Space lasers may benefit blood banks

Researchers are using dyes and lasers to kill disease-causing viruses, including the one that causes AIDS, in stored blood. The Department of Defense, which financed part of the research, is touting the laser technique as a positive spin-off of its “Star Wars” program. In fact, in research published in the January/February TRANSFUSION, the system is reported to have a 100 percent viral kill rate without any detectable damage to normal blood elements - a better kill rate than its parent system is expected to have against incoming Soviet missiles.

More thorough screening of donated blood has successfully reduced the risk of viral contamination. But screening procedures are expensive and time-consuming, may generate false results and are altogether incapable of detecting some viruses. The new treatment, developed by a team of researchers at the Baylor (Tex.) Research Foundation, Southern Methodist University in DAllas and the Southwest Foundation for Biomedical Research in San Antonio, treats flowing suspensions of blood with a light-sensitive dye and a narrow-wavelength zenon arc lamp. The dye preferentially binds to the protein envelopes that enclose the viral particles. When the dyed viruses are exposed to laser light, a chemical reaction occurs that destroys them.

The method is effective against measles virus, herpes simplex virus type 1, cytomegalovirus and the AIDS-causing human immunodeficiency virus at a flow rate of about one pint every 15 minutes. The researchers say it may also prove effective against other viruses with similar envelopes, such as hepatitis B, Epstein-Barr virus and human lymphotropic virus type 1. They predict it will be ready for use in blood banks within the next two to five years.