Scientists take first step towards Blood, Made in Lab

The ability to make blood in the lab would guarantee that hospitals and blood banks have access to an ample supply of all types of blood, including the rare AB-negative and O-negative, the universal donor. It would also ensure that patients are never at risk of contracting diseases such as Hepatitis C or HIV, which can be acquired from donor blood, said Dr Dan Kaufman, associate director of the University of Minnesota8217;s Stem Cell Institute, who wasn8217;t involved in the study.

8220;People don8217;t usually think about these types of cells when they talk about human embryonic stem cell therapy, but it is important,8221; Kaufman said. 8220;There8217;s more infections all the time, and the number of donors is more and more limited.8221;

Researchers have tried to harness the so-called adult stem cells that are responsible for making blood in the body, but their methods were far too inefficient to be put to practical use, experts said. In the new study, the researchers were able to make up to 100 billion red blood cells 8212; enough to fill two or three collection tubes 8212; from a single plate of embryonic stem cells.

After allowing the stem cells to begin the earliest stages of embryonic development, the researchers prompted some of them to grow into red blood cells by exposing them to a variety of proteins. Up to 65 per cent of the resulting cells matured to the point where they shed their nucleus, which allows them to take on the distinctive doughnut shape of circulating red blood cells, said Dr Robert Lanza, chief scientific officer at Advanced Cell Technology Inc. and the study8217;s senior author.

The team, which also included researchers from the University of Illinois at Chicago and the Mayo Clinic in Rochester, produced blood of types A-positive, A-negative, B-positive, B-negative and O-positive.

The method was 100 times more efficient than previous efforts, said Eric Bouhassira, a professor of stem cell biology and regenerative medicine at Albert Einstein College of Medicine in New York. But most of the cells had embryonic or fetal versions of globin, the compound in red blood cells that carries oxygen. Only a relative handful appeared to contain the adult globin that would be needed by patients, he said.

8220;Whether they would be good enough for transfusion is very unclear,8221; said Bouhassira, who was not involved in the research.

Lanza said the research team is conducting additional experiments to see whether the stem cells will produce more adult globin if given more time to mature in the lab.

Even with substantial improvements, the method faces another big hurdle. Roger Dodd, vice president of research and development at the American Red Cross8217; Holland Laboratory in Rockville, said producing blood in the lab could cost thousands of dollars per unit 8212; far too expensive to replace the 14 million pints of red blood cells that are transfused every year. 8220;It8217;s a rather ambitious goal,8221; Dodd said.

Potential: no blood shortage

Growing blood in the lab potentially means the end of both blood shortages and blood donations. No one will ever die for lack of blood, rare groups like AB-negative will no longer be rare, and no one will ever contract HIV or Hepatitis C from an infected donor.

What still needs to be done

Only a few lab-grown cells contain mature versions of globin, the critical compound that carries oxygen in red blood cells. Researchers are trying to produce more adult globin by leaving the cells longer to mature. Also, it could take thousands of dollars to grow a single unit of blood in the lab.