It’s always good news when Congress and the president can agree, with strong bi-partisan support, on legislation that will improve medical research. But it’s worth taking a moment to realize that yesterday’s bill signing on “stem-cell” legislation is not quite what it seems to be.
President Bush signed legislation to establish a national databank of umbilical cord blood and bone marrow that would allow doctors to quickly find a match for patients who need a transplant.
The Senate passed the bill by voice vote on Friday. The House passed the bill in May by a vote of 431-1. The legislation will provide $79 million in federal funding to increase the number of cord blood units available for matches. The objective is 150,000 units, which would mean 90% of patients needing them would have a match.
The measure also reauthorizes the national bone marrow transplant system, combining it and the cord blood in the same database.
What’s wrong with this effort? Absolutely nothing; it was a good bill that will help a lot of people. But the problem comes from possible confusion over just how beneficial this legislation is and to which areas of research it will apply.
The bill, for example, is called the “Stem Cell Therapeutic and Research Act of 2005.” The fact that Bush put his signature on it led to unhelpful headlines like this one: “Bush Signs Stem Cell Bill into Law.”
One might see this and think that the key stem-cell bill that’s generated so much support nationwide — the Stem Cell Research Enhancement Act (H.R. 810), generally known as Castle-DeGette — has finally become law. It hasn’t. There have been two stem-cell bills working their way through Congress — and their differences are important.
Unlike Castle-DeGette, the bill Bush put his signature on yesterday invests federal funds in research on stem cells from umbilical cords, not embryos. The consensus seems to be that there are genuine opportunities for scientific advancement through this research.
Umbilical cord cells, squeezed harmlessly from discarded umbilical cords and frozen for later use, are clearly of great medical value. Since 1988, doctors have transplanted them into thousands of patients whose bone marrow had succumbed to disease or been obliterated by chemotherapy. After being transfused into a patient’s vein, cord cells work their way into the marrow, where they produce a constant supply of fresh blood for the rest of the patient’s life.
In this sense, the bill was a no-brainer. People who suffer from blood-related illnesses can and probably will benefit from this research. So far, so good.
Umbilical cord cells, however, are not the same thing as stem-cells, and offer researchers less of what they need and want. Indeed, many conservatives, including James Dobson’s Focus on the Family, argue that embryonic stem-cell research is now unnecessary because of umbilical cord cells and adult stem cells. David Shaywitz, an endocrinologist and stem cell researcher at Harvard, explained in a Wall Street Journal op-ed earlier this year that the right is selling a bill of goods.
To be sure, one of the great successes of modern medicine has been the use of adult blood stem cells to treat patients with leukemia. The trouble is generalizing from this: There are very strong data suggesting that while blood stem cells are good at making new blood cells, they are not able to turn into other types of cells, such as pancreas or brain. The limited data purported to demonstrate the contrary are preliminary, inconclusive, unsubstantiated, or all three. Thus, it seems extremely unlikely that adult blood cells — or blood cells from the umbilical cord — will be therapeutically useful as a source of anything else but blood.
Moreover, while stem cells seem to exist for some cell types in the body — the blood and the intestines, for example — many adult tissues, such as the pancreas, may not have stem cells at all. Thus, relying on adult stem cells to generate replacement insulin-producing cells for patients with diabetes is probably an exercise in futility. […]
[T]here has been a concerted effort to establish adult stem cells as a palatable alternative to embryonic stem cells. In the process, conservatives seem to have left their usual concern for junk science at the laboratory door, citing in their defense preliminary studies and questionable data that they would surely — and appropriately — have ridiculed were it not supporting their current point of view. In fact, there is little credible evidence to suggest adult stem cells have the same therapeutic potential as embryonic stem cells. Conservatives often speak of the need to abide by difficult principle; acknowledging the limitations of adult stem cell research would seem like a good place to start.
In this sense, Bush did the right thing yesterday signing a good bill — but in terms of stem-cell research, the president is less than half way there.