Nav: Home

SLU researchers show how to stop muscle weakness caused by myasthenia gravis

December 20, 2007

Severe muscle weakness caused by myasthenia gravis - a highly debilitating autoimmune disorder - can be prevented or reversed by blocking a key step in the immune response that brings on the disease, researchers at the Saint Louis University School of Medicine have found.

Myasthenia gravis, which affects about 120,000 Americans, is caused when the immune system produces antibodies that attack and damage acetylcholine receptors, which are mechanisms that play a key role in transmitting the electrical impulses that cause muscles to move and contract.

The immune response at the heart of this process is called a complement cascade - a complex chain of chemical reactions in which proteins bind together to attack a cell by punching a hole in it. When acetylcholine receptors are damaged in this way, muscle movement is severely impaired.

Using an animal model, the SLU scientists found they could prevent muscle weakness, or restore muscle strength, caused by myasthenia gravis by stopping the complement cascade at a step called C5 - before the series of chemical reactions had finished. They did this by administering an anti-C5 agent, which targets one of the proteins involved in the cascade and thus stops the process.

The researchers' findings are published in a recent edition of the Journal of Immunology (http://www.jimmunol.org/cgi/reprint/179/12/8562).

Henry J. Kaminski, M.D., professor and chairman of the department of neurology and psychiatry at the Saint Louis University School of Medicine, one of the study's authors, said the findings are promising enough that human clinical trials involving the anti-C5 agent - called eculizumab - are likely within a year.

"We believe this therapeutic approach has strong potential for improving the lives of patients with myasthenia gravis," Kaminski said. "And if it proves successful there, it could also one day help us find new therapies for other auto-immune disorders, such as rheumatoid arthritis and lupus."

Myasthenia gravis affects approximately 400 per 1 million people. The severe muscle weakness caused by the disease brings a host of other complications, including difficulty breathing, difficulty chewing and swallowing, slurred speech, droopy eyelids and blurred or double vision. By preventing or reversing the muscle weakness, the other symptoms are prevented or reversed as well.

Myasthenia gravis can't be cured, but it is sometimes be treated with surgery to remove the thymus (which plays a role in the immune system) or with various drugs. Surgery often doesn't bring relief, however, and the medications typically decrease in effectiveness over time or, in the case of immunosupressants and corticosteriods, have severe side effects.
-end-
In addition to Kaminski, the study's authors include Yuefang Zhou, Ph.D., and Bendi Gong, Ph.D., both of Saint Louis University; M. Edward Medof, M.D., and Feng Lin, Ph.D., both of the Institute of Pathology at Case Western Reserve University in Cleveland; and Russell Rother, Ph.D., of Alexion Pharmaceuticals in Cheshire, Conn.

The research was supported by grants from the National Institutes of Health.

Established in 1836, Saint Louis University School of Medicine has the distinction of awarding the first medical degree west of the Mississippi River. The school educates physicians and biomedical scientists, conducts medical research, and provides health care on a local, national and international level. Research at the school seeks new cures and treatments in five key areas: cancer, liver disease, heart/lung disease, aging and brain disease, and infectious disease.

Saint Louis University

Related Immune System Articles:

The immune system may explain skepticism towards immigrants
There is a strong correlation between our fear of infection and our skepticism towards immigrants.
New insights on how pathogens escape the immune system
The bacterium Salmonella enterica causes gastroenteritis in humans and is one of the leading causes of food-borne infectious diseases.
Understanding how HIV evades the immune system
Monash University (Australia) and Cardiff University (UK) researchers have come a step further in understanding how the human immunodeficiency virus (HIV) evades the immune system.
Carbs during workouts help immune system recovery
Eating carbohydrates during intense exercise helps to minimise exercise-induced immune disturbances and can aid the body's recovery, QUT research has found.
A new model for activation of the immune system
By studying a large protein (the C1 protein) with X-rays and electron microscopy, researchers from Aarhus University in Denmark have established a new model for how an important part of the innate immune system is activated.
Guards of the human immune system unraveled
Dendritic cells represent an important component of the immune system: they recognize and engulf invaders, which subsequently triggers a pathogen-specific immune response.
How our immune system targets TB
Researchers have seen, for the very first time, how the human immune system recognizes tuberculosis (TB).
How a fungus inhibits the immune system of plants
A newly discovered protein from a fungus is able to suppress the innate immune system of plants.
A new view of the immune system
Pathogen epitopes are fragments of bacterial or viral proteins. Nearly a third of all existing human epitopes consist of two different fragments.
TB tricks the body's immune system to allow it to spread
Tuberculosis tricks the immune system into attacking the body's lung tissue so the bacteria are allowed to spread to other people, new research from the University of Southampton suggests.

Related Immune System Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...