Systemic immune‐inflammation index in patients with generalized stage III grade C periodontitis

Abstract Objectives Systemic immune‐inflammation index (SII) is a novel, inflammatory biomarker whose role in predicting several chronic systemic diseases has been recently identified. However, its association with generalized stage III grade C periodontitis in young adults remains unknown. Material and Methods The study is a multicentered, double‐blind, hospital‐based case–control clinical study. Periodontal examination comprised of recording plaque index, sites with bleeding on probing, pocket depth and clinical attachment loss for patients with generalized stage III grade C periodontitis and periodontally healthy group. Complete blood counts were obtained and used for calculating SII, neutrophil‐lymphocyte ratio (NLR) and platelet‐lymphocyte ratio. Collected data were then subjected to statistical analyses. Results SII was significantly higher in patients with generalized stage III grade C periodontitis compared to periodontally healthy individuals (723.87 vs. 537.74 × 10 9 /L, p < 0.0001). SII is associated with severe periodontitis in young adults (odds ratio [OR]:11.86, 95% CI 9.61–20.76, p < 0.0001) after adjusting for factors found significant in univariate analysis. Receiver operative curve analysis demonstrated a fair predictive validity of SII in detecting generalized stage III grade C periodontitis in young adults (AUC: 0.766, 95%CI 0.731–0.799, p < 0.0001, sensitivity 81.27%, specificity 76.50% and diagnostic accuracy 78.89%). SII did not exhibit superior predictive validity when compared with NLR in the context of generalized stage III grade C periodontitis (AUC for SII: 0.766, 95%CI 0.731–0.799, AUC for NLR: 0.788, 95% CI 0.754–0.819; p = 0.28). Conclusion SII is associated with generalized stage III grade C periodontitis in young adults.