The Corpus Callosum

Background
Autologous non-myeloablative haemopoietic stem cell transplantation is a method to deliver intense immune suppression. We evaluated the safety and clinical outcome of autologous non-myeloablative haemopoietic stem cell transplantation in patients with relapsing-remitting multiple sclerosis (MS) who had not responded to treatment with interferon beta.
Methods
Eligible patients had relapsing-remitting MS, attended Northwestern Memorial Hospital, and despite treatment with interferon beta had had two corticosteroid-treated relapses within the previous 12 months, or one relapse and gadolinium-enhancing lesions seen on MRI and separate from the relapse. Peripheral blood haemopoietic stem cells were mobilised with 2 g per m2 cyclophosphamide and 10 μg per kg per day filgrastim. The conditioning regimen for the haemopoietic stem cells was 200 mg per kg cyclophosphamide and either 20 mg alemtuzumab or 6 mg per kg rabbit antithymocyte globulin. Primary outcomes were progression-free survival and reversal of neurological disability at 3 years post-transplantation. We also sought to investigate the safety and tolerability of autologous non-myeloablative haemopoietic stem cell transplantation.
Findings
Between January, 2003, and February, 2005, 21 patients were treated. Engraftment of white blood cells and platelets was on median day 9 (range day 8--11) and patients were discharged from hospital on mean day 11 (range day 8--13). One patient had diarrhoea due to Clostridium difficile and two patients had dermatomal zoster. Two of the 17 patients receiving alemtuzumab developed late immune thrombocytopenic purpura that remitted with standard therapy. 17 of 21 patients (81%) improved by at least 1 point on the Kurtzke expanded disability status scale (EDSS), and five patients (24%) relapsed but achieved remission after further immunosuppression. After a mean of 37 months (range 24--48 months), all patients were free from progression (no deterioration in EDSS score), and 16 were free of relapses. Significant improvements were noted in neurological disability, as determined by EDSS score (p<0·0001), neurological rating scale score (p=0·0001), paced auditory serial addition test (p=0·014), 25-foot walk (p<0·0001), and quality of life, as measured with the short form-36 (SF-36) questionnaire (p<0·0001).
Interpretation
Non-myeloablative autologous haemopoietic stem cell transplantation in patients with relapsing-remitting MS reverses neurological deficits, but these results need to be confirmed in a randomised trial.
Funding
Division of Immunotherapy, Northwestern University.

There are two articles already in the popular press: one in Bloomberg, of all places, and one in New Scientist. 

Note that the patients were treated with their own (adult) stem cells, so this is not directly pertinent to the controversy over embryonic stem cells.  It is indirectly pertinent, however, in a way.  One argument against the use of embryonic stem cells is that it is not permissible to use embryonic cells, when adult cells could be used instead.  This is a bogus argument, but we can expect that it will be aired again.

Now, as for the study itself: is was not randomized, it was not a double (or even single) blind study, and it was small.  But the results are impressive, especially since the patients were all people who had not responded to treatment with steroids and/or interferon.

Note, however, that the treatment is hardly benign.  After the cells are harvested from the patients, the patients undergo obliteration of their immune systems.  From the New Scientist article:

They removed stem cells from the patients' bone marrow, and then used chemicals to destroy all existing immune cells in the body, before re-injecting the stem cells. These then developed into naïve immune cells that do not see myelin as alien, and hence do not attack it.

Presumably, this is why some of the patients had complications: two developed herpes zoster; one developed Clostridium difficile colitis.  In addition, two patients developed ITP. 

The Bloomberg article mentions that a second study is underway.  This one will include 55 patients.  Presumably, it will be many years before treatment based upon this concept will be available to the general public.