307 Plasma Exchange in the Treatment of Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis: A Retrospective Analysis Ebru Gök Oğuz 1  , Saime Paydaş 2  , Nuri Barış Hasbal 3  , Didem Turgut 4  , Hatice Şahin 1  , Bülent Kaya 2  , Zerrin Bicik Bahçebaşı 5  , Serap Yadigar 5  , Serdal Gök 6  , Mehmet Deniz Aylı 1   1 Department of Nephrology, University of Health Sciences, Dışkapı Yıldırım Beyazıt Education and Research Hospital, Ankara, Türkiye 2 Department of Nephrology, Çukurova University, Faculty of Medicine, Adana, Türkiye 3 Department of Nephrology, Başakşehir Cam and Sakura City Hospital, Istanbul, Türkiye 4 Department of Nephrology, Başkent University, Faculty of Medicine, Ankara, Türkiye 5 Department of Nephrology, Dr Lütfi Kırdar Training Hospital, Istanbul, Türkiye 6 Department of Internal Medicine, Kahramanmaraş Sütçü Imam University, Faculty of Medicine, Kahramanmaraş, Türkiye Original Article ABSTRACT Objective: Immunosuppressive therapy in anti-neutrophil cytoplasmic antibody-associated vasculitis is indispensable for patient and kidney survival. There is a controversy about whether the risks of plasma exchange treatment override the probability of kidney-related outcomes. Hence, the question arises in which conditions the plasma exchange will be required? In this study, we aimed to evaluate the effect of plasma exchange adding to immunosuppressive therapy in anti- neutrophil cytoplasmic antibody-associated vasculitis patients. Methods: We retrospectively analyzed 57 patients with biopsy-proven anti-neutrophil cytoplasmic antibody-associated vasculitis. We grouped patients according to treatment options with or without plasma exchange. We investigated the 1-year and 5-year patients and kidney outcomes. Results: Thirty-six (63.2%) of 57 patients were treated with plasma exchange besides the routine immunosuppressive treatment. Sixteen (44.5%) of 36 patients were with active pulmonary hemorrhage and the remaining 20 (55.5%) were with vasculitic pulmonary involvement. The survival rate was 80.7% and 68.8% in the first and fiſth year, respectively. In the multivariate Cox regression analysis model, risk factors affecting patient survival were age >50 years (hazard ratio = 17.11 P = .034), pulmonary involvement (hazard ratio = 13.25, P =.02), positive perinuclear anti-neutrophil cytoplas- mic antibody-associated vasculitis (hazard ratio = 5.93, P =.036), and lower albumin level (hazard ratio = 0.18, P =.014). It is found that C-reactive protein level and plasma exchange did not relate to better patient and kidney outcomes (P > .05). Conclusions: In anti-neutrophil cytoplasmic antibody-associated vasculitis, although pulmonary hemorrhage and pulmo- nary involvement are serious complications, plasma exchange did not provide additional benefit to standard treatment. Keywords: ANCA-associated vasculitis, kidney survival, plasma exchange, end-stage kidney disease Corresponding author: Ebru Gök Oğuz  ebrugokoguz@hotmail.com Received: September 23, 2021 Accepted: November 12, 2021 Publication Date: October 5, 2022 Cite this article as: Gök Oğuz E, Paydaş S, Hasbal NB, et al. Plasma exchange in the treatment of anti-neutrophil cytoplasmic antibody- associated vasculitis: A retrospective analysis. Turk J Nephrol. 2022;31(4):307-313. INTRODUCTION Anti-neutrophil cytoplasmic antibody (ANCA)- associated vasculitis (AAV) involves a group of disorders which are composed of inflammation and destruction of small vessels with necrotizing inflammation, absence (pauci-immune) or presence of immune complex depo- sition with circulating ANCA. 1 The characteristic lesion of pauci-immune glomerulonephritis is focal necrotizing and crescentic glomerulonephritis. 2 Treatment strategies may differ between the centers. Immunosuppressive therapy started on time alters the course of the disease, mainly patient and kidney sur- vival. 3,4 The addition of cyclophosphamide to corticoste- roid during induction increases the remission rates from 55% to 85%, while decreases the recurrence rates by 3 times. 5,6 Immunosuppressive therapy is recommended for all patients with kidney involvement unless they were with severe glomerular loss and severe tubulointerstitial injury. 7 And patients with extra-kidney organ involvement are recommended to be treated with immunosuppressive 10.5152/turkjnephrol.2022.21119175 This work is licensed under a Creative Commons Attribution 4.0 International License.