Background: The IL-23/IL-17 axis plays an important role in the immunopathogenesis of periodontal disease. A systematic review was conducted to synthesize all research reporting on the levels of the IL-23/IL-17 axis in gingival crevicular fluid (GCF) from subjects with gingivits, and periodontitis, compared to healthy controls. Methods: The protocol followed the PRISMA, and Cochrane guidelines, and was registered with the Open Science Framework (OSF): https://doi.org/10.17605/OSF.IO/7495V. A search was conducted in the electronic databases PubMed/MEDLINE, Scopus, Google Schoolar, and Cochrane from November 15th, 2005, to May 10th, 2023. The quality of the studies was assessed using the JBI tool for cross-sectional studies. Results: The search strategy provided a total of 2,098 articles, of which 12 investigations met the inclusion criteria. The total number of patients studied was 537, of which 337 represented the case group (subjects with gingivitis, and chronic periodontitis), and 200 represented the control group (periodontally healthy subjects). The ages of the patients ranged from 20 to 50 years, with a mean (SD) of 36,6 ± 4,2, of which 47% were men, and 53% were women. 75% of the investigations collected GCF samples with absorbent paper strips, and analyzed cytokine IL-17 levels individually. In addition, qualitative analysis revealed that there are differences between IL-23/IL-17 axis levels in subjects with chronic periodontitis, gingivitis and healthy controls. Conclusions: Thus, IL-23/IL-17 axis levels could be used in the future as a diagnostic tool to distinguish between periodontal diseases.

Background: Rheumatoid arthritis (RA) and periodontitis (P) are chronic inflammatory diseases characterized by joint and radiographic bone loss, respectively. IL‐23 and IL‐17 have an essential role in the immunopathogenesis of RA, and P. IL‐23 stimulates Th17 cells through which produces IL‐17, IL‐21, and RANKL. IL‐17 stimulates fibroblasts to produce RANKL, which initiates bone loss in the joints in RA and the periodontal tissue in periodontitis. The aim of this study was to determine the expression pattern of IL‐23/IL‐17 axis and soluble receptors isoforms sIL‐23R and sIL‐17RA of patients with RA presenting P (RAP).Material and methods: Healthy subjects (HS) (n = 42), patients with P (n = 40), RA (n = 20), and patients with RAP (n = 40) were included. Plasma samples were obtained to evaluate the IL‐23, IL‐17A, sIL‐23R, and sIL‐17RA by ELISA technique. A nonparametric Mann‐Whitney U test was used to compare the differences between groups. A Chi‐square was used to compare gender, grade and stage of periodontitis, and DAS28‐ESR between the groups. Spearman's rank correlation coefficient was used to study the association between the molecules and clinical parameters.Results: IL‐23 levels were increased in the RAP group, and lower sIL‐23R levels were found in the RAP groups. However, IL‐17A was lower in the P and RAP group but not in RA patients. RAP group showed a decrease IL‐17A levels in advanced stages of the periodontal disease.Conclusion: These results suggest that IL‐23 and IL‐17A tend to downregulate their expression patterns when patients present both rheumatoid arthritis and periodontitis.

Background: Periodontitis (P) is a chronic inflammatory disease characterized by the destruction of periodontium support tissue generated by different immuno-inflammatory mechanisms, including the RANK/RANKL/OPG and the IL-23/IL-17 axis. Methods: The study was performed with healthy subjects (HS) and patients with periodontitis. Plasma samples were obtained from peripheral blood and the gingival tissue (GT) during periodontal surgery. The ELISA technique was used to evaluate the levels of IL-23, IL-17A, IL-23R, and IL-17RA. Results: In the plasma, a significant decrease in IL-17A was observed in patients with periodontitis than HS. In the GT, IL-23, IL-17A, and IL-17RA levels were increased in periodontitis patients; on the contrary, IL-23R levels were decreased in periodontitis patients when compared with HS. Finally, several positive correlations were found: soluble IL-17RA (sIL-17RA) levels in plasma between the percentage of radiographic bone loss (RBL%), and IL-23 with IL-17A in gingival tissue. Conclusions: The detection of the IL-23/IL-17A axis in gingival tissue and plasma provides us with more information on the behavior of this axis in a localized way in the periodontal microenvironment, in contrast to the systemic levels evaluated according to the new classification of periodontitis.

Chronic periodontitis (CP) is characterized by gingival inflammation and bone destruction. It has been reported that interferon-gamma (IFN-γ) levels are high in CP patients; however, the IFN-γ receptor (IFN-γR) has not been studied in gingival tissue from these patients.