Pocked erythrocyte counts in patients with hereditary spherocytosis before and after splenectomy.

The pocked (pitted or vacuolated) erythrocyte count has become increasingly utilized as a simple inexpensive test of splenic reticuloendothelial function. Values are less than 2.0% in normal subjects and 20 to 70% following splenectomy. Because scant and conflicting data are available about pocked erythrocyte measurements in hemolytic anemias other than the hemoglobinopathies, we performed pocked erythrocyte counts in 27 patients with hereditary spherocytosis. Prior to splenectomy patients often had elevated values (mean 4.9%). This unexpected observation suggests that hemolytic anemia may result in congestion of the red pulp and/or induced mild splenic reticuloendothelial blockade. As expected, but contrary to a previous report, pocked erythrocyte values following splenectomy were markedly increased (mean 54.9%).