Bartolucci P, Brugnara C, Teixeira-Pinto A, et al. Erythrocyte density in sickle cell syndromes is associated with specific clinical manifestations and hemolysis. Blood. 2012;120(15):3136-3141.

On pages 3136 and 3137 in the 11 October 2012 issue, the red blood cell density cutoff value is incorrect. On both pages, the correct density value of 1.112 was misstated as 1.120. On page 3136, in “Introduction,” the fourth sentence of the second paragraph reads, “Notably, in dense RBCs (DRBCs), defined as having a density exceeding 1.120, the intracellular total Hb concentration is increased from the normal (∼ 33 g/dL) to 40-50 g/dL.” The sentence should have read, “Notably, in dense RBCs (DRBCs), defined as having a density exceeding 1.112, the intracellular total Hb concentration is increased from the normal (∼ 33 g/dL) to 40-50 g/dL.”

On page 3137, in “Methods,” the second to last sentence under “RBC density measurements” reads, “For each of these curves, the DRBC percentage was determined as the percentage of RBCs with density > 1.120.” The sentence should have read, “For each of these curves, the DRBC percentage was determined as the percentage of RBCs with density > 1.112.”