The relationship between serum IgG levels to subgingival gram-negative bacteria and degree of periodontal destruction.

The relationship between the serum IgG antibody titer against seven species of Gram-negative periodontopathic bacteria and clinical parameters (including plaque index, gingival index, periodontal pocket depth, and alveolar bone loss) was studied in 38 subjects. IgG antibody titer against the sonicated antigens was determined by micro-ELISA. A statistically significant correlation was found between the serum antibody titer against B. gingivalis and the degree of clinical parameters, especially pocket depth. The serum IgG levels against the seven micro-organisms in 16 periodontal patients before and after clinical treatment were also determined. Responses to B. gingivalis decreased (p less than 0.001), whereas responses to E. corrodens (p less than 0.01) increased slightly. No marked differences were noted between pre- and post-treatment sera in titers against B. intermedius, B. loescheii, F. nucleatum, A. actinomycetemcomitans, and C. ochracea.