Spleen tissue iron in hereditary spherocytosis
Hereditary Spherocytosis (HS), a disorder of the red cell membrane, is the dominant cause of hemolytic anemia in people of northern European descent. As the condition is characterised by increased erythropoiesis and may result in increased iron absorption, pathological iron overload may develop. The condition responds well to splenectomy, however few asymptomatic patients now undergo splenectomy in childhood. Frozen, stored splenic tissue was available from 10 pediatric patients who had undergone splenectomy for HS in the early 1990's. The patients (3 male) were aged 5-12 years (median age =8.6 years)at splenectomy. Only 2 had been transfused, each with I transfusion in the neonatal period. The indication for splenectomy was splenomegaly alone in 9 patients and cholecystitis and splenomegaly in 1 patient. All the examined spleens were enlarged and histological assessment revealed non-homogeneous hemosiderin deposition. Gross tissue iron content was determined by Mossbauer spectroscopy and iron was found to exist in a ferrihydrite and hem environment within the tissue. The protein content was separated by ion-exchange chromatography into tranferrin, ferritin, hemosiderin and hemprotein fractions. While the individual iron protein levels fell within the established normal ranges, there was a decrease in the proportion of iron carried by ferritin(mean=20% : normal=50%) and an increase in the proportion of iron carried as hemosiderin (mean=48% ; normal=10-15%) such that the ferritinthemosiderin ratios suggested mild iron overload (range 2:1-1:17. Nonnal=4: t ). This has implications for cumulative iron overload in patients with chronic hemolytic disease.
|Publication Type:||Journal Article|
|Murdoch Affiliation:||School of Mathematical and Physical Sciences|
|Publisher:||American Society of Hematology|
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