1806PSalivary cytokines and oral mucosa cells apoptosis in patients during hematopoietic cell transplantation: Possible relationship with oral mucositis

Abstract Background Apoptosis has a central role in the process of oral mucositis and can be sustained by proinflammatory cytokines. Some studies have demonstrated increased levels of tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6) in saliva after radiotherapy and chemotherapy, which has been associated to severe oral mucositis. However, little is known about the role of these cytokines in the pro and anti-apoptosis process of oral cells exposed to antineoplastic agents. The aim of this study was to verify whether there was an association of salivary cytokines with oral cells exhibiting apoptosis or anti-apoptotic Bcl-2 expression in patients who experienced oral mucositis during hematopoietic cell transplantation (HCT). Methods We collected saliva and oral mucosa cells from 77 HCT patients before the conditioning (T0), during the neutropenia period (T1), and after the marrow recovery (T2). We quantified the oral exfoliated cells exhibiting TUNEL positivity and immunocytochemical expression of Bcl-2. We also determined the salivary levels of TNF-α, IL-1β, and IL-6 in the three periods. Results The number of cells exhibiting positivity to TUNEL (p = 0.021) and Bcl-2 (p = 0.020) increased from T0 to T2. The levels of TNF-α increased significantly from T0 to T1 (p