A potential role of an intracellular signaling defect in neutrophil functional abnormalities and promotion of tissue damage in patients with localized juvenile periodontitis

Gingival crevicular fluid levels of monocyte chemoattractant protein-1 and tumor necrosis factor-alpha in patients with chronic and aggressive periodontitis

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) is a well-known chemotactic cytokine that regulates mononuclear inflammatory cell recruitment. This recruitment has particular importance in the oral cavity because inflammatory cells will be challenged with periodontopathogenic bacteria during infections. Tumor necrosis factor-alpha (TNF-alpha) is a cytokine that induces bone resorption by stimulating proliferation and differentiation of osteoclasts' progenitors and also stimulates MCP-1 expression. The aims of this study were to investigate the presence of MCP-1 in gingival crevicular fluid (GCF) samples from patients with chronic periodontitis (CP) and aggressive periodontitis (AgP) and to examine the possible correlations between the GCF levels of MCP-1 and TNF-alpha.

METHODS

Twenty-five CP, 20 AgP, and 20 healthy control (C) patients were selected for the study. Plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) measurements were recorded from each sampling area. Assays for GCF MCP-1 and TNF-alpha were carried out by an enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

The concentration (nanograms per microliters) and total MCP-1 and TNF-alpha (nanograms per site) were not statistically significant between CP and AgP groups, but total MCP-1 and TNF-alpha was statistically different between CP and C and between AgP and C groups (P <0.001). All clinical parameters were statistically different between CP and C and between AgP and C groups (P <0.001). A positive statistical correlation was detected between the levels of MCP-1 and TNF-alpha, and there was also a positive correlation between all clinical parameters and total MCP-1 and TNF-alpha levels.

CONCLUSIONS

These results suggest that MCP-1 could have an important role in the activation and recruitment of inflammatory and immune cells in periodontal diseases, and both AgP and CP patients may have the same pattern of MCP-1 expression. A strong positive correlation between the GCF levels of MCP-1 and TNF-alpha may account for the mechanism of amplification of inflammatory events in gingival inflammation.

Immunolocalization of inducible nitric oxide synthase in localized juvenile periodontitis patients

Localized juvenile periodontitis (LJP) is associated with a destruction of periodontal tissues and the presence of Actinobacillus actinomycetemcomitans (AA). Lipopolysaccharide (LPS) from AA was found to induce a significant macrophage production of nitric oxide (NO). Increased nitric oxide synthase (NOS) activity was found to be negatively correlated with the neutrophil chemotactic response. The aim of this study was to determine the occurrence and distribution of inducible NOS (iNOS) in human gingival tissue from LJP patients. The distribution of iNOS was assessed by monoclonal antibody against iNOS. Cellular markers (CD 3, CD 20, and CD 68) were used to determine the cellular origin of iNOS. The immunostaining revealed the appearance of iNOS in inflamed compared to noninflamed gingival tissues. Macrophages expressed high levels of iNOS that may cause some damage to the periodontal tissues. This study suggests that iNOS activity in macrophages may modify abnormalities of neutrophil function.