Balanced globin synthesis in idiopathic myelofibrosis.

Four patients with idiopathic myelofibrosis were found to have microcytic and/or hypochromic red cell indexes. The alpha/beta globin synthetic ratio determined by incubating peripheral blood with [14C]leucine was within normal limits in all patients studied. This is unlike a recent report of acquired hemoglobin H disease with decreased alpha/beta synthetic ratio in primary myelofibrosis. This indicates that mechanisms other than alpha-thalassemia-like defects may also be involved in the production of microcytic and hypochromic red cells in myelofibrosis.