Ultrastructural studies of the bone marrow in sickle cell anaemia. I. The structure of sickled erythrocytes and reticulocytes and their phagocytic destruction.
Br J Haematol
; 31(2): 135-48, 1975 Oct.
Article
en En
| MEDLINE
| ID: mdl-1201233
ABSTRACT
Marrow aspirates from sickle cell patients were examined without prior deoxygenation and revealed the presence of a variable proportion (10-30%) of sickled red cells and reticulocytes. The main feature of sickled red cells was the presence of 17.6 nm fibres arranged in hexagonal order, and to a lesser extent in square or rectangular array, to form bundles of varying size and compactness which occupied the entire cytoplasm. The sickling pattern in reticulocytes was more variable. Some reticulocytes contained highly-ordered bundles of 17.6 nm fibres whose structure and distribution was identical to that in red cells from whiich they could be distinguished only by their content of organelles. Many reticulocytes exhibited less-organized fibre patterns ranging from localized aggregates to poorly-ordered regions of short fibres and filaments lacking apparent preferential orientation. In these cells, the bulk of the cytoplasm was not polymerized. Haemoglobin polymerization in reticulocytes led to entrapment of ribosomes in concentrated foci among the fibres. Frequently, iron-laden mitochondria were associated with sickled reticulocytes. The variation in pattern of sickling seen in reticulocytes is attributed to possible differences in concentration of Hb S. Correlative studies have shown that fibres were not induced by fixation procedures. Marked phagocytic degradation of sickled cells by macrophages was observed. The results are interpreted to indicate the possible intramedullary phagocytosis of red cells and reticulocytes, predisposed to sickling in the marrow. However, the data are also consistent with the removal of sickled elements from the circulating blood.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fagocitosis
/
Reticulocitos
/
Médula Ósea
/
Células de la Médula Ósea
/
Eritrocitos Anormales
/
Anemia de Células Falciformes
Límite:
Humans
Idioma:
En
Revista:
Br J Haematol
Año:
1975
Tipo del documento:
Article