Antibody-dependent cellular cytotoxicity in recurrent aphthous ulceration

Antibody-dependent cellular cytotoxicity (ADCC) was investigated as s possible mechanism of pathogenesis in recurrent aphthous ulceration (RAU). ADCC induced by mononuclear cells from patients at various stages of RAU was compared with ADCC induced by mononuclear cells from paired controls. Chicken red blood cells (ChRBC) coated with rabbit anti-ChRBC antibody were used as targets. A significant increase in ADCC (P less than 0.01, paired sample t-test) in patients' samples as compared with controls was found only at the early stage of the disease. No increased cytotoxicity over control values was observed at any other single stage of the disease. The transient increased cytotoxicity observed in the early stage of RAU may reflect a number of possible mechanisms, including an increased number of ADCC effector cells only at the early stage, an increase in Fc receptor avidity, or an increase in efficiency of the existing effector cell population.