Perpetua Gomes

Prof. Perpetua Gomes

Instituto Universitário Egas Moniz - IUEM
+1
orcid

Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 August 2016 in Journal of Clinical Virology
Verified
Journal Article
Open access
VKVladimir Kartashev
Vladimir Kartashev
MDMatthias Döring
Matthias Döring
LNLeonardo Nieto
Leonardo Nieto
ECEleda Coletta
Eleda Coletta
RKRolf Kaiser
Rolf Kaiser
THT. Haque
T. Haque
HCV affects 185 million people worldwide and leads to death and morbidities. HCV has a high genetic diversity and is classified into seven genotypes and 67 subtypes. Novel anti-HCV drugs (Direct-Acting-Antivirals) eligibility, resistance and cure rates depend on HCV geno/subtype (GT). Analysis of epidemiological information and viral GT from patients undergoing viral genotyping in 2011-2015. Anonymized information from 52 centers was analyzed retrospectively. 37,839 samples were included in the study. We show that the GT distribution is similar throughout Western European countries, with some local differences. Here GTs 1 and 2 prevalences are lower and of GT4 higher than in all previous reports. Israel has a unique GT pattern and in South Russia the GT proportions are more similar to Asia. GTs 5 and 6 were detected in very low proportions. Three cases of the recombinant genotype P were reported in Munich (Germany). In addition, we observed that GT proportion was dependant on patientś gender, age and transmission route: GTs 1b and 2 were significantly more common in female, older, nosocomially-infected patients, while GTs 1a, 3 and 4 were more frequent in male, younger patients infected by tattooing, drug consume, and/or sexual practices. In infections acquired by drug consume, GTs 1a (35.0%) and 3 (28.1%) prevailed. In infections related to sexual practices lower proportion of GT3 (14.0%) and higher of GT4 (20.2%) were detected. GT4 was mostly abundant in MSM (29.6%). HIV coinfection was significantly associated with higher proportions GTs 1a and 4 (42.5% and 19.3%, respectively). Genotype prevalence evolves and correlates to epidemiological factors. Continuous surveillance is necessary to better assess hepatitis C infection in Europe and to take appropriate actions.

4 November 2005 in AIDS
Verified
Journal Article
Closed access
AAAna Abecasis
Ana Abecasis
KDKoen Deforche
Koen Deforche
JSJoke Snoeck
Joke Snoeck
LBLee T Bacheler
Lee T Bacheler
PMPaula McKenna
Paula McKenna
AVAnne-Mieke Vandamme
Anne-Mieke Vandamme
To investigate whether and how mutations at position 89 of HIV-1 protease were associated with protease inhibitor (PI) failure, and what is the impact of the HIV-1 subtype. In a database containing pol nucleotide sequences and treatment history, the correlation between PI experience and mutations at codon 89 was determined separately for subtype B and several non-B subtypes. A Bayesian network model was used to map the resistance pathways in which M89I/V is involved for subtype G. The phenotypic effect of M89I/V for several PIs was also measured. The analysis showed that for the subtypes C, F and G in which the wild-type codon at 89 was M compared to L for subtype B, M89I/V was significantly more frequently observed in PI-treated patients displaying major resistance mutations to PIs than in drug-naive patients. M89I/V was strongly associated with PI resistance mutations at codons 71, 74 and 90. Phenotypically, M89I/V alone did not confer a reduced susceptibility to PIs. However, when combined with L90M, a significantly reduced susceptibility to nelfinavir was observed (P < 0.05) in comparison with strains with L90M alone. The results of the present study show that M89I/V is associated with PI experience in subtypes C, F and G but not in subtype B. M89I/V should be considered a secondary PI mutation with an important effect on nelfinavir susceptibility in the presence of L90M.

1 December 2016 in Infection, Genetics and Evolution
Verified
Journal Article
Open access
GMGkikas Magiorkinis
Gkikas Magiorkinis
KAKonstantinos Angelis
Konstantinos Angelis
IMIoannis Mamais
Ioannis Mamais
AKAris Katzourakis
Aris Katzourakis
AHAngelos Hatzakis
Angelos Hatzakis
Dimitrios ParaskevisDimitrios Paraskevis
Dimitrios Paraskevis
Human immunodeficiency virus type 1 (HIV-1) was discovered in the early 1980s when the virus had already established a pandemic. For at least three decades the epidemic in the Western World has been dominated by subtype B infections, as part of a sub-epidemic that traveled from Africa through Haiti to United States. However, the pattern of the subsequent spread still remains poorly understood. Here we analyze a large dataset of globally representative HIV-1 subtype B strains to map their spread around the world over the last 50years and describe significant spread patterns. We show that subtype B travelled from North America to Western Europe in different occasions, while Central/Eastern Europe remained isolated for the most part of the early epidemic. Looking with more detail in European countries we see that the United Kingdom, France and Switzerland exchanged viral isolates with non-European countries than with European ones. The observed pattern is likely to mirror geopolitical landmarks in the post-World War II era, namely the rise and the fall of the Iron Curtain and the European colonialism. In conclusion, HIV-1 spread through specific migration routes which are consistent with geopolitical factors that affected human activities during the last 50years, such as migration, tourism and trade. Our findings support the argument that epidemic control policies should be global and incorporate political and socioeconomic factors.

