Receptor activator of NF-kappaB ligand (RANKL) and CD 31 expressions in chronic periodontitis patients before and after surgery

The present study investigated the hypothesis that upregulation of receptor activator of NF-kappaB ligand (RANKL) expression may be associated with upregulation of endothelial cell activitiy, which is common for periods of periodontal bone loss in chronic periodontitis. RANKL expression of activated cells in soft tissue biopsies with CD 31 activity and the presence of RANKL and osteoprotegerin (OPG) in gingival crevicular fluid (GCF) were assessed in chronic periodontitis patients. Biopsies from 17 patients and 10 healthy subjects were immunohistochemically analyzed. Clinical measurements [plaque index (PI), the gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL) and gingival bleeding index (GBI)] and GCF samples were obtained before and after periodontal therapy. CD31 staining did not support the assumption that endothelium-like cells were predominantly associated with RANKL expression. RANKL-positive cells were widely distributed in periodontitis patients giving only partial support to the hypothesis that RANKL expression is restricted to T- and B-cell activation.