Ricardo Diaz

Ricardo Diaz
Universidade Federal de São Paulo | UNIFESP · Departamento de Medicina

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226
Publications
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Publications

Publications (226)
Article
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Background The co-circulation of Chikungunya (CHIKV), Dengue (DENV) and Zika (ZIKV) viruses increased the risk of outbreaks and coinfections among them. Here, we report cases of coinfection in clinical samples from state of Tocantins, Brazil. Methods In 2017, the Central Public Health Laboratory (LACEN) received samples of patients who consulted h...
Article
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Human immunodeficiency virus (HIV) infections are typically accompanied by high levels of secreted inflammatory cytokines and generation of high levels of reactive oxygen species (ROS). To elucidate how HIV-1 alters the cellular redox environment during viral replication, we used human HIV-1 infected CD4+T lymphocytes and uninfected cells as contro...
Article
Objectives: The presence of minority transmitted drug resistance mutations was assessed using ultra-deep sequencing and correlated with disease progression among recently HIV-1-infected individuals from Brazil. Methods: Samples at baseline during recent infection and 1 year after the establishment of the infection were analysed. Viral RNA and pr...
Data
Table S1. Distribution of samples stratified in Brazil's five major geographical regions Table S2. Prevalence of drug resistance according to State
Article
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Introduction: In Brazil, more than 487,450 individuals are currently undergoing antiretroviral treatment. In order to monitor the transmission of drug-resistant strains and HIV subtype distribution in the country, this work aimed to estimate its prevalence and to characterize the nationwide pretreatment drug resistance in individuals recently diag...
Article
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Objectives: The present study investigated the relationship between genomic variability and resistance of HIV-1 sequences in protease (PR) and reverse transcriptase (RT) regions of the pol gene. In addition, we analysed the resistance among 651 individuals presenting antiretroviral virological failure, from 2009 to 2011, in the state of São Paulo,...
Article
Despite all the efforts to contain the HIV/AIDS epidemics there still are individuals of unknown diagnosis. These present high risk of mortality, and following diagnosis respond very poorly to treatment. Late testing also represents a reduced opportunity in controlling the transmission of HIV and causes an indirect increase in the transmission rate...
Article
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Trial design: Open-label, randomised, controlled, pilot proof-of-concept clinical trial. Methods: Participants: Antiretroviral naïve adult males with CD4 count ≥350cells/mm(3). Interventions: Patients were randomised to receive thalidomide 200mg QD for 3weeks (Thalidomide group) or not (Control group) and followed for 48weeks. Objective: We...
Article
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HIV-1 entry into target cells influences several aspects of HIV-1 pathogenesis, including viral tropism, HIV-1 transmission and disease progression, and response to entry inhibitors. The evolution from CCR5- to CXCR4-using strains in a given human host is still unpredictable. Here we analyzed timing and predictors for coreceptor evolution among rec...
Article
HIV-1 has the Vif protein, which binds to human antiviral proteins APOBEC3 to form complexes to be degraded by cellular proteolysis. To further explore HIV-1 diversity at the population level, we analyzed blood samples from 317 treatment-naïve patients in Brazil. Here, we explored the correlations of Vif polymorphisms with clinical parameters of th...
Data
Comparison between the multivariate ROC curves obtained in training and validation sets using the 5 HIV predictive metabolites described in Table 1. The empirical p values after 100 permutation rounds are also shown. (TIF)
Data
Viral load and CD4+ T cell count linear regression from a period before 2 years of follow up in elite controllers (Panel A) and rapid progressors (panel B). (TIF)
Data
PLS-DA and permutation testing analysis (p<5e-04 after 2000 permutations) revealing clear differences between patients with HIV and controls. (TIF)
Article
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Two hundred forty million people are chronically infected with hepatitis B virus (HBV) worldwide. The rise of globalization has facilitated the emergence of novel HBV recombinants and genotypes. We evaluated HBV genotypes and recombinants, mutations associated with resistance to antivirals (AVs), progression of hepatic illness, and inefficient hepa...
Article
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A 33-year-old male, first time blood donor with a past history of HBV vaccination and no declared risk factors for HBV infection, was found with an absence of reactivity to HBV markers, HBV DNA fluctuation, and a strong and unremitting host cellular immune response to HBV detected over time. HBV genome sequencing identified a genotype F strain, sub...
Article
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Objective: To examine the feasibility of identifying HIV negative at risk individuals in HIV serodiscordant couples, during voluntary HIV testing in South Brazil. Methods: We surveyed HIV testers at 4 public testing sites in Rio Grande do Sul. We obtained information on risk behaviors and sexual partnerships. HIV testing and testing for recent i...
Article
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Background: Immunological and virological status of HIV-infected individuals entering the Brazilian public system over time was analyzed. We evaluated the impact of ART on virological, immunological and antiretroviral resistance over time. Methods: CD4+ T cell counts, viral loads and genotypes from patients over 13 years old from 2001-2011 were...
