Interleukin-8 and granulocyte elastase in gingival crevicular fluid in relation to periodontopathogens in untreated adult periodontitis

Background: This study aimed to determine the relationships among interleukin (IL)-8 and granulocyte elastase levels in gingival crevicular fluid (GCF) and the concomitant presence of periodontopathogens in untreated adult periodontitis. Methods: GCF and subgingival plaque samples were collected from 16 patients with untreated adult periodontitis and 10 healthy control subjects. IL-8 levels were determined by enzyme-linked immunosorbent assay (ELISA). Granulocyte elastase was analyzed with a neutrophilic granulocyte-specific, low molecular weight and chromogenic substrate, L-pyroglutamyl-Lprolyl-L-valine-p-nitroanilide, and the maximal rate of elastase activity (MR-EA) was calculated. Five DNA probes were used to detect the presence of A. actinomycetemcomitans (A.a.), B. forsythus (B.f.), P. gingiualis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.). Results: Lower IL-8 concentrations and higher granulocyte elastase activities were found in patients than in healthy controls as well as in diseased conditions co-infected with B.f., P.g., P.i., and T.d. as compared to healthy conditions without the target species (P < 0.05). IL-8 concentrations were positively correlated with MR-EA levels in the periodontitis conditions coinfected with B.f., P.g., P.i., and T.d. (P < 0.05). A wide range of IL-8 concentrations was found among 15 patients when the periodontitis condition was characterized by co-infection with B.f., P.g., P.i., and T.d. MR-EA levels in the high IL-8 group of subjects were significantly higher than those in the low IL-8 group of subjects (P < 0.01). Conclusions: The present study shows that the local host-bacteria interactions in untreated periodontitis are diverse in terms of the intensity of inflammatory responses measured by IL-8-related granulocyte elastase activity in GCF This might reflect different phases of the inflammatory response due to shifts in host-bacteria interactions and therefore be indicative of a range of periodontal disease activity levels.