells depletion. The dynamic of R5 to X4 shift is not associated with the initial amplitude of humoral immune response or intensity of positive selection.
Characterization of virologic failure after an initially successful 48-week course of antiretroviral therapy in HIV/AIDS outpatients treated in Santos, Brazil
Caseiro, Marcos M.;Goleg?, Alcino A.C.;Etzel, Arnaldo;Diaz, Ricardo Sobhie;
Brazilian Journal of Infectious Diseases , 2008, DOI: 10.1590/S1413-86702008000300001
Abstract: we characterized the virologic failure after an initially successful 48-week course of antiretroviral therapy among hiv/aids patients in a retrospective cohort study involving patients from santos, brazil. patients with plasma hiv rna below 500 copies/ml for 48 weeks were included. variables analyzed included gender, age, level of education, marital status, mode of hiv acquisition, viral load, and cd4 cell count upon admission. there were 4,909 patients registered with the clinic, of which 669 patients met all the inclusion criteria (41.6% female and 58.4% male). only 27.5% of the patients maintained undetectable viral loads during up to one year of follow-up. after 48 weeks, virologic failure occurred earlier in females and in patients first treated with an antiretroviral regimen other than highly active antiretroviral therapy. patients who were married or had a steady partner experienced virologic failure later than did those who were separated or widowed. the percentage of public health clinic patients who maintain undetectable viral loads for a period of over a year is much lower than that observed among patients enrolled in clinical trials. females, individuals in unstable relationships, single individuals and widowed individuals should be given special attention in order to improve durability of viral suppression.
Prevalence of Human Leukocyte Antigen HLA-B*5701 in HIV-1 Infected Individuals in Brazil  [PDF]
Claudinéia de Araújo, Cristina Valetta de Carvalho, Miriam Estela de Souza Freire, Amanda Yamaguti, Ivens Cuiabano Scaff, Fernando José de Souza, Flávia Galindo Silvestre Silva, Ricardo Sobhie Diaz, Ismael Dale Cotrim Guerreiro da Silva
Open Journal of Genetics (OJGen) , 2014, DOI: 10.4236/ojgen.2014.41008

This study was designed to establish the prevalence of HLA-B*5701 at HIV-1 infected individuals in Brazil. A total of 517 consecutive individuals were followed in this study from February 2009 through July 2011. The presence of HLA-B*5701 was determined by Nested-PCR with HLA-B*57 and HLA-B*5701 sequence-specific primers (PCR-SSP). The expression of HLA-B*57 was negative in the 385 (74.5%) and positive in the 103 (19.9%) of infected individuals. Among these, the expression of HLA-B5701 was positive in the 29 (5.6%) of individuals. No demographic or ethnic differences were found between HLA-B*57/HLA-B*5701 HIV-1 negative patients, with a prevalence of Caucasians (57.1%) individuals. During the period of study, 68 patients were submited to an abacavir contain- ing regimen. The HLA-B*5701 allele was observed in 7 (10.3%) patients, with a significant incidence of Hypersensitivity reactions at 4 of them (p < 0.001). Conclusions: Although Brazilian population consists of a mixture of individuals of Caucasian, African and Native American genetic background, prevalence of HLA-B*5701 in this population is similar to the one found in pure Caucasians.

Estimating HIV-1 incidence using the serologic testing algorithm for recent HIV infections at HIV counseling and testing centers in the city of S?o Paulo, Brazil
Bassichetto, Katia Cristina;Bergamaschi, Denise Pimentel;Veras, Maria Amelia;Sucupira, Maria Cecilia Araripe;Mesquita, Fabio;Diaz, Ricardo Sobhie;
Brazilian Journal of Infectious Diseases , 2009, DOI: 10.1590/S1413-86702009000100004
Abstract: the network of hiv counseling and testing centers in s?o paulo, brazil is a major source of data used to build epidemiological profiles of the client population. we examined hiv-1 incidence from november 2000 to april 2001, comparing epidemiological and socio-behavioral data of recently-infected individuals with those with long-standing infection. a less sensitive elisa was employed to identify recent infection. the overall incidence of hiv-1 infection was 0.53/100/year (95% ci: 0.31-0.85/100/year): 0.77/100/year for males (95% ci: 0.42-1.27/100/year) and 0.22/100/ year (95% ci: 0.05-0.59/100/year) for females. overall hiv-1 prevalence was 3.2% (95% ci: 2.8-3.7%), being 4.0% among males (95% ci: 3.3-4.7%) and 2.1% among females (95% ci: 1.6-2.8%). recent infections accounted for 15% of the total (95% ci: 10.2-20.8%). recent infection correlated with being younger and male (p = 0.019). therefore, recent infection was more common among younger males and older females.
