The purpose of this study was to observe and quantify the expression of interleukin-4 (IL-4), interferon-γ (IFN-γ), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) in the gingival tissue of patients with type 2 diabetes mellitus (DM) and healthy adults with chronic periodontitis.

Twelve patients with type 2 DM and chronic periodontitis (Group 3), twelve patients with chronic periodontitis (Group 2), and twelve healthy individuals (Group 1) were included in the study. Clinical criteria of gingival (sulcus bleeding index value, probing depths) and radiographic evidences of bone resorption were divided into three groups. The concentrations of cytokines were determined by a western blot analysis and compared using one-way ANOVA followed by Tukey's test.

The expression levels of IFN-γ and TIMP-2 showed an increasing tendency in Groups 2 and 3 when compared to Group 1. On the other hand, the expression of IL-4 was highest in Group 1.

The findings suggest that IFN-γ and TIMP-2 may be involved in the periodontal inflammation associated with type 2 DM. IL-4 may be involved in the retrogression of the periodontal inflammation associated with type 2 DM.