Gingival crevicular fluid levels of leukotriene B4 in periodontal health and disease

Background: Leukotriene B-4 (LTB4) is a membrane-derived lipid mediator formed from arachidonic acid. LTB4 is among the most potent stimulants of polymorphonuclear leukocytes (PMNs) and, thus, participates in tissue injury by recruiting PMNs in a pathophysiologic scenario of periodontal diseases. The aim of the present study was to assess the relationship between clinical parameters and concentrations of LTB4 within gingival crevicular fluid (GCF) from inflamed gingiva and periodontitis sites before and after the treatment of periodontitis. Methods: Sixty subjects were divided into three groups with 20 subjects in each group: healthy (group 1), gingivitis (group 2), and chronic periodontitis (group 3). Groups were based on periodontal disease index (PDI), clinical attachment loss (CAL), and radiographic evidence of bone loss. Group 4 consisted of the subjects in group 3 at 6 to 8 weeks after treatment, i.e., scaling and root planing (SRP). GCF samples collected from each patient were quantified for LTB4 using an enzymatic immunometric assay. In addition, the correlation between in situ LTB4 levels and clinical parameters was analyzed in each group. Results: The highest mean LTB4 concentration in GCF was observed in group 3 (185.2 pg/mu l), and the lowest was observed in group 1 (39.6 pg/mu l). Its level in group 3 decreased to 79.35 pg/mu l after treatment (group 4). Further, GCF LTB4 levels in all groups showed a statistically significant positive correlation with PDI and CAL (P < 0.005). Conclusion: The substantial increase in GCF LTB4 concentrations with the severity of periodontal disease and a concomitant decrease in its level following SRP in subjects with periodontitis suggest a possible role for LTB4 in the progression of periodontal disease.