Abstract: 【Abstract】Objective The objective of this study was to investigate the effect of double-filtration plasmapheresis (DFPP) therapy on anti- neutrophil cytoplasmic antibody (ANCA)- associated vasculitis that requires renal replacement therapy (RRT) and its effect on survival rate. Methods A total of 25 patients with ANCA-associated vasculitis diagnosed in the First People's Hospital of Zigong from January 2015 to March 2017 were enrolled in this study. RRT was required at the time of diagnosis. Patients were randomly divided into the DFPP group (n=12) and the control group (n=13). Both groups received glucocorticoid and cyclophosphamide
immunosuppressive therapy; the DFPP group also treated with DFPP therapy. Demographic data and clinical parameters of the patients were collected. ANCA and IgG levels were measured before and after DFPP therapy for three times. Their survival rate was calculated after follow-up for 12 months. Results In the DFPP group, myeloperoxidase (MPO)- ANCA and IgG levels after the treatment decreased by 53.2% (t=12.131, P＜0.001) and 47.4% (t=10.798, P＜0.001) respectively. In the control group, MPO-ANCA level after the treatment decreased 16.7% (t=10.319, P=0.069), and IgG level decreased by 14.1% (t=10.134, P=0.035). In the DFPP group, IgG level decreased by 33.8% as compared with that in the control group (t=5.334, P=0.012). During the follow-up period of 12 months, the cumulative survival rate was 61.5% in the DFPP group and 58.3% in the control group (c2= 0.193, P=0.046). All survival patients still relied on dialysis during the follow-up study. Conclusion DFPP can effectively reduce the levels of IgG and MPO-ANCA and improve one year survival rate. However, DFPP cannot change dialysis dependence of the patients.

Key words: double-filtration plasmapheresis therapy, Renal replacement therapy, Anti-neutrophil granulocyte cytoplasmic antibody, Prognosis