Long-term follow-up of two patients with multiple sclerosis treated with allogeneic stem cell transplantation for chronic myeloid leukaemia

Background: We report on the longterm follow-up of two patients with relapsing-remitting multiple sclerosis and concomitant chronic myeloid leukemia (CML) treated with allogeneic hematopoietic stem cell transplantation (HSCT).

Case presentation: The first patient was 35 years old with a 4 year history of relapsing remitting MS (RRMS) when diagnosed with philadelphia chromosome positive CML and treated with allogeneic HSCT in 1997. Her symptoms so far included optic neuritits with persistent reduced visual acuity and recurrent sensory abnormalities. Visual acuity was found normal 2 years after the transplantation and no new relapses were reported after follow-up until 10/2007. In addition, cerebral MRI performed in 2000 showed no increase of the white matter lesions compared to before the HSCT. The second woman was 36 years old with a 5 year history of RRMS when diagnosed with CML and treated with allogeneic HSCT in 1998. Before transplantation she presented with recurrent episodes of vertigo, decline in balance, acroataxia, sensory abnormalities and persistent left sided latent weakness and internuclear ophtalmoplegia. The persistent clinical deficiencies were stable up to 8 years after transplantation. Both patients were diagnosed before Imatinib was available.

Conclusion: The profound immunological changes by severe immunosuppression and HSCT performed mostly in patients with aggressive relapsing-remitting or progressive MS, have been reported to arrest progression in many patients or even improvement of EDSS score for an extendend period of time providing a possible new therapeutic strategy.

Due to the higher treatment-related morbidity in allogeneic HSCT vs. autologous HSCT it has not yet been performed with the intention of treating MS, but reports on MS patients who underwent it because of coincidental hematological malignancy support that allogeneic HSCT may offer additional advantages over autologous HSCT by providing additional mechanisms such as restoration of self-tolerance, introduction of a healthy immune system or graft-versus-autoimmunity effect. At present, the risk of allogeneic HSCT outweighs its potential benefit entailing the need of search for methods with lower treatment risk.

Our 10-year follow-up data underlines the so far collected results of longterm progression free survival after allogeneic HSCT.