Immune cell composition and inflammatory profile of human peri-implantitis and periodontitis lesions

Peri-implantitis and periodontitis are common oral inflammatory diseases, which seem to exhibit critical differences in some of their molecular features. Thus, we assessed the immune cell composition of peri-implantitis and periodontitis lesions and the corresponding inflammatory profile in soft tissues and crevicular fluid. Peri-implantitis, periodontitis and control patients were recruited (n=62), and soft tissue biopsies were collected during surgery. Crevicular fluid around implant or tooth was collected. The proportions of major immune cell populations in tissues were analyzed by flow cytometry, and the inflammatory profile in tissue and crevicular fluid by a multiplex immunoassay. No significant difference was seen between peri-implantitis and periodontitis lesions in the proportions of immune cells. Peri-implantitis tissues showed an increased frequency of B cells in comparison with control tissues, along with higher levels of IL-1β, TNF-α, IL-4, and BAFF in tissue and crevicular fluid. Moreover, TNF-α, IL-17A and BAFF were higher in peri-implantitis tissues, but not in periodontitis, than in control tissues. The immune cell composition did not differ significantly between peri-implantitis and periodontitis, but an enhanced inflammatory profile was seen in peri-implantitis tissue. Peri-implantitis lesions were enriched in B cells, and displayed increased levels of IL-1β, TNF-α, IL-4, and BAFF in both tissue and crevicular fluid.