Erythrophagocytosis in the Human Bone Marrow

Erythrocyte destruction by erythrophagocytosis and red blood cell disintegration has been studied in methacrylate embedded human bone marrow. Phagocytosis of erythrocytes is demonstrated in macrophages within the bone marrow sinusoids, in the bone marrow reticulum cells and in the nursing cells of the erythroclastic islands. Red cell destruction takes place both in normal and in pathologically altered bone marrow, but is often markedly increased in hypoplastic bone marrow disease. The bone marrow is considered representing the main erythroblastic organ in normal individuals, removing aged red cells from the circulation by erythrophagocytosis within bone marrow sinusoids. Further disintegration of the erythrocytes in the bone marrow reticulum cells provides directly components for rebuilding of new erythrocytes in the erythroblastic islands.