Double-blind analysis of the relation between adult periodontitis and systemic host response to suspected periodontal pathogens.

By using a sensitive enzyme-linked immunosorbent assay, 200 randomly selected sera from Red Cross blood donors were screened for immunoglobulin G (IgG), IgA, and IgM levels against Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Bacteroides intermedius. A subgroup of 79 blood donors was clinically examined for type and extent of periodontal destruction, and serological and clinical data were subjected in all possible dual combinations to correlation analyses. The results revealed that the majority of the blood donors suffered from moderate to severe adult periodontitis, often coupled with severe gingival inflammation. No cases of localized juvenile periodontitis or rapidly progressive periodontitis were observed. The extent of periodontal destruction proved to be significantly correlated only to the IgG response levels against B. gingivalis. Corresponding correlation tests assessing the relationships of loss of attachment, bone loss, pocket depth, and papillary bleeding index with the IgG responses to A. actinomycetemcomitans were of marginal significance, while the IgG responses to B. intermedius revealed no relationship to the periodontal health status. The specific IgM responses proved to be unrelated to the clinical parameters, but interestingly, they were found to be highly correlated with each other. Specific IgA levels were frequently too low for enzyme-linked immunosorbent assay testing and, therefore, had to be exempted from statistical analyses. Assessments of the serotype specificity of strongly elevated IgG responses to A. actinomycetemcomitans disclosed no evidence for an association of a particular serotype-specific IgG response with the occurrence of adult periodontal destruction. In contrast to results of earlier studies, a number of sera were found to contain strongly elevated IgG levels against two or even all three serotypes. Although derived by an alternative approach, the reported results largely corroborate earlier observations linking only the occurrence of elevated anti-B. gingivalis IgG responses to the presence of marked periodontal lesions in adults.