Steven L. Spitalnik, MD, discusses the evolution of red blood cell storage and the potential impact the Hemanext storage technique could have on patients with hematologic malignancies.
According to Steven L. Spitalnik, MD, improvements in blood storage that prolong the lifespan of red blood cells (RBCs) will ultimately allow patients with hematologic malignancies to receive fewer transfusions. This is the goal of a new Hemanext storage system, which stores red blood cells under hypoxic conditions, to reduce oxidative stress on stored red blood cells.
“The concept behind Hemanext is to leverage our understanding of the storage biology of red blood cells and use it to hopefully create a better product, where we better understand the dosage, we better understand the activity and the patient gets better results, ”said Spitalnik. “The data to date suggests that this is true, and that when you break down, we have more red blood cells circulating, and they circulate for longer. Particularly in the context of chronic transfusion, this should lead to fewer transfusions and a better quality of life for our patients. “
In an interview with OncLive®, Spitalnik, Co-Director of the Transfusion Biology Laboratory, Professor of Pathology and Cell Biology and Vice President of Laboratory Medicine at Columbia University Medical Center, discussed the evolution of red blood cell storage and the potential impact that the Hemanext storage technique could have for patients with hematologic malignancies.
OncLive®: What is the current standard for storing blood? What changes have we observed in these methods?
Spitalnik: Currently, the Hemanext product is only for RBC storage. The way we currently store red blood cells is similar to what we have done for the past 30 to 40 years. Whole blood is collected from voluntary donors, plasma and platelets are removed by centrifugation, and the remaining red blood cells are resuspended in a storage solution and stored in the refrigerator. The major breakthroughs of the last 30 to 40 years have been to change the preservation solution for the better. Blood can now be stored in the US for 6 weeks, whereas when I started my residency it was probably 3 or 4 weeks. This is due to improvements in the understanding of red blood cell metabolism.
In this perspective, what does the Hemanext product bring? What is the benefit of hypoxic blood for patients?
There is a lot of published evidence to support the idea that the reason we keep red blood cells for only 6 weeks is because they experience oxidative stress during the storage process in the refrigerator. This oxidative stress mainly damages the membrane of red blood cells and, therefore, decreases the quality of storage over time. The Hemanext approach is to store red blood cells under hypoxic conditions, in the hope that this would reduce oxidative stress on the stored red blood cells, and this indeed appears to be true. The major effect of storage injury, where we believe oxidative stress is the main etiologic cause, is to damage red blood cells so that they are quickly cleared from the circulation.
By current FDA standards, by the expiration date for storage, which is now 6 weeks in the United States, approximately 75% or more of transfused red blood cells must circulate 24 hours later. This means that up to 25% of the transfused red blood cells have been eliminated and are no longer circulating 24 hours later. Most of this clearance occurs within the first hour or two after the transfusion. With the most recent preservative solutions, the average survival of red blood cells is approximately 85%. This means that by the expiration date 85% of red blood cells are still circulating 24 hours later and 15% are not. We can imagine that as red blood cells are stored we are giving a lower dose than we think. The eliminated red blood cells have potential consequences in terms of alloimmunization or iron biology.
The idea behind the Hemanext product is to improve the quality of red blood cell storage, so that even at 6 weeks of storage, significantly more than 85% of the transfused red blood cells will circulate. The overall goal is to make a better product so that more red blood cells are circulating and there is less iron deposition. Particularly with a chronic transfusion, such as sickle cell anemia, beta thalassemia or MDS, ideally we could get by with fewer transfusions over a period of time. It would be better for the patient in terms of being transfused less and having to go to the outpatient clinic less frequently. [Additional benefits include] decrease in iron overload, decrease risk of alloimmunization and achieve the same result with fewer transfusions.
What is the purpose of this product?
Red blood cells are similar to drugs, and many of us have tried for years to make transfusion biology and blood products more similar to pharmacological products and pharmacological interventions. We would never want to give a chemotherapy drug or any kind of drug that is only 85% good. Whatever dose we give the patient, we want it to be 100% good. We want it to be pure, and we want to understand what’s in it [the drug]. We want to understand the pharmacokinetics and pharmacodynamics of the drug. Many of us have the same goal for red blood cell transfusions and platelet transfusions.