Abstract
OBJECTIVE: To analyze the inflammatory indexes and cytokines levels in serum and saliva of patients with chronic periodontitis (CP), and to explore the value of single index or multiple indexes combined detection in the clinical diagnosis and treatment of CP. METHODS: The serum and saliva specimens of 42 CP patients and 38 periodontal healthy people admitted to the Department of Periodontology in Peking University Hospital of Stomatology were detected by inflammatory indexes and cytokines. According to clinical periodontal parameters, CP patients were performed by clinical staging, and the correlation between inflammatory indexes and cytokines levels and the severity of CP was analyzed. To evaluate the levels of inflammatory indexes and cytokines in serum and saliva samples in the periodontal health group and CP group. Three inflammatory indexes were involved in this study: C-reactive protein (CRP), serum amyloid A (SAA), procalcitonin (PCT); and 12 cytokines: Interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12P70, IL-17, interferon (IFN)-α, IFN-γ, and tumor necrosis factor α (TNF-α). The Spearman correlation statistical method was used to analyze the correlation between the levels of inflammatory indexes and cytokines and the severity of chronic periodontitis. Mann-Whitney U test was used to identify the indicators with differences between the groups, the optimal indicators were identified through binary Logistic regression analysis with stepwise selection, and the area under the curve (AUC) of receiver operating characteristic (ROC) was used to evaluate the diagnostic efficiency. RESULTS: By testing the levels of inflammatory markers and cytokines in patients with chronic periodontitis with dif-ferent clinical stages, it was found that CRP, SAA, IL-8 in serum and IL-1β, IL-6, IL-8, IL-12P70, IL-17, TNF-α in saliva were significantly positively correlated with the severity of chronic periodontitis. Compared with the periodontal healthy group, the serum levels of CRP, SAA, IL-2, IL-5, IL-8, IL-12P70, IL-17 and IFN-α in the CP group were significantly increased (All P < 0.05). The AUC of SAA, IL-2, IL-8, IL-12P70, IL-17, IFN-α, combination 1 (IL-2+IL-8) and combination 2 (CRP+SAA+IL-12P70) were >0.7, and the AUC of combination 2 (0.998) was the highest, with high sensitivity (97.6%) and specificity (97.4%). The levels of IL-1β, IL-6, IL-8 and IL-12P70 in the saliva of the CP group were significantly higher than those in the periodontal healthy group, while the levels of IL-4 in the saliva were significantly lower than those in the periodontal healthy group (All P < 0.05). The AUC of IL-6, IL-8 and combination 3 (IL-4+IL-6+IL-8) were >0.7, and the AUC of combination 3 (0.852) was the highest. In the comparative analysis of diagnostic efficacy between single index and multi-index combined, combination 2, combination 1, and serum IL-8 demonstrated the highest AUC values (ranked top 3), with multi-index combinations exhibiting superior discriminative power over single index. CONCLUSION: Serum levels of IL-8, CRP, SAA, and salivary levels of IL-1β, IL-6, IL-8, and other indicators may be helpful for the clinical diagnosis and treatment of CP. Serum IL-8 and multiple indicators may be used as an auxiliary diagnostic indice to identify CP.