THE EFFECT OF DIETARY MAGNESIUM SUPPLEMENTATION ON THE CELLULAR ABNORMALITIES OF ERYTHROCYTES IN PATIENTS WITH BETA-THALASSEMIA-INTERMEDIA

Background and Objective. Reduced serum or erythrocyte Mg have been re ported in human beta thalassemia. These deficiencies may play a role i n the cellular abnormalities characteristic of this disorder. We have therefore studied the effect of dietary Mg supplementation in patients with beta thalassemia intermedia in order to establish whether it imp roves the abnormalities of thalassemic erythrocytes. Design and Method s. Plasma and erythrocyte Mg were determined in 11 patients with b tha lassemia intermedia, not requiring chronic transfusion therapy, and in 17 normal controls. Inclusion criteria included normal renal and live r function and performance status of 70% or greater. Seven patients we re enrolled for the Mg supplementation study, after the appropriate in formed consent was obtained. They were given a starting dose of 0.6 mE q/kg/day of magnesium pidolate, divided into two oral daily doses, for four weeks. In a 70-kg subject, a daily Mg dose of 42 mEq corresponds to 504 mg of Mg, with the daily Mg intake of normal subjects being 41 8+/-120 mg for males and 343+/-94 mg for females. After 28 days of tre atment, five of the patients continued the protocol with a daily dosag e increased to 1.2 mEq magnesium pidolate/kg/day, divided into two ora l administrations, for an additional four weeks. Results. In patients with untransfused beta thalassemia intermedia we found reduced erythro cyte Mg (in mmol/kg Hb, 6.12+/-1.5, n=11 vs. 8.69+/-0.89, n=17, respec tively, p < 0.0001) and normal serum Mg. In the seven patients given o ral Mg supplements, at Mg dosages of 0.6 mEq/kg/day we observed signif icant increases in erythrocyte Mg, and significant improvement in some of the characteristic abnormalities of beta thal erythrocytes (increa sed Na-K pump, K-Cl cotransport, cell dehydration, increased osmotic r esistance). These changes were maintained in the 5 patients who were t reated with 1.2 mEq of Mg/kg/day. Follow-up studies showed a return to baseline conditions. There were no signs of Mg toxicity, with the onl y side effect being diarrhea, which was generally mild, but led to dis continuation for one patient after the first four weeks. Interpretatio n and Conclusions. These data indicate that dietary Mg supplementation improves some of the characteristic cellular function abnormalities o f b thalassemia intermedia. The possible therapeutic value of this str ategy should be further tested in these patients. (C) 1998, Ferrata St orti Foundation.