Compromiso renal y digestivo en infecciones por COVID-19 / Renal and digestive engagement in COVID-19 infections

Resumen La infección por el síndrome respiratorio agudo severo (SARS-CoV-2) ha causado una de las emergencias epidemiológicas más grandes de los últimos 10 años y sus efectos patológicos son aún estudiados. Por lo anterior, resulta importante describir los mecanismos asociados al compromiso renal y digestivo en la infección por SARS-CoV-2. Los mecanismos patológicos en tejido renal y en intestino causados por la infección por SARS-CoV-2 son propios del tropismo viral por células de estos sistemas y de los mecanismos citopáticos de etapa lítica de la infección, con una liberación continua de viriones que favorece la generación de un entorno inflamatorio con la consecuente secreción descontrolada de citoquinas proinflamatorias que conducen a la infección entérica del intestino y a las alteraciones en el riñón.

Abstract Infection with Severe Acute Respiratory Syndrome (SARS-CoV-2) has caused one of the largest epidemiological emergencies in the last 10 years and its pathological effects are still studied. Due to the aforementioned, it is important to describe the mechanisms associated with renal and digestive compromise in SARS-CoV-2 infection. The pathological mechanisms in kidney tissue and in the intestine caused by SARS-CoV-2 infection are characteristic of the viral tropism by cells of these systems and of the lymphocytic mechanisms of the lytic stage of the infection, with a continuous release of virions that favors the generation of an inflammatory environment with the consequent uncontrolled secretion of proinflammatory cytokines that lead to enteric infection of the intestine and alterations in the kidney.

Role of SARS-CoV-2 neurotropism and neuroinvasion in COVID-19 patients disease severity / Papel del neurotropismo y neuroinvasión de SARS-CoV-2 en la gravedad de los pacientes con COVID-19

Abstract The disease caused by the new SARS-CoV-2 coronavirus (COVID-19) spread rapidly from China to the entire world. Approximately one third of SARS-CoV-2-infected patients have neurological disorders, especially those classified as severe cases and that require mechanical ventilation. On the other hand, almost nine out of 10 patients admitted to an Intensive Care Unit could not breathe spontaneously, thus requiring invasive and non-invasive ventilatory support. So far, whether early neurological disorders such as hyposmia or anosmia, dysgeusia or ageusia, headache and vertigo are significant in the progression to the severe form of the disease or whether they are related to entry to the central nervous system via peripheral nerves has not been determined. Considering the great similarity between SARS-CoV and SARS-CoV-2, and that the severity of the condition that leads to death cannot be explained solely by lung involvement, it is important to determine whether SARS-CoV-2 potential invasion to the central nervous system is partially responsible for the severe respiratory component observed in patients with COVID-19.

Resumen La enfermedad (COVID-19) producida por el nuevo coronavirus SARS-CoV-2 se extendió rápidamente desde China a todo el mundo. Aproximadamente una tercera parte de los pacientes infectados de SARS-CoV-2 presenta alteraciones neurológicas, con mayor frecuencia los clasificados como graves que requirieron ventilación mecánica. Por otro lado, casi nueve de cada 10 pacientes admitidos en una unidad de cuidados intensivos no podían respirar espontáneamente, por lo que ameritaron apoyo ventilatorio invasivo y no invasivo. Hasta el momento no se ha determinado si las alteraciones neurológicas tempranas como la hiposmia o anosmia, disgeusia o ageusia, cefalea y vértigo son significativas en la progresión a la forma grave de la enfermedad y se relacionan con la entrada al sistema nervioso central a través de los nervios periféricos. Considerando la gran similitud entre SARS-CoV y SARS-CoV-2 y que la severidad del cuadro que conduce a la muerte no puede ser explicado únicamente por la afección pulmonar, es importante determinar si la invasión potencial del SARS-CoV-2 al sistema nervioso central es parcialmente responsable del componente respiratorio severo que presentan los pacientes con COVID-19.

