Evaluation of the levels of Fractalkine (CX3CL1), TNF-α, and TGF-β in the gingival crevicular fluid/tissue of patients with gingival overgrowth: a cross-sectional observational study.

BACKGROUND

Fractalkine (CX3CL1) is expressed by various cells, contributing to the pathogenesis of diseases such as diabetes mellitus, vascular pathologies, and rheumatoid arthritis via immunological mechanisms. The CX3CL1-CX3CR1 axis regulates cellular responses such as proliferation and collagen production, which are implicated in gingival overgrowth (GO).

OBJECTIVES

This study aimed to assess the levels of CX3CL1, tumor necrosis factor-α (TNF-α), and transforming growth factor-beta (TGF-β) in both gingival crevicular fluid (GCF) and gingival tissues among patients with biofilm- and amlodipine-induced GO. Additionally, the potential relationship between these biomarkers and clinical periodontal parameters was evaluated.

METHODS

The study included 17 participants with biofilm-induced GO (Group I), 18 participants with amlodipine-induced GO (Group A), and 10 systemically healthy participants without GO (Control). CX3CL1, TNF-α, and TGF-β levels in GCF samples were assessed using enzyme-linked immunosorbent assay (ELISA). Moreover, mRNA expression levels of CX3CL1, TNF-α, and TGF-β in tissue samples were determined by quantitative real-time PCR (qPCR).

RESULTS

The total GCF CX3CL1 level was significantly higher in Group I and Group A compared to controls. However, tissue CX3CL1 and TNF-α levels were significantly higher in Group I than Group A (p<0.05). In Group A, total GCF CX3CL1 levels showed a positive correlation with the gingival index (GI) (r=0.644), bleeding on probing (BOP) (r=0.622), and GCF volume (r=0.720). A significant positive correlation was observed between tissue CX3CL1 and TNF-α levels (r=0.762) (p<0.05). In Group I, a significant correlation was observed between total GCF CX3CL1 and TNF-α, TGF-β, and GCF volume levels, respectively (r=0.865, r=0.845, r=0.651). A positive correlation (p<0.05) was also found between tissue CX3CL1 and TNF-α and TGF-β levels, respectively (r=0.689, r=0.903).

CONCLUSION

CX3CL1 may have a potential role in the development of GO-associated tissue fibrosis and its inflammatory mechanisms.