Synthetic Peptides Could Potentially Treat Blood Disorders

A new study suggests that synthetic peptides called minihepcidins are able to restore normal red blood cell level, reduce spleen enlargement, and control the accumulation of iron in animal models mimicking certain blood disorders.

Researchers believe that the findings, published in Blood, suggest minihepcidins could be used to treat the blood disorders beta-thalassemia and polycythemia vera.

"It seems counterintuitive that one compound could treat two diseases that are quite different, but by restricting iron absorption, it also helps to normalize red blood cell levels in animals," said study leader Stefano Rivella, PhD. "If these preclinical results translate to humans, this could represent a new treatment for both disorders."

Minihepcidins are a modified version of the hormone hepcidin that regulates iron. Minihepcidins are smaller than hepcidin, have long-term stability, and long-lasting biological activity in animal models, according to the study.

In beta-thalassemia, a mutation impairs hemoglobin production and results in defective red blood cells that have a diminished ability to carry oxygen. Due to low levels of hepcidin, the body continues to collect iron, destroys RBCs, and can cause liver and heart damage.

In polycythemia vera (PV), a mutation overproduces RBCs and thickens the blood, which increased the risk or high blood pressure and thrombosis that could cause a stroke. Enlarged spleen is also a side effect. The current treatment, phlebotomy, does not stop the body from overproducing RBCs.

Researchers in the study bred mouse models of both diseases.

In young beta-thalassemia mice, minihepcidins were able to normalize RBD+C levels and stop anemia and iron overload. In older mice, it improved RBC production and did not interfere with a chelating drug that removes excess iron deposits, according to the study.

In PV mice, minihepcidins were also able to normalize RBC production by reducing iron absorption. This also reduced spleen enlargement.

Should these findings prove successful in clinical trials, researchers believe minihepcidins could be used to treat these blood disorders, but it would not treat the disease causing the mutations.

"In animal affected by beta-thalassemia, the compound blocks iron from getting into organs, but doesn't remove excess iron already in organs and tissues. If minihepcidins are used in older patients, they would need to be combined with existing chelating drugs that remove the already-accumulated iron,” Dr Rivella concluded.