An experimental gene therapy treatment for chronic pain enabled rats with this
condition to go symptom-free for three months, a study released on Monday
said.
The rats were injected
with a gene that tricks the body into releasing endorphins, a natural
painkiller, in the nerve cells surrounding the spinal
cord.
The treatment simulates
the effect of painkilling drugs but is much narrower in scope, targeting nerve
cells along the spinal cord, but not in the brain or in other parts of the
central nervous
system.
Researchers are hopeful
that the therapy could potentially be used to treat people with severe or
chronic pain sparing them some of the debilitating side effects of the opiod
drugs currently on the market which act systemically, rather than
locally.
"Chronic pain patients
often do not experience satisfactory pain relief from available treatments due
to poor efficacy or intolerable side effects like extreme sleepiness, mental
clouding and hallucinations," said Andreas Beutler, an assistant professor of
medicine, hematology and medical oncology at Mount Sinai School of Medicine in
New York.
In some cases, "the
side effects become dose limiting," Beutler said, noting that some patients opt
for less pain relief in exchange for greater lucidity. "Targeted gene therapy
will likely avoid the unwanted side effects associated with opiod painkillers
such as morphine."
For this
experiment, the researchers packaged the prepro-b-endorphin gene in a disabled
cold virus and injected it into the rats’ spinal fluid by means of a lumbar
puncture, or spinal tap. The rats, which had an animal version of neuropathic
pain, were symptom free for over three
months.
The treatment is in a
preliminary testing phase, but if it’s shown to be safe and effective in humans,
it could ultimately help patients who cannot tolerate the side effects of the
existing painkilling drugs, or who don’t get sufficient relief from those drugs.
Beutler said.
Patients with
advanced cancer fall are among the potential beneficiaries, he said. The paper
appears in the Proceedings of the National Academy of Sciences.
Via Times of India