[Cytokine production in inflamed human gingival tissues--interleukin-6]

Interleukin-6 (IL-6) is involved in the final differentiation of B cells into antibody-producing cells. Recent studies reveal that IL-6 plays an important role in inflammation. Histopathological studies showed that a large number of plasma cells in periodontitis is usually seen in the apical parts of cellular infiltrates beneath the periodontal connective tissues. This evidence suggests that IL-6 may play a critical role in the development of periodontitis. Therefore, we examined IL-6 production in the gingival tissues. Twelve periodontitis patients and five gingivitis patients were included in this study. Nine individuals with healthy periodontium acted as control subjects. Biopsy specimens were dissected into fragments 3 mm in diameter and plated onto 24-well culture plates with RPMI 1640 medium. IL-6 activity in the culture supernatants was measured by IgM production assay using the cell line SKW6-CL4. IL-6 activity was detected at significantly higher levels (P less than 0.001) in culture supernatants from the gingival tissues in periodontitis (23.2 +/- 14.4 units/ml) and gingivititis (12.5 +/- 3.4 units/ml) than in control tissues (2.3 +/- 1.2 units/ml). Subsequently, the relationship between IL-6 activity and clinical stages was examined. The IL-6 levels before initial preparation (23.2 +/- 14.4 units/ml) were significantly higher (P less than 0.001) than those after initial preparation (1.4 +/- 1.8 units/ml), but were not associated with either periodontal pocket depth or the extent of alveolar bone resorption in periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)