EARLY-ONSET AND ADULT PERIODONTITIS ASSOCIATED WITH ABNORMAL CYTOKINEPRODUCTION BY ACTIVATED T-LYMPHOCYTES

THERE IS GROWING EVIDENCE for an important role of the immune system i n the pathogenesis of periodontitis. To further characterize the possi ble immunoregulatory dysfunction of peripheral blood mononuclear cells (PBMC) in periodontitis patients, we investigated functional aspects of PBMC from patients with early-onset periodontitis (EOP) and adult p eriodontitis (AP). Compared to controls, we observed decreased prolife rative responses of PBMC from patients with EOP following stimulation with a mitogenic stimulus (phytohemagglutinin). To investigate whether this abnormality reflects a modulation in cytokine production, we mea sured the in vitro production of interleukin (IL)-3, IL-5, granulocyte macrophage colony-stimulating factor (GM-CSF), and interferon-gamma ( IFN-gamma) by activated PBMC. PBMC in EOP patients expressed significa ntly decreased levels of IFN-gamma protein in response to mitogenic st imulation. Reduced IFN-gamma secretion was associated with decreased I FN-gamma and IL-2 mRNA expression in these cells, as well as decreased HLA-DR surface expression on monocytes. On the other hand, we observe d significantly higher levels of IL-5 and GM-CSF in the same system us ing PBMC from AP patients. These were comparable to the levels observe d for patients with allergic asthma, These data imply that EOP is asso ciated with decreased Th1-like cytokine expression, and that the PBMC response from patients with AP is predominantly Th2/Th0 in nature.