Response of patients with IgM and IgA-associated peripheral polyneuropathies to "off-line" immunoadsorption treatment using the Prosorba protein A column.

Abstract

Sensory or sensorimotor demyelinating polyneuropathies may be associated with monoclonal immunoglobulins (paraproteins). Our prior experience suggests that "off-line" Prosorba(R) column treatments may be effective therapy for patients with polyneuropathies associated with paraproteins of the IgG class. We report herein the treatment, using Prosorba(R), of 2 patients with peripheral neuropathies and paraproteins of the IgM class and 1 patient with peripheral neuropathy whose paraprotein was of the IgA class. All three patients were treated "off-line" with Prosorba(R) six times in a 2-week period. Each time they were phlebotomized 1 U of whole blood. The plasma and red cells were separated in the blood bank. The plasma was passed over the column while the red blood cells were returned to the patient through a heparin lock. Then the treated plasma was returned separately. There were no adverse effects of treatment, and, in one patient with an IgM paraprotein and one with an IgA paraprotein, neurological symptoms and signs improved over the subsequent 2 weeks. Prosorba(R) appears effective for predominantly sensory demyelinating polyneuropathies associated with M-components of all major immunoglobulin classes. Our current experience further suggests that the mechanism of action of Prosorba(R) may not depend on removal of small amounts of IgG-containing immune complexes from patients' plasma. A proper large-scale clinical trial is warranted.