Science / Medicine : Blood-Cleansing Technique

Viruses and virally infected cells can be removed from blood before it is transfused into humans using a new process developed at the University of Michigan. The technique has already been shown to work for herpes viruses and cytomegalovirus, and preliminary results suggest it will also work for hepatitis B and the AIDS virus.

Viruses initiate their attack on cells by binding at specific sites on the cellular surface called receptors. Chemical engineers Henry Y. Wang and I. Fu Tsao chemically attached cells containing such receptors to small glass or plastic beads, then treated the cells with other chemicals so that they would not rupture and spill their contents.

The type cell used is determined by the type of virus to be removed. Liver cells, for example, would be used to remove the hepatitis virus and white blood cells to remove the AIDS virus.

When contaminated blood was passed through a tube containing the beads, both viruses and infected cells became attached to the immobilized cells and were removed from the blood with no deleterious effects on other cells or components of the blood, Tsao said.

Wang and Tsao are working with the American Red Cross to refine the technique. Wang suggested that blood to be cleansed could be passed through a tube containing the beads immediately before it enters a patient.