CORRELATION BETWEEN SOLUBLE TRANSFERRIN RECEPTOR AND SERUM FERRITIN LEVELS FOLLOWING BONE-MARROW TRANSPLANTATION FOR THALASSEMIA

This study analyzes the serum transferrin receptor (sTfR) levels in a series of 230 ex-thalassemics with a follow-up of 1 to 9 years after b one marrow transplantation (BMT) for homozygous beta thalassemia. Ex-t halassemics are individuals, cured of homozygous beta thalassemia by B MT, who maintain different degrees of iron overload acquired during th e pretransplant period. Both in experimental and clinical conditions, sTfR concentrations have been shown to be a quantitative measure of bo dy iron status. This study was carried out to assess whether the level of sTfR may be of help in determining the extent of iron overload in ex-thalassemics, Patients who received the marrow from their HLA-ident ical sibling donor heterozygous for beta thalassemia, namely heterozyg ous ex-thalassemics, displayed significantly higher levels of sTfR tha n patients transplanted from their normal sibling donors (normal ex-th alassemics). This finding suggests that increased erythropoiesis, albe it in part ineffective in heterozygous ex-thalassemics, is responsible for the sTfR increment. Both heterozygous and normal ex-thalassemics had significant lower sTfR levels than their heterozygous (p<0.003) or normal(p<0.0001) donors, respectively. These differences may be ascri bed to the presence of iron overload in ex-thalassemics in comparison to their normal or heterozygous donors who did not present excess of i ron in the body. A significant inverse correlation between sTfR and se rum ferritin levels (r = -0.54, p<0.0001) was found when normal ex-tha lassemics were considered. In heterozygous ex-thalassemics, the lack o f correlation between these two parameters may be explained by the enh anced erythropoietic activity of individuals with thalassemic trait. T hese results suggest that the level of sTfR may be a useful indicator of iron overload in normal ex-thalassemics.