Association of interleukin-1 α (–889) gene polymorphism in patients with generalized aggressive and chronic periodontitis

Abstract

Background: There is a strong evidence that genetic as well as environmental factors affect the

age of onset, severity and lifetime risk of developing periodontitis. The objective of the present

study was to compare and to evaluate the association between interleukin (IL)-1α(-889) and gene

polymorphisms in patients with generalized aggressive periodontitis, chronic periodontitis and

healthy controls.

Materials and Methods: A total of 60 Indian patients, with 20 aggressive periodontitis, 20 chronic

periodontitis and 20 healthy controls were recruited for this study. From each patient, a volume

of 2 ml of blood was collected by venipuncture in the ante-cubital fossa and was stored in sodium

EDTA vacutainers and was used for genotyping assays with the polymerase chain reaction restriction

fragment length polymorphism technique. Clinical parameters such as oral hygiene index, gingival

index and clinical attachment loss (CAL) were evaluated for each patient. Genotype distribution

between different groups were analyzed using Chi-square test. A P = 0.05 or less was set for

signifi cance.

Results: The mean oral hygiene index was 3.7 ± 0.86 and 3.25 ± 0.30 for chronic and aggressive

periodontitis cases respectively. The CAL was 4.29 ± 0.63 mm for chronic periodontitis and

6.44 ± 0.57 mm for aggressive periodontitis. Homozygous genotype 2,2 was more predominant in

cases of aggressive periodontitis whereas in chronic periodontitis, heterozygous genotype 1,2 was

more predominant when compared with others (P < 0.001). Odds ratio for aggressive versus

chronic periodontitis was calculated as 6.2 (95% confi dence interval 6.019-7.892).

Conclusion: The results of the present study support a positive association between aggressive

periodontitis and the presence of the IL-1α-889, allele 2 polymorphism in Indian patients.

Key Words: Aggressive periodontitis, interleukin-1, single nucleotide polymorphism