Peripheral memory T-cell profile is modified in patients undergoing periodontal management.

Aims: T-cells are known to have a role in periodontitis, however, the effect of periodontal therapy on peripheral memory T-cells is unclear. This study evaluated variation in peripheral memory T-cells and red complex bacteria in sub-gingival plaque in patients undergoing periodontal management.

Methods: Peripheral blood mononuclear cells and sub-gingival plaque were collected from 54 periodontitis patients at baseline, 3-, 6- and 12-months post-therapy and 40 healthy controls. Periodontitis patients were divided into treatment outcome (TxO) groups based on prevalence of sites with probing depth ≥5 mm as good (<10% of sites), moderate (10-20%) or poor (>20%) at study conclusion. Naïve (T -CCR7 CD45RA ), central memory (T -CCR7 CD45RA ), effector memory (T -CCR7 CD45RA ) and effector memory T-cells re-expressing CD45RA (T -CCR7 CD45RA ) were phenotyped using flow cytometry in CD4 , CD8 , CD4 CD8 and CD4 CD8 T-cells and red complex bacteria were quantified using qPCR.

Results: At baseline, periodontitis subjects had significantly greater mean probing depths and Porphyromonas gingivalis proportions, lower T but higher CD4 T , CD8 T , CD4 CD8 T and CD4 CD8 T cell proportions compared to health. Periodontal therapy decreased mean probing depths, P. gingivalis proportions, T and CD4 and CD8 T cells, but increased T and CD4 and CD8 T cells. The T-cell profile in the good TxO group showed therapy-related changes in CD4 T , and CD8 T and T cells, whereas, no changes were observed in the poor TxO group.

Conclusion: Management and the reduction in red complex bacteria were associated with changes in peripheral memory T-cells in periodontitis.