Lack of blood flow to the intestines during surgery, to the heart during a heart attack or to the brain during a stroke can cause damage to the organ involved.
However, more damage occurs when the blood returns to the organ.
Sherry Fleming, assistant professor of biology at Kansas State University, thinks she knows why and is working to find therapeutic ways to prevent this damage. Fleming has received various funding for her research, including, most recently, a five-year, $1.79 million grant from the National Institute of Allergy and Infectious Diseases for "Natural Antibodies and Tissue Injury."
Fleming said a type of white blood cell called a B cell makes antibodies; some of these antibodies are responsible for damage to organs after ischemia, or lack of blood flow. When an organ is deprived of blood and oxygen, white blood cells and antibodies cannot enter. These cells "clean up" when a part of the body is damaged and if they are not available at the time when the damage is occurring to constantly work on the problem, they tend to do more harm than good when they are finally let in, like after a heart attack.
The antibodies bind and identify the damaged tissue for removal by the white blood cells when they return to the organ. Fleming is working to isolate B cells that make the antibodies that bind and identify the damaged tissue. When too many antibodies are bound, proteins in the blood called complement bind the antibodies and kill more cells indiscriminately. This leads to more tissue damage.
However, the goal is not to stop all B cells from making antibodies since many of them are helpful to the immune system; only some are harmful.
"We have performed tests without antibodies and the damage doesn't occur," Fleming said. "We want to figure out which B cells are making the harmful antibodies and stop them." Stopping them includes delivering other therapeutic molecules that prevent complement proteins from damaging tissue.
Fleming's research will be beneficial to those experiencing intestinal ischemia, which she said can have a mortality rate of 70 percent to 100 percent. This research could also help heart attack and hemorrhage victims and those with lupus.