Hemochromatosis alters the sensitivity of red blood cells to mechanical stress.

Background: Hemochromatosis (HH) is characterized by chronic iron accumulation, leading to deleterious effects to various organ systems. A common approach to managing iron load involves large-volume venesection. Some countries authorize HH venesections to be used in the development of transfusable blood products, although concerns remain regarding suitability.

Mechanical sensitivity of red blood cells improves in individuals with hemochromatosis following venesection therapy.

Background: Individuals with hereditary hemochromatosis (HH) receive frequent blood withdrawals (ie, venesections) as part of their primary treatment to assist in normalizing blood iron levels. It remains unclear whether this source of blood is suitable for use in blood product development, as current data indicate that red blood cell (RBC) deformability, both before and after shear stress exposure, is impaired in individuals with HH, relative to healthy controls. Given that venesection therapy is known to significantly reduce circulating iron levels in individuals with HH, the current study examined whether venesection therapy is effective at improving RBC mechanical properties, both before and after shear stress exposure, in individuals with HH.

Beyond oxygen transport: active role of erythrocytes in the regulation of blood flow.

It was classically thought that the function of mammalian red blood cells (RBCs) was limited to serving as a vehicle for oxygen, given the cells' abundance of cytosolic hemoglobin. Over the past decades, however, accumulating evidence indicates that RBCs have the capacity to sense low-oxygen tensions in hypoxic tissues, and, subsequently, release signaling molecules that influence the distribution of blood flow. The precise mechanisms that facilitate RBC modulation of blood flow are still being elucidated, although recent evidence indicates involvement of ) adenosine triphosphate, capable of binding to purinergic receptors located on the vascular wall before initiating nitric oxide (NO; a powerful vasodilator) production in endothelial cells, and/or ) nonvascular NO, which is now known to have several modes of production within RBCs, including an enzymatic process via a unique isoform of NO synthase (i.

Haemochromatosis: Pathophysiology and the red blood cell1.

Haemochromatosis remains the most prevalent genetic disorder of Caucasian populations in Australia and the United States, occurring in ∼1 of 200 individuals and having a carrier frequency of 10-14%. Hereditary haemochromatosis is an autosomal recessive condition, that is phenotypically characterised by a gradual accumulation of iron, above and beyond that required for biological function. Once the binding capacity of iron carriers reaches saturation, the highly reactive free iron generates radicals that may lead to widespread cellular dysfunction.