Printer Friendly

Blood cleansing gets report card.

Blood cleansing gets report card

Plasmapheresis is one of those medical procedures that seem to make inherent sense: Where a blood-borne agent such as an antibody is responsible for a disease, treat the illness by essentially washing the culprit out of the blood Clinical experience doesn't always go along with what seems to make sense, though. Last week, a panel of experts concluded that plasmapheresis is useful in treating certain neurological diseases in which antibodies are suspected of causing the problem, but not in others.

After reviewing sometimes-conflicting data from clinical trials, the panel, which was convened by the National Institutes of Health in Bethesda, Md., declared that plasmapheresis is helpful in treating Guillain-Barre syndrome and acute myasthenia gravis but is not useful in amyotrophic lateral sclerosis (ALS). According to the panel, more data are needed to determine its value in multiple sclerosis and other neurological diseases.

In the procedure, which costs about $1,000, blood is removed from the patient and centrifuged to separate the plasma from the blood cells. The cells are put back into the patient, along with a reconstituted plasma component from donated blood. Each year about 15,000 people with neurological diseases in the United States undergo plasmapheresis; another 15,000 undergo it for other conditions such as metabolic disorders.

In myasthenia gravis, a condition marked by muscle weakness and fatigue, plasmapheresis removes an antibody against a receptor on muscle cells that normally responds to a nerve signal. While researchers have yet to conduct a trial comparing plasmapheresis to sham treatment, uncontrolled trials suggest it helps during acute stages of the disease when respiratory function is seriously impaired, the panel found.

The panel also concluded that plasmapheresis is useful in managing Guillain-Barre syndrome, characterized by loss of muscle strength, reflexes and sensation. As with myasthenia gravis, no controlled trials have been done, but the panel recommends the procedure for patients with severe weakness. Since the cause of the syndrome is unknown, the efficacy of plasmapheresis "challenges us to figure out what it is in the patient that is being removed," says Barry G. Arnason of the University of Chicago, who headed the panel.

But plasmapheresis isn't of help in ALS, a disease marked by unrelenting deterioration of the nerves that stimulate voluntary muscles. "The fact that [plasmapheresis] isn't helpful makes the possibility that ALS is an autoimmune disease less likely," says Arnason.
COPYRIGHT 1986 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1986, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Author:Silberner, Joanne
Publication:Science News
Date:Jun 14, 1986
Previous Article:Professors minding their own business.
Next Article:Hormone conversion key to long life?

Related Articles
Electronics recycling bill advances.
Incumbent Hall, newcomer McCown capture LCC seats.
Springfield's weekly police blotter.
Enters Turkey Into The Regional Game.
Women aren't "small men": women's health issues are different than men's and need to be addressed specifically.
Lethal injection is inhumane, say researchers.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters