U.S. Food and Drug Administration issued the following announcement on 26.
Blood products are critical to public health. They offer potentially life-saving benefits for a variety of acute and chronic conditions ranging from the treatment of trauma victims to the supportive care of individuals receiving chemotherapy for cancer. They also facilitate important modern surgical procedures such as coronary artery bypass grafting, hip replacement, and liver transplantation.
Ensuring the safety of blood products is one of our highest priorities. This owes not only to the important role that they play in medical care, but also to their unique risks. Blood products can be susceptible to contamination by both existing and emerging pathogens. In cases where the pathogens aren’t readily identified, there’s a risk that many people receiving blood products could be exposed to an emerging pathogen even before the danger is identified.
For these and other reasons, there’s a need for better safety measures to mitigate the potential risks to blood products. The good news is that the technology exists to potentially transform our assurance of safety of these blood products, while potentially reducing their cost.
Some of the potential dangers come from year-round infectious risks such as hepatitis B, hepatitis C, and Human Immunodeficiency Virus, and seasonal or local risks, which include West Nile virus and Babesia. Although donor screening and testing can mitigate the risk of transfusion transmission of infectious diseases, they don’t eliminate the risk entirely. Donor screening and testing of collected blood also adds to the complexity and cost of maintaining a safe blood supply.
Pathogen reduction technologies can address the infectious risk from viral and bacterial pathogens, enabling us to improve our assurance of safety and reduce the cost of testing. Current pathogen reduction technologies use nucleic acid binding compounds and/or ultraviolet light, either alone, or in combination. They work by binding to and eliminating pathogens directly, or by inactivating them to render them harmless. Some of the current pathogen reduction technologies can also potentially reduce the risk of transfusion-associated graft versus host disease without the need for a radiation source. Avoiding the need for radiation sources reduces cost and avoids a potential security risk.
Current pathogen reduction technologies have certain limitations. For example, they don’t inactivate some viruses like parvovirus, and they don’t address prions, which are protein based infectious agents. But they address more than 95 percent of the existing and emerging pathogens that are of concern for the blood supply. Another downside is that the currently available pathogen reduction technologies are somewhat cumbersome to implement in practice. They must be applied to each of the different blood components after they are separated, rather than prior to separation. This adds to the cost of implementation. But we believe these technologies could offer a big advantage to the current approaches for screening blood, and we believe with continued investments these new approaches will improve.
The ideal pathogen reduction technology would be relatively inexpensive, simple to implement on Whole Blood, and would allow the blood to subsequently be easily separated into the different components such as packed red blood cells, platelets, and plasma. In addition, it would provide sufficiently robust pathogen inactivation. This could potentially enable many of the existing donor screening requirements – such as those for travel to malaria-endemic areas – to be reduced or removed. Moreover, several current tests, such as those for West Nile virus and Babesia, could potentially be eliminated. This could reduce the cost of screening blood, improve safety, and increase the donor pool.
Whether an existing technology can be advanced to fully meet the above ideal is not certain, but preliminary work shows that achieving something close to the ideal is potentially possible. Such a technology would represent a major public health advance over our current screening tools.
Given the importance of blood safety and availability to public health, the Center for Biologics Evaluation and Research at the U.S. Food and Drug Administration is working with a variety of different partners to pursue multiple avenues of research to advance pathogen reduction technology. We believe perfecting these approaches is a critical priority.
This technology isn’t a panacea for blood safety. But by addressing both a variety of known pathogens and offering protection against many emerging pathogens, the application of a simple, safe and effective pathogen reduction technology potentially could measurably increase the safety of the blood supply while reducing cost. It’s only a matter of time before the emergence of the next infectious pathogen of concern. We believe we have at hand the technology that could help dramatically reduce these threats.