Cutaneous susceptibility to SARS-CoV-2 infection according to the expression of viral entry factors in the skin / Susceptibilidad cutánea a la infección por SARS-CoV-2 según la expresión de los factores de entrada viral en la piel

Abstract Introduction: Reports of dermatological manifestations in patients with COVID-19 suggest a possible cutaneous tropism of SARS-CoV-2; however, the capacity of this virus to infect the skin is unknown. Objective: To determine the susceptibility of the skin to SARS-CoV-2 infection based on the expression of viral entry factors ACE2 and TMPRSS2 in this organ. Method: A comprehensive analysis of human tissue gene expression databases was carried out looking for the presence of the ACE2 and TMPRSS2 genes in the skin. mRNA expression of these genes in skin-derived human cell lines was also assessed. Results: The analyses showed high co-expression of ACE2 and TMPRSS2 in the gastrointestinal tract and kidney, but not in the skin. Only the human immortalized keratinocyte HaCaT cell line expressed detectable levels of ACE2, and no cell line originating in the skin expressed TMPRSS2. Conclusions: Our results suggest that cutaneous manifestations in patients with COVID-19 cannot be directly attributed to the virus. It is possible that cutaneous blood vessels endothelial damage, as well as the effect of circulating inflammatory mediators produced in response to the virus, are the cause of skin involvement.

Resumen Introducción: Reportes de manifestaciones dermatológicas en pacientes con COVID-19 sugieren un posible tropismo cutáneo del virus SARS-CoV-2; sin embargo, se desconoce la capacidad de este virus para infectar la piel. Objetivo: Determinar la susceptibilidad de la piel a la infección por SARS-CoV-2 con base en la expresión de los factores de entrada viral ACE2 y TMPRSS2 en dicho órgano. Método: Se buscaron los genes ACE2 y TMPRSS2 en la piel, para lo cual se realizó un análisis extenso de las bases de datos de expresión genética en tejidos humanos. Asimismo, se evaluó la expresión de dichos genes en líneas celulares humanas derivadas de la piel. Resultados: Los análisis mostraron alta expresión conjunta de ACE2 y TMPRSS2 en el tracto gastrointestinal y en los riñones, pero no en la piel. Solo la línea celular de queratinocitos humanos inmortalizados HaCaT expresó niveles detectables de ACE2 y ninguna línea celular de origen cutáneo expresó TMPRSS2. Conclusiones: Los resultados sugieren que las manifestaciones dermatológicas en pacientes con COVID-19 no pueden ser atribuidas directamente al virus; es posible que sean originadas por el daño endotelial a los vasos sanguíneos cutáneos y el efecto de los mediadores inflamatorios circulantes producidos en respuesta al virus.

Nicotinamide activates latent HIV-1 ex vivo in ART suppressed individuals, revealing higher potency than the association of two methyltransferase inhibitors, chaetocin and BIX01294

ABSTRACT Background: Latent HIV-1 is a major hurdle in obtaining HIV-1 sustained virological remission (SVR). Here we explored histone deacetylation inhibition property of nicotinamide (NAM; n = 17) for the first time in comparison to a combination of methyltransferase inhibitors (MTIs; Chaetocin and BIX01294; n = 25) to reactivate latent HIV ex vivo in CD8-depleted PBMCs from antiretroviral treated aviremic individuals. Results: NAM reactivated HIV-1 from 13/17 (76.4%) samples compared to 20/25 (80.0%) using MTIs with mean viral load (VLs) of 4.32 and 3.22 log10 RNA copies/mL, respectively (p = 0.004). Mean purging time after NAM and MTIs stimulation was 5.1 and 6.75 days, respectively (p = 0.73). Viral purging in autologous cultures exhibited blunted HIV recovery with fluctuating VLs followed by a complete viral extinction when expanded in allogenic system. Electron microscopy from five supernatants revealed anomalous viral particles, with lack of complete viral genomes when characterized by ultradeep sequencing through metagenomics approach (n = 4). Conclusion: NAM alone was more potent HIV-1 activator than combination of MTIs, with potential of clinical use.

