Abstract:Objective To observe the curative efficacy of double filtration plasmapheresis (DFPP) combined with immunosuppressant on the treatment of anti-neutrophil cytoplasmic antibodies (ANCA)associated systemic vasculitis (AASV)with renal damage. Methods Out of 12 patients diagnosed as AASV with renal damage treated from May 2016 to April 2019,there were 7 cases with positive MPO-ANCA group and 5 cases with positive PR3-ANCA group.All the patients were treated with DFPP combined with shock therapy of prednisolone and cyclophosphamide.The changes of disease activity index,ANCA titer,immunoglobulin G (Ig),serum albumin (ALB) and serum creatinine (Scr) were compared before and after treatment. Results In positive MPO-ANCA group,Birmingham vasculitis activity score (BVAS),MPO-ANCA titer and Scr level were significantly lower at the end of follow-up than those before treatment (P<0.05,P<0.01),and there were no significant differences in 24-hour urinary protein quantity (Upro),urinary sediment red blood cell count (URBC),ALB and IgG (all P>0.05).One patient underwent maintenance dialysis,and 6 patients achieved partial remission.In positive PR3-ANCA group,BVAS,ANCA titer and the levels of Scr,URBC,ALB and IgG were significantly lower than those before treatment (P<0.05,P<0.01),and there were 1 case of undergoing maintenance dialysis,1 case of complete remission and 3 cases of partial remission. Conclusion DFPP combined with immunosuppressive therapy can effectively reduce ANCA titer and improve renal function in AASV patients with renal damage.