Primary resistance of HIV to antiretrovirals among individuals recently diagnosed at voluntary counselling and testing centres in the metropolitan region of Recife, Pernambuco
Cavalcanti, Ana Maria Salustiano;Brito, Ana Maria de;Salustiano, Daniela Medeiros;Lima, Kledoaldo Oliveira de;Silva, Sirleide Pereira da;Diaz, Ricardo Sobhie;Lacerda, Heloisa Ramos;
Memórias do Instituto Oswaldo Cruz , 2012, DOI: 10.1590/S0074-02762012000400002
Abstract: determining the prevalence and type of antiretroviral (arv) resistance among arv-na?ve individuals is important to assess the potential responses of these individuals to first-line regimens. the prevalence of primary resistance and the occurrence of recent infections among individuals with human immunodeficiency virus (hiv)/acquired immune deficiency syndrome (aids) were identified among recently diagnosed patients at five sexually transmitted disease/aids testing and counselling centres in the metropolitan region of recife (rmr), pernambuco, brazil, between 2007-2009. one-hundred and eight samples were analysed using the calypte? bed assay. males predominated (56%), as did patients aged 31-50 years. twenty-three percent presented evidence of a recent hiv infection. the median cd4+ t lymphocyte count was 408 cells/mm3 and the median viral load was 3.683 copies/ml. the prevalence of primary resistance was 4.6% (confidence interval 95% = 1-8.2%) based on criteria that excluded common polymorphisms in accordance with the surveillance drug resistance mutation criteria. the prevalence of resistance to non-nucleoside reverse transcriptase, nucleoside/nucleotide reverse transcriptase and protease inhibitors were 3.8%, 1.5% and 0.8%, respectively. fifty-seven percent of strains were from clade b, 37.7% were clade f and 3.1% were clade c; there were no statistically significant differences with respect to resistance between clades. recent infection tended to be more common in men (p = 0.06) and in municipalities in the south of the rmr (jaboat?o dos guararapes and cabo de santo agostinho) (p = 0.046). the high prevalence of recent infection and the high prevalence of non-b strains in this poor brazilian region merit further attention.
Frequency of polymorphisms of genes coding for HIV-1 co-receptors CCR5 and CCR2 in a Brazilian population
Munerato, Patrícia;Azevedo, Maria Lúcia;Sucupira, Maria Cecília Araripe;Pardini, Regina;Pinto, Gedson Humberto Novaes;Catroxo, Márcia;Souza, Inara Espinelli;Diaz, Ricardo Sobhie;
Brazilian Journal of Infectious Diseases , 2003, DOI: 10.1590/S1413-86702003000400002
Abstract: entry of human immunodeficiency type 1 virus (hiv-1) into target cells requires both cd4and one of the chemokine receptors. viruses predominantly use one, or occasionally both, of the major co-receptors ccr5 and cxcr4, although other receptors, including ccr2b and ccr3, function as minor co-receptors. a 32-nucleotide deletion (d32) within the b-chemokine receptor 5 gene (ccr5) has been described in subjects who remain uninfected despite extensive exposition to hiv-1. the heterozygous genotype delays disease progression. this allele is common among caucasians, but has not been found in people of african or asian ancestry. a more common transition involving a valine to isoleucine switch in transmembrane domain i of ccr2b (64i), with unknown functional consequences, was found to delay disease progression but not to reduce infection risk. as the brazilian population consists of a mixture of several ethnic groups, we decided to examine the genotype frequency of these polymorphisms in this country. there were 11.5% ccr5 heterozygotes among the hiv-1 infected population and 12.5% among uninfected individuals, similar to data from north america and western europe. the prevalence of ccr2-64i homozygotes and heterozygotes was 0.06 and 15.2%, respectively, also similar to what is known for north america and western europe.