Profile of HIV subtypes in HIV/HBV- and HIV/HCV-coinfected patients in Southern Brazil

Abstract INTRODUCTION: HIV and viral hepatitis infections are major causes of chronic disease worldwide and have some similarities with regard to routes of transmission, epidemiology, front barriers faced during access of treatment, and strategies for a global public health response. The objective was to describe the HIV-1 subtypes, viral tropism and single-nucleotide polymorphisms (SNPs) of interleukin 28B (IL28B) from a case series of HIV/viral hepatitis coinfected patients from southern Brazil. METHODS: Clinical and epidemiological data were evaluated by a review of medical records. Periodic blood draws were taken to determine the viral and host characteristics. RESULTS: This study included 38 patients with HIV/HBV or HIV/HCV coinfection; the median age was 49 years. Thirty-seven (97.4%) were on antiretroviral therapy, 32 (84.2%) had an undetectable viral load, a median CD4+ T-cell count of 452 cells/mm3. HIV-1 subtyping showed 47.4 and 31.6% of patients with subtypes C and B, respectively. Analysis of viral co-receptor usage showed a predominance of the R5 variant (64.7%), with no significant difference between the subtypes. Twenty patients with HIV/HCV coinfection were eligible to receive HCV therapy with pegylated-interferon-alpha plus ribavirin, and 10/20 (50%) of them achieved sustained virological response. SNPs of IL28B were evaluated in 93.3% of patients with HIV/HCV coinfection, and 17 (60.7%) presented the CC genotype. CONCLUSIONS: In the present case series, a higher frequency of HIV subtype C was found in coinfected patients. However such findings need to be prospectively evaluated with the inclusion of data from regional multicenter analyses.

Eficacia y seguridad del uso de maraviroc para el tratamiento de VIH-1 con tropismo ccr5 positivo, en pacientes multidrogorresistentes en estadio sida / Efficacy and safety of the use of maraviroc for the treatment of HIV-1 with ccr5 positive tropism in multidrug-resistant patients in AIDS stage

INTRODUCCIÓN: Antecedentes: El presente dictamen presenta la evaluación de tecnología de la eficacia y seguridad de maraviroc para el tratamiento de pacientes infectados con VIH01 con tropismo CCR5 positivo, multidrogorresistentes, en estadio SIDA. Aspectos Generales: Hacia el final de 2014, alrededor de 36.9 millones de personas en el mundo vivian con VIH. De estas, aproximadamente 1.2 millones murieron por causas relacionadas al VIH ese mismo año. Las terapias antirretrovirales han permitido reducir el número de muertes en un 42% desde el 2004. Tecnología Sanitaria de Interés: Maraviroc es un antagonista del receptor de quimoquina C-Ctipo 5 (CCR5 por sus siglas en inglés) en las membranas de los linfocitos CD4. El receptor CCR5, junto con el receptor de quimioterapina C-X-C tipo 4 (CXCR4 por sus siglas en inglés), son los co´receptores más relevantes en la infección con VIH-1, ya que permiten la fusión de las membranas celular y viral, y la consecuente entrada del ARN viral al citoplasma. METODOLOGIA: Se llevó a cabo una búsqueda de la literatura con respecto a la eficacia y seguridad de maraviroc para el tratamiento de VIH-1 con tropismo CCR5 positivo, en pacientes multidrogorresistentes en las bases de datos de PubMed, TRIPDATABASE y www.clinicaltrials.gov. Adicionalmente, se realizó una búsqueda de evaluaciones de tecnologías y guías de práctica clínica en las páginas web de gruposdedicados a la investigación y educación en salud en general como The National Institute for Health and Care Excellence (NICE) y The USA Department of human and health services (DHHS); y especializados en VIH como The British HIV Association (BHIVA), The International \r\nAntiviral Society (IAS), The British Columbia Centre for Excellence in HIV/AIDS (BC-CfE) y The European AIDS Clinical Society. RESULTADOS: Sinopsis de la Evidencia: se llevó a cabo una búsqueda de evidencia científica relacionada al uso de maraviroc como tratamiento de pacientes infectados con VIH-1 con tropismo CCR5, multidrogorresistentes y en estadio SIDA. En la presente sinopsis se describe la evidencia disponible según el tipo de publicación, siguiendo lo indicado en los criterios de elegibilidad (GPC, ETS, RS, MA y ECA fase III). CONCLUSIONES: A la fecha (Mayo 2016) no existe evidencia de ensayos clínicos en fase III que \r\ncomparen directamente la eficacia y seguridad de maraviroc vs enfuvirtide en la población de pacientes con SIDA, multidrogorresistentes e infectados con VIH-1 con tropismo CCR5 positivo. Sin embargo, se toma como evidencia indirecta dos ensayos clínicos multicéntricos de fase III que evaluaron la eficacia y seguridad de maraviroc en comparación con placebo, y un posterior análisis de sub-grupo de los mismos, así como estudios sobre los eventos adversos relacionados al uso de enfuvirtide. El Instituto de Evaluación de Tecnologías Sanitarias-IETSI, aprueba por el periodo de 2 años a partir de la fecha de publicación del presente \r\nFiesT Es. dictamen preliminar, el uso de maraviroc para el tratamiento de pacientes infectados con VIH-1 con tropismo CCR5 positivo, multidrogorresistentes y en estadio SIDA, ya que se ha demostrado su eficacia en dicha sub-población de pacientes con VIH-1, y representa un beneficio para la calidad de vida de estos pacientes y un menor costo para la institución.

