Serum IgG antibodies to lipopolysaccharides in various forms of periodontal disease in man.

Serum IgG antibody titres to lipopolysaccharides (LPS) from two strains of Actinobacillus actinomycetemcomitans were significantly elevated in juvenile periodontitis compared with other types of periodontal disease and with controls (p less than 0.05). The highest antibody titres to Bacteroides gingivalis LPS were in juvenile periodontitis, but this difference was significant only against the control group (p less than 0.01). In adult mild periodontitis there were higher antibody levels to LPS from Veillonella parvula compared with all other groups and controls (p less than 0.05). The possibility that high antibody titres to LPS from A. actinomycetemcomitans may play a protective role in juvenile periodontitis needs further investigation.