Leukocyte reduction seen as significant advance in transfusion medicine

Experts called on government and medical organizations involved in blood transfusion to “reverse one of the most serious public health policy errors in the history of transfusion therapy in the United States.” Neil Blumberg, M.D. and Joanna M. Heal, M.D., specialists in transfusion medicine and hematology at the University of Rochester Medical Center, urged that universal adoption of leukocyte reduction, the removal of leukocytes (white blood cells) from all transfused blood by filtration, be mandated throughout the United States. In a commentary in the October 15, 2007 issue of Clinical Infectious Diseases, they refer to leukocyte reduction as “the greatest advance in preventing short-term complications and death due to blood transfusion in the past half-century.”

Leukocyte reduction is a filtration approach that removes more than 99.9 percent of the leukocytes in a unit of blood in less than 30 minutes. Leukocytes in transfused blood represent a danger because they can carry agents causing bacterial, viral, and protozoal infections. Leukocyte reduction is mandated for universal use in most of the developed world. Whereas in the U.S., about 80 percent of donated blood is leukocyte reduced.

Calling universal leukocyte reduction “that rarest of therapeutic advances that prevents suffering, illness and death, yet saves money,” Drs. Blumberg and Heal cite studies showing that surgical patients receiving transfusions that have not been leukocyte reduced have a 50 percent higher rate of post-operative infection. Dr. Blumberg is Professor of Pathology and Laboratory Medicine and Director of the Transfusion Medicine/Blood Bank at the University of Rochester and Director of Clinical Laboratories at Strong Memorial Hospital. Dr. Heal is a member of the Hematology-Oncology Unit of the University of Rochester Department of Medicine.

Also in the October 15 issue, the article “Leukocyte Reduction’s Role in the Attenuation of Infection Risks among Transfusion Recipients” presents evidence of the benefits of leukocyte reduction beyond its established role in reducing fever, transmission of cytomegalovirus (CMV) and preventing alloimmunization, the formation of antibodies that can prevent the body from accepting a platelet transfusion. Joseph S. Cervia, M.D., Clinical Professor of Medicine & Pediatrics, Albert Einstein College of Medicine, New York City and Medical Director of Pall Medical and colleagues authored the review article. Pall Corporation (NYSE: PLL) pioneered the development of leukocyte reduction with filtration.

A significant percentage of the population harbors latent infection-causing bacteria and viruses that, without leukocyte reduction, may be transmitted during a blood transfusion but not show up until years, even decades, later. Analysis of recent studies suggest that leukocyte reduction may be effective in reducing the risk of transmission of a number of transfusion-transmitted infectious agents, including herpes viruses, such as Epstein Barr; retroviruses, such as HTLV-1 and HIV; and other emerging threats. These emerging pathogens include bacteria, such as Yersinia enterocolitica; protozoa such as Leishmania species and Trypanosoma cruzi; and infectious prions, believed to be the cause of several fatal neurodegenerative diseases, including variant Creutzfeldt-Jakob Disease (vCJD), commonly known as the human form of “mad cow disease.”

The authors point out that leukocyte reduction may reduce the risk of transfusion-related immunomodulation (TRIM), depression of the immune system which may predispose a patient to post-operative infection. Drs. Blumberg and Heal describe blood transfusion as “temporary organ transplantation,” noting that blood that has not been leukocyte reduced has the potential for profound, long-term adverse effects on the immune system’s ability to fight disease.

They conclude, “All treating physicians should insist on administering leukocyte reduced blood transfusions to all of their patients and at all times. . . Anything less is suboptimal medical care, will cause needless harm to patients in the short and long term and will, in the final analysis, cost their hospital and the health care system nationally more money than implementation of universal LR.”

Dr. Cervia adds, “As an infectious disease specialist, I am particularly sensitive to the emerging threats of more recently recognized infectious agents and welcome this much needed attention to proactive prevention. Leukocyte reduction is a simple, inexpensive way to reduce the risk of infection from blood transfusions. The case is clear and a change in policy is long overdue."

Source : Pall Corporation