Zika virus damages the human placental barrier and presents marked fetal neurotropism

An unusually high incidence of microcephaly in newborns has recently been observed in Brazil. There is a temporal association between the increase in cases of microcephaly and the Zika virus (ZIKV) epidemic. Viral RNA has been detected in amniotic fluid samples, placental tissues and newborn and fetal brain tissues. However, much remains to be determined concerning the association between ZIKV infection and fetal malformations. In this study, we provide evidence of the transplacental transmission of ZIKV through the detection of viral proteins and viral RNA in placental tissue samples from expectant mothers infected at different stages of gestation. We observed chronic placentitis (TORCH type) with viral protein detection by immunohistochemistry in Hofbauer cells and some histiocytes in the intervillous spaces. We also demonstrated the neurotropism of the virus via the detection of viral proteins in glial cells and in some endothelial cells and the observation of scattered foci of microcalcifications in the brain tissues. Lesions were mainly located in the white matter. ZIKV RNA was also detected in these tissues by real-time-polymerase chain reaction. We believe that these findings will contribute to the body of knowledge of the mechanisms of ZIKV transmission, interactions between the virus and host cells and viral tropism.

High degree of concordance between flow cytometry and geno2pheno methods for HIV-1 tropism determination in proviral DNA

Use of CCR5 antagonists requires previous viral tropism determination. The available methods have high cost, are time-consuming, or require highly trained personnel, and sophisticated equipment. We compared a flow cytometry-based tropism assay with geno2pheno method to determine HIV-1 tropism in AIDS patients, in Bahia, Brazil. We tested peripheral blood mononuclear cells of 102 AIDS patients under antiretroviral therapy by using a cytometry-based tropism assay and geno2pheno assay. Cellular membrane receptors were identified by using CXCR4, CCR5 and CD4 monoclonal antibodies, while detection of cytoplasmic mRNAs for gag and pol HIV regions was achieved by using a labeled probe. Genotypic identification of X4 and R5 tropic viruses was attempted by geno2pheno algorithm. There was a high degree of concordance between cytometry-based tropism assay and geno2pheno algorithm in determination of HIV-1 tropism. Cytometry-based tropism assay demonstrated higher sensitivity and specificity in comparison to geno2pheno, which was used as a gold-standard. One sample could not be amplified by geno2pheno method, but was classified as duotropic by cytometry-based tropism assay. We did not find any association between CD4+ count or plasma HIV-1 RNA viral load and tropism results. The overall performances of cytometry-based tropism assay and geno2pheno assay were almost identical in determination of HIV-1 tropism.

