Authors
Advisor(s)
Abstract(s)
Estudos epidemiológicos têm sido realizados com o propósito de compreender as
diferentes suscetibilidades à infeção e manifestações da doença pelo novo coronavírus. A
sintomatologia pode variar desde os assintomáticos até casos mais graves de pneumonia
que podem resultar em morte. Estudos de associação entre os grupos sanguíneos do
sistema ABO e o risco e severidade da COVID-19 têm vindo a corroborar o facto da
presença do grupo sanguíneo O conferir menor suscetibilidade, enquanto a presença do
grupo A confere maior suscetibilidade à infeção. Contudo, há estudos com resultados
contraditórios onde a mesma associação não foi observada. Está estabelecido que
determinados grupos do sistema ABO está associado a um maior risco para várias doenças
infeciosas, incluindo hepatite B e dengue hemorrágico. Os mecanismos que podem
explicar esta associação não estão totalmente esclarecidos, carecendo de investigação
mais aprofundada. Com este trabalho pretendeu-se contribuir para elucidar esta possível
associação entre o genótipo ABO e o risco de infeção e severidade da doença COVID-19
na população portuguesa, bem como, estabelecer frequências genótipicas do gene ABO.
Foi selecionada, aleatoriamente, uma amostra de conveniência de profissionais de saúde
da ULSNE. Para a análise molecular do gene ABO foram sequenciadas as regiões dos
exões 6 e 7 do gene ABO, pelo método de Sanger.
Os resultados obtidos evidenciam a presença de polimorfismos que definem novas
classes genotípicas, sendo o A101/O01 e A101/O02 os mais frequentes e A102/B101 e o
O02/O03 os menos frequentes. Na análise dos resultados de associação do fenótipo e
genótipo com a presença de infeção e a severidade da doença COVID-19, apontou para
um risco de infeção para indivíduos do grupo O em relação ao grupo A (OR= 2.545:
1.216-5.327). A análise de regressão binária, incluindo outros preditores, revelou um
resultado diferente, o risco de infeção maior para indivíduos do grupo A e menor para o
grupo O (A vs não-A OR= 1.998: 1.007-3.965; O vs não-O OR= 0.366:0.177-0.759). Não
foi observada associações entre o grupo sanguíneo e a severidade da doença.
Epidemiological studies have been carried out with the purpose of understanding the different susceptibilities to infection and manifestations of the disease by the new coronavirus. Symptoms can range from asymptomatic to more severe cases of pneumonia that can result in death. Studies of the association between the blood groups of the ABO system and the risk and severity of COVID-19 have corroborated the fact that the presence of blood group O confers lower susceptibility, while the presence of group A confers greater susceptibility to infection. However, there are studies with contradictory results where the same association was not observed. It is established that certain groups of the ABO system are associated with an increased risk for several infectious diseases, including hepatitis B and dengue hemorrhagic fever. The mechanisms that may explain this association are not fully understood and require further investigation. The aim of this work was to contribute to elucidate this possible association between the ABO genotype and the risk of infection and severity of COVID-19 disease in the Portuguese population, as well as to establish genotypic frequencies of the ABO gene. A convenience sample of ULSNE health professionals was randomly selected. For the molecular analysis of the ABO gene, the regions of exons 6 and 7 of the ABO gene were sequenced using the Sanger method. The results show the presence of polymorphisms that define new genotypic classes, with A101/O01 and A101/O02 being the most frequent and A102/B101 and O02/O03 being the least frequent. In the analysis of the results of the association of phenotype and genotype with the presence of infection and the severity of the COVID-19 disease, it pointed to a risk of infection for individuals in group O compared to group A (OR= 2.545: 1.216-5.327). Binary regression analysis, including other predictors, revealed a different result, the risk of infection higher for individuals in group A and lower for group O (A vs non-A OR= 1.998: 1.007-3.965; O vs non-O OR= 0.366:0.177-0.759). No associations were observed between blood group and disease severity.
Epidemiological studies have been carried out with the purpose of understanding the different susceptibilities to infection and manifestations of the disease by the new coronavirus. Symptoms can range from asymptomatic to more severe cases of pneumonia that can result in death. Studies of the association between the blood groups of the ABO system and the risk and severity of COVID-19 have corroborated the fact that the presence of blood group O confers lower susceptibility, while the presence of group A confers greater susceptibility to infection. However, there are studies with contradictory results where the same association was not observed. It is established that certain groups of the ABO system are associated with an increased risk for several infectious diseases, including hepatitis B and dengue hemorrhagic fever. The mechanisms that may explain this association are not fully understood and require further investigation. The aim of this work was to contribute to elucidate this possible association between the ABO genotype and the risk of infection and severity of COVID-19 disease in the Portuguese population, as well as to establish genotypic frequencies of the ABO gene. A convenience sample of ULSNE health professionals was randomly selected. For the molecular analysis of the ABO gene, the regions of exons 6 and 7 of the ABO gene were sequenced using the Sanger method. The results show the presence of polymorphisms that define new genotypic classes, with A101/O01 and A101/O02 being the most frequent and A102/B101 and O02/O03 being the least frequent. In the analysis of the results of the association of phenotype and genotype with the presence of infection and the severity of the COVID-19 disease, it pointed to a risk of infection for individuals in group O compared to group A (OR= 2.545: 1.216-5.327). Binary regression analysis, including other predictors, revealed a different result, the risk of infection higher for individuals in group A and lower for group O (A vs non-A OR= 1.998: 1.007-3.965; O vs non-O OR= 0.366:0.177-0.759). No associations were observed between blood group and disease severity.
Description
Mestrado em parceria com a Escola Superior de Saúde do Instituto Politécnico da Guarda
Keywords
Coronavírus-19 SARS-CoV-2 Suscetibilidade Grupo sanguíneo ABO Genética