Biomarcadores de translocação microbiana, inflamação e risco cardiovascular em indivíduos infectados pelo HIV

Abstract

Cardiovascular disease is classified as a major cause of morbidity and mortality in HIV-infected individuals. Evidence indicates that systemic inflammation and chronic immune activation are related to increased cardiovascular risk. Some studies have suggested that these mechanisms can be triggered by microbial translocation products from the gut to the systemic circulation, due to damage on intestinal epithelium, during the progression of HIV infection. The identification of the risk for the development of cardiovascular diseases using soluble biomarkers proves to be an important tool to assist physicians in the early treatment of HIVinfected individuals. Therefore, this study aimed to investigate the possible relationships between the biomarkers of microbial translocation, inflammation and cardiovascular risk in HIV-infected individuals. This research was divided into two stages. In the first stage a systematic review was carried, with the purpose of: i) synthesize the available evidence in the literature on the most widely used soluble biomarkers of microbial translocation, inflammation and cardiovascular risk and ii) evaluate the possible associations between them in HIV-infected individuals. Based on the results of the systematic review, the research strategy for the second stage of this doctoral thesis was developed. In the second stage, a quantitative study was performed with venous blood collection and laboratory tests of HIV-infected individuals. This stage of the work presented as a criterion to evaluate the plasma biomarkers in HIV infected individuals in different situations: i) risk of developing cardiovascular disease; ii) immunological status; iii) therapeutic regimen used and iv) time of HIV infection. The results of the present study demonstrated considerable relationships among the biomarkers that can be inserted in the diagnosis of the clinical laboratory, aiming at the interconnection between microbial translocation, inflammation and cardiovascular risk. High sensitivity C-reactive protein (hs-CRP) was the biomarker that showed a greater association with the other biomarkers, both in the systematic review and in the quantitative research. However, the plasma levels of myeloperoxidase (MPO) had no relation with the biomarkers of microbial translocation (direct and indirect). Therefore, prospective longitudinal studies are necessary for the insertion of the relationships between these biomarkers in the laboratory follow-up of HIVinfected individuals.