Determination o viral tropism by genotyping an phenotyping assays in Braziliaan hiv-1-infected patients / Determinação do tropismo viral por ensaios genotípicos e fenotípicos em pacientes brasileiros infectados por HIV-1

The clinical application of CCR5 antagonists involves first determining the coreceptor usage by the infecting viral strain. Bioinformatics programs that predict coreceptor usage could provide an alternative method to screen candidates for treatment with CCR5 antagonists, particularly in countries with limited financial resources. Thus, the present study aims to identify the best approach using bioinformatics tools for determining HIV-1 coreceptor usage in clinical practice. Proviral DNA sequences and Trofile results from 99 HIV-1-infected subjects under clinical monitoring were analyzed in this study. Based on the Trofile results, the viral variants present were 81.1% R5, 21.4% R5X4 and 1.8% X4. Determination of tropism using a Geno2pheno[coreceptor] analysis with a false positive rate of 10% gave the most suitable performance in this sampling: the R5 and X4 strains were found at frequencies of 78.5% and 28.4%, respectively, and there was 78.6% concordance between the phenotypic and genotypic results. Further studies are needed to clarify how genetic diversity amongst virus strains affects bioinformatics-driven approaches for determining tropism. Although this strategy could be useful for screening patients in developing countries, some limitations remain that restrict the wider application of coreceptor usage tests in clinical practice.

A aplicação clínica dos antagonistas de CCR5 envolve em primeiro lugar determinar o uso de co-receptor pela cepa viral infectante. Programas de bioinformática que prevêem o uso co-receptor poderiam fornecer um método alternativo para selecionar candidatos para o tratamento com os antagonistas do CCR5, particularmente em países com poucos recursos financeiros. Assim, o presente estudo teve por objetivo identificar a melhor abordagem utilizando ferramentas de bioinformática para determinar qual o tipo de co-receptor do HIV-1 que poderia ser usado na prática clínica. Sequências de DNA proviral e Trofile resultados a partir de 99 pacientes infectados pelo HIV-1 sob monitorização clínica foram avaliadas. Com base nos resultados do Teste Trofile, as variantes virais presentes eram R5 (81,1%), R5X4 (21,4%) e X4 (1,8%). Determinação do tropismo pela análise do Geno2pheno, com taxa de falso positivos de 10% apresentou desempenho mais adequado para esta amostragem: as cepas R5 e X4 foram encontradas em frequências de 78,5% e 28,4%, respectivamente, e foi de 78,6% a concordância entre os resultados fenotípicos e genotípicos. Mais estudos são necessários para esclarecer como a diversidade genética entre as cepas do vírus afeta abordagens baseadas na determinação do tropismo pelas ferramentas de bioinformática. Embora esta estratégia possa ser útil para o rastreio de pacientes em países em desenvolvimento, permanecem algumas limitações que restringem a aplicação mais ampla para utilização de testes de co-receptor na prática clínica.

Association of X4 tropism with disease progression in antiretroviral-treated children and adolescents living with HIV/AIDS in São Paulo, Brazil

Management of children with HIV/AIDS is specially challenging. Age-related issues do not allow for direct transposition of adult observations to this population. CXCR4 tropism has been associated with disease progression in adults. The geno2pheno web-base is a friendly tool to predict viral tropism on envelope V3 sequences, generating a false positive rate for a CXCR4 prediction. We evaluated the association of HIV-1 tropism prediction with clinical and laboratory outcome of 73 children with HIV/AIDS in São Paulo, Brazil. The CXCR4 tropism was strongly associated with a lower (nadir) CD4 documented during follow-up (p < 0.0001) and with disease severity (clinical event and/or CD4 below 200 cells/mm3) at the last observation, using commonly applied clinical cutoffs, such as10%FPRclonal (p = 0.001). When variables obtained during follow-up are included, both treatment adherence and viral tropism show a significant association with disease severity. As for viremia suppression, 30% (22/73) were undetectable at the last observation, with only adherence strongly associated with suppression after adjustment. The study brings further support to the notion that antiretroviral treatment adherence is pivotal to management of HIV disease, but suggests that tropism prediction may provide an additional prognostic marker to monitor HIV disease in children.

