Incidence of hyperthyroidism after unrelated donor allogeneic stem cell transplantation.

We report on three patients who developed overt thyrotoxicosis after volunteer unrelated donor bone marrow transplantation for Philadelphia chromosome positive chronic myeloid leukemia shortly after the onset of chronic graft versus host disease. In all three cases, the etiology of hyperthyroidism is likely to be a combination of toxic factors and an immune process. Systematic evaluation of thyroid function tests in 97 unrelated allograft recipients from our center who survived at least 100 days from stem cell or bone marrow transplantation for hematological diseases gave a rate of overt thyrotoxicosis at 3.1% in this cohort.