Cytokine concentrations in plasma from patients with periodontitis

Methods: 67 patients with severe periodontitis were compared to 47 periodontally healthy individuals. Of these, 44 completed the treatment and came back for the one year follow up. Plasma samples were collected at baseline, after 3 months and one year. The cytokines IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IFNγ and TNFα levels were determined by Multiplex bead analysis using a Luminex 100 (Luminex Corp., Austin, TX, USA) and commercial immunoassays (Lincoplex, High sensitivity human cytokine panel, Linco Research Inc., St. Charles, MO, USA). IL-18 levels were determined using a commercial immunoassay kit according to the manufacturers' recommended protocols (R&D Systems Europe Ltd., Abingdon, UK).

Results: At baseline the median values of IL-4 (1.4 ng/L vs 9.7 ng/L, p=0.009) and IL-8 (3.6 vs 6.2 ng/L, p<0.018) were lower in the patient group as compared to the control group. IL-18 was significantly higher in the patient group (245 vs 188 ng/L, p=0.001). IL-1β, IL-5, IL-6, IL-10, INFγ and TNFα did not differ significantly.

The treatment was clinically successful. The number of pockets 4 mm or deeper decreased from 47 to 2 (p<0.001) and bleeding on probing decreased from 44% to 15% (p<0.001). However, the treatment did not change most of the cytokine concentrations. Only IL-18 decreased significantly from 288 ng/L to 232 ng/L (median), p=0.044.

Conclusion: This study showed that there were differences in cytokine concentratin between patients and controls. Some the differences did not change after treatment indicating that they were not a consequence of the periodontal inflammation.

This study was supported by the Swedish research council K2006-73X-20138