Longitudinal Salivary Immunophenotyping Reveals Distinct Cellular Signatures of Periodontal Disease Activity and Resolution

Aim: To investigate whether salivary immune cell profiling can serve as a non-invasive approach to monitor periodontal disease activity and therapeutic response by characterizing innate and adaptive immune cell dynamics in periodontitis. Materials and Methods: This longitudinal study included systemically healthy adults with periodontitis and healthy controls. Periodontal parameters (PPD, BOP, plaque/calculus, and radiographic bone loss) were recorded by calibrated examiners following established criteria. Stimulated saliva and gingival biopsies were collected before and 4-6 weeks after non-surgical periodontal therapy (NSPT), and from healthy controls. Multiparametric flow cytometry was used to characterize myeloid and lymphoid cell populations and polarization markers. Bacterial transcripts and host inflammatory markers were assessed by qRT-PCR. Statistical analyses were performed using one-way ANOVA. Results: Periodontitis subjects exhibited significantly elevated salivary bacterial transcripts, which decreased but did not normalize following NSPT. Both myeloid and lymphoid immune cell populations increased in periodontitis compared with healthy controls and declined after therapy. This was accompanied by a pronounced pro-inflammatory shift with elevated IFN-gamma-producing macrophages, dendritic cells, Th1/Th17 cells, and B cells, including the novel identification of IFN-gamma-producing B cells in saliva and mirrors the gingival immune cell profiles. In contrast, anti-inflammatory populations (IL-10-producing myeloid cells, Tr1 cells, and regulatory B cells) were reduced in disease and partially restored following NSPT. Conclusions: Salivary immunophenotyping non-invasively monitors PD activity and therapeutic response by capturing dynamic immune changes that reflect gingival signatures and track post-therapy resolution.