Studies in the Anaemias of Infancy and Early Childhood

In Part I of this series we have emphasized the fact that ansemia must be regarded as a disease of the erythron, that is, as a disease which not only may affect the red cells in the circulating blood, but also their precursors in haemopoietic centres of the marrow and elsewhere, although both portions of the erythron do not necessarily suffer to the same extent nor even at the same time. Such a conception is of particular importance in the consideration of the destructive diseases of the erythron. These disorders are usually spoken of as the haemolytic anaemias, and although we shall make use of this term, it is, in our view, not sufficiently embracing. It stresses the destruction of red cells in the blood stream (haemolysis), whereas often there is also evidence of damage to, or sometimes paralysis or destruction of, the haemopoietic centres (aplastic anaemia). Therefore we suggest that these destructive diseases of the erythron should be called ' erythronoclastic anaemias ' as a more correct, if less euphonious, title than haemolytic anaemia. These anaemias are of the hyperchromic type and show marked anisocytosis and poikilocytosis. If the haemopoietic centres are not too severely damaged to respond to the call for new cells, reticulocytosis, polychromasia, megaloblastosis and normoblastosis occur. The presence of megaloblasts and normoblasts in the peripheral circulation has not the same significance as in the deficiency anamias, because in them the maturation of the erythrocyte cannot take place unless the missing factors are supplied, whereas in the erythronoclastic anvemias these immature cells appear in the peripheral circulation only because blood formation is extremely active.