Immunoinflammatory assessment of TNFα, RANKL, and calprotectin in gingival crevicular fluid of periodontitis patients with type 1 diabetes mellitus

This study aimed to evaluate the levels of tumor necrosis factor-α (TNFα), receptor activator of nuclear factor-κB ligand (RANKL), and calprotectin in gingival crevicular fluid (GCF), as well as serum C-reactive protein (CRP), in periodontitis patients with and without T1DM compared with periodontally healthy controls. A total of 90 participants were enrolled and divided into three groups (n = 30 each): healthy controls, periodontitis patients without diabetes, and periodontitis patients with T1DM. Clinical periodontal parameters, including probing depth (PD), clinical attachment loss (CAL), plaque index (PI), and bleeding on probing (BOP), were recorded. GCF samples were analyzed for TNFα, RANKL, and calprotectin using ELISA technique, while serum CRP and HbA1c levels were measured using automated analyzers. Statistical comparisons were performed using ANOVA and post-hoc tests.Clinical periodontal parameters were significantly worse in both periodontitis groups compared with controls (PD: 3.00±0.00 vs 4.53±0.51, and 4.63±0.49 mm; CAL: 2.00±0.00 vs 3.53±0.51 and 3.63±0.49 mm; p < 0.0001). TNFα levels were significantly elevated in periodontitis patients with T1DM (15.11±2.98 pg/mL) and without diabetes (13.90±2.91 pg/mL) compared with controls (8.72±2.35 pg/mL; p = 0.000). RANKL levels were highest in the diabetic periodontitis group (314.98±74.65 pg/mL) compared with controls (270.46±35.89 pg/mL; p = 0.021). Calprotectin levels showed a significant increase in periodontitis patients with T1DM (0.285±0.149 ng/mL) compared with controls (0.223±0.018 ng/mL; p = 0.017). A strong positive correlation was observed between TNFα and RANKL in both periodontitis groups (r = 0.812, p < 0.001). Periodontitis is associated with significant elevations in local inflammatory and bone-resorptive biomarkers, with T1DM further amplifying neutrophil-mediated inflammation and osteoclastogenic activity. GCF biomarkers, particularly TNFα, RANKL, and calprotectin, may serve as valuable adjunctive tools for periodontal disease assessment in diabetic patients.