Analysis of HIV-1 Protease Gene Reveals Frequent Multiple Infections Followed by Recombination among Drug Treated Individuals Living in S?o Paulo and Santos, Brazil
Edsel Renata De Morais Nunes, Jean Paulo Zukurov, Juliana Terzi Maricato, Maria Cecília Araripe Sucupira, Ricardo Sobhie Diaz, Luíz Mário Ramos Janini
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084066
Abstract: The present study investigated the prevalence of HIV-1 multiple infections in a population composed by 47 patients under HAART failure and enrolled at the National DST/AIDS, Program, Ministry of Health, Brazil.Detection of multiple infections was done using a previously published RFLP assay for the HIV-1 protease gene, which is able of distinguishing between infections caused by a single or multiple HIV-1 subtypes. Samples with multiple infections were cloned, and sequence data submitted to phylogenetic analysis. We were able to identify 17 HIV-1 multiple infections out of 47 samples. Multiple infections were mostly composed by a mixture of recombinant viruses (94%), with only one case in which protease gene pure subtypes B and F were recovered. This is the first study that reports the prevalence of multiple infections and intersubtype recombinants in a population undergoing HAART in Brazil. Based on the data there was a steep increase of multiple infections after the introduction of the combined antiretroviral therapy in Brazil. Cases of multiple infections may be associated with HIV-1 genetic diversity through recombination allowing for the generation of viruses showing a combination of resistance mutations.
Faster HIV-1 Disease Progression among Brazilian Individuals Recently Infected with CXCR4-Utilizing Strains
Maria Cecilia Araripe Sucupira, Sabri Sanabani, Rodrigo M. Cortes, Maria Teresa M. Giret, Helena Tomiyama, Mariana M. Sauer, Ester Cerdeira Sabino, Luiz Mario Janini, Esper Georges Kallas, Ricardo Sobhie Diaz
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030292
Abstract: Introduction Primary HIV infection is usually caused by R5 viruses, and there is an association between the emergence of CCXR4-utilizing strains and faster disease progression. We characterized HIV-1 from a cohort of recently infected individuals in Brazil, predicted the virus's co-receptor use based on the env genotype and attempted to correlate virus profiles with disease progression. Methods A total of 72 recently infected HIV patients were recruited based on the Serologic Testing Algorithm for Recent HIV Seroconversion and were followed every three to four months for up to 78 weeks. The HIV-1 V3 region was characterized by sequencing nine to twelve weeks after enrollment. Disease progression was characterized by CD4+ T-cell count decline to levels consistently below 350 cells/μL. Results Twelve out of 72 individuals (17%) were predicted to harbor CXCR4-utilizing strains; a baseline CD4<350 was more frequent among these individuals (p = 0.03). Fifty-seven individuals that were predicted to have CCR5-utilizing viruses and 10 individuals having CXCR4-utilizing strains presented with baseline CD4>350; after 78 weeks, 33 individuals with CCR5 strains and one individual with CXCR4 strains had CD4>350 (p = 0.001). There was no association between CD4 decline and demographic characteristics or HIV-1 subtype. Conclusions Our findings confirm the presence of strains with higher in vitro pathogenicity during early HIV infection, suggesting that even among recently infected individuals, rapid progression may be a consequence of the early emergence of CXCR4-utilizing strains. Characterizing the HIV-1 V3 region by sequencing may be useful in predicting disease progression and guiding treatment initiation decisions.
HIV-1 drug resistance genotypic profiles in children with undetectable plasma viremia during antiretroviral therapy
Angelis, Daniela Souza Araújo de;Tateno, Adriana Fumie;Diaz, Ricardo Sobhie;Succi, Regina Célia de Menezes;Pannuti, Claudio Sergio;Gouvea, Aida de Fátima Barbosa;Machado, Daisy Maria;
Brazilian Journal of Infectious Diseases , 2011, DOI: 10.1590/S1413-86702011000100011
Abstract: treatment of hiv-1 infection with highly active antiretroviral therapy has led to sustained viral suppression in the plasma in a large number of children. however, studies have suggested that the integrated provirus in resting cd4+ t lymphocytes could be a source of reactivatable virus and maintain drug-resistant virus. we evaluated the resistance-related mutations in children receiving antiretroviral therapy with prolonged viral suppression. thirty-two peripheral blood mononuclear cell samples from 16 children with viral loads that had been below detection limits for at least 12 months were obtained at two different time points and the dnas sequenced. the median cd4 cell count was 1,016 cells/mm3 (347-2,588) and 938 cells/mm3 (440-3,038) at the first and second time points, respectively. the median follow-up time was 15 months (9-27). six (37.5%) and seven (43.75%) of the 16 patients showed at least one nrti-associated mutation in the first and second samples, respectively. two out of 16 (12.5%) had an nnrti-associated mutation at the first time point and three out of 16 (18.75%) at the second. in addition, 14 out of 16 (87.5%) had at least one pi-associated mutation at both time points. despite plasma hiv-1 rna suppression for at least 12 months, resistance-related mutations from previous antiretroviral failures could still be detected in archival virus. furthermore, viral evolution occurred at the reverse transcriptase region in spite of viral suppression to levels below 400 copies/ml. persistence of archival resistant virus may be relevant when considering future treatment options.
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