Ultrastructure and cell cycle distribution of bone marrow cells in protein-energy malnutrition

Abstract

Bone marrow aspirates from four children with kwashiorkor and three with marasmus were studied using the techniques of electron microscopy and combined Feulgen microspectrophotometry and 3H-thymidine autoradiography. The majority of the erythroblasts were ultrastructurally normal, the distribution of the early polychromatic erythroblasts between the various stages of the cell cycle was normal or almost normal, and the macrophages did not contain ingested erythroblasts. Since erythropoietin production has been shown to be normal in protein-energy malnutrition, these findings suggest that at least in some cases of PEM the impairment of erythropoiesis results primarily from an abnormality in the erythroid progenitor cell pool rather than from dyserythropoiesis and ineffective erythropoiesis. In one afebrile and apparently uninfected patient with marasmus, a substantial proportion of the neutrophil granulocytes and their more mature precursors contained electron-dense, myelin-containing intracytoplasmic structures which were presumed to be abnormal primary granules. In four of the patients, the 3H-thymidine labelling index of the neutrophil promyelocyte-myelocyte pool was increased. In addition, in all of the cases, neutrophils at various stages of degradation were readily found within the cytoplasm of some of the macrophages. Thus, whereas the techniques employed did not reveal a major disturbance in the morphologically recognizable precursor cells of the erythroid series in PEM, they demonstrated some abnormalities in such cells of the neutrophil series.

Nutritional anaemias*

“…The main biochemical reaction investigated by the test is the efficiency of the 5,10-methylenetetrahydrofolate-dependent methylation of deoxyuridylate to thymidylate. Although abnormal dU-suppressed values are usually found in vitamin B I 2 or folate deficiency, they are also found in a few other conditions, including PEM (Wickramasinghe 1983;Wickramasinghe et al 1983a, b). The disadvantages of the test are that it has to be performed on marrow cells within a few hours of the marrow aspiration and that it requires f3-counting equipment when 3H-thymidine is used.…”

“…This test has proved to be an invaluable research tool in the investigation of nutritional anaemias and of macrocytosis (Killmann 1964;Metz et al 1968;Wickramasinghe 1983;Matthews & Wickramasinghe 1986). The main advantage of the dU suppression test is that it assesses vitamin B 12 -and folate-dependent biochemical reactions within marrow cells.…”