Erythropoietin dependent erythropoiesis during the erythroblastic phase of juvenile chronic granulocytic leukaemia.

A child aged 3 1/2 years with typical juvenile chronic granulocytic leukaemia whose course terminated in an erythroblastic phase is described. Both in-vivo transfusion studies and in-vitro bone marrow culture studies indicate that red cell production remains erythropoietin dependent in this situation. The relationship of erythropoietin to the reversion to fetal haematopoiesis which characterizes juvenile chronic granulocytic leukaemia is discussed.