Reversible acceleration of disease progression following cyclosporin A treatment in a patient with myelodysplastic syndrome.

A 38-year-old Japanese man with myelodysplastic syndrome (MDS), whose bone marrow smears demonstrated hypercellularity, was treated with oral cyclosporin A (CsA) therapy. During the course of this therapy, the numbers of peripheral blood and bone marrow blasts increased and the level of serum lactate dehydrogenase increased. After discontinuation of CsA treatment, all of these levels rapidly decreased. We consider that CsA might accelerate disease progression in certain MDS cases.