Friday, November 07, 2008

On the stem cell controversy

Let me begin with a quote from Maria Rossbauer's report Unproven stem-cell therapy ban published in Nature journal on Aug. 20:
"The Bulgarian deputy minister for health has resigned over the country's decision to ban the use of a controversial stem-cell therapy to treat neurological disorders. The therapy, which since 2005 has been carried out on around 250 patients at St Ivan Rilski Hospital in Sofia, contravenes European Union regulations and is of unproven value, the Bulgarian health ministry ruled on 8 August."
Subscribers to Nature can read the whole text here.
I wasn't going to blog about the stem cell controversy, after it had a relatively happy ending, but on Oct. 3 our Faculty Board decided to "condemn the unethical and unscientific statements of members of our community (Prof. Bobev, Prof. Svinarov, Prof. Kremenski) in the campaign against the (Department of) Neurosurgery on the occasion of stem cells". Bulgarian readers can find the protocol of the Faculty Board session here. The three condemned professors apparently blew the whistle and this led to banning the therapy.
I am not a doctor, let alone a neurosurgeon, but let me share my thoughts on the subject.
First, bone marrow contains hematopoietic and mesenchymal stem cells. Both belong to the connective tissue, which isn't close to the nervous tissue, so I think it isn't very likely for these stem cells to "convert" and differentiate into neurons. Therefore, to my opinion, this low probability hardly justifies injecting bone marrow stem cells into the brain or the spinal cord, which is invasive and (I guess) not 100% safe procedure. At least not until the treatment has been shown to work in an animal model.
Second, after this experimental treatment has still been given a try, I think that after a reasonable number of treated patients (much fewer than 250) the results must have been submitted to a peer-reviewed journal for publication, no matter whether they have been negative or positive. The team claims positive results - improvement in as many as 50% of patients. However, without a publication it is unclear whether this improvement has been detected in a "blind" manner (i.e. by people unaware of the treatment) or by the treating doctors or even by the patients themselves. In the latter cases of course we cannot distinguish real improvement from placebo effect.
Third, what I disapprove most in the story is that the patients have paid for the therapy. I think that people undergoing experimental medical procedures must never pay (in some cases they may ever receive payments).
Still, I wouldn't like to condemn anybody because I want to believe in the good intentions of all people involved. However, I don't understand why the Faculty members haven't given such a benefit of the doubt to their opponents. So I wish to express solidarity with the three condemned professors.
Thanks to the colleague who informed me about the above cited documents (you know who you are).

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