Genetic variation at the IFITM3 and Influenza A(H1N1)pdm09 infection severity in the Portuguese population

Gaio, Vânia; Nunes, Baltazar; Pechirra, Pedro; Conde, Patrícia; Guiomar, Raquel; Matias Dias, Carlos; Silva, Marta Barreto da

http://hdl.handle.net/10400.18/2402

Use this identifier to reference this record.

Name:	Description:	Size:	Format:
PowerPoint - VaniaGaio_Oxford_20140910.pdf		1.7 MB	Adobe PDF	Download

Send Feedback

Authors

Silva, Marta Barreto da

Abstract(s)

Interferon-inducible transmembrane protein (IFITM3) inhibits the entry of viruses to the host cell, mediating resistance to influenza infection. It has been demonstrated that a genetic variation in the IFITM3 gene (rs12252) alters a splice-site, originating a protein with reduced activity. In this context, our aim was to determine if the C allele of the IFITM3 rs12252 polymorphism is associated with influenza infection or hospitalizations related to Influenza A(H1)pdm09 in the Portuguese population. To achieve our goal, a case-control study design was developed using the nasal swabs collected during the 2009 pandemic, on the context of the National Influenza Surveillance Program. Non-hospitalized influenza cases were defined as patients with influenza like illness (ILI) who tested positive for influenza A(H1)pdm09 and did not require hospitalization. Hospitalized-influenza cases were defined as ILI patients who tested positive for A(H1)pdm09 infection and who were hospitalized. For these cases groups two types of controls were selected: non-hospitalized ILI cases negative for A(H1)pdm09 and hospitalized ILI patients negative for A(H1)pdm09 infection. We have therefore selected 212 non-hospitalized influenza cases, 96 hospitalized influenza cases, 403 non-hospitalized negative controls and 198 hospitalized negative controls. We found that hospitalized negative controls had the highest frequency of allele C carriers (22.5%) and the lowest frequency was found among the non-hospitalized negative controls (11.11%). No association was found between testing positive for A(H1)pdm09 infection (susceptibility to infection) and the C allele of rs12252. We have also found that the risk of being hospitalized (independently of infection status) for the allele C carriers is the highest, after adjustment for age and gender, (OR: 1.59 (95% CI: 1.05-2.43). Our results suggest that the allele C of the IFITM3 rs122252 polymorphism was associated with respiratory disease hospitalizations but not specifically associated with the infection by Influenza A(H1N1)pdm09.

Keywords

Influenza IFITM3 Severidade da Infeção Suscetibilidade Genética do Hospedeiro Estados de Saúde e de Doença Infecções Respiratórias Saúde Pública Portugal