Surveying immune and inflammatory alterations in periodontitis among individuals with Down syndrome: A preliminary cross-sectional study

Background: Individuals with Down syndrome (DS) are particularly vulnerable to early-onset and rapidly progressing periodontitis, yet the local immune-inflammatory alterations that contribute to this susceptibility are not fully understood. This study aimed to characterize cytokine profiles in gingival crevicular fluid (GCF) from individuals with DS and periodontitis and to compare them with those of periodontitis patients without DS and periodontally healthy controls. Methods: Forty-five participants were enrolled and divided equally into three groups (n = 15 each): DS with periodontitis (DSP), periodontitis without DS (P), and systemically and periodontally healthy controls (C). GCF samples were collected from two interproximal sites per participant and analyzed for IL-1β, IL-4, IL-6, IL-10, TNF-α, and IFN-γ using multiplex immunoassays. Standard periodontal parameters, including probing depth, attachment level, bleeding on probing, and plaque index, were also recorded. Non-parametric comparisons and multivariate approaches, including principal component analysis and hierarchical clustering, were employed to explore cytokine distribution patterns. Results: Individuals with DS and periodontitis exhibited a heterogeneous but predominantly pro-inflammatory cytokine profile, characterized by elevated IL-1β, IL-6, TNF-α, and higher Th1/Th2 and IL-1β/IL-10 ratios. In contrast, the P group demonstrated a Th2-skewed response with higher levels of IL-4, IL-10, and IFN-γ, suggestive of compensatory immune regulation. Healthy controls consistently displayed the lowest cytokine concentrations. Conclusion: This preliminary study identifies a distinct pro-inflammatory cytokine profile in Down syndrome-associated periodontitis, characterized by heightened IL-1β responses and a Th1-skewed immune pattern. While limited by sample size and the absence of a DS-healthy control group, these findings provide initial mechanistic insights into the accelerated periodontal breakdown observed in DS and lay the groundwork for future, larger-scale investigations. Plain language summary: People with Down syndrome (DS) often develop gum disease, called periodontitis, much earlier and more severely than others. This condition damages the tissues and bone that support the teeth and can lead to tooth loss. Researchers believe that an overactive immune system may play a role, but the exact reasons are not well understood. In this study, we examined the levels of several immune signaling molecules, called cytokines, in the fluid around the gums of people with DS and periodontitis, comparing them with individuals with periodontitis but without DS and with healthy participants. We found that people with DS and periodontitis had higher levels of inflammatory cytokines, showing an exaggerated immune reaction dominated by molecules that promote inflammation. In contrast, people with periodontitis but without DS showed signs of a more balanced immune response, including molecules that help to limit inflammation. These findings suggest that individuals with DS experience a stronger and less controlled inflammatory reaction in their gums, which may explain why their gum disease progresses so rapidly. Understanding these immune differences may help to develop better prevention and treatment strategies for people with Down syndrome.