Inflammatory protein interleukin-6 (IL-6) serves a critical role in the duration of acute pancreatitis in animal models with this condition, as found by scientists from the Universities of Illinois and California. Their report, in the June 2012 issue of the Journal of Leukocyte Biology, describes experiments in lean and obese mice that identify the presence of high IL-6 as one of the reasons why the disease is more devastating in obese people.
"The study helps to understand why acute pancreatitis is more prolonged in obese subjects," said Giamila Fantuzzi, Ph.D., the senior researcher of this work, from the Department of Kinesiology and Nutrition at the University of Illinois at Chicago. "Our data indicate that IL-6 participates in prolonging inflammation in obese mice with acute pancreatitis, but also show that this inflammatory mediator is not the most important factor in determining the severity of the acute response."
To make this discovery, researchers used lean and obese mice that do and do not produce IL-6. They induced acute pancreatitis in all mice and studied them at different times of the disease. Both groups of the lean mice developed mild disease and then promptly recovered. Both sets of obese mice developed more severe disease at its onset. For the obese mice that did not produce IL-6, the course of the disease was much shorter than in the obese mice that did produce IL-6. It is also important to note that obesity leads to elevated levels of IL-6 and other inflammatory proteins.
"There is an increasing awareness that obesity and inflammation are connected," said John Wherry, Ph.D., Deputy Editor of the Journal of Leukocyte Biology. "Not only does this new report demonstrate an important set of interactions between obesity, pancreatitis, and inflammation, but it also identifies the inflammatory pathway, IL-6, which could represent an important new therapeutic target in these settings."