During plasmapheresis (plasma exchange, or PE), blood is removed from the patient, and the liquid plasma and the cells are separated by centrifuge. The plasma (including many lymphocytes) is discarded and replaced by normal plasma or human albumin to avoid loss of protein and fluid. The “reconstituted” blood is then returned to the patient. This process may be repeated a number of times. It is believed that substances that can damage myelin and/or impair nerve conduction are removed in this way.

There remain numerous reports (most of them uncontrolled and reporting on only very small numbers of patients) that PE may be effective in fulminant acute syndromes of MS (or acute disseminated encephalomyelitis).

A randomised controlled trial was performed at the Mayo Clinic in the USA. 36 patients with recently acquired, severe neurological deficits resulting from attacks of inflammatory demyelinating disease, who failed to recover after treatment with IVMP, were treated with either plasma exchange or sham treatment. Moderate or greater improvement in neurological disability occurred during eight of 19 courses of active treatment compared with one of 17 courses of sham treatment. Moderate or marked improvement was associated with the male sex, preserved reflexes, and early initiation of treatment. Successfully treated patients improved rapidly following treatment and the improvement was sustained.

In the opinion of the Committee, this therapy should be considered for those rare cases that present with acute, fulminant symptomatology and do not respond to intravenous steroids.