From Noblood

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Moderated by Bassam F. Matar, MD - NoBlood Editorial Team

You can look most anywhere in healthcare today and see the changes.

One of the fastest developments has been in the area of hematology/oncology. As technology advances it "learns" by the trial and error method.

With the advent of new techniques and new insight into pharmaceuticals, developments in this field have moved forward, especially for those who would like to avoid the use of blood. Over a period of time we have had a few that looked promising, such as Fluosol; this first generation product was developed by Green Cross Corp. in Japan and marketed by a US firm. The only approved use for this oxygen carrier was for enhancing oxygenation of the heart during coronary artery balloon angioplasty procedures. PolyHeme® is different, though. It is manufactured by Northfield Labs in Evanston, Illinois. Having finished clinical trials, the prospects are good for use on trauma patients and in other applications that are being tested (including it’s use in the transplantation of pancreatic islet cells.) The results of the Phase III clinical trials just completed will not be available until November or December 2006. According to Richard DeWoskin, Northfield’s chairman and chief executive officer in 1998, “PolyHeme® has been infused without negative results in more than 100 patients over a two year period. In its Phase II trials, PolyHeme® has replaced the need for red cell transfusions on a one-to-one basis.”

What is PolyHeme® and How is It Made?

It has been scientifically found that raw hemoglobin can be toxic outside of the red blood cell and that in order to make a safe, effective substitute the hemoglobin molecule must be made larger than its natural state.

PolyHeme®, according to the Northfield Labs website, is a solution of chemically modified hemoglobin derived from human blood. A major component of blood, the red blood cells (the others are white cells, plasma, and platelets) are from the donated human blood that Northfield Labs purchases from The American Red Cross and Blood Centers of America. This becomes the starting material for PolyHeme®. It requires approximately two units of red cells (a component of whole blood) to create one unit of PolyHeme®, according to Northfield. Outdated red cells, not acceptable for transfusions, can be used as a raw material for PolyHeme®, giving outdated blood a “second life” as a transfusion medium. Using a proprietary process (OWNERSHIP belongs to Northfield Labs and is therefore unavailable for us to determine or detail)of separation, filtration and chemical modification, the hemoglobin molecule is extracted from the red blood cells. This now makes that hemoglobin molecule a fraction of the blood component. This hemoglobin (Hgb) molecule is known as a monomer (one molecule). Using a multi-step process of chemical modification or change, a “polymerized” (from Greek "polymers", having many parts, from poly: many + meros: part- more at MERIT: a chemical compound or mixture of compounds formed by polymerization and consisting essentially of repeating structural units) plural form or chain of hemoglobin molecules is the result.

This polymerized form of hemoglobin molecules could be said to be the same molecules only in a different format (now linked to each other rather than stand-alone molecules). Except for the fact that these have been chemically altered, the hemoglobin's oxygen carrying capability remains but the harmful side effects have been eliminated. Historically hemoglobin-based substitutes have had undesirable effects including vasoconstriction, kidney dysfunction, liver dysfunction and gastro-intestinal distress. This modified hemoglobin is then incorporated into an electrolyte solution and can now be administered as an alternative to transfused blood.

How does PolyHeme® work?

PolyHeme® replaces both lost blood volume and lost hemoglobin, both of which are associated with traumatic injury. Patients in the hospital trauma trial received up to 20 units (pints), replacing double the average adult’s blood volume. One unit of PolyHeme® contains 50 grams of modified hemoglobin, approximately the same amount of hemoglobin delivered by one unit of transfused blood. PolyHeme® requires no cross matching and has a shelf life in excess of 12 months. It is immediately available and steps to reduce the risk of viral transmission are used in the manufacture of PolyHeme®.

How is PolyHeme® used?

PolyHeme® infusion has been given during resuscitation, intraoperatively and postoperatively. The rate of infusion has varied with the clinical setting. The most rapid rate consisted of the infusion of 20 units in 20 minutes during rapid hemorrhage. This dose is equivalent to two times the blood volume of an average adult.

Is it available?

Until all the data is compiled and presented the FDA has deferred it’s priority review. In the meantime Northfield Labs announced to it’s board members that Northfield has purchased a new building for the first commercial production of a hemoglobin based oxygen carrier.

Watch for the results of the trials and the approval by the FDA and for the other uses for PolyHeme® that even surpass it’s futuristic use as a “blood substitute.”

See also

• Patients That Refuse Blood Transfusions - FAQs
• Nicole Davis (November 2006). Better Than Blood?. Popular Science. Retrieved on 2006-11-2. “A man-made, pure-white compound called Oxycyte carries oxygen 50 times as effectively as our own blood. Researchers are betting that it’s the best way to treat America’s leading cause of accidental death: traumatic brain injury”