Plasma exchange in the treatment of Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome and renal limited vasculitis.

PURPOSE OF REVIEW: The article reviews the use of plasma exchange (PLEX) in the management of the antineutrophil cytoplasm antibody-associated vasculitides (AAV). RECENT
FINDINGS: Early mortality and end-stage renal disease (ESRD) remain frequent outcomes for AAV patients. Demonstration of the pathogenic potential of anti-neutrophil cytoplasm antibody (ANCA) has provided a rationale for antibody removal by PLEX in vasculitis therapy; however, other mechanisms may contribute to the therapeutic effect. Clinical studies have focused on the use of PLEX to rescue organ function in rapidly progressive glomerulonephritis and lung haemorrhage; other indications, including immunomodulatory actions, have received little attention. Randomized controlled trials of PLEX in renal vasculitis suggest a reduction in the risk of development of ESRD with adjunctive PLEX, although the data are not sufficiently strong to make firm recommendations and there are no controlled trials in alveolar haemorrhage.
SUMMARY: It is unclear at what severity of renal failure PLEX is beneficial, the optimal PLEX dosing and type and dosing of concomitant medications. These subjects are the focus of an ongoing study (PEXIVAS). PLEX remains a nonselective, expensive therapy with common adverse events. Selective apheresis techniques (cytapheresis, immunoadsorption) offer theoretical advantages but their use is limited by incomplete understanding of the mechanism of PLEX in AAV and expense.