Evaluation of Serum Interleukin-33 Level in Iraqi Patients with and without Periodontal Disease

Objective: Periodontitis is a multifactorial inflammatory illness characterized by periodic tissue support deterioration. Interleukin-33 has recently been discovered as a new pro-inflammatory cytokine implicated in the pathogenesis of periodontitis. The objective of this case control study is to compare IL-33 levels among periodontitis patients and healthy volunteers using serum samples and investigate the potential association with clinical periodontal parameters. Materials and Methods: A total of 100 subjects (50 patients with periodontal disease and 50 healthy individuals) were included in this case control study. Clinical plaque index (PLI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment loss (CAL) were assessed. Serum was extracted from the venous blood that was collected. Serum IL-33 values were measured using an enzyme-linked immunosorbent assay (ELISA). Results: Serum levels of interleukin-33 showed considerably elevated level in the patient's group than in the healthy control group (P< 0.01). There was a strong correlation between the blood levels of IL-33 and PLI, GI, and BOP (P≤ 0.05). While PPD and CAL demonstrated a non-significant relationship (P˃0.05). Conclusion: The results of this study suggested that IL-33 may be used as a potential indicator of the inflammation associated with periodontitis and might have a role in the development of the disease. Further studies with large sample sizes are needed to improve knowledge about the role of IL-33 in periodontal health and disease. Clinical Significance: Owing to the noticeable role that IL-33 plays in the pathogenicity of periodontitis as a local waring clue for the periodontal tissue breakdown, tissue-specific therapeutic strategies may improve. Keywords: periodontitis, interleukin, serum, ELISA, pathogenesis, periodontal parameters