Increased levels of soluble CD163 in periodontitis patients

Aim: Soluble CD163 (sCD163) has been implicated as a new biomarker in inflammatory conditions. The aim of this cross-sectional study was to assess CD163 levels systemically and locally in patients with chronic periodontitis. Methods: sCD163 levels were measured by ELISA in serum samples from 70 periodontitis and 70 periodontally healthy subjects, and in saliva samples in a subset of the population. Two gingival biopsies were harvested per subject from 20 periodontitis patients: one from a periodontally affected site, the other from a healthy site, and the relative expression of CD163 mRNA was assessed by real-time PCR. Results: Serum sCD163 was significantly higher in periodontitis patients compared to periodontally healthy subjects (720.0330.6 ng/ml versus 510.7 +/- 219.6 ng/ml, respectively; p < .001). Similarly, sCD163 levels in saliva were significantly increased in periodontitis compared to healthy subjects (3.01 +/- 5.07 ng/ml versus 1.98 +/- 4.95 ng/ml, respectively; p = .009). Serum and saliva sCD163 levels showed a positive correlation (Kendall's tau .27, p = .018). Importantly, CD163 gene expression was significantly higher in affected sites compared to unaffected sites in periodontitis patients, with a mean fold upregulation of 9.9 (STD: 15.3, p = .010). Conclusion: Our findings suggest that CD163 may be involved in the pathogenesis of periodontitis and its link with systemic conditions.