Intestinal immune cells implicated in iron deficiency in body

Researchers have found evidence implicating certain intestinal immune cells in the absorption of iron, resulting in its inability to enter the bloodstream and causing iron deficiency in the body.

The researchers from MedUni Vienna, Austria, have shown that certain immune cells called macrophages control iron absorption in the intestine’s duodenum, where one to two milligrams of iron, a trace element, need to be absorbed for a balanced iron metabolism.

Their study results, published in the journal Blood, could provide therapeutic measures to address iron deficiency, is one of the five main causes of impaired health and affects 30 per cent of the world’s population, particularly women.

The research revealed that activation of macrophages directly in the duodenum leads to a halt in iron availability in the body.

”We were able to determine that the macrophages in the duodenum eat away the iron transport molecule transferrin, so to speak. This means that the iron remains in the intestinal cells and can no longer enter the bloodstream,” explained first author Nyamdelger Sukhbaatar from MedUni Vienna.

The study also found that macrophages are also activated during fasting, food intake or during an intestinal infection, thereby changing the amount of transferrin in the intestine.

”Our findings thus represent a real paradigm shift, as it was previously assumed that transferrin is always present in equal amounts everywhere in the body and does not actually play any role in iron regulation,” underlined study leader Thomas Weichhart.

The research team is currently investigating whether the macrophages in the intestine and their regulation of transferrin could also be disturbed in inflammatory bowel diseases, intestinal infections or gastritis.

A balanced iron metabolism is an essential prerequisite for health.

Iron, an important component of the blood pigment haemoglobin, is responsible for transporting oxygen in the red blood cells, a lack of which causes anaemia.

Equally fatal is an excess of iron triggered by certain genetic diseases such as haemochromatosis, whereby the excess iron deposition destroys many organs in the long term.

Nonetheless, the most common causes of iron deficiency and anaemia include not only iron-deficient nutrition, but also impaired iron absorption despite sufficient availability of iron in the diet.