Evaluation of therapeutic plasma exchange in anti-neutrophil cytoplasmic antibody-associated vasculitis in real-life settings: long-term results of propensity score matching analysis in high-risk patients

To evaluate the prognostic significance and safety of therapeutic plasma exchange (TPE) in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) with severe organ or system involvement. Data of patients diagnosed with AAV between 2011 and 2021 were evaluated retrospectively. Patients with baseline estimated glomerular filtration rate (eGFR) ≤ 50 mL/min/1.73m² or diffuse alveolar haemorrhage (DAH) were included in the analysis (n = 71). Patients who underwent TPE were compared with others in the groups formed after two models of propensity score matching (PSM). Initial PSM was performed according to the presence of DAH, age, gender, eGFR, and BVAS. A data-driven approach was conducted for the second model. In the initial PSM cohort (n = 48), the remission rate at 6 months was lower in the TPE group (p = 0.04). There were no significant differences in mortality and improvement of eGFR at 6 and 12 months. No severe complications due to TPE were observed. Rates of serious infections (SIs) and end-stage renal disease (ESRD) at 12 months were higher in the TPE group (p = 0.016 and 0.02, respectively). Data-driven PSM analysis (n = 44) revealed no significant differences between groups. We did not demonstrate a positive effect of TPE on remission, ESRD, and mortality in AAV in this study. Despite low short-term complication rates, the increased risk of SIs possibly associated with ESRD was remarkable. The limited long-term benefits of TPE should be carefully weighed against its associated risks when selecting patients for treatment.