Erythrocyte sialic acid in human sickle-cell disease.

Membrane-bound erythrocyte surface sialic acid concentrations in sickle-cell human patients (SS) and in control patients with sickle-cell trait (AS) and normal genes (AA) were assayed. The erythrocyte sialic acid concentration was significantly (P less than 0.001) higher in sickle-cell patients than in non-sicklers and although the concentration was higher in AS than AA individuals the difference was not significant (P greater than 0.05). The anaemic state of the SS patients was shown by a significantly (P less than 0.001) lower PCV than in non-sicklers. This finding is discussed in relation to membrane toughness and subsequent membrane loss leading to irreversible sickling of red cells in the deoxygenated state.