In people with systemic mastocytosis (SM), mast cells may contribute to anemia (low red blood cell counts) by breaking down red blood cells, according to a recent study published in the journal Biochemistry and Biophysics Reports.
SM occurs when certain immune cells called mast cells build up in the body. These cells release chemicals that cause symptoms such as flushing, itching, abdominal pain, dizziness and fatigue. Many people with SM also develop anemia, but until now, it wasn’t well understood why this happens.
In the new study, which was done in mice, researchers found that even a small increase in mast cells caused a drop in red blood cells and platelets, similar to what doctors often see in people with SM.
When mast cells were removed in mice, damaged red blood cells started to build up in the spleen, suggesting that mast cells normally help “clean up” old or damaged blood cells. However, in SM, when there are too many mast cells, this process may go into overdrive and contribute to anemia.
Read more about SM signs and symptoms
The study found that mast cells can “eat” damaged red blood cells directly. They do this using special receptors — tiny “sensors” on the cell surface (called RAGE and TIM3) that help mast cells recognize when a red blood cell is old or damaged and needs to be cleared away.
The researchers say that mast cells may also cause anemia indirectly, by releasing chemicals like interleukin-6 (IL-6), which increase hepcidin, a hormone that traps iron in the body. This limits iron needed to make red blood cells and can lead to anemia.
“These in vivo studies led to the conclusion that mast cells affect erythrocyte (red blood cell) depletion or clearance directly or indirectly,” the researchers said.
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