Preliminary results on embryonic stem cell blindness trial

Tuesday, January 24. 2012

Preliminary results on embryonic stem cell blindness trial

Yesterday it was reported that a human embryonic stem cell derived treatment has improved the vision in two women. From The Washington Post:

For the first time, an experimental treatment made from human embryonic stem cells has shown evidence of helping someone, partially restoring sight to two people suffering from slowly progressing forms of blindness.

Although the purpose of the experiment was to test the safety of stem cells injected into the eye, both patients “had measurable improvement in their vision that persisted through the duration of the study,” said Robert Lanza, chief scientific officer at Advanced Cell Technology, the Massachusetts biotech company that sponsored the closely watched experiment.

The women are not reporting any adverse side effects and I do hope, for their health, that this remains the case. But researchers are cautious. Delving deeper, there are concerns that this improvement in their vision may be a placebo effect or that it will be temporary:

Lanza cautioned that the findings are preliminary, the improvements could disappear and complications could emerge. Nevertheless, he thinks the two cases will provide useful lessons for the field....

The researchers initially weren’t sure whether her improvement was attributable to the operation or a placebo effect. They couldn’t see clear evidence of new cells in their examination, and she said vision in both eyes was better. Further testing, however, has convinced the team that Freeman’s sight is better.

This is a two-person, uncontrolled, non-blinded study, so preliminary reports of vision improvements are just that, preliminary.

A reader asked about the fact that it was reported that ACT extracted the embryonic stem cells without destroying the embryo. They perform what is called an embryo biopsy, removing a single cell from the early embryo and using that to create an embryonic stem cell line instead of ripping open and destroying the embryo all together. This same procedure is also performed in preimplantation genetic diagnosis (PGD) where embryos are screened for certain genetic traits like tissue compatibility, genetic disease and gender.

I have heard it argued many times that because ACT can create embryonic stem cell lines this way, that it solves every problem any pro-lifers could ever have against embryonic stem cell research. It doesn't. Just because an embryonic stem cell line can be derived with an embryo biopsy does not mean that every embryo survives the process. (Actually, as reported by The Post, the embryo used for this stem cell line was later destroyed.) ACT, or any PGD practitioner, cannot claim that no embryo is ever harmed by such an invasive procedure. In fact, researchers have discovered that mice that were subjected to embryo biopsy as embryos were at high risk for neurological disorders as adults. These scientists called for more rigorous research on the long term effects of embryo biopsy. Let us keep this in perspective, life in a dish is already a precarious proposition. Extracting cells at such an early stage makes it even more so.

Posted by Rebecca Taylor in Stem cells, Embryonic at 09:19 | Comments (2) | Trackbacks (0)

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Hello. You have a great site with very well articulated content. Thank you.

I have read somewhere that stem lines once created can be multiplied in a dish indefinitely thus not requiring the need for more stem cells from source. I believe it was in relation to the actc NED1,2,3,4 lines that used the blastomere method of creation and did not kill the embryonic cell. Is this true? Is this true with both embryonic and adult stem cells?

Thanks in advance, john.

#1 john on 2012-02-02 21:05 (Reply)

That is the point of a stem cell line, or any cell line for that matter, for it to continue to divide indefinitely. Some cells, like cancer cells, grow very easily, some are much harder to keep growing in culture.

Preliminary results on embryonic stem cell blindness trial

Mary Meets Dolly

Tuesday, January 24. 2012

Preliminary results on embryonic stem cell blindness trial

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