Evaluation of serum and salivary interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF- α) biomarkers in patients with temporomandibular disorders

Abstract

Biomarkers like TNF-α and IL-1 are increasingly recognised as promising tools for enhancing TMD diagnosis and treatment. These biomarkers are detectable in synovial fluid, saliva, and blood. Salivary and serum biomarkers are increasingly favoured over synovial fluid biomarkers because they are easier to access. Despite this, no study has assessed the levels of these biomarkers in Nigerian patients with TMD. Therefore, this study aimed to evaluate salivary and serum levels of IL-1β and TNF- α in Nigerian patients with TMDs. Methods This 12-month study included 50 participants aged 18 years and above, who were assessed using the Diagnostic Criteria for TMDs and assigned in equal numbers of 25 to either the case group (patients with TMD) or the control group. Venous blood (5mls) and 5mls of unstimulated whole saliva were collected from each participant. The samples were assayed for the biomarkers using the Enzyme-linked Immunosorbent assay (ELISA) method. Data were analysed using SPSS version 26 with significance set at p <0.05. Results The salivary levels of IL-1β in the case group ranged from 317.3-1231.0pg/ml, with the median value of 963.5(265.0)pg/ml, while those of the control group ranged from 12.2-1187.0pg/ml, with a median value of 560.6(491.80)pg/ml. The level of IL-1β in the saliva of the case group was significantly higher than that of the control group ( p <0.001). The salivary levels of TNF- α in the case group ranged from 120.1-891.7pg/ml with a median value of 616.9(194.7)pg/ml, while those of the control group ranged from 105.8-810.2pg/ml with the median being 524.7(283.3)pg/ml. There was no statistically significant difference in the groups ( p = 0.154). Conclusion The TMD patients have a significantly higher level of salivary IL-1β than the normal individuals. Hence, it may be a more reliable biomarker for assessing the effectiveness of therapeutic intervention in TMDs.