Comparison of circulating tumour necrosis factor superfamily cytokines in periodontitis patients undergoing supportive therapy: a case-controlled cross-sectional study comparing smokers and non-smokers in health and disease.

BACKGROUND: B-cells are prominent immune cells in established periodontitis lesions. Tumour necrosis factor superfamily (TNFSF) cytokines play roles in supporting B-cell function as well as bone re-modelling. The influence of smoking on factors that support B-cell function in periodontitis remains unclear. AIM: To investigate plasma concentrations of TNF (TNSF1A), soluble receptor activator of nuclear-factor Kappa-B ligand (sRANKL/TNFSF11), a proliferation-inducing ligand (APRIL/TNFSF13), B-cell activating factor (BAFF/TNFSF13B) and Osteoprotegerin (OPG/TNFRSF11B) in smokers and non-smokers with and without chronic periodontitis MATERIALS &
METHODS: Plasma concentrations of TNFSF and OPG were evaluated in 200 systemically healthy subjects divided into four groups: non-smokers with periodontitis (n = 101), smokers with periodontitis (n = 55), healthy non-smokers (n = 27) and healthy smokers (n = 17).
RESULTS: Periodontitis patients had significantly higher plasma sRANKL, TNF, APRIL and BAFF and lower OPG than healthy subjects (p < 0.01). TNF and sRANKL were significantly greater in smokers with periodontitis (p = 0.011, p = 0.001) and OPG concentrations significantly lower (p = 0.001), whereas APRIL or BAFF were little changed. Plasma APRIL, BAFF, sRANKL and TNF correlated with probing depth and clinical attachment loss.
CONCLUSION: TNFSF cytokines correlate with periodontitis disease severity. However, only TNF, sRANKL and OPG levels were altered by cigarette smoking. APRIL and BAFF appear as good indicators of disease severity.