摘要:The present study examined the IgG antibody activity in sera from a case:control population against whole cell proteins of Porphyromonas gingivalis and four other presumed periodontal pathogens: Bacteroides intermedius; Capnocytophaga ochracea; Wolinella recta; Fusobacterium nucleatum. Whole cell enzyme-linked immunosorbent assays (ELISA) were performed to provide quantitative data on levels of IgG antibody and immunoblotting of whole cell lysates was carried out on 10 case:control pairs to identify the major individual antigens of each organism. For all organisms the mean level of IgG antibody activity against whole cells was higher in the cases compared to controls. For P. gingivalis the difference was highly significant (p <0.0005). For C. ochracea the difference approached statistical significance (p=0.058). Case sera with high antibody activity against P. gingivalis reacted with a large number of components on immunoblots in the molecular weight range 20 000-90 000, whereas control sera reacted weakly with only a small number of components of 80 000-90 000. Cases and controls showed high reactivity with B. intermedius whole cell lysates on immunoblots. Although numerous proteins of the other organisms were recognised by case and control sera, no discriminatory antigens were detected. The demonstration of discriminatory antigens of P. gingivalis justifies further work on their characterisation and possible role as virulence factors.Keywords: Porphyromonas gingivalis; Antibody; Immunoblots; ELISA; Periodontitis-related pathogens.