Bioethics lecture series kicks off with look at stem cell banks

Hilary Bok, Associate Professor of Bioethics, and Luce Professor in Bioethics and Moral and Political Theory, kicked off the Hopkins Undergraduate Bioethics Society’s spring lecture series this Wednesday.

Bok’s lecture explored the thorny issues surrounding the potential creation of a national stem cell bank.

One of the most exciting features of stem cell therapy is the ability for a stem cell line to be created using the cells of each individual patient. This would eliminate the issues of immunorejection that plague organ and bone marrow donations.

However, these therapies are “never going to be a good solution for diseases where time is of the essence,” Bok said.

If a patient has a stroke or heart attack, for example, the week-long wait for stem cells to be created from his or her own cells would be unrealistic.

One solution is to make “over-the-counter” stem cells available — that is, create a national stem cell line bank.

Obviously, including lines that match every single person is impossible. How should we decide which lines to include and which ones to exclude?

“It turns out that which genetic profile you have, which alleles you have, tends to sort with where your ancestors are from,” Bok said. “For the alleles in question, the most common variants among whites are not the most common variants among African Americans are not the most ocommon variants among east Asians are not the most common variants among North and South Native Americans.”

Bok outlined two strategies to answer the question of which stem cell lines should be included.

The first is the cover-maximizing strategy. The stem cell bank would be stocked strictly on the basis of which lines match with the greatest number of people. After all, “a government program shold try to help as many citizens as it can,” Bok said.

However, the most common genetic variants in the US are the most common genetic variants among Caucaisans, simply because the country’s population is predominantly Caucaisan. Using this strategy, minorities would be significantly underrepresented in the stem cell bank.

An alternative strategy is the equal representation strategy.

This strategy would make sure that equal fractions of ethnic groups have equal coverage in the stem cell line bank.

“In order to get close to half the ethnic groups covered, it takes about 20 lines to cover half of whites and 60 lines to cover about half of blacks,” Bok said.

Bok held a lively debate with the audience about the pros and cons of each side, as well as possible alternative strategies. For instance, audience members suggested privately funded stem cell line centers, or prioritizing stem cell line development based on what groups are affected by certain diseases such as diabetes.

Bok ultimately came down on the side of teh equal representation strategy.

Significant health disparities among different ethnic groups already exist in the US. “We should not do anything that makes those health disparities worse,” Bok said.

Additionally, minority groups have been historically excluded and short-changed by governmental health policies.

“I think of [the equal representation strategy] as absolutely something that needs to be done only because of history,” Bok said.