Role of cell--cell interaction in normal and abnormal erythropoiesis.

A number of studies have demonstrated that certain immunocompetent cells play a role in the regulation of normal erythropoiesis. These regulatory cells (monocytes--macrophages, lymphocytes) modulate almost every phase of the erythropoietic process, and along with erythropoietin represent the major controlling force in erythropoiesis. Evidence indicate that pathological alterations of these cell-mediated activities can lead to clinical disturbances of red cell production such as is seen in patients with Diamond-Blackfan syndrome and aplastic anemia.