Abstract: Objective To investigate antineutrophil cytoplasmic antibody resulting in antineutrophil cytoplasmic antibody-associated vasculitides by influencing the expression of FcγRⅡa in the cell membrane. Methods Human neutrophils were stimulated by different concentration serum (anti-myeloperoxidase antibody positive and anti-proteinase 3 positive), healthy human serum as control. Flow cytometry was used to detect the expression of FcγRIIa in the neutrophil membrane. FcγRIIa were analyzed by Western blots. Reactive oxygen species(ROS) production was measured by chemiluminescence technique in the presence of 10 mM luminol. Enzyme linked immunosorbent assay (ELISA) was applied to detect the level of serum cytokines TNF-α, IL-6, anti-myeloperoxidase antibody and anti-proteinase 3. Results With the decrease of serum concentration, fluorescence intensity of FcγRIIa expression, the expression of FcγRIIa, ROS generation and secretion of cytokines TNF-α and IL-6 reduced(P<0.05). Conclusion Anti-myeloperoxidase antibody and anti-proteinase 3 antibody maybe play a role in mediating ROS, TNF-α and IL-6 levels through FcγRIIa, and induce the generation of antineutrophil cytoplasmic antibody associated vasculitis.

Key words: ANCA associated vasculitis, Fc gamma receptor IIa, Cytokines