July 18, 2002 == FOR IMMEDIATE RELEASE
A cooperative research project between Calvin College and the Spectrum Health
Flow Cytometry Laboratory has confirmed the benefits of a drug used to treat
osteoarthritis, a degenerative disease that affects 90% of people over the age
of 65.
Calvin biology professor David DeHeer and 2001 Calvin graduate Kyle Sheehan
have spent the last three years researching the reasons why a substance called
hyaluronic acid helps relieve the pain of osteoarthritis in people who are not
helped by such typical anti-inflammatories as ibuprofen. Hyaluronic acid is
injected right into the joint, typically the knee joint, in a physician's office
and usually given once a week for five weeks. Its benefits, reduced pain and
inflamation, last anywhere from six to nine months.
But some physicians and researchers have doubted the worth of hyaluronic acid,
which has been used in Europe to treat osteoarthritis since 1987. It's been
called "goo," in not all-together flattering terms by some researchers. And
DeHeer himself admits: "It's a long, simple, rather unexciting molecule. It's
basically repeating sugar units."
But, despite its simplicity, what DeHeer and Sheehan discovered over the last
three years is that hyaluronic acid, a natural chemical found in the body in
particularly high amounts in joint tissue, is an incredibly effective
anti-inflammatory agent in and around the human knee joint (and non-human joints
too as evidenced by years of use on race horses).
This summer they are reporting their findings in papers for three different
medical journals, including the Journal of Biological Chemistry and the Journal
of Orthopaedic Research.
What they'll describe in those papers is their conclusion and how they got to
it.
Their conclusion is simple: hyaluronic acid works. But there's more to how it
works than meets the eye. The drug is injected into the synovial sac, which
protects the joint and also secretes the synovial fluid, which oils the joint.
But the half life of the acid is 24 hours, so after about a week the typical
injection of two millilitres has disappeared. Yet it continues to work. What
DeHeer and Sheehan hoped to figure out was how. What they discovered is that
the acid, before it disappears, interacts with a cell called a macrophage.
Macrophages produce inflammation.
"Hyaluronic acid," says Sheehan, "basically tells the macrophages to be quiet,
calm down, to die. Fewer macrophages means less inflammation." In fact Sheehan
and DeHeer found that hyaluronic acid will eliminate about 99% of the macrophage
cells. In patients this could contribute to a significant reduction in
inflammation and pain.
Their work was done, says DeHeer, at a very basic scientific level. They grew
macrophage cell cultures. And they studied the impact of clinical preparations
of hyaluronic acid, which they purchased from the two major manufacturers, on
those cell cultures, using a sophisticated piece of equipment at Spectrum Health
called a flow cytometer. The results, they say, were dramatic. Macrophage cell
cultures treated with the acid were decimated. Those not treated thrived.
"The result," says DeHeer, "is that macrophage cells behave like they do in a
person without osteoarthritis. There are lots of big molecules of hyaluronic
acid, but hardly any macrophage cells. Thus a reduction in inflammation and a
reduction in pain. This 'unexciting' molecule has a very exciting role in the
knee joint."
Contact David DeHeer at 616-957-6083 or dehe@calvin.edu
-end-
This archive was generated by hypermail 2b29 : Thu Jul 18 2002 - 10:38:36 EDT