Erythroblastic Islands and Ineffective Erythropoiesis in Acute Myeloid Leukaemia

Abstract

The erythropoietic part of the bone marrow has been morphologically analysed in 34 untreated, anaemic patients with acute myeloid leukaemia and in 17 healthy controls. In the patients with leukaemia the percentage of basophilic erythroblasts was abnormally high and elevated mitotic indices of the erythroblasts were recorded. The accumulation of basophilic erythroblasts and a high frequency of megaloblastoid changes of the cells may indicate ineffective erythropoiesis. A threefold increase of ‘erythroblastic islands’, i. e. erythroblasts in contact with reticulum cells were recorded in the patients with erythroleukaemia and a twofold increase in the patients with acute myeloid leukaemia. The erythroblastic islands may indicate phagocytosis of defective erythroblasts and an intramedullary haemolysis may thus contribute to the development of anaemia.

Erythroblastic Islands and Extra-Medullary Erythropoiesis in Chronic Myeloid Leukaemia

“…It has been suggested that the abundance of erythroblastic islands in acute myeloid leukaemias with a high frequency of megaloblastoid erythroblasts may be signs of ineffective erythropoiesis [10].…”

“…Special interest was devoted to the abundance of erythroblastic islands in the bone marrow, spleen and liver of the CML patients. It has previously been suggested that the presence of such formations may indicate phagocytosis of erythroblasts into reticulum cells [9,10], thus being a sign of increased death rate of abnormal erythroblasts.…”

Morphologic Studies of the Erythropoietic Part of the Bone Marrow in Myeloid Leukaemias

“…Nowadays cytogenetic, kinetic and morphologic investigations confirm this. Thus cytophotometric-autoradiographic studies in acute leukaemias have shown a marked proliferation disturbance which was almost limited to the early polychromatic erythroblasts representing a nonproliferative population (Queisser et a1 1973, 1975, Mitrou et a1 1975. A maturation arrest of the polychromatic cells results in a shift to the left within the erythropoietic pool.…”

“…However, previous reports on the MI of the erythroblasts do not coincide well. Thus subnormal MI have been reported in acute erythroleukaemia (AEL) (Tsuchiya & Maekawa 1973) but also significantly elevated indices (Sjogren 1975). In acute myeloblastic leukaemia (AML) Huber et al (1971) found low MI and Sjogren (1975) values above those of the normals.…”

“…Thus subnormal MI have been reported in acute erythroleukaemia (AEL) (Tsuchiya & Maekawa 1973) but also significantly elevated indices (Sjogren 1975). In acute myeloblastic leukaemia (AML) Huber et al (1971) found low MI and Sjogren (1975) values above those of the normals. Normal mitotic activity of the basophilic erythroblasts in both the AEL and the AML has however been found by Ernst et a1 (1973).…”