Antigens of Actinobacillus actinomycetemcomitans identified by immunoblotting with sera from patients with localized human juvenile periodontitis and generalized severe periodontitis.

Sonicated whole cell extracts and outer membrane proteins from this bacterium were analysed using sera from 31 young patients with localized juvenile periodontitis, 55 young adults with generalized severe periodontitis and from 31 healthy control subjects. The sonicate contained 13 major bands (14-78 kDa); a greater proportion of sera from patients with generalized periodontitis reacted with 40 and 70 kDa antigens when compared with sera from localized juvenile periodontitis and controls. In contrast, a lower proportion of sera from localized juvenile periodontitis reacted with the 29 kDa antigen when compared with severe periodontitis and controls. The outer membrane proteins contained four main antigens of 19, 24, 35 and 67 kDa, which reacted with sera from all three groups. Although, so far, the findings do not allow discrimination between the two diseases, antibody responses to the 29, 40 and 70 kDa antigens of A. actinomycetemcomitans may help in the assessment of severity of the disease in patients with periodontitis.