Plasma iron and erythrocytic glutathione peroxidase activity. A possible mechanism for oxidative haemolysis in iron deficiency anemia.

The red cell glutathione-peroxidase (GSH-Px) activity of 9 normal subjects is compared with that of 15 cases of iron deficiency anaemia and with 13 cases of heterozygous beta-thalassemia with the same degree of anaemia and hypochromia. 2 cases of sideroblastic anaemia with high serum iron levels were also examined. Enzymatic activity was found to be significantly decreased in iron deficiency anaemia (about 55% of normal range), while it was not affected in heterozygous beta thalassaemia and it was increased in the 2 cases of sideroblastic anaemia. Moreover, GSH-Px activity exhibited a significant correlation with serum iron levels in all the patients studied. The observed modifications in GSH-Px activity are not correlated with erythrocyte ageing because reticulocyte-poor fractions exhibited GSH-Px activity which was not significantly reduced in respect of the reticulocyte-rich ones. These data seem to suggest that iron has a crucial connection with erythrocyte GSH-Px and that the enzyme deficiency may be of some importance in explaining the decreased red cell survival observed in severe iron-deficiency anaemias.