Evaluation of Polymorphisms in IL8 and IL16 Genes in Patients with Acute Coronary Syndrome

Abstract Background: Acute coronary syndrome (ACS) is a cardiovascular disease caused by obstruction of coronary arteries by atheromatous plaque. Susceptibility to this disease may be related to genetic variations, such as single nucleotide polymorphisms (SNPs). Objective: In this study, we evaluated the relationship between SNPs in IL8 (rs4073; -251 A/T) and IL16 (rs11556218; T/G) genes and SCA in a Brazilian population. Materials and Methods: A sample of 200 patients with ACS and 50 non-ACS patients hospitalized at the Real Hospital Português, Recife - PE, Brazil, and 220 blood donors (donors) was used. Genotyping was carried out by polymerase chain reaction, and DNA sequencing. Statistical analyzes were performed using the Williams G, Chi-square and Kruskal Wallis tests, using the BioEstat 5.0 program, and the data with a value of p < 0.05 were considered significant. Results: In the IL8 gene, the AT genotype was the most frequent (p > 0.05) in all three groups. In the IL16 gene, genotypic distributions were different between patients with ACS and the donor group (p = 0.002), with the most frequent G allele in the second group (p = 0.0052). The IL-16 cytokine was higher in donors than in patients with ACS (p = 0.04) and the G (TG + GG) allele had higher values of this cytokine (p = 0.01). Conclusions: The results demonstrate the important role of the rs11556218 SNP in IL16 gene in SCA, evidencing that the G allele may be associated with a decreased risk of the disease.

Avaliação do Polimorfismo -174 G/C do gene IL-6 na Síndrome Coronariana Aguda no Nordeste do Brasil / Evaluation of IL-6 (-174 G/C) Polymorphism in Acute Coronary Syndrome in the Northeast of Brazil

Fundamento: A síndrome coronariana aguda (SCA) é a principal causa de morbidade e mortalidade no mundo. É uma doença multifatorial causada por obstrução das artérias coronárias por placa ateromatosa que leva à isquemia cardíaca. Diversos estudos sugerem que alguns polimorfismos genéticos alteram os níveis de citocinas e influenciam o desenvolvimento de SCA. Objetivo: Neste estudo, avaliamos o polimorfismo - 174 G/C do gene IL-6 , níveis séricos de citocina e sua relação com SCA e escore de risco de thrombolysis in myocardial infarction (TIMI). Materiais e métodos: Foram selecionados 200 pacientes com SCA [risco de TIMI ­ Baixo (70), Intermediário (89), Alto (41)] na população brasileira. A genotipagem foi feita pela reação em cadeia da polimerase (PCR), seguida de sequenciamento de DNA. Resultados: Não houve diferenças significativas na distribuição dos genótipos (p = 0,53) e dos alelos (p = 0,32) entre grupos de pacientes com SCA e sem SCA no polimorfismo alélico do IL-6 , nem entre os três escores de risco TIMI (p > 0,05). Além disso, o polimorfismo do IL-6 não afetou os níveis de citocina, os quais não estavam relacionados ao escore de TIMI. Conclusões: Com esses resultados, sugerimos que o polimorfismo ­ 174 G/C do gene IL-6, até agora, não está relacionado à SCA e não alterou os níveis de citocina na população estudada. Novos estudos em populações diferentes devem ser feitos para verificar esses resultados. É importante enfatizar que, como a SCA é uma doença multifatorial, outros fatores de risco e outras citocinas pró-inflamatórias devem ser avaliadas para o conhecimento dessa patologia

Background: Acute coronary syndrome (ACS) is a leading cause of morbidity and mortality worldwide. It is a multifactorial disease caused by obstruction of the coronary arteries by atheromatous plaques and leads to heart ischemia. Several studies suggest that some genetic polymorphisms change the cytokines levels and influence ACS development. Objective: In this study, we evaluated the IL-6 polymorphism -174 G/C, serum levels of cytokine and its relationship with ACS and the thrombolysis in myocardial infarction (TIMI) risk score. Materials and Methods: A sample of 200 patients with ACS [TIMI risk ­ Low (70); Intermediate (89); High (41)] in Brazilian population was used. Genotyping was carried out by polymerase chain reaction, followed by DNA sequencing. Results: There was no significant differences in genotype (p = 0.53) and allele (p = 0.32) distributions between ACS patient and without ACS patients groups on IL-6 allelic polymorphism and between the three different TIMI risk score (p > 0.05). Moreover IL-6 polymorphism did not affect the cytokine levels and these levels were not related to the TIMI score. Conclusions: With these results, we suggest that the IL-6 (-174 G/C) polymorphism, until now, is not related to ACS and did not change the levels of the cytokine in studied population. Further studies with different populations should be done to verify those results. It is important to emphasize that, since ACS is a multifactorial disease, other risk factors and other pro-inflammatory cytokines should be assessed to better understand this pathology