Salivary IL-4: A Bleeding Predictor on Probing in Descendants of Severe Periodontitis Patients

Objective: Periodontitis in younger patients can cause severe periodontal destruction, and cases are usually more numerous in members of the same family due to the sharing of susceptibility factors. Thus, the use of a familial study design could improve our understanding of initial alterations in periodontal tissue. This observational study aimed to evaluate the salivary inflammatory pattern in descendants of periodontitis patients and identify any correlation with the clinical periodontal condition. Study design: Fifteen children of Generalized Aggressive Periodontitis (GAgP) patients and 15 children with periodontally healthy parents were evaluated for their plaque index (PI), gingival index (GI), bleeding on probing (BoP), and probing depth (PD). The concentrations of interferon (IFN)-γ, interleukin (IL)-10, IL-17, IL-1β, IL-4, and tumor necrosis factor (TNF)-α were measured in unstimulated saliva using the Luminex MAGPix platform. Results: Children from the GAgP group presented higher probing depth (PD) and bleeding on probing (BoP) (p<0.05) and lower release of IL-4 in saliva (p<0.05) than the periodontally healthy group. The cytokines IL-10, IFN-γ, IL-17, and IL-4 were negatively correlated with the gingival index, while IL-4 was negatively correlated with BoP. A regression analysis revealed that salivary IL-4 and plaque were predictors of BoP. Conclusions: Children of GAgP parents presented lower salivary IL-4 and higher BoP and PD than children from periodontally healthy families. Additionally, salivary IL-4 was a predictor of bleeding on probing in the children, suggesting that the lower presence of this anti-inflammatory cytokine is related to higher clinical inflammation.