Sideroblastic anemia: Differences in bone marrow erythroid colony (CFU_e) growth responses to erythropoietin in plasma clot and methylcellulose cultures

Abstract

Bone marrow cells from three patients with idiopathic acquired sideroblastic anemia and one with X-linked sideroblastic anemia were simultaneously cultured in plasma clot and methylcellulose cultures in order to evaluate their erythroid colony (CFUE) cloning potential in these two systems. In contrast to normals, sideroblastic anemia bone marrow cells demonstrated a marked ability to form erythropoietin (Epo)-independent CFUE in methylcellulose culture, and were inhibited in their ability to generate CFUE in plasma clot culture even in the presence of Epo. Addition of citrated plasma to methylcellulose cultures inhibited Epo-independent CFUE growth, but not Epo-dependent growth, by both a normal and patients' bone marrow cells. These results demonstrate that bone marrow cells from some patients with sideroblastic anemia can undergo Epo-independent and Epo-dependent CFUE growth in vitro, and that there is a marked difference in CFUE growth depending on the type of clonal culture method used. It is suggested that the culture microenvironment, plasma, and sensitivity to Epo may be contributing factors which allow specific clones of sideroblastic anemia CFUE-forming cells to proliferate in vitro.

A paediatric case of sideroblastic anaemia

“…Moreover, no endogenous CFU-E or BFU-E growths (without EPO) were obtained, in contrast to the extremely abundant endogenous CFU-E reported by Lutton et al [10] in X-linked SA.…”

“…To date, there are very few reports on the functional and morphological characteristics of colonies grown in vitro from erythroid burst forming units (BFU-E) or from colony forming units (CFU-E) from patients with SA [8,10,12]. In addition most of them concerned adult patients.…”

Iron dose-dependent differentiation and enucleation of human erythroblasts in serum-free medium

“…Although the erythroblastic island niche is a fundamental feature of in vivo erythropoiesis, this process can be replicated ex vivo . The cells are able to differentiate in cultured clot (Lutton et al ., ), semi‐solid (Metcalf, ) or liquid (Gartner and Kaplan, ) media. Fibach et al .…”

“…Although the erythroblastic island niche is a fundamental feature of in vivo erythropoiesis, this process can be replicated ex vivo. The cells are able to differentiate in cultured clot (Lutton et al, 1984), semi-solid (Metcalf, 1981) or liquid (Gartner and Kaplan, 1980) media. Fibach et al (1989) further advanced the use of liquid suspension cultures of erythroblasts using primary human haematopoietic cells.…”

Eclectic mechanisms of heme regulation of hematopoiesis

“…Others have shown that SA bone marrow and peripheral blood mononuclear cells yield a marked reduction in erythroid colony growth when cultured in plasma clot culture with erythropoietin (Epo) [20,21]. In other experiments, we found that there is a considerable difference in SA bone marrow CFU-e growth in the absence or presence of Epo, depending on the type of culture method used [22]. In this respect, SA marrows demonstrated a marked ability to form Epo-dependent and Epo-independent CFU-e in methylcellulose cultures, but failed to do so in plasma-containing cultures.…”