Avaliação da resposta à terapia antirretroviral de resgate contendo antagonista do correceptor CCR5 em pessoas vivendo com HIV/AIDS / Assessment of antiretroviral salvage therapy response to CCR5 co-receptor antagonist containing regimen in people living with HIV/AIDS

O presente estudo apresenta um novo algoritmo de ferramentas de bioinformática capaz de determinar de forma robusta o tropismo do HIV analisando sequências da região V3 do envelope viral. O critério ...A análise do tropismo viral usando a genotipagem da V3 e o Critério IAL foi empregada em 157 pacientes do Programa Estadual de Aids de São Paulo, que necessitavam de terapia de resgate, dos anos de 2008 a 2012. Foram detectados, 89 pacientes com tropismo HIV para o correceptor CCR5 (R5) e 68 CXCR4 (X4). Com base nestes resultados foi estabelecido o esquema terapêutico pelo médico e comissão estadual, e indicado antagonista do CCR5 (maraviroque–MQV) para alguns pacientes.Em 73 casos (41R5 e 32X4) foi possível obter o desfecho clínico, levando em consideração dados virológicos e imunológicos. Foi calculada a pontuação.....Houve aumento de células T CD4+ de mais de 100 células/mm3 de sangue quando comparado ao baseline em 76% dos pacientes: 86% do Grupo 1, 75% do Grupo 2 e 69% do Grupo 3. O grupo 1 apresentou o menor nadir e o maior aumento de células T CD4, embora semsignificância estatística. Não houve diferença na pontuação de drogas entre os Grupos 1 e 2 (2,75 – 2,38), mas quando foi retirado o MQV da análise, houve queda da pontuação do Grupo 1 com valores semelhantes ao Grupo 3 (1,75–2). Concluindo, o Critério IAL para determinar o tropismo HIV se mostrou mais sensível e específico que as ferramentas de bioinformática isoladamente e com sensibilidade e especificidade semelhantes ao ensaio de imunofenotipagem, sendo considerado útil na indicação do melhor esquema terapêutico de resgate ao paciente. O estudo longitudinal com MQV mostrou ser esta uma boa opção terapêutica em pacientes com vírus R5.

HI-1 viral tropism is an important phenotypic characteristic may be classified as CCR5 tropic, CXCR4 tropic or dual tropic. As phenotypic assays are complex and expensive, genotypic prediction has been largely used. This study presents a new bioinformatics algorithm capable of robustly determining the tropism of HIV analyzing sequences of V3 region of the viral envelope tools. The criterion, .... The analysis of viral tropism using the V3 genotyping and IAL Criterion was used in 157 patients with advance disease in Sao Paulo from 2008 to 2012. CCR5 HIV tropism (R5) was predicted for 89 patients and X4 in 68. Based on these results, the therapeutic regimen was established by the physician and state commission. In 73 cases (41R5 and 32X4) it was possible to obtain the clinical outcome, including virological and immunological data. Scores of salvage ...There was an increase of more than 100 cells/mm3 of blood CD4cells when compared to baseline in 76% of patients: 86% of group 1, 75% in group 2 and 69 % of Group 3. Group 1 had the lowest nadir and the highest increase of CD4 + cells, although without statistical significance. There was no difference in the scores of drugs between Groups 1 and 2 (2.25 - 3), but when MQV was removed from the analysis, there was a drop in the scores of Group 1 with values similar to Group 3 (1.25-2). In conclusion, the IAL criterion to determine HIV tropism was more sensitive and specific than the tools of bioinformatics alone and showing comparable results to that of the phenotype, and its use to predict viral tropism allowed the use MQV for some R5 patients. Its use as part of salvage therapy showed a good therapeutic response suggesting that the test was useful in predicting CCR5 antagonist drug activity.

