The Role of Inflammatory Clusters in Gingivitis and Periodontitis.

INTRODUCTION

Individual variability determines host responses and disease progression. Inflammatory clusters (ICs) have been shown to influence host responses against bacterial challenges during the induction of human experimental gingivitis.

OBJECTIVES

This study aimed to evaluate the role of ICs in naturally occurring gingivitis and periodontitis.

METHODS

Using a cross-sectional and split-mouth design, this study evaluated the immune regulation and tissue-remolding responses in sites with different disease severity of periodontal diseases to provide a comprehensive assessment of disease features on the basis of analyzing gingival crevicular fluids. Cluster analysis was performed based on the clinical indices, including gingival index, plaque index, and probing depth. Further comparisons of the host mediators and clinical indices among clusters based on the disease severity were also performed.

RESULTS

A total of 48 patients were recruited in this study, including 24 patients with gingivitis only and 24 patients with stage III grade B generalized periodontitis. Our results demonstrate that 2 distinct ICs were found in the sites with naturally occurring gingivitis: low-ICs had less expression of myeloperoxidase, intercellular adhesion molecule-1, and interleukin-12 as well as greater expression of angiopoietin-1 than high-ICs did. At the sites with generalized severe periodontitis, however, low-ICs had significantly elevated expression of angiopoietin-1, fractalkine, granulocyte-macrophage colony-stimulating factor, matrix metalloproteinase-2, osteopontin, and vascular endothelial growth factor versus high-ICs. Our results for the first time confirmed the influence of ICs in naturally occurring gingivitis, showing that low-ICs displayed minimal inflammation and less neutrophil involvement compared with high-ICs. The influence of ICs in periodontitis was site specific rather than patient specific.

CONCLUSION

Our collective findings highlight the importance of ICs in disease progression, benefiting the modulation of immune responses and preventing further periodontal tissue destruction. By identifying specific ICs, clinicians can better predict disease progression and recurrence, ultimately improving patient outcomes through targeted interventions.Knowledge Transfer Statement:The present study discovered the role of inflammatory clusters (ICs) on the host responses in a cross-sectional setting, including immune regulation and tissue remodeling, during naturally occurring gingivitis, whereas the disease progression to periodontitis seems to be site specific. Low-ICs were more prevalent in the gingivitis-only group compared with the periodontitis group, suggesting that gingivitis sites in periodontitis patients may be at increased risk for disease progression compared with gingivitis sites in gingivitis-only patients.