Systematic review and meta-analysis of the association of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio with periodontitis.

introductionRecent evidence suggests the relationship between periodontitis and systemic inflammation, which complete blood count can assess (CBC)-derived biomarkers such as neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). We conducted this meta-analysis to evaluate the levels of NLR and PLR of patients with periodontitis compared to those of healthy controls. 

methodsWeb of Science, PubMed, ProQuest, Scopus, and Open Grey were searched for studies published before October 20, 2024, without any limitation on date and language; then, using the random-effects model, we reported a standardized mean difference (SMD) with a 95% confidence interval (CI). In order to assess the quality of publications, we used the Newcastle-Ottawa scale (NOS). Our study was registered in PROSPERO (CRD42023475214).

resultsOverall, 11 articles were included in the analysis. We found that patients with periodontitis had elevated levels of NLR compared to healthy controls (SMD = 0.30, 95% CI 0.08-0.52, p = 0.007) In the subgroup analysis according to race, patients with periodontitis had elevated levels of NLR compared to healthy controls in among East Asian patients (SMD = 0.35, 95% CI 0.15-0.55, p = 0.001), but not among Turkish (SMD = 0.15, 95% CI - 0.30-0.61, p = 0.50) and Indian (SMD = 0.38, 95% CI - 0.17-0.94, p = 0.18) patients. In addition, PLR level was not different among patients with periodontitis and healthy controls (SMD = 0.06, 95% CI - 0.71-0.83, p = 0.87).

conclusionsThe findings of our investigation, which indicate higher NLR levels in periodontitis patients, show that immune dysregulation plays a role in the etiology of the disease.