Erythrokinetics in Cooley’s Anemia

Blood production and destructions have been measured in four patients with Cooley’s anemia. Methods employed included the determination of erythroid/ myeloid ratio of the marrow, reticulocyte count, plasma iron turnover and red cell utilization, Cr⁵¹ survival and fecal urobilinogen. Rates of production obtained by these measurements have been compared to normal.

Patients with Cooley’s anemia have been shown to have an increased turnover of hemoglobin constituents comparable to the maximal response seen in other hemolytic anemias. There is, howvever, a marked decrease in maximal delivery of erythrocytes to the peripheral blood amounting to about 50 per cent in the mildly anemic patients and 85 per cent in severely anemic patients. The rate of destruction of circulating erythrocytes was similar in the three patients studied. The severity of anemia was therefore largely related to the production defect.

It was concluded that the defect in Cooley’s anemia is not in total hemoglobin synthesis, but in the fabrications of circulating erythrocytes, which in turn have the associated manifestations of hypochromia, increased percentage of fetal hemoglobin and shortened survival time.