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Letter: Stem cell trials

Published 23 May 2007

From Júlio Voltarelli, University of São Paolo School of Medicine

Reporting our work on haematopoietic stem cell transplantation for type 1 diabetes (DM-1), Peter Aldhous wrote: “risky stem cell treatments are increasingly taking place in Asia and Latin America, where approval may be granted more readily than in the US or Europe” (21 April, p 13).

I cannot speak for all Latin American or Asian countries, but this is absolutely not true for Brazil.

Our national Ministry of Health Committee of Ethics in Research (CONEP) analyses each proposed clinical trial that will use stem cells.

I can report that it is very difficult to get approval for any of these. It took more than a year to get approval for the diabetes trial we published in the Journal of the American Medical Association. I have had several trials rejected by CONEP – not always, I believe, with good reasons.

Moreover, Aldhous suggests that our patients might have entered a “honeymoon period” during which they can live without insulin injections.

Any endocrinologist will doubt that 14 consecutive type 1 diabetes patients would become insulin-free in this way for up to three years, as shown in our paper.

Aldhous also mentions the possibility that the effect may have been due to antithymocyte globulin – but this and other anti-T-cell antibodies like OKT3 have already been tested and found to show only very transient and modest results judged by the rate of insulin-independence achieved by DM-1 patients.

Children are the predominant group of DM-1 patients. They suffer faster beta-cell destruction and worse long-term complications from DM-1, and they would benefit most from insulin independence.

These facts justify the test of haematopoietic stem cell transplantation in children, and we intend to do this test soon.

Ribeirão Preto, Brazil

Issue no. 2605 published 26 May 2007

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