Benefits of an expanded use of plasma exchange for anti-neutrophil cytoplasmic antibody-associated vasculitis within a dedicated clinical service

Abstract

Background: Current recommendations for ANCA-associated vasculitis (AAV) support its management within a dedicated clinical service. Therapies for AAV are imperfect with many patients failing to achieve disease control and others experiencing disease relapse. Plasma exchange (PEX) may be beneficial especially when the kidney is involved.

Methods: Within a new, dedicated service we retrospectively assessed, over a 6-year period, the benefits of PEX in two patient cohorts, discriminated by PEX treatment alone. Patients received PEX alongside standard of care if they fulfilled any of the following criteria: 1. serum creatinine >500 μmol/l or dialysis-requiring renal failure, 2. alveolar haemorrhage, 3. renal biopsy showing ≥30 % focal and necrotising lesions ± cellular crescents. Outcome measures included disease remission and relapse, cumulative immunosuppression, and morbidity and mortality.

Results: Of 104 new patients, 58 patients received PEX at presentation, 46 did not. Cyclophosphamide and/or rituximab dosing was similar for both groups. Although patients receiving PEX had poorer renal function, a higher C-reactive protein and disease activity score at presentation disease remission rate was similar in both groups (no PEX vs. PEX: 96 % vs. 98 %). The PEX group entered remission quicker (no PEX vs. PEX: 3.9 ± 4.0 vs. 2.8 ± 1.3 months, p < 0.05), with a lower 3-month cumulative glucocorticoid dose (no PEX vs. PEX: 2.5 ± 0.4 vs. 2.3 ± 0.2 g, p < 0.001). Relapse was similar between groups but adverse events lower in the PEX group.

Conclusions: PEX may be of benefit in AAV. Larger, longer randomised controlled trials are now needed.

Fig. 1

Age distribution, source of referral and relapse-free survival curves for all study patients. a age distribution at presentation of all patients cared for within the vasculitis service. Data are shown as % frequency within each 10-year period. b source of referral of vasculitis patients up to 2007 (left) and 2009 – 2013 (right). c relapse-free survival curves for patients in the groups defined by their ANCA status at presentation (PR3: proteinase-3, red line, n = 51; MPO: myeloperoxidase, blue line, n = 46; ANCA-: ANCA negative, green line, n = 7). p = 0.02 for PR3 vs. MPO and for PR3 vs. ANCA- by log rank analysis

Fig. 2

Change in eGFR and relapse-free survival curves for PEX vs. no PEX patients. a change in abbreviated 4-variable MDRD estimated glomerular filtration rate (eGFR) over the 12 months since starting treatment. Data are shown as mean ± standard deviation. Blue circles: received no plasma exchange (PEX); red squares: received PEX. At each time point eGFR was different between the two groups (p < 0.05) based on a repeated measures ANOVA. Between 0 and 12 months there was no change in eGFR in the no PEX group whereas eGFR improved in the PEX group (p < 0.001). b relapse-free survival curves for patients in the group receiving plasma exchange (PEX, red line, n = 58) up to 6 years and for those not receiving it (blue line, n = 46) up to 10 years. p = 0.64 by log rank analysis