The percentage of dense red cells does not predict incidence of sickle cell painful crisis

Abstract

To test the hypothesis that the tendency of hemoglobin S (Hbs) to polymerize within cells is the major determinant of the incidence of vaso-occlusive episodes, we have examined the effect of the percentage of dense cells (as measured by Percoll-Stractan continuous density gradient centrifugation) on the frequency of painful crises in a group of 36 patients with sickle cell disease. No correlation was found between the percentage of dense cells and admissions for crisis. Among the patients with known a-gene status (n=25), the strong correlation between decreased dense cells and a-thalassemia (-a/aa) reported previously was confirmed (P