Characterization of immune cells in periodontitis using a new histological immunologic gingival (IG) score.

Periodontitis is a prevalent chronic inflammatory disease due to the host response to dysbiotic biofilm. Immunohistochemistry is often used for a better and more functional tissue characterization. The main objective of this study was to create a semi-quantitative Immunologic Gingival (IG) score for characterizing immune cells in periodontitis based on five immunohistochemical stainings. The study included 11 healthy controls and 11 periodontitis patients. To determine the IG score, an atlas was drawn up with five immunohistochemical stainings (CD138, CD3, CD20, CD68, CD66b). The mean IG score was higher for periodontitis patients than for healthy controls. For each marker of the IG score, a positive correlation was found between the semi-quantitative score and the respective percentage of positive cells. An IG score of 4 out of 15 was the best cut-off for discrimination between healthy controls and periodontitis patients, with a specificity and a sensitivity exceeding 90%. The IG score provides standardized information on the immune cell signature in gingival samples from patients with periodontitis. This score could be applied in translational research but also in clinical practice, particularly for the development of personalized therapies for patients with recurrent periodontitis.