Plasma exchange treatment for CNS inflammatory demyelinating disease

Introduction Research into therapeutic applications of apheresis is limited by the rarity of many of the diseases for which plasma exchange (PLEX) is indicated and by the uncommon and often dire circumstances in which apheresis is considered for common diseases (e.g. myasthenic crisis and acute severe demyelinating disease attacks unresponsive to standard treatment). It is often difficult to perform randomized or appropriately powered studies for these reasons. As a result, case reports, case series, and underpowered trials dominate the literature with respect to clinical application of apheresis. To address this weakness, the American Society for Apheresis (ASFA) Apheresis Categories Subcommittee reviews the medical literature concerning the use of apheresis to treat disease every three years and publishes evidence-based guidelines in a special edition of the Journal of Clinical Apheresis. The guidelines include an apheresis category and a recommendation grade for each evaluated disease. The categories define the role of apheresis in disease treatment: Category I – first-line therapy, Category II – second-line therapy, Category III – role of apheresis not established so decisions should be individualized, and Category IV – apheresis is ineffective or harmful. The recommendation grade defines strength of recommendation, either strong (grade 1) or weak (grade 2), and provides an assessment of the literature quality: A – high, B – moderate, or C – low or very low quality evidence. In the recently published special edition, multiple sclerosis (MS), neuromyelitis optica (NMO), acute disseminated encephalomyelitis (ADEM), and progressive multifocal leukoencephalopathy (PML) associated with natalizumab were assigned categories and recommendation grades (see Table 39.1). Strong recommendations were given for its use for acute severe attacks of central nervous system (CNS) demyelination and for NMO. Over the past decade, apheresis has been applied frequently for these indications. This chapter will review the history and current use of these techniques for CNS demyelinating diseases, as well as apheresis techniques and their complications.