LAUSR

BACKGROUND Immune response leading to increased systemic inflammation is one of the mechanisms linking periodontitis to chronic inflammatory diseases. The aim of this study was to compare the expression of toll-like receptors 2 and 4 in monocytes and neutrophils (TLR2M, TLR2N, TLR4M and TLR4N) and its endogenous ligands [cellular fibronectin (cFN) and heat shock protein 60 (HSP60)] in patients with and without periodontitis. Additionally, the relationship between cFN and HSP60 expression with innate immunity activation and systemic inflammatory response [interleukin 6 (IL-6)] was also evaluated. METHODS A case-controlled study was designed in which 30 patients with periodontitis (cases) and 30 age- and gender-matched participants without periodontitis (controls) were included. Fasting blood samples were collected to determine: a) expression of TLR2N, TLR2M, TLR4N and TLR4M by flow cytometry; and b) serum concentrations of cFN, HSP60 and IL-6 by ELISA technique. RESULTS Expression of TLR2M (411.5 [314.2, 460.0] vs 236.5 [204.0, 333.0] AFU), TLR2N (387.0 [332.0, 545.5] vs 230.0 [166.2, 277.7] AFU), TLR4M (2478.5 [1762.2, 2828.0] vs 1705.0 [1274.5, 1951.2] AFU) and TLR4N (2791.0 [2306.7, 3226.2] vs 1866.0 [1547.5, 2687.2] AFU) as well as serum levels of cFN (301.1 [222.2, 410.9] vs 156.4 [115.3, 194.0] ng/mL) and IL-6 (10.4 [6.5, 11.5] vs 3.5 [2.6, 4.9] pg/mL) were significantly higher in periodontitis patients than those without periodontitis. A positive association was found between periodontitis and cFN (OR = 1.028, p<0.001), TLR2N (OR = 1.026, p<0.001), TLR4M (OR = 1.001, p = 0.002), and IL-6 (OR = 1.774, p<0.001). CONCLUSIONS Periodontitis patients exhibited high expression of TLRs, cFN and IL-6. This article is protected by copyright. All rights reserved.