Introduction: The myelodysplastic syndrome (MDS) is featured by cytopenia in one or more cell lineages. Until recently the only possible treatment was supportive care with transfusions and antibiotics, but new options have now become available. In this article the results of immunosuppressive treatment are described and discussed.
Material and methods: We present seven patients who were treated with antithymocyte globulin (ATG) and cyclosporine. Previous series of patients with MDS treated with ATG are summarized.
Results: Two of the seven patients treated with ATG and cyclosporine achieved a complete response, one had a partial response and one had a minor response.
Discussion: In MDS an acquired insult to the hemopoietic stem cell leads to impaired differentiation and myelodysplasia. A model of MDS pathophysiology suggests that transformation of normal stem cells induces an autoimmune T cell response with the bone marrow as the target organ. This autoimmune attack results in chronic overproduction of pro-apoptotic cytokines, especially TNF-alpha. This may contribute to a dysplastic morphology and increased apoptosis in the marrow. It is suggested that the mechanism of action of ATG in MDS may involve elimination of CD8+ lymphocyte mediated suppression of granulocyte/monocyte progenitor cells.