Predição do tropismo viral do HIV-1 utilizando plasma e célula em amostras de sangue de pessoas vivendo com HIV/AIDS / Prediction of HIV-1 viral tropism using plasma and cell from blood sample from people living with HV/AIDS

O HIV-1 geralmente utiliza o receptor CD4 em conjunto com um correceptor principal, CCR5 ou CXCR4, na etapa fundamental de entrada na célula hospedeira, determinando assim o tropismo viral por células que expressam estas moléculas. Diferenças no tropismo de HIV-1 têm contribuído para a compreensão da patogênese do HIV e são necessárias para suportar a decisão médica em relação ao uso de antagonistas do CCR5. O teste fenotípico de tropismo determina diretamente esta característica biológica, porém os custos e a complexidade restringem a sua utilização, sendo assim, a predição genotípica tem sido proposta como uma alternativa. O objetivo desse estudo foi padronizar e avaliar um teste de predição genotípica do tropismo. Foi adaptado para o nosso laboratório o protocolo desenvolvido pelo Centro de Excelência em HIV/Aids da Columbia Britânica (CECB)usando sequência em replicatas, avaliamos os parâmetros que possam influenciar na predição do tropismo e comparamos a predição na célula e no plasma. Produtos de PCR e plasma enviados pelo CECB foram sequenciados e analisados de forma independente no CECB e no IAL, com alta concordância. Sequências da V3 do envelope viral de 81 pacientes com consentimento informado mostraram uma correlação entre o número de ambiguidades e o menor valor de FPR, uma tendência a ter uma maior distância genética inter-sequência entre os isolados preditos como X4 e sem correlação entre o número de repetições de sequências e o menor FPR. Estudamos também diferenças na origem do material genético viral (RNA viral ou DNA pró-viral) e sua influência sobre a predição de tropismo. Em 56 amostras pareadas observou-se uma tendência na ocorrência de mais X4 em DNA pró-viral de células. Nós observamos maior distância genética entre as sequências de célula em comparação com as de plasma, e documentamos as discrepâncias na determinação do tropismo viral utilizando diferentes cut offs de uso clínico. Nosso trabalho permitiu o desenvolvimento...

Relevancia del CCR5 co-receptor del HIV-1 y su ligando CCL3L1 en el tropismo viral en pediatría / Relevance of the CCR5 co-receptor of HIV-1 and its ligand CCL3L1 in viral tropism in pediatrics

El objetivo del trabajo fue determinar la participación del coreceptor CCR5 y su ligando CCL3L1 en relación a una de las características del fenotipo del HIV-1, el tropismo viral. Los resultados que obtuvimos así como otras investigaciones que estamos desarrollando tienen implicancias clínicas y terapéuticas en los niños HIV-1 infectados. Para lograr el objetivo hemos evaluado en forma conjunta y combinada los datos que habíamos obtenido a lo largo de casi 15 años en relación a las variantes genéticas del CCR5, en particular la mutación Δ32 y su ligando CCL3L1 en función del número de copias del gen en los niños HIV-1 infectados por transmisión vertical que son asistidos en el Hospital Garrahan, investigando la probable asociación de ellas con el tropismo viral. Hallamos que los niños en primoinfección tienen una proporción considerable de variantes HIV-1 SI que emplean como co-receptor al CXCR4 en lugar del CCR5. Otro hecho relevante fue que la presencia de las variantes SI predominaron en los niños heterocigotas para la variante genética CCR5Δ32. En este último grupo encontramos además que estaba significativamente asociado con un número de copias del CCL3L1 alto (≥2). Probablemente ambos factores participan favoreciendo la reducción en el número de moléculas del co-receptor CCR5 expresadas en la superficie celular facilitado la infección por las variantes X4. Aunque las variantes SI en la etapa crónica alcanzan a un 40% no parecieran asociadas con el genotipo CCR5Δ32 ni con el número de copias del CCL3L1. En resumen, hemos demostrado que las variantes SI X4 T-trópicas del HIV-1 pueden estar presentes en los estadios muy tempranos de la infección viral sugiriendo que puede ser transmisible verticalmente. Además, el genotipo CCR5Δ32 en el contexto de copias altas del CCL3L1 en el niño HIV-1 infectado, contribuyen a un mayor riesgo a ser infectado por variantes SI en primoinfección. Este hecho no pareciera suceder en la etapa crónica de la infección viral.

