Expression and secretion levels of Th1 and Th2 cytokines in patients with aggressive periodontitis

The role of Th1 and Th2 cytokines in the pathogenesis of aggressive periodontitis has not been previously examined. The aim of this study was to analyse the expression and production of IL-2, IFN-γ, IL-4 and IL-13 in CD4+ cells from the peripheral blood of patients with aggressive periodontitis (AgP) and periodontally healthy controls. Gene expression was analysed in inactivated and activated CD4+ cells by real-time PCR. Cells were activated for 4, 8 and 24 h with anti-CD3/CD28 antibody, phytohemagglutinin (PHA), and Porphyromonas gingivalis (P.g.) outer membrane protein (OMP). Protein levels were measured in supernatants of activated CD4+ cells by bead-based immunoassay (CBA). Statistics were performed using U test (p < 0.05). In controls, IL-4 expression was increased in inactivated CD4+ cells (p = 0.05), and IFN-γ and IL-2 expressions were increased in activated CD4+ cells: IFN-γ with anti-CD3/anti-CD28, P.g. OMP and PHA (p < 0.05); IL-2 with P.g. OMP and PHA (p < 0.05). In patients, although IL-4 and IL-13 expressions were higher in activated CD4+ cells, there were no differences compared to controls. The production of IL-4 and IL-2 was higher in the patients' CD4+ cells activated with PHA (p < 0.05). Although the results showed a predominantly Th1 mRNA profile in activated CD4+ cells of controls, protein concentrations showed no clear Th1 or Th2 profiles. The functional pathways of the Th cell immune response in aggressive periodontitis are still not well understood in order to develop individualised diagnostic and treatment plans.