Disease-related cytokine markers in persistent apical periodontitis – associated with comorbidities?

Abstract

Objectives: This study aimed to identify disease-related markers in persistent apical periodontitis (PAP) biopsies and examine whether these were associated with comorbidities. Materials and method: The levels of the cytokines GM-CSF, IFN-γ, IL-2, IL-6, IL-9, IL-10, IL-13, IL-15, IL-17E/IL-25, IL-21, IL-23, IL-27, IL-28A/IFN -λ2, IL-33, MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodontitis (n = 20) and compared to healthy bone samples (n = 20). Results: We identified eleven cytokines to be differently expressed, and among them, IL-2, IL-6, IL-17E, IL-21, and IL-27 appeared to drive the discrepancy between the disease and healthy groups. The levels of T follicular helper (Tfh) cell promoting cytokines (IL-21, IL-6, IL-27) were enhanced while T helper (Th) 1 cell promoting cytokine (IL-2), Th2 cell promoting cytokine (IL-13), and Th17 cell promoting cytokine (IL-17E) were reduced in the PAP group. The data also indicate that Tfh cell differentiation (IL-21), along with Th1 (GM-CSF, IFNγ), Th2 (IL-13), and Th17 (GM-CSF) cell differentiation, might be increased in the subpopulation of patients suffering from rheumatoid arthritis, whereas no differences were found in patients with cardiovascular diseases. Conclusions: A cluster of potential cellular markers for PAP was identified. The lesions contained additional factors that might be associated with differentiation of various T cell populations. Clinical Relevance: Molecular analyses of PAP may result in identification of prognostic markers.