Haplotype Analysis of Interleukin-8 Gene Polymorphisms in Chronic and Aggressive Periodontitis

<jats:p><jats:italic>Objectives</jats:italic>. Periodontitis is an inflammatory disease characterized by connective tissue loss and alveolar bone destruction. Interleukin-8 (<jats:italic>IL8</jats:italic>) is important in the regulation of the immune response. The aim of this study was to analyze four polymorphisms in the<jats:italic>IL8</jats:italic>gene in relation to chronic (CP) and aggressive (AgP) periodontitis.<jats:italic>Methods</jats:italic>. A total of 492 unrelated subjects were included in this case-control association study. Genomic DNA of 278 patients with CP, 58 patients with AgP, and 156 controls were genotyped, using the 5′ nuclease TaqMan assay, for<jats:italic>IL8</jats:italic>(rs4073, rs2227307, rs2227306, and rs2227532) gene polymorphisms. Subgingival bacterial colonization was investigated by the DNA-microarray detection kit in a subgroup of subjects<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mrow><mml:mo stretchy="false">(</mml:mo><mml:mrow><mml:mi>N</mml:mi><mml:mo>=</mml:mo><mml:mn>247</mml:mn></mml:mrow><mml:mo stretchy="false">)</mml:mo></mml:mrow></mml:mrow></mml:math>.<jats:italic>Results</jats:italic>. Allele and genotype frequencies of all investigated<jats:italic>IL8</jats:italic>polymorphisms were not significantly different between the subjects with CP and/or AgP and controls (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>P</mml:mi><mml:mo>></mml:mo><mml:mn>0.05</mml:mn></mml:mrow></mml:math>). Nevertheless, the A(−251)/T(+396)/T(+781) and T(−251)/G(+396)/C(+781) haplotypes were significantly less frequent in patients with CP (2.0% versus 5.1%,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.02</mml:mn></mml:mrow></mml:math>, OR = 0.34, 95% CI: 0.15–0.78, resp., 2.0% versus 4.5%,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>P</mml:mi><mml:mo><</mml:mo><mml:mn>0.05</mml:mn></mml:mrow></mml:math>, OR = 0.41, 95% CI: 0.18–0.97) than in controls.<jats:italic>Conclusions</jats:italic>. Although none of the investigated SNPs in the<jats:italic>IL8</jats:italic>gene was individually associated with periodontitis, some haplotypes can be protective against CP in the Czech population.</jats:p>