Nov. 23, 2009 -- Stomach
acid may only be part of the problem when it comes to esophagus
injury related to gastroesophageal reflux disease (GERD). A new study
suggests that an immune system response may be the real culprit behind reflux
Researchers say it's been assumed that reflux esophagitis develops when
cells in the lining of the esophagus become burned and damaged by stomach acid
backing up into the esophagus.
But in a rat model of GERD, researchers found that this acid
reflux didn't directly damage the lining of the esophagus. Instead, the
acid triggered the release of chemicals called cytokines that attract
inflammatory immune cells to the area, which were responsible for the real
If further studies in humans confirm these results, researchers say new GERD
treatments that target this immune response may be needed to effectively manage
"Currently, we treat GERD by giving medications to prevent
the stomach from making acid," says Rhonda Souza, MD, associate professor of
internal medicine at the University of Texas Southwestern Medical Center, in a
news release. She says "maybe we should create medications that would prevent
these cytokines from attracting inflammatory cells to the esophagus and
starting the injury in the first place."
In the study, published in Gastroenterology, researchers created GERD
in rats by performing an operation to connect the duodenum (first section of
the small intestine) to the esophagus, allowing stomach acid and bile to enter
The results showed damage to the lining of the esophagus did not occur
immediately after exposure to the stomach acids. It happened weeks later.
"That doesn't make sense if GERD is really the result of an acid burn," says
researcher Stuart Spechler, MD, professor of internal medicine at UT
Southwestern, in the news release. "Chemical injuries develop immediately. If
you spill battery acid on your hand, you don't have to wait a month to see the
Within three days after the operation, researchers found no damage to the
cells on the surface layer of the esophagus, but they found inflammatory cells
in the deeper layers. Those inflammatory cells rose to the surface three weeks
later after the initial stomach acid exposure.