The aim of the study was to assess the role of co-receptor CCR5 and its ligand CCL3L1 in viral tropism, one of the char-acteristics of the HIV-1 phenotype. The results of this study as well as those found in our other ongoing research have clini-cal and therapeutic consequences for HIV-1 Infected children. For the aim of the study we collected and evaluated the data obtained over a period of almost 15 years on genetic variants of CCR5, specially the 32 mutation and its ligand CCL3L1 (MIP-1 P), in relation to the number of copies of the gene in HIV-1-mother-to-child infected children seen at the pediatric hospital J.P. Garrahan, to investigate a probable association with viral tropism. We found that children with a primary in-fection have a considerable number of HIV-1 SI (syncytium-inducing, i.e. cytopathic) variants that use CXCR4 instead of CCR5 as a co-receptor. Another relevant finding was that SI variants were predominant in children that were homozygous for the genetic CCR5 32 variant. In this latter group we additionally found that this was significantly associated with a high number of CCL3L1 copies ( 2). Both factors may play a favorable role in the decrease of the number of molecules of the CCR5 co-receptor expressed on the cell surface that facilitate infection through X4 variants. Although in the chronic stage SI variants reach 40%, they do not seem to be associated with either the CCR5 32 genotype or the number of CCL3L1 copies. In sum-mary, we have shown that SI X4 T-tropic variants of HIV-1 may be present in very early stages of viral infection suggesting that they may be transmitted from mother to child. In addition, the CCR5 32 genotype in the setting of a high number of CCL3L1 copies in an HIV-1 infected child contribute to a higher risk of being infected by SI variants in primary infection, however, this mechanism does not seem to occur in the chronic stage of viral infection.

HIV-1 tropism and CD4 T lymphocyte recovery in a prospective cohort of patients initiating HAART in Ribeirão Preto, Brazil

While human immunodeficiency virus (HIV)-1 chemokine co-receptors 5 tropism and the GWGR motif in the envelope third variable region (V3 loop) have been associated with a slower disease progression, their influence on antiretroviral response remains unclear. The impact of baseline V3 characteristics on treatment response was evaluated in a randomised, double blind, prospective cohort study with patients initiating highly active antiretroviral therapy with lopinavir or efavirenz plus azithothymidine/3TC (1:1) over 48 weeks. Similar virological and immunological responses were observed for both treatment regimens. The 43 individuals had a mean baseline CD4 T cell count of 119 cells/mm³ [standard deviation (SD) = 99] and a mean viral load of 5.09 log10 copies/mL (SD = 0.49). The GWGR motif was not associated with a CD4 T cell response, but predicted R5 tropism by the geno2pheno[clinical20 percent] algorithm correlated with higher CD4 T cell levels at all monitoring points (p < 0.05). Moreover, higher false-positive rates (FPR) values from this analysis revealed a strong correlation with CD4 T cell recovery (p < 0.0001). Transmitted drug resistance mutations, documented in 3/41 (7.3 percent) cases, were unrelated to the assigned antiretroviral regimen and had no impact on patient outcomes. In conclusion, naÏve HIV-1 R5 infected patients exhibited higher CD4 T cell counts at baseline; this difference was sustained throughout therapy. The geno2pheno[clinical] option FPR positively correlated with CD4 T cell gain and may be useful in predicting CD4 T cell recovery.