Review: Squeezing for Life – Properties of Red Blood Cell Deformability, 2018, Huisjes et al

[Andy]

Deformability is an essential feature of blood cells (RBCs) that enables them to travel through even the smallest capillaries of the human body. Deformability is a function of (i) structural elements of cytoskeletal proteins, (ii) processes controlling intracellular ion and water handling and (iii) membrane surface-to-volume ratio. All these factors may be altered in various forms of hereditary hemolytic anemia, such as sickle cell disease, thalassemia, hereditary spherocytosis and hereditary xerocytosis. Although mutations are known as the primary causes of these congenital anemias, little is known about the resulting secondary processes that affect RBC deformability (such as secondary changes in RBC hydration, membrane protein phosphorylation, and RBC vesiculation). These secondary processes could, however, play an important role in the premature removal of the aberrant RBCs by the spleen. Altered RBC deformability could contribute to disease pathophysiology in various disorders of the RBC. Here we review the current knowledge on RBC deformability in different forms of hereditary hemolytic anemia and describe secondary mechanisms involved in RBC deformability.

Open access, https://www.frontiersin.org/articles/10.3389/fphys.2018.00656/full

 

[duncan]

Our's would be an acquired altered RBC deformability, if applicable - I think (it could be genetic, but adult onset in some and childhood onset in others makes that proposition seem less likely).

This paper addresses hereditary hemolytic anemia. What about acquired hemolytic anemia, or diseases/infections that result in altered RBC deformability?

 

[Andy]

I haven't got the time/energy to read further, but these parts looked to be of interest, to me at least.

Deformability is also affected by metabolic processes controlling ATP levels and redox state. These factors control ion handling by pumps and passive transport pathways (Chu et al., 2012; Bogdanova et al., 2016), proteolytic activity of Ca2+-dependent protease calpain (Bogdanova et al., 2013), and mutations and structural integrity of each element of the membrane architecture (Gallagher, 2004b). Failure to sustain deformability results in shortening of RBC life span and, when not compensated by de novo RBC production, in hemolytic anemia.

Intravascular hemolysis is, as the name suggests, lysis of RBC in the vasculature. The cause can be hereditary, as seen in sickle cell disease (Pauling and Itano, 1949; Kato et al., 2017), but intravascular hemolysis can also be initiated by certain drugs (Cappellini and Fiorelli, 2008), by mechanical stress (for example through shear forces generated by artificial heart valves), by cold-agglutination (Körmöczi et al., 2006) or as a result of exhaustive exercise (Jordan et al., 1998).

 

[duncan]

"...ion handling..." A potential channelopathy reference again? Are we talking channelopathies as downstream effects, and abnormal RBC deformability simply further downstream? I know - way too speculative. Also, I always thought of channelopathies as the starting point, ie, genetic, usually, of all kinds of problems, not a mid-stream effect.