concanavalin-a and Hemochromatosis

Total serum ferritin and the proportion of serum ferritin binding to concanavalin A (glycosylated ferritin) was measured in 18 healthy volunteers and in 84 patients, eight with primary haemochromatosis, 43 with beta-thalassaemia major and secondary iron overload and 33 with chronic liver diseases without iron overload. The total serum ferritin was either equally or even more closely related than either the non-binding or the concanavalin A binding ferritin, to the liver iron concentration in all patients with iron overload, and with the units of blood transfused in non-chelated thalassaemic patients. The total serum ferritin showed a significant correlation with serum aminotransferase for the group of 84 patients. In the thalassaemic patients the ferritin binding to concanavalin A also correlated with aminotransferase. However, in the other groups it was the ferritin not binding to concanavalin A which showed a significant correlation with aminotransferase activity. These results suggest that measuring the fraction of serum ferritin which binds to concanavalin A does not offer any advantage over estimation of the total serum ferritin concentration in the assessment of iron stores in patients wit iron overload and liver damage.

Topics: Binding Sites; Chronic Disease; Concanavalin A; Ferritins; Hemochromatosis; Humans; Iron; Liver; Liver Diseases; Thalassemia; Transaminases

Ferritin was purified 33,000-fold from the plasma of patients with idiopathic hemochromatosis. The plasma ferritin was labeled with 131I and injected into 2 normal men. Clearance was found to be relatively slow, with 50% 131I-ferritin remaining in the plasma at 27-30 hr. The fraction of plasma ferritin that bound to concanavalin-A was found to be cleared more slowly than the nonbinding fraction. These findings confirm our previous suggestion that glycosylation is a major factor prolonging the survival of ferritin in the plasma, but differ from the results of earlier studies in experimental animals and preterm infants, which indicated very rapid plasma ferritin turnover.

Topics: Animals; Concanavalin A; Ferritins; Hemochromatosis; Humans; Iodine Radioisotopes; Metabolic Clearance Rate; Protein Binding; Rabbits

Ferritin was purified from the serum of two patients with idiopathic haemochromatosis. The protein contained three types of subunit--the H and L subunits of tissue ferritins (although only a trace of H could be detected) and a third subunit, 'G', with the highest apparent molecular weight. Only the 'G' subunit band stained for carbohydrate, indicating that a proportion of the subunits of human serum ferritin are glycosylated. Although serum was obtained from patients with idiopathic haemochromatosis, it is probable that the 'G' subunit is a component of normal serum ferritin.

Topics: Concanavalin A; Electrophoresis, Polyacrylamide Gel; Ferritins; Glucose; Hemochromatosis; Humans; Isoelectric Focusing

1. Ferritin has been partially purified from the serum of patients with idiopathic haemochromatosis. 2. Incubation with neuraminidase of this partially purified serum ferritin eliminated much of the microheterogeneity of the protein so that only ferritin of isoelectric point approximately 5.8 was present. 3. There was no change in the total amount of ferritin present (measured immunologically) or in the percentage of ferritin binding to concanavalin A. 4. Incubation of liver, spleen or heart ferritin with neuraminidase did not change the isoelectric focusing patterns.

Topics: Concanavalin A; Ferritins; Hemochromatosis; Humans; Isoelectric Focusing; Liver; Myocardium; Neuraminidase; Protein Binding; Sialic Acids; Spleen