Nov. 9, 2009 -- Cells surrounding joints affected by rheumatoid arthritis
may spread the disease to other joints by traveling through blood vessels,
according to a new study.
Rheumatoid arthritis is a progressive disease that causes joint inflammation
and destruction. Researchers say initially the disease starts out in just a few
joints but soon spreads to other joints in the body.
Until now, the method of how the disease spreads from joint to joint was
unknown. But a study in Nature Medicine suggests that cells called
synovial fibroblasts may be to blame.
The cells, which are present in lining of the joints, are already implicated
in the cartilage destruction associated with rheumatoid arthritis.
In the study, researchers implanted healthy human cartilage tissue plus
synovial fibroblasts from people with rheumatoid arthritis into one side of lab
mice. The opposite side was injected with healthy cartilage without the
After 60 days, the results showed that synovial fibroblasts had actively
moved from one side of the mice's body to the other via blood vessels and were
already causing cartilage damage.
Researcher Stephanie Lefevre of the department of internal medicine and
rheumatology at the Kerckhoff-Clinic, Bad Nauheim, Germany, and colleagues say
the study supports the notion that the spread of rheumatoid arthritis between
joints is at least partially due to the migration of affected synovial
fibroblasts through the bloodstream.