Resumen de Distribution of Interleukin-1β+3954 and IL-1α–889 Genetic Variations in a Thai Population Group

Dr. Orasa Anusaksathien, Angkana Sukboon, Piyawan Sitthiphong, Rawee Teanpaisan

• Background: The severe form of chronic periodontitis (CP) has been reported to be strongly associated with the presence of allele 2 of composite IL-1β+3954 and IL-1α–889 genetic polymorphisms (genotype positive). However, other studies have reported conflicting findings, not only on the association between the composite IL-1 gene polymorphisms and CP, but also the link between IL-1 gene polymorphisms and aggressive periodontitis (AgP). These might have resulted from differences in ethnic background and disease entities. The aim of this study was to determine the distribution of IL-1β+3954 and IL-1α–889 genetic polymorphisms in a group of Thai subjects based on their periodontal status, including CP, AgP, and healthy groups.

  Methods: A total of 123 Thai subjects were clinically and radiographically assessed for their periodontal status. Blood samples were collected by fingerstick and adsorbed onto filter paper. The IL-1β+3954 and IL-1α–889 genotypes were performed by polymerase chain reaction, digested with restriction enzymes, and separated by gel electrophoresis.

  Results: The distribution of allele 1 homozygous genotype was 97.6% and 84.6% for IL-1β+3954 and IL-1α–889, respectively. No allele 2 homozygous genotype was detected in either of these two gene loci. Only 1.6% (2 out of 123) of the subjects were genotype positive, which was too low to determine the association between the composite genotype of IL-1β+3954 and IL-1α–889 and severe forms of periodontal disease.

  Conclusion: Genetic polymorphism of IL-1 genes in these two loci may not be useful in predicting the severity of periodontal disease in the Thai ethnic group.