1 March 2011 in Journal of Virology
Verified
Journal Article
Closed access
PDF file
Rui SoaresRui Soares
Rui Soares
RTRita Tendeiro
Rita Tendeiro
RFRussell B. Foxall
Russell B. Foxall
ABAntónIo P. Baptista
AntónIo P. Baptista
RCRita Cavaleiro
Rita Cavaleiro
ASAna E Sousa
Ana E Sousa
Viremia is significantly lower in HIV-2 than in HIV-1 infection, irrespective of disease stage. Nevertheless, the comparable proviral DNA burdens observed for these two infections indicate similar numbers of infected cells. Here we investigated this apparent paradox by assessing cell-associated viral replication. We found that untreated HIV-1-positive (HIV-1+) and HIV-2+individuals, matched for CD4 T cell depletion, exhibited similargagmRNA levels, indicating that significant viral transcription is occurring in untreated HIV-2+patients, despite the reduced viremia (undetectable to 2.6 × 104RNA copies/ml). However,tatmRNA transcripts were observed at significantly lower levels in HIV-2+patients, suggesting that the rate ofde novoinfection is decreased in these patients. Our data also reveal a direct relationship ofgagandtattranscripts with CD4 and CD8 T cell activation, respectively. Antiretroviral therapy (ART)-treated HIV-2+patients showed persistent viral replication, irrespective of plasma viremia, possibly contributing to the emergence of drug resistance mutations, persistent hyperimmune activation, and poor CD4 T cell recovery that we observed with these individuals. In conclusion, we provide here evidence of significant ongoing viral replication in HIV-2+patients, further emphasizing the dichotomy between amount of plasma virus and cell-associated viral burden and stressing the need for antiretroviral trials and the definition of therapeutic guidelines for HIV-2 infection.

1 July 2006 in Antiviral Therapy
Verified
Journal Article
Closed access
AAAna Abecasis
Ana Abecasis
KDKoen Deforche
Koen Deforche
LBLee T Bacheler
Lee T Bacheler
PMPaula McKenna
Paula McKenna
ACAna Patrícia Carvalho
Ana Patrícia Carvalho
RCRicardo Jorge Camacho
Ricardo Jorge Camacho
Objective: To compare baseline susceptibility to protease inhibitors among HIV-1 isolates of subtypes C, F, G and CRF02_AG, and to identify polymorphisms that determine the differences in susceptibility. Methods: A total of 42 samples of drug-naive patients infected with subtypes G ( n=19), CRF02_AG ( n=10), F ( n=6) and C ( n=7) were phenotyped and genotyped with the Antivirogram and the ViroSeq 2.0 genotyping system, respectively. A Bayesian network approach was used for a preliminary analysis of the collected data and the dependencies indicated by the network were statistically confirmed. Results: CRF02_AG samples were found to be more susceptible to nelfinavir and ritonavir than other subtypes. Hypersusceptibility to these drugs was associated with the 70R polymorphism. 37D/S/T was associated with reduced susceptibility to indinavir and 89M with reduced susceptibility to lopinavir. Susceptibility to tipranavir was the lowest among the subtype F samples and the highest for subtype G samples, with samples carrying 57R being more susceptible than samples carrying 57K. Conclusions: Our study suggests that there are baseline susceptibility differences between subtypes and these differences are due to naturally occurring polymorphisms in these subtypes. The predictive value for phenotype of these polymorphisms was even valid in subtypes where these polymorphisms are less prevalent. Taking into account such polymorphisms should improve current algorithms for interpretation of genotyping results in a subtype-independent way.

1 April 2017 in EBioMedicine
Verified
Journal Article
Open access
SRSoo-Yon Rhee
Soo-Yon Rhee
VVVici Varghese
Vici Varghese
SHSusan P. Holmes
Susan P. Holmes
GZGert van Zyl
Gert van Zyl
KSKim Steegen
Kim Steegen
RSRobert W. Shafer
Robert W. Shafer
Tenofovir disoproxil fumarate (TDF) genotypic resistance defined by K65R/N and/or K70E/Q/G occurs in 20% to 60% of individuals with virological failure (VF) on a WHO-recommended TDF-containing first-line regimen. However, the full spectrum of reverse transcriptase (RT) mutations selected in individuals with VF on such a regimen is not known. To identify TDF regimen-associated mutations (TRAMs), we compared the proportion of each RT mutation in 2873 individuals with VF on a WHO-recommended first-line TDF-containing regimen to its proportion in a cohort of 50,803 antiretroviral-naïve individuals. To identify TRAMs specifically associated with TDF-selection pressure, we compared the proportion of each TRAM to its proportion in a cohort of 5805 individuals with VF on a first-line thymidine analog-containing regimen. We identified 83 TRAMs including 33 NRTI-associated, 40 NNRTI-associated, and 10 uncommon mutations of uncertain provenance. Of the 33 NRTI-associated TRAMs, 12 - A62V, K65R/N, S68G/N/D, K70E/Q/T, L74I, V75L, and Y115F - were more common among individuals receiving a first-line TDF-containing compared to a first-line thymidine analog-containing regimen. These 12 TDF-selected TRAMs will be important for monitoring TDF-associated transmitted drug-resistance and for determining the extent of reduced TDF susceptibility in individuals with VF on a TDF-containing regimen.