ORAL MAGNESIUM SUPPLEMENTS REDUCE ERYTHROCYTE DEHYDRATION IN PATIENTSWITH SICKLE-CELL DISEASE

Intracellular polymerization and sickling depend markedly on the cellu lar concentration of sickle hemoglobin (Hb S). A possible therapeutic strategy for sickle cell disease is based on reducing the cellular con centration of Hb S through prevention of erythrocyte dehydration. The K-Cl cotransporter is a major determinant of sickle cell dehydration a nd is inhibited by increasing erythrocyte Mg content. We studied 10 pa tients with sickle cell disease before treatment and after 2 and 4 wk of treatment with oral Mg supplements (0.6 meq/kg/d Mg pidolate). Hema tological parameters, erythrocyte Na, K, and Mg content, erythrocyte d ensity, membrane transport of Na and K, and osmotic gradient ektacytom etry were measured. We found significant increases in sickle erythrocy te Mg and K content and reduction in the number of dense sickle erythr ocytes. Erythrocyte K-Cl cotransport was reduced significantly. We als o observed a significant reduction in the absolute reticulocyte count and in the number of immature reticulocytes. Ektacytometric analysis s howed changes indicative of improved hydration of the erythrocytes. Th ere were no laboratory or clinical signs of hypermagnesemia. Mild, tra nsient diarrhea was the only reported side effect. We conclude that or al Mg supplementation reduces the number of dense erythrocytes and imp roves the erythrocyte membrane transport abnormalities of patients wit h sickle cell disease.