Article
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Itajaí is a port city in southern Brazil with one of the highest incidence and mortality rates from AIDS in the country. The prevalence and incidence of HIV infection were investigated in 1085 of 3196 new HIV-1 infection cases evaluated in the counseling and testing center (CTC) of Itajaí from January 2002 to August 2008. Recent infections were ass...
Conference Paper
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Introdução: As estratégias de prevenção da transmissão da infecção pelo vírus da imunodeficiência humana (HIV) em casais sorodiscordantes geralmente são voltadas para as pessoas HIV positivas, não havendo consenso sobre a abordagem das parcerias soronegativas. Objetivo: Identificar e quantificar a ocorrência de comportamentos de risco em pessoas HI...
Article
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Epigenetic modifications refer to a number of biological processes which alter the structure of chromatin and its transcriptional activity such as DNA methylation and histone post-translational processing. Studies have tried to elucidate how the viral genome and its products are affected by epigenetic modifications imposed by cell machinery and how...
Article
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Background In this study, clustering was performed using a bitmap representation of HIV reverse transcriptase and protease sequences, to produce an unsupervised classification of HIV sequences. The classification will aid our understanding of the interactions between mutations and drug resistance. 10,229 HIV genomic sequences from the protease and...
Article
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Background and aims Antibody responses to vaccines are suboptimal in immunosuppressed HIV-positive individuals. This study aimed to evaluate the potential benefits of MF59® adjuvant or a second A/H1N1 influenza vaccine dose in HIV-positive adults. Method HIV-positive adults (n = 61) and HIV-negative controls (n = 93) aged 18–60 years received two...
Article
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Introduction In Brazil, the use of antiretrovirals is widespread: more than 260,000 individuals are currently undergoing treatment. We conducted a survey targeting antiretroviral-naïve individuals who were initiating antiretroviral therapy (ART) according to local guidelines. This survey covered five Brazilian regions. Methods The HIV Threshold Su...
Article
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Background: Hypermutation alludes to an excessive number of specific guanine-to-adenine (G->A) substitutions in proviral DNA and this phenomenon is attributed to catalytic activity of cellular APOBECs. Population studies relating hypermutation and the progression of infection by human immunodeficiency virus type 1 (HIV-1) have been performed to elu...
Article
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Human immunodeficiency virus type 1 (HIV-1) genetic diversity is one of the most important features of HIV-1 infections and the result of error accumulation during reverse transcription and of high viral turnover. HIV-1 reverse transcription is influenced by factors such as the level of nucleotides and/or the cellular activation state. HIV-1 divers...
Article
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Cellular and Molecular Immunology aims to report the dynamic progress being made in China and abroad in immunological research, and welcomes high-quality Research Articles, Reviews and Brief Reports across a broad range of topics including, but not limited to, clinical immunology, comparative immunology, immunobiology, immunogenetics, immunological...
Article
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The aims of this study were to compare the automated AxSYM avidity assay index with the BED capture enzyme immunoassay test and to calculate the HIV-1 incidence using the BED capture enzyme immunoassay and AxSYM avidity assay index algorithms within a population seeking the Voluntary Counselling and Testing Centres in two municipalities in the Metr...
Article
HIV has extraordinary genetic mutability, both among individuals and at the population level. However, studies of primary HIV-1 infection and serum-converters indicate that the viral population is homogeneous at the sequence level, which suggests clonal HIV transmission. It remains unclear whether this feature applies to the female population. Ten...
Article
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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 distinguishi...
Article
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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 o...
Article
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Background. During routine donor screening in the blood bank, it is not uncommon to find isolated reactivity for anti-HBc in the absence of detectable HBV DNA in a first donation but absence of reactivity to anti-HBc in subsequent donations, suggesting a false-positive result for anti-HBc. Study Design and Methods. The blood donor population was sc...
Article
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Genotropism was determined in 608 Brazilian samples collected in dried blood spots using Polyethersulfone collection cards. Patients were infected by subtype B (88.8%), F (5.6%), C (3.3%), A (1.8%) and G (0.5%). All patients were exposed to three classes of antiretrovirals, and 59.8% of the samples harbored R5 viruses, 35% non-R5-tropic and 5.1% ha...
Article
Although biological differences among HIV-1 subtypes have been suggested to exist, their possible influence on disease progression has not been fully revealed. Particularly, the increasing emergence of recombinants stresses a need for characterization of disease presentation in persons whom these diverse HIV-1 forms infect. We explored this issue a...
Article
Background Estimates of incidence and prevalence are important tools for the investigation of regional trends of the HIV epidemic. Currently, the use of immunoassays for epidemiology investigation is referred by RITA (Recent Infection Testing Algorithm). This study aimed to determine the prevalence HIV-1 incidence in two Voluntary and Counseling Te...
