WEDNESDAY, June 30 (HealthDay News) -- An immune cell known to
cause inflammation in autoimmune disorders may play a role in back
pain associated with herniated discs, says a new study.
This finding adds to growing evidence that an immune response is
a major factor in spinal disc disease. It may eventually help lead
to new treatments that target a specific immune process to treat or
even possibly reverse disc disease, according to the Duke
University Medical Center researchers.
The immune cell -- known as cytokine molecule interleukin-17
(IL-17) -- appears to help set in motion the painful inflammation
associated with disc disease.
A herniated disc occurs when the outer layer of cartilage
cracks, and pieces of the softer inner material of the disc
protrude into the spinal canal, first author Dr. Mohammed Shamji, a
senior neurosurgery resident at the Ottawa Hospital in Canada,
explained in a Duke news release.
The inner material of the disc has never been exposed to the
immune system, which attacks the material as it would any virus or
foreign body. This causes the nerve root, which is present or near
the protruding disc material, to became inflamed and damaged.
The researchers found that IL-17 plays a key role in this
cascade of events.
"By identifying the specific subpopulation of lymphocytes (immune cells that are excited into action by the cytokine), it may soon be possible to arrest the body's inflammatory response to disc cells," senior author Dr. William J. Richardson, an orthopedic surgeon at Duke, said in the news release.
Researchers speculate that by targeting a treatment to these
specific cells involved in disc inflammation, the body's ability to
fight off invaders will be left intact.
"It's a product of a specific subgroup of immune cells that involved in autoimmune phenomena like rheumatoid arthritis and asthma, but not in the body's response against infection or tumor. If you target this specific lymphocyte, you may avoid compromising the body's ability to protect itself against infection or tumor," Shamji added.
He and colleagues say they're still several steps away from
human studies of IL-17 blockers.
The study, published online June 29, appears in the July issue
of the journal
Arthritis and Rheumatism.
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