Reaction of human sera with Eubacterium brachy: isolation and characterization of an extracellular antigen

A comparison of the reactivity of Eubacterium species with localized and serum immunoglobulins from rapidly progressive and adult periodontitis patients

Immunoglobulins in sera and in supernatant fluids of explant cultures of diseased gingival tissues from 20 rapidly progressive and 20 adult periodontitis sites were tested by an ELISA assay for reactivity with typed strains of Eubacterium alactolyticum, E. brachy, E. limosum and E. nodatum. Immunoglobulins present in tissue culture fluids from both rapidly progressive and adult periodontitis samples reactive with E. brachy and E. nodatum were significantly greater (P less than 0.05) than those reactive with E. alactolyticum or E. limosum. The titers to E. brachy in tissue culture fluids from adult periodontitis were significantly greater (P less than 0.05) than those from rapidly progressive periodontitis; there was no difference in titers to the other three species. The only significant difference in serum titers was that sera from patients with rapidly progressive periodontitis had significantly greater reactivity to E. alactolyticum than did sera from adult periodontitis patients. These data indicate that immunoglobulins in the sera of rapidly progressive and adult periodontitis patients do not necessarily reflect the reactivity of localized immunoglobulins present in the diseased gingival tissue explant culture fluids from these patients.