Gene-Altered Mouse a Boon to Rheumatoid Arthritis Research

Animal model closely mirrors disease progression in humans, experts say.

By Alan Mozes
HealthDay Reporter
Friday, December 29, 2006; 12:00 AM

Copyright © 2006 ScoutNews, LLC. All rights reserved.

FRIDAY, Dec. 29 (HealthDay News) -- Researchers believe they've developed an important new tool in understanding rheumatoid arthritis: a genetically altered mouse that closely mimics the disease in humans.

The new mouse model might also help explain why women are much more prone to the crippling illness than men.

"This is a big step forward, because for the first time, we have mice that actually have the human genes which makes humans susceptible to rheumatoid arthritis," said study author Veena Taneja, an assistant professor in the department of immunology at the Mayo Clinic, in Rochester, Minn.

The importation of these human genes into the rodent means that "any treatment which is studied in this mouse would be a relevant treatment in humans," she explained.

Taneja's team reported the advance in the January issue of Arthritis & Rheumatism.

According to the Arthritis Foundation, more than 2 million Americans suffer from rheumatoid arthritis, most of whom initially begin coping with this autoimmune disease between the ages of 30 and 50.

While 70 percent of patients are women, the illness tends to be more aggressive in men.

Nailing down the exact cause of rheumatoid arthritis has been tough. Researchers have started to explore the possibility that the degenerative joint disease may, in fact, be the product of several different pathologies.

Once under way, rheumatoid arthritis harnesses the patient's otherwise healthy immune system to behave abnormally -- attacking healthy tissue as if it were a foreign invader.

The disease typically strikes the smaller joints of the hand, wrist and fingers first. Accompanying symptoms include fatigue, stiffness (especially in the morning), weakness and muscle pain, weight loss, depression and flu-like complications.

To date, there is no known cure. Treatments focus on pain relief and the reduction of joint inflammation but do not halt the illness.

Efforts to get at a cure have run into one major roadblock: The most useful and available study subjects -- mice -- do not naturally mimic the human course of rheumatoid arthritis.