Erythropoietic protoporphyria (EPP) results from deficiency of ferrochelatase (FECH). Accumulation of protoporphyrin IX causes life-long acute photosensitivity. Microcytic anemia occurs in 20% to 60% of patients. We investigated 178 patients with dominant EPP confirmed by molecular analysis. Erythropoiesis was impaired in all patients; all had a downward shift in hemoglobin (Hb), and the mean d...

The RBTN2 LIM-domain protein, originally identified as an oncogenic protein in human T-cell leukemia, is essential for erythropoiesis. A possible role for RBTN2 in transcription during erythropoiesis has been investigated. Direct interaction of the RBTN2 protein was observed in vivo and in vitro with the GATA1 or -2 zinc-finger transcription factors, as well as with the basic helix-loop-helix p...

The acute erythroleukemia induced in mice by the anemia-inducing strain of the Friend virus complex is caused to regress by normal macrophages. We examined the possibility that reversal of leukemia is related to a macrophage regulatory function in erythropoiesis. We found that the ability of macrophages to induce leukemia regression correlates with nonimmunological, in vivo suppression of norma...