Article
Background The highly active anti-retroviral therapy (HAART) has increased survival of patients with HIV/AIDS. However, some individuals may present therapeutic failure due to a variety of factors, including transmitted antiretroviral resistance. Thus, the objective of the study was investigate frequency of primary resistance and recent infection a...
Article
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Background The human APOBEC3G (A3G) protein activity is associated with innate immunity against HIV-1 by inducing high rates of guanosines to adenosines (G-to-A) mutations (viz., hypermutation) in the viral DNA. If hypermutation is not enough to disrupt the reading frames of viral genes, it may likely increase the HIV-1 diversity. To counteract hos...
Article
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Background: The immunomodulatory nutritional product NR100157 was developed for human immunodeficiency virus (HIV)-infected individuals. We hypothesized that targeting the compromised gastrointestinal tract of HIV-infected individuals would result in systemic immunological benefits. Methods: In a multicenter, randomized, controlled, double-blind...
Article
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To evaluate antiretroviral phenotypic susceptibility of wild-type HIV-1 strains circulating in Brazil, samples from antiretroviral-naïve individuals infected with subtypes C (n=16), F (n=9), or B/F (n=7), where reverse transcriptase is B and protease is F, were phenotyped using the AntivirogramTM Assay (Virco, Mechelen, Belgium). Reduced susceptibi...
Article
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In the present study, we investigated the influence of HIV-1 subtype in the response to the dendritic cell (DC) therapeutic vaccine for HIV. HIV-1 viral load and TCD8+/TCD4+ cell counts for up to 48 weeks after vaccination. Out of 19 immunized subjects, 13 were infected by subtype B, 5 by subtype F, and 1 by subtype D. Overall, 42.1% (8/19) achieve...
Article
A total of 82 plasma samples of HIV-1 infected antiretroviral-naive individuals had genotyping and subtyping performed between 2005-2008. Fourteen (17.1%) were identified as having recent infection. The overall prevalence of resistance with protease or reverse transcriptase mutations was 7.3%. The frequency of mutations known to decrease susceptibi...
Article
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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...
Data
CD4+ T cell levels during HIV-1 infection. The numbers of CD4+ T cells per mm3 of each time point of the infection are represented by colored lines. Each line represents one individual. (TIFF)
Data
Virus load of each patient during infection time. The x-axis represents the sampling time of the study. Y-axis depicts the amount of viruses measured in RNA copies per ml of plasma. (TIFF)
Data
Neutralization of the heterologous MN strain of HIV-1. Humoral immune response against the MN strain of HIV-1 was measured in the plasma of patients during the over the infection time. Each line represent one individual and points are the measured immune response detected in each year (x-axis). (TIFF)
Data
Glycosylation pattern of the V3 loop of HIV-1. Numbers above branches indicate glycosylated sites in the V3 region. The tree shows clones of within-host sequences of the blood donor DO (depicted in pink color) and the recipients RA (depicted in green) and RB (depicted in blue and red color for X4 isolates). Highlighted areas represent clusters of i...
Data
Antibody affinity by autologous synthetic peptides. The humoral immunity of each patient was measured by the affinity of their antibody to recognize peptides based on consensus sequences of virus isolated in distinct time points. Affinity was measured independently in each individual in distinct time points. (TIFF)
Data
Maximum a posteriori tree of the recipient RB and the patient SC. This tree was constructed using molecular clones of the recipient RB and her sexual partner SC. Sequences from all time points were included. The sampling time of clones are indicated in the sequences names (last two digits). Numbers above the branches indicate the Bayesian posterior...
Article
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Determining the prevalence and type of antiretroviral (ARV) resistance among ARV-naïve 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 deficien...
Article
Vicriviroc, a novel HIV CCR5 antagonist, demonstrated significant efficacy and favorable tolerability in phase II trials in treatment-experienced subjects, supporting further evaluation in phase III studies. Two identical double-blind, placebo (PBO)-controlled trials in CCR5-tropic HIV-infected subjects with documented resistance to two antiretrovi...
Article
The impact of Structured Treatment Interruption (STI) in peripheral blood mononuclear cell (PBMC) proviral reservoirs in 41 highly active antiretroviral therapy (HAART)-treated viremic individuals at baseline and 12 weeks after STI was determined using quantitative PCR (qPCR). Viral load increased 0.7 log10 and CD4 decreased 97.5 cells/mm3 after 12...
Article
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We studied the presence of primary resistance to raltegravir (RAL), natural polymorphisms, and selection pressure on HIV-1 integrase. We found a high frequency of integrase polymorphisms related to the resistance to RAL and sequence stability. Further studies are needed to determine the importance of these polymorphisms to RAL resistance.
Article
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This study shows HIV-1 incidence in the northeastern region of Brazil, where the HIV epidemic has spread recently. Incidence was higher among men (1.34%; 95% confidence interval [CI], 1.00% to 1.69%) than among women (0.55%; 95% CI, 0.43% to 0.68%) (P < 0.0001), and there was an association between younger age and recent HIV infection (P < 0.004).