INSA - Dissertações de mestrado
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- Conhecer a epidemiologia da infeção por vírus da imunodeficiência humana tipo 2 (VIH-2) em indivíduos residentes em Portugal: o que mudou nas últimas décadas?Publication . Mendes, Inês Filipa Santos; Pádua, Elizabeth; Piedade, JoãoThe main objectives of this study were to analyse the epidemiological evolution of HIV-2 infection in Portugal using demographic, clinical and laboratory data corresponding to samples from HIV-2-infected parturients received at INSA, and to conduct the molecular characterisation of HIV-2 in a convenience sample, focusing on the phylogenetic classification of viruses and identification of resistance mutations. The analysis of the overall sample received at the laboratory between 2006 and 2023 was based on known demographic and clinical data. The molecular analysis of HIV-2 was performed on selected samples, subjected to DNA extraction, nested-PCR amplification of the PR-RT and IN regions of the pol gene and the amplified samples sequenced by the Sanger method. The results obtained were discovered with several bioinformatics programs, the respective phylogenetic trees were constructed and the search for resistance mutations was carried out with available international databases. An analysis of data from samples of the total population (n=183) revealed that 16.6% of the parturients infected with HIV-2 were Portuguese, but there was a clear predominance of women born in Africa (83.4%), mostly in Guinea-Bissau and in the age group of 30-39 years. Between 2006 and 2023, an apparent general improvement in the immunological situation was observed, with an increase in the proportion of women with CD4+ T cells above 500 cells/μL and an increase in the rate of adherence to ART during pregnancy (56.2% to 64.0%), which was higher among African women (69.6%) compared to Portuguese women (66.7%). Over time, a transition from ART regimens containing only NRTI to NRTI regimens combined with INSTI was achieved, and between 2018 and 2023, this regimen was prescribed to 56.5% of parturients. The analysis of the selected convenience sample (n=99) proved to be representative of the total samples received in the laboratory between 2011 and 2023, for the demographic and clinical variations analysed. Amplification was successful in 48.5% of the samples for PR-RT and 46.5% of the samples for IN, with all sequences phylogenetically in HIV-2 group A and excluded of cluster A2. It was observed that 12 sequences derived from samples of 12 women presented mutations of interest, namely, in 7 of 45 sequences of the RT group and in 5 of 35 sequences of the IN group. Three sequences from each group presented accessory mutations associated with a possible reduction in susceptibility to antiretrovirals (I75V, V111I and F214L in RT and I84V, A153S in IN). However, resistance mutations were identified in 4 RT sequences and 2 IN sequences (K70R, Q151M, M184V and S215Y in RT and R263K and N155H in IN). This study revealed the need for greater efforts to implement measures to increase adherence to ART, as well as screening for HIV-2 infection, to prevent transmission and improve clinical outcomes in patients. The results produced in this study may contribute to updating knowledge about the epidemiological and molecular characteristics of HIV-2 in Portugal, as well as evidence of the existence of resistance mutations with an impact on the treatment of the infection.