Increased levels of soluble CD163 in periodontitis patients

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.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.Serum sCD163 was significantly higher in periodontitis patients compared to periodontally healthy subjects (720.0 ± 330.6 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).Our findings suggest that CD163 may be involved in the pathogenesis of periodontitis and its link with systemic conditions.