Plasma exchange treatment of peripheral neuropathy associated with plasma cell dyscrasia.

Plasma exchange was used to treat 10 patients with polyneuropathy and a monoclonal antibody (plasma cell dyscrasia). Six patients had improvement of the neuropathy, while three patients had stabilisation of the neuropathy during plasma exchange. The patients who improved maintained a 64% or greater decrease in the monoclonal antibody between exchanges. Patients with axonal polyneuropathy as well as patients with demyelinating polyneuropathy recovered some neurologic function. With cessation of plasma exchanges, the monoclonal antibody titre approached pre-treatment levels and the neuropathy progressed. Plasma exchange was effective in rapidly lowering the level of monoclonal antibody and allowing for some recovery of neurologic function.