Neutrophil superoxide release and plasma C-reactive protein levels pre- and post-periodontal therapy

Aim: To determine peripheral blood neutrophil superoxide release and C-reactive protein (CRP) concentration in chronic periodontitis patients, before and after non-surgical periodontal treatment.

Materials and methods: Neutrophils were isolated from patient and control volunteers (n = 20) and superoxide measured by lucigenin-enhanced chemiluminescence with and without stimulation with unopsonized Porphyromonas gingivalis, unopsonized Fusobacterium nucleatum and phorbol 12-myristate 13-acetate (PMA) before and 2-months following non-surgical therapy. Corresponding high-sensitivity plasma CRP concentrations were also determined.

Results: At pre-treatment baseline, patient neutrophils released more superoxide in the absence (p ≤ 0.032) and presence of periodontal bacteria (p ≤ 0.013) and after PMA stimulation (p = 0.041) compared to control cells. Post-therapy, patient neutrophil superoxide release was reduced to control cell levels. Median patient plasma CRP concentrations were non-significantly higher than control values and were reduced after therapy (1.80-1.36 mg/l). Patient pre-treatment baseline, unstimulated neutrophil superoxide release showed a significant, positive correlation with plasma CRP concentration (p = 0.01).

Conclusions: Chronic periodontitis is characterized by peripheral neutrophils exhibiting superoxide hyperactivity and hyper-reactivity to periodontal pathogens that is not a constitutive feature of periodontitis patients. The positive, pre-therapy relationship between unstimulated neutrophil superoxide release and plasma CRP is consistent with a protective role for CRP in reducing oxidative stress and systemic inflammation in vivo.