The extent of periodontal disease and the IL‐6−174 genotype as determinants of serum IL‐6 level

Abstract

To study the extent of periodontal disease and the IL-6(-174) genotype as determinants of serum and mouthwash IL-6 concentration in subjects with moderate to severe periodontal disease. Fifty-two generally healthy subjects volunteered to participate. Probing pocket depth (PD) and periodontal attachment level (AL) were clinically examined and alveolar bone level (BL) was measured on orthopantomographs. IL-6 concentrations in mouthwash, collected by rinsing with 3 ml saline for 30 s and in serum, obtained by venipuncture, were measured using ELISA. IL-6(-174) polymorphism was studied using a polymerase chain reaction. Eleven subjects carried the GG genotype, and 41 subjects, carried the CG/CC genotype. The mean (+/- SD) concentration of IL-6 in serum was 1.6 (+/- 1.5) pg/ml and, 2.8 (+/- 5.04) pg/ml in mouthwash. The serum concentration of IL-6 was higher in subjects with the GG genotype than with the CG/CC genotype. In regression analyses the percentages of sites with PD> or =6 mm, AL> or =6 mm and BL> or =8 mm, the IL-6(-174) genotype, body mass index and gender associated significantly with serum IL-6 concentration. The extent of moderate to severe periodontal disease and the IL-6(-174) genotype contribute significantly to serum IL-6 concentration.