Host responses to bacteria and bacterial products in periodontal disease: immunosuppressive effects of periodontitis-related microorganisms?

Several recent investigations indicate that some patients with adult periodontitis have lowered serum antibody levels or reduced lymphoproliferative responses to certain periodontitis-related microorganisms. Many such patients tend to show increased responses after therapy. Some suggested mechanisms of such responses are reviewed and the possible significance of immunosuppressive effects of periodontitis-related microorganisms are briefly discussed.