# Similar Individual Serum Levels of MCP‐1, TNF‐α, and IL‐6 From Periodontitis Patients Before and 1 Year After Treatment

## TL;DR

Periodontitis patients show similar levels of certain inflammatory cytokines before and after treatment, suggesting a stable immune profile unique to each individual.

## Contribution

The study reveals a cytokine equilibrium in periodontitis patients that remains stable over a year, with individual-specific patterns of cytokine levels.

## Key findings

- MCP-1, TNF-α, and IL-6 levels in periodontitis patients remained similar before and after treatment.
- Cytokine levels strongly correlated within individuals but not between cytokines.
- The findings suggest a unique, stable immune system profile for these cytokines in each patient.

## Abstract

Treatment of periodontitis may lower the inflammation status as measured in sera from patients. To investigate this in a biological assay, we co‐cultured periodontal ligament fibroblasts (PDLFs) from a healthy donor and peripheral blood mononuclear cells (PBMCs) as a source for osteoclasts. PDLFs were primed for 3 days with serum from periodontitis patients before and from 1 year after successful treatment of periodontitis (n = 13). After priming, PBMCs were added. No significant differences in the number of osteoclasts that formed after 3 weeks were found between baseline and after‐treatment serum priming. To find an explanation, we analysed the serum composition on the presence of inflammatory, pro‐osteoclastogenic cytokines. We found no differences between before and after treatment for cytokines MCP‐1, TNF‐α, and IL‐6. Interestingly, these levels of cytokines at baseline and after treatment strongly correlated per individual (correlation p‐value between p = 0.03 and p < 0.0001, correlation r
2 between 0.37 and 0.89). Strikingly, between each other, MCP‐1, TNF‐α, and IL‐6 did not correlate. These results show that over the 1‐year time frame a cytokine equilibrium, the relatively similar levels of cytokines over a longer period, exists that is unique per individual. This suggests that the immune system is a constant for these cytokines, adapted to the needs of the individual. Larger cohorts, the inclusion of healthy individuals and longer time intervals need to be studied to further establish the true magnitude of these intriguing findings.

Periodontitis patients before and 1 year present with similar levels of MCP‐1, TNF‐α, and IL‐6, cytokine equilibrium. MCP‐1, TNF‐α, and IL‐6 are not correlated per individual, meaning that some individuals may present with relatively high levels of one of the cytokines with lower levels of the other cytokines or cytokine signature.