An extra margin of safety is now available to the approximately 400,000 people in the US who receive transfusions of blood plasma annually. PLAS+SD (Pooled Plasma, Solvent/Detergent Treated) is an FDA-approved product that virtually eliminates specific viruses in the plasma component of the blood. PLAS+SD will be marketed by the American Red Cross and manufactured and distributed by V. I. Technologies, Inc., the developers of the new, specially treated pooled plasma.
"The American Red Cross is continually researching, developing, and implementing new testing and treatment methods to ensure the greatest possible protection of our nations blood supply," said American Red Cross president Elizabeth Dole. "The US blood supply is safer than ever before, and we are proud to introduce an added layer of protection with PLAS+SD, the first virus-inactivated blood plasma product," she said.
Special Process Reduces Virus Transmission
The increased protection afforded by PLAS+SD is due to a special process called solvent-detergent treatment. This process dissolves the lipid coating of certain viruses that may be present in the blood, while leaving needed plasma proteins, such as fibrinogen and immunoglobulins, intact. Clinical studies show that solvent-detergent treatment reduces the risk of transmitting lipid-enveloped viruses, including those responsible for AIDS (HIV, or human immunodeficiency virus), hepatitis B (HBV), and hepatitis C (HCV).
Approximately 4 million people each year receive blood or blood products as part of their medical or surgical care. Blood banks today practice two methods to safeguard the supply--screening of the donor and viral testing of donations--to reduce the transmission of virally infected blood. However, the risk of transmission of viral infection through blood transfusion remains because of donations of blood during the infectious "window period." Currently, a window period exists between the time a blood donor contracts an infectious disease and its detection by standard serologic tests--thus heightening the risk of blood from infectious donors appearing in the blood supply.
Improved screening tests that shorten the window periods for HIV, HBV, and HCV will reduce the risk of transfusion-acquired infections but will not completely eliminate the residual risk of infection from these viruses. In addition, there are viruses and possibly new strains of viruses that are not routinely screened.
"Our vision is to eliminate the risk of blood-borne pathogens in the US blood supply through the use of viral inactivation technologies," said Bernard Horowitz, MD, executive vice president and chief scientific officer of V. I. Technologies. "The approval of PLAS+SD is another key step in closing the window of viral infection completely." Dr. Horowitz led the team that developed the solvent-detergent process while employed at the New York Blood Center.
Indications for PLAS+SD
The indications for PLAS+SD are the same as for fresh frozen plasma (FFP). Specifically, PLAS+SD is indicated for the treatment of patients with documented deficiencies of coagulation factors for which there are no concentrate preparations available, including congenital single-factor deficiencies of factors I, V, VII, XI, and XIII. The new product is also indicated for the treatment of patients with acquired multiple coagulation factor deficiencies, reversal of warfarin(Drug information on warfarin) effect, and patients with chronic relapsing or acute thrombotic thrombocytopenic purpura.
The method of SD treatment adapted for plasma involves the incubation of pooled thawed plasma from volunteer donors with the organic solvent tri(n-butyl)phosphate (TNBP) and the detergent Triton X-100. Since PLAS+SD is a pooled product, it offers the advantage of relatively uniform protein composition from lot to lot. It is also sterile-filtered to eliminate bacteria and intact leukocytes.
"Certain people with coagulation disorders will especially benefit," said Chris Lamb, vice president of plasma operations for the American Red Cross. "The benefits, in addition to viral inactivation, are sterile filtration and uniformity of product."
"The American Red Cross will use its national network to make PLAS+SD available to all US community blood centers, blood banks, hospitals and transfusion centers as quickly as possible." Mr. Lamb added.