Blood production and destruction were measured in 10 patients with the megaloblastic anemia of tropical sprue. Methods employed included the determination of the erythroid/myeloid ratio of the marrow, plasma iron turnover, red cell utilization of Fe59 and Cr51 red blood cell survival. Rates of production and destruction were compared to normal.
Patients with the megaloblastic anemia of sprue were usually not iron deficient. Total bone marrow erythroid activity did not approach the maximal response seen in other hemolytic anemias, and there was a marked decrease in the delivery of erythrocytes to the peripheral blood. The rate of red blood cell destruction was increased, but as the red cell volume decreased, the total mass of erythrocytes destroyed per day varied from less than normal to twice normal. Bilirubinemia was not marked, because the amount of hemoglobin destroyed daily was usually not excessive and excretory function was not impaired. The severity of the anemia was largely related to the erythrocyte production defect.