RESUMO
BACKGROUND: The importance of influenza is increasing mainly because of the appearance of novel pandemic strains such as swine and avian. Each year, influenza has spread around the world causing about 250,000-500,000 deaths and more than 5 million cases of severe illness.The objective is as follows: evaluating the outcomes of patients with influenza A (H1N1) virus in relation to certain TNF-308, IL6, and IL8 polymorphisms and identifying the associated factors with the severe outcome. SUBJECT AND METHODS: This is a case-control study. The cases were patients confirmed by real-time polymerase chain reaction (RT-PCR) to be influenza A (H1N1) virus infected. The controls were healthy individuals. Medical history and outcome of the disease was registered. In all study participants, polymorphisms of TNF rs1800629, IL6 rs18138879, and IL8 rs4073; odds ratio (OR); and the 95% confidence interval (95% CI) were calculated. RESULTS: Infection with influenza A (H1N1) virus was associated more with the following genotypes: TNF-308 AA (OR = 4.041; 95% CI = 1.215-13.4) and IL8 AA (OR = 3.273; 95% CI = 1.372-7.805). According to our study results, HCV (OR = 3.2, 95% CI 1.2-8.5), renal disease (OR = 3.4, 95% CI 0.9-13.6), cancer (OR = 3.1, 95% CI 0.3-31.1), TB (OR = 8.4, 95% CI 1.8-39.7), ICU (OR = 2.9, 95%1.2-7.1), and mortality (OR = 7.9, 95% CI 0.9-67.4) are considered as risk factors for influenza A (H1N1)-infected patients. CONCLUSIONS: Our findings concluded that TNF-308 (AA) and IL8 (AA) polymorphisms may increase the susceptibility to be infected with H1N1influenza virus.
