UCLA researchers found that a member of the immune system’s defense team stimulates a chain reaction leading to chronic anemia in many patients with infections and major inflammatory diseases. The study may help target new interventions to help prevent anemia in patients with
rheumatoid arthritis and inflammatory bowel disease, which affect millions worldwide.
The new study, published in the May 1 issue of The Journal of Clinical Investigation, found that interleukin 6 – a protein that is part of the immune system is the signal that sets off a chain reaction during an infection or inflammatory state. Interleukin 6 stimulates an increase in the hormone Hepcidin, which in turn lowers the amount of iron in the bloodstream.
“We knew previously that the iron level in the blood drops during an infection or inflammatory state, but didn’t know the molecular mechanism that sparks this response,” said Tomas Ganz, Ph.D., M.D., principal investigator and professor of medicine and pathology at the David Geffen School of Medicine at UCLA. “For the first time, we now can show the complete biological sequence of events leading to anemia in specific inflammatory diseases and infections.”
Ganz adds that early during infection the body lowers the amount of iron in the bloodstream so infecting bacteria are starved for iron and can’t grow. However, some inflammatory diseases ignite this reaction, even when no true infection is present, which can lead to chronic low iron, and inadequate iron supply for red blood cell production. Severe anemia caused by inflammatory diseases can lead to weakness and other symptoms, requiring blood transfusions or treatments that stimulate red cell production.
Infections and inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease are the second leading cause of anemia worldwide. Children with rheumatoid arthritis are especially susceptible to severe anemia.