Evidence for local production of antibodies to auto and non-self antigens in periodontal disease.
Autoimmune mechanisms may contribute to periodontal disease (PD) pathogenesis; autoantibody to collagen type 1 is produced at the periodontal site and local levels are found to be higher than in serum.


OBJECTIVE
To find any evidence of autoimmune destruction in diseased periodontal tissues in patients with periodontitis. The study examines the relationship of antibodies to a self antigen collagen Type 1 and antigens from two periodontal pathogens namely Porphyromonas gingivalis (Pg), Actinobacillus actinomycetemcomitans (Aa) and a non-oral bacterium Bacteroides fragilis (Bf) in disease sites and in serum.


METHODS
Granulomatous tissues from periodontally diseased sites and serum samples were obtained from 13 patients (15 sites) undergoing surgical therapy. Tissues were homogenized at 4 degrees C on Tris saline buffer [1 g (5 ml)-1], homogenate was centrifuged and the resultant supernatants were used in assays. Antibody to collagen and Aa, Pg and Bf in tissue eluates and serum were determined by competitive enzyme linked immunosorbant assay (ELISA) and conventional ELISA respectively using an alkaline phosphatase/p-nitrophenyl phosphate enzyme-substrate system. Sera from age and sex matched healthy subjects and pooled human serum were used as controls. Antibody (Ab) levels in tissues and serum were standardized by concomitant albumin assay.


RESULTS
Level of antibodies to collagen type 1 in tissue was significantly higher than in serum (P = 0.0001). Antibody levels in tissue to Pg were significantly higher than in serum (P = 0.0271). Ab levels to both Aa and Bf in tissues and serum were not significantly different from each other.


CONCLUSIONS
These findings confirm the process of the local production of antibodies to autoantigen namely collagen type-1 and to bacterial antigens in the granulomatous tissues housed within the periodontal lesions in patients with periodontitis.
Rajapakse
P S
PS
Department of Oral Medicine and Periodontology, Faculty of Dental Science, University of Peradeniya, Peradeniya, Sri Lanka. sunethraraj@pdn.ac.lk
Dolby
A E
AE
D000328:Adult; D016976:Aggregatibacter actinomycetemcomitans / Q000276:immunology; D000907:Antibodies, Bacterial / Q000096:biosynthesis / Q000097:blood; D001323:Autoantibodies / Q000032:analysis / Q000096:biosynthesis* / Q000097:blood; D001441:Bacteroides fragilis / Q000276:immunology; D016022:Case-Control Studies; D024042:Collagen Type I / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010518:Periodontitis / Q000097:blood / Q000276:immunology*; D016966:Porphyromonas gingivalis / Q000276:immunology; D018709:Statistics, Nonparametric
D000907:Antibodies, Bacterial; D001323:Autoantibodies; D024042:Collagen Type I