Plasmapheresis combined with prednisone and azathioprine therapy produced striking clinical improvement in five patients with myasthenia gravis who still had moderate to severe disability despite thymectomy, high-dose prednisone therapy and optimal doses of cholinesterase inhibitors. Serial determinations of titers of serum antibody toward the acetylcholine receptor demonstrated a fall to 21 +/- 5 per cent (mean +/- S.D.) of the original levels concurrently with the patients' increasing strength. Clinically improved patients maintained lowered titers, whereas clinical relapses were associated with a rebound in titer. Our results suggest that plasmapheresis will find a place in the management of patients with myasthenia gravis, and they implicate antibodies to acetylcholine receptor as a pathogenic factor in this disease.

We enrolled 116 patients in a multicenter, randomized, double-blind controlled trial of an 8-week course of 11 plasma exchange (PE) treatments in exacerbations of MS. The control group received sham PE, and both groups received identical treatment with IM ACTH and oral cyclophosphamide. Serum IgG decreased in the PE and sham treatment groups by 76% versus 22% by treatment 5, and by 64% versus 14% by treatment 11. PE also produced significant reductions in IgA, IgM, C3, and fibrinogen. PE patients had moderately enhanced improvement at 2 weeks relative to the sham group. PE patients with relapsing/remitting disease had significantly enhanced improvement at 4 weeks and there was also an increased improvement at 12 months, although this latter effect disappeared when we analyzed relapsing/remitting patients as a separate subgroup. Life table analysis showed the median time to recover preattack disability status was shorter in PE- than in sham-treated relapsing/remitting patients (4 vs. 13 weeks), a result confirmed by raw disability status scores in which there was recovery to their average preattack disability score by 3 months. PE given with ACTH plus cyclophosphamide enhances recovery from an exacerbation of disease in relapsing/remitting patients, although we observed no clear long-term benefits.

No abstract

Plasmapheresis in the treatment of myasthenia gravis has led to disparate results when applied by different investigators because of considerable differences in the volume, number, and tempo of plasmaphereses and in the type and amount of concomitant immunosuppressive drug therapy. Used as short-term crisis intervention, plasmapheresis produces temporary clinical improvement and reduction in titer of antibody to acetylcholine receptor, even without accompanying drug therapy. When applied as long-term primary therapy under optimal conditions, plasmapheresis is capable of generating stable improvement in most patients. This response appears to result from a synergistic action with immunosuppressive drugs, since it is characterized by a sustained reduction in titer of antibody to acetylcholine receptor. Where clinical circumstances warrant cytotoxic immunosuppression in patients with myasthenia gravis, consideration should be given to the simultaneous employment of plasmapheresis, in order to maximize benefit to the patient from a given exposure to drug therapy.