Research Article: Association of Cytokine Gene Alleles with the Inflammation of Human Periodontal Tissue

Date Published: , 2011

Publisher: A.I. Gordeyev

Author(s): A.V. Safonova, A.N. Petrin, S.D. Arutyunov, V.N. Tsarev, L.A. Akulenko, A.O. Zorina, D.V. Rebrikov, A.V. Rubanovich, S.A. Borinskaya, N.K. Yankovsky.



Gingivitis and periodontitis are chronic inflammatory diseases of the periodontal tissue in humans caused by both environmental and genetic factors. The human cytokine genes that regulate the immune response may play an important role in the development of these chronic inflammatory diseases. The aim of this study is to analyze the allele status of eight human cytokine genes and to associate it with the inflammation of periodontal tissue in humans. A total of 296 unrelated males of Russian origin were studied. A significant association of theIL1BandIL6 minor alleles and gingivitis was found. In addition, we found a significant association of the OHI-S index with theIL18gene alleles. The influence of genetic factors on gingivitis may contribute to the understanding of the mechanisms of interaction between genetic and environmental factors in periodontal conditions, and to the identification of risk groups for effective prevention and treatment.

Partial Text

Gingivitis (inflammation of the gum tissue) and periodontitis (inflammation of tissues surrounding and supporting the teeth) are widespread oral diseases. Gingivitis can appear both in tandem with periodontitis and independently. Signs of periodontal tissue involvement might appear even in children 6—7 years old [1]; these indicators are found in more than 50% of 15-year-old adolescents, and the prevalence of periodontal diseases among adults in Moscow and other large cities reaches 98%. Moreover, symptoms of gingivitis are found in more than 80% of people [2].

A group of 296 male soldiers from 20 to 52 years of age (the average age is 27.0 ± 6.3 years) was examined. The examination was performed during a routine medical examination; the procedure of informed consent was followed; the data were collected on the nationality and place of birth of the volunteers and two generations of their ancestors. The examined group included mainly Russian males (proportion of children from mixed marriages (the percentage of descendants from mixed marriages between Russians, Ukrainians, and Belarusians was 6.5%)). All patients underwent a standard external dental checkup and instrumental examination of the oral cavity. The description of the dental status contained the assessment of the intensity of inflammation and destructive processes and the index of oral hygiene.

In only 1% (three patients) of the group examined (296 males), no sign of inflammation of gum tissue (PMA = 0) was observed Mild gingivitis was found in 67.6% of males (205 patients), and 31.4% of males were suffering from gingivitis of moderate severity (93 patients) and severe gingivitis (12 patients) (PMA > 30%). The probing pocket depth varied from 0.6 to 4.5 mm. The mean value across the group examined was 1.50 ± 0.73 mm (±S.D.). The values of the OHI-S indices was in a range from 0 to 3.8 points, the mean value was 1.79 ± 0.73; it corresponds to an unsatisfactory hygiene level. The genotypes of all males examined were determined for each from eight loci. Due to technical difficulties, the genotypes of some SNPs were not determined for each individual; hence, the total number of genotypes for each gene is different.