Increased levels of interleukin-32 isoforms alpha, beta, gamma, and delta in the gingival crevicular fluid and plasma of the patients with periodontitis

Background and Objective Interleukin (IL)-32, which has been recently reported to be associated with periodontitis, has been suggested to have pleiotropic effect due to its 9 different isoforms. The aim of this study was to investigate the levels of IL-32 alpha, IL-32 beta, IL-32 gamma, IL-32 delta isoforms in gingival crevicular fluid (GCF) and plasma before and after non-surgical periodontal treatment in patients with periodontitis (P). Materials and Methods Twenty-seven P and 27 periodontally healthy controls (C) were recruited in this study. Non-surgical periodontal treatment was performed to periodontitis patients. GCF and plasma sampling and clinical periodontal parameters were evaluated before and 1 month after treatment. Enzyme-linked immunosorbent assay was used to analyze the levels of IL-32 alpha, IL-32 beta, IL-32 gamma, IL-32 delta isoforms in GCF and plasma samples. Results The levels of IL-32 alpha, IL-32 beta, IL-32 gamma, and IL-32 delta in plasma and GCF were significantly higher in patients with periodontitis than healthy controls (P < .001). In P group, plasma and GCF IL-32 alpha, IL-32 beta, IL-32 gamma, and IL-32 delta levels after non-surgical periodontal treatment were lower when compared to baseline (P < .001). Moreover, there was a positive correlation between GCF and plasma IL-32 alpha, IL-32 beta, IL-32 gamma, and IL-32 delta levels in all groups at baseline and after treatment (P < .05). Conclusion The study supported that there was a relationship between elevated levels of IL-32 isoforms and periodontitis. Also, our novel findings suggest that the pro-inflammatory role of IL-32 in the periodontitis may be originated from IL-32 alpha, IL-32 beta, IL-32 gamma, and IL-32 delta isoforms.