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. Naive (T(N) -CCR7(+) CD45RA(+) ), central memory (T(CM) -CCR7(+) CD45RA(-) ), effector memory (T(EM) -CCR7(-) CD45RA(-) ) and effector memory T-cells re-expressing CD45RA (T(EMRA) -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(N) but higher CD4(+) T(CM) , CD8(+) T(CM) , CD4(+) CD8(+) T(EM) and CD4(-) CD8(-) T(EM) cell proportions compared to health. Periodontal therapy decreased mean probing depths, P. gingivalis proportions, T(EM) and CD4(+) and CD8(+) T(CM) cells, but increased T(N) and CD4(+) and CD8(+) T(EMRA) cells. The T-cell profile in the good TxO group showed therapy-related changes in CD4(+) T(EM) , and CD8(+) T(N) and T(EM) 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.