Dinamica Viral do Subtipo B do HIV-1 Brasileiro / Viral Dinamic Of Brazilian HIV-1 Subtype B

Analises do comportamento da viremia plasmatica apos a introducao de esquemas terapeuticos contendo associacoes de drogas potentes tem sido alvo de estudos, os quais conduziram a importantes informacoes sobre o comportamento do HIV-1 quando exposto a estas drogas. Nesta pesquisa, foram avaliados dez pacientes infectados pelo subtipo B brasileiro, nunca expostos a drogas anti-retrovirais, com o objetivo de avaliar possiveis diferencas na resposta virologica dos mesmos em comparacao aos estudos publicados anteriormente, os quais avaliaram o subtipo B americano. Usou-se o esquema terapeutico mais potente disponivel no momento do estudo, baseados em dados mais recentes de avaliacao da supressao viral, tendo como resultado curvas de decaimento estremamente semelhantes aos resultados de estudos previamente publicados, com queda importante destas particulas virais nas primeiras duas semanas de tratamento, correspondendo a eliminacao de particulas virus livres e a perda de celulas produtivamente infectadas, com valor medio de decaimento de 2,51logs na maioria dos pacientes estudados, seguidos por um declinio mais lento, correspondendo a manutencao da eliminacao de virions pelos reservatorios virais. Conclui-se com este estudo, o ja comprovado anteriormente, que esquemas mais potentes causam declinios mais rapidos da viremia plasmatica devido a acao destes nos compartimentos infectados pelo HIV-1.

Estimating the length of the first antiretroviral therapy regiment durability in Säo Paulo, Brazil

Brazil was the first country to provide unrestricted, cost-free access to antiretroviral (ARV) medicine for AIDS treatment. However, there is little data about the benefits of such a policy for these patients. We evaluated the duration of benefit obtained with the introduction of ARVs, defined as the durability of the first ARV regiment. We reviewed the medical charts of patients attended from 1996-2000, at the outpatient clinics of the Federal University of Säo Paulo, Brazil. A total of 120 drug-naive HIV-1 infected patients were eligible to participate in the study. About half of the individuals (53 percent) presented with disease symptoms; 59 percent of them had CD4 count below 200 cells/mm³. Mean estimated duration of the benefit of therapy was 14.1 months. The most used regimen in this cohort was Zidovudine/3TC/Indinavir (26 percent), followed by Zidovudine/DDI (17 percent), and Zidovudine/3TC/Nelfinavir (13 percent). The most frequent cause of interruption of therapy was gastrointestinal intolerance. Use of treatment regimens with three drugs was more effective than with two drugs, but only for patients with CD4<200 cells/mm³ or CV>100,000 copies RNA/mL. However, the use of triple therapy was associated with a significantly higher probability of reaching maximum viral suppression, during a longer period (p<0.05).The patients enrolled in the study benefitted from therapy for a limited time, after the introduction of double or triple antiretroviral therapy. The incidence of adverse events was significantly associated with loss of the benefits provided by the initial therapeutic regimen.