Necrotizing periodontal diseases in HIV-seropositive subjects: pathogenic mechanisms

Necrotizing gingivitis (NG) is a well-known periodontal condition characterized by marginal gingival necrosis, bleeding and pain. Necrotizing periodontitis is an extension of NG into the periodontal attachment apparatus, and the two stages are referred to collectively as necrotizing periodontal diseases (NPD). Necrotizing periodontal diseases in HIV-seropositive subjects are similar with regard to the spectrum of periodontopathic bacteria, the clinical manifestations, the natural course and the response to treatment when compared to NPD in HIV-seronegative subjects. However, in the former group, there is an increase in the prevalence of candidal species and herpesviruses in the subgingival plaque and gingival biopsy specimens. In the periodontal tissues, spirochaetes, activated herpesviruses, Candida species and HIV have the capability of deregulating host innate and adaptive immune responses and of stimulating host inflammatory reactions, and may therefore explain the greater prevalence of NPD in HIV-seropositive subjects compared to immunocompetent subjects.