A Cochrane review included 13 studies with a total of 702 subjects. Plasma exchange as adjunctive therapy significantly reduces the risk of end-stage kidney disease (ESKD) at three months (RR 0.45, 95% CI 0.24 to 0.84; 1 study) and 12 months (RR 0.47, CI 0.24 to 0.86; 5 studies). Three studies compared the use of pulse and continuous administration of cyclophosphamide (CPA). Overall analysis showed a significant increase in remission with pulse CPA (RR 1.17; 95%CI 1.02-1.35; 2 studies) but there was an increased risk of relapse with pulse versus continuous therapy (RR 1.75, 95% CI 1.00 to 3.05; P = 0.05; 3 studies). A single study addressed the use of azathioprine (AZA) after three months of CPA therapy compared to remaining on CPA, showing no difference in outcome except for significantly less leukopenia in patients on AZA. One study into the use of antibiotics to prevent relapse in Wegener's granulomatosis failed to show a significant effect